INTEGRATING RIPARIAN ZONES WITH RIGHTOFW A Y MANAGEMENT
by
Jim Scouras
B.Sc., Simon Fraser University, 1991

THESIS SUBMITTED IN PARTIAL FULIFILLMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
m

NATURAL RESOURCE MANAGEMENT

© Jim Scouras, 1999
THE UNIVERSITY OF NORTHERN BRITISH COLUMBIA
November 1999
All rights reserved. This work may not be
reproduced in whole or in part, by photocopy or
other means, without permission of the author.

Abstract
This study tests the applicability of using an Integrated Resource Management (IRM) strategy for
more effectively managing riparian zones along electric transmission Rightofways (ROWs). A
literature search revealed that while there is an extensive body of information about the
importance of riparian zones in creating and maintain aquatic habitat, there has been no research
conducted on the effects of transmission powerline vegetation management on riparian zones in
British Columbia (BC). Further, an apparent management contradiction exists because electric
utilities traditionally manage vegetation on ROWs by cutting all tall trees, whereas in most other
situations, tall growing riparian communities are being preserved or restored. In response to this
the primary research question for this study is "Is it possible for riparian zone function to be
integrated with current vegetation management practices along electric transmission ROWs in
BC?"
To investigate the problem 12 separate sites across the BC Hydro transmission facility were
studied. Variables were selected as indicators of four separate, but functionally related riparian
ecosystem functions; energy flow, stream hydrology, bank stability and habitat complexity. Site
data was collected, processed and then each case was described and evaluated independently
before trends were compared between sites. Vegetation management practices were investigated
by reviewing BC Hydro's documents and by conducting guided interviews with BC Hydro staff.
Trends between ecosystem function and vegetation management activities were then compared to
the literature to complete analysis.
The key findings of the study are that traditional vegetation maintenance activities appear to have
mixed, site sensitive impacts on the riparian ecosystem functions studied. BC Hydro is
implementing a management process designed to integrate site specific issues and varied
technical information into workplans. As a result, most of the conditions necessary for
integrating riparian function with electric transmission ROWs maintenance are present in BC.
Recommendations are provided which describe the remaining conditions necessary for a
successful IRM approach to this issue. Hence, the project links IRM theory to a case study
example and describes a set of parameters necessary to more effectively manage riparian zones
along electric transmission corridors.

<'

11

Table of Contents
llitle
Abstract
llable of Contents
List of Tables
List of Tables
List of Figures
Acknowledgments

J>age
n
m
v
v1
vn
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Chapter One: Introducing the Issues
1.0 Introduction

1

Chapter Two: Managing Electric Transmission Rightofways and Riparian Zones
2.0 Introduction
2.1 Managing ROWs
2 .1.1 Vegetation Management
2.2 Riparian Zones
2.2.1 Features of a Riparian Zone
2.2.2 Riparian Zones and Aquatic Ecosystems
2.2.2 Riparian Zones and Morphological !>rocesses
2.3 Managing Riparian Zones
2.3 .1 Setting Ecosystem Functions as Criteria for Managing Riparian Zone
2.4 Integrated Resource Management
2.5 Summary

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Chapter Three: The Methods Used in this Study
3.0 Introduction
3.1 Research Design
3 .2 Research J>rotocol
3.2.1 Criteria Used to Select Case Sites
3 .2.2 Selecting the Case Sites
3.2.3 Relevant Site Information
3 .2.4 Collecting Site Data
3.3 Summary

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Chapter Four: Case Study Results
4.0 Introduction
4.1 Case Studies
4.1.1 Case Study 1: Kelvin Creek
4.1.2 Case Study 2: Currie Creek
4.1.3 Case Study 3: Nile Creek
4.1.4 Case Study 4: French Creek Tributary
4.1.5 Case Study 5: West Noons Creek
4.1.6 Case Study 6: Donegani Creek
4.1.7 Case Study 7: Mahood Creek

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66
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4.1.8 Case Study 8: Cluculz Creek
4.1.9 Case Study 9: Sweden Creek
4.1.1 0 Case Study 10: South Sisters Creek
4.1.11 Case Study 11 : no name creek
4.1.12 Case Study 12: no name creek
4.2 Case Summaries
4.2.1Vegetation Management
4.2.1 Ecosystem Function 1: Energy Flow
4.2.2 Ecosystem Function 2: Hydrology
4.2.3 Ecosystem Function 3: Bank Stability
4.2.4 Ecosystem Function 4: Habitat Complexity
4.3 Summary

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Chapter Five: Analysis
5.0 Introduction
5.1 Vegetation Management
5 .1.1 Ecosystem Function 1: Energy Flow
5.1.2.Ecosystem Function 2: Hydrology
5 .1.3 Ecosystem Function 3: Bank Stability
5.1.4 Ecosystem Function 4: Habitat Complexity
5.2 Summary

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102
108
113
116
118

Chapter Six: Conclusions and Recommendations
6.0 Conclusions
6.0.1 Ecosystem Function
6.0.2 Integrated Resource Management
6.1 Recommendations

119
119
123
125

References
Appendix 1
Appendix 2

127
138
187

Case Study Data
The Questionnaire used in this study.

IV

List of Tables

Table 1.

Case Study Sites

52

Table 2.

Vegetation Management and Ecosystem Function Trends

91

Table 3.

Diurnal Temperatures

95

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List of Figures
Figure 1.

The Features and Functions of a Riparian Zone

12

Figure 2.

The Study Areas

36

Figure 3.

Mode of Triangulation and Analysis

39

Figure 4.

Distribution of Aggradation Across Case Study Sites

97

Figure 5.

Correlation Between Light Levels and Maximum Water
Temperatures

103

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List of Photographs
Photograph 1. Kelvin Creek and the Rightofway.
Photograph 2. Looking upstream through the Rightofway.

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Photograph 3. Currie Creek and the Rightofway.
Photograph 4. Looking upstream through the Rightofway .

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Photograph 5. Nile Creek and the Rightofway.
Photograph 6. Looking upstream from the end of the ROW.

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Photograph 7. French Creek tributary and vegetation downstream ofRightofway
Photograph 8. Looking upstream through lower end of the ROW stream section.

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Photograph 9. Vegetation across Rightofway at Noons Creek.
Photograph 10. Looking upstream from the lower end of the ROW stream section.

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Photograph 11. ROW and stream facing downstream section at Donegani Creek
Photograph 12. Looking upstream in the middle ofthe ROW stream section.

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Photograph 13. East side of the ROW with groomed section and riparian trees.
Photograph 14. Looking upstream in the middle ofthe ROW stream section.

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Photograph 15. The east side of the ROW with access road and mixed vegetation.
Photograph 16. Looking upstream in the middle of the ROW stream section.

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Photograph 17. The vegetation and stream across the ROW.
Photograph 18. Looking downstream at the lower end of the ROW section

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Photograph 19. The ROW, creek and vegetation looking north.
Photograph 20. Looking upstream through the middle of the ROW section

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Photograph 21. The ROW looking south from the left bank of the creek
Photograph 22. Looking upstream from the middle of the ROW.

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Photograph 23. The ROW crossing looking north along the corridor.
Photograph 24. Looking upstream from the middle of the ROW.

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Vll

Acknowledgments
I would like to thank my wife Tanya and my parents, George and Pat Scouras, for their
unconditional love and support. Further thanks to my parents-in-law Dr. Chee and Joan Ling for
their inquiry, support and love. I acknowledge a debt of gratitude to Dr. Doug Baker, my
supervisor and friend, for providing direction and support essential to completing this journey. I
would also like to acknowledge Dr. Zig Hathorn for being a mentor, and for being a financial and
spiritual champion of this project, even through times of great difficulty. I also would like to
acknowledge the other members of my graduate committee Dr. Ellen Petti crew, Dr. Steve
Macdonald, External Examiner Dr. Chris Hawkins and Chair of my examination Dr. Bill
Morrison for taking the time to critically review all work, and for posing powerful comments and
questions thereby providing me the opportunity to grow as a scientist. I would like to mention
BC Hydro ' s David Balser, Daryl Fields and Brenda McGuire for taking a chance on me and still
providing the opportunity to complete this pursuit. And finally a debt of gratitude to my research
assistant Jennifer MacMillan for working effectively and tirelessly, while always keeping a
smile on her face, both when crashing through the bush at difficult sites or helping to assemble
and organize huge quantities of information.

Vlll

CHAPTER!
Introducing the Issues
1.0

Introduction

Natural resource management has traditionally involved extracting raw resources or target
populations while minimizing, when possible, impacts to the natural environment. Most often the
management goal was applied within a static framework and simply involved maximizing
extraction without crippling the natural environment system's ability to keep providing the
required resources. With increasing recognition and understanding of the dynamic interdependent
linkages within natural systems, resource managers are now being pressured to explicitly manage
for all components of a natural system (Mitchell, 1990). This can often include trying to integrate
and set appropriate goals for complex, and at times, conflicting issues and scenarios. More
research is necessary to aid in establishing processes that help create broader holistic resource
management goals, objectives and techniques. New management approaches are needed that help
integrate biophysical and anthropogenic issues that often change over both time and space.

This project contributes to the body knowledge by assessing the applicability of using an
Integrated Resource Management (IRM) strategy for more effectively managing environmentally
sensitive areas that are also critically important to a resource-based industry. In this case, the
function of riparian zones along electric transmission Rightofways (ROWs) is examined as the
unit of study. Applied research is used to explore the impact ofROW maintenance on the
functioning of riparian zones, a topic that has largely been overlooked.

The principal research problem of this project is to determine if it is possible to integrate riparian
zone function with current vegetation management practices along electric transmission ROWs
1

in British Columbia (BC). The research goal was accomplished by investigating four secondary
questions: What are the current maintenance techniques for riparian zones along electric
transmission ROWs and what are their effects on key ecosystem functions? What are the
constraints to managing for riparian values along ROWs? What are the opportunities for
managing for riparian values along ROWs? What recommendations can be made concerning
integrating riparian zone health with ROW vegetation management strategies? The answers to
these questions may provide guidance to future management strategies on electric transmission
ROWs.

BC Hydro is British Columbia' s major electricity provider and generates over 90% of its
nameplate capacity at large hydroelectric facilities located far from heavily populated areas. Its
transmission system is composed of a mix of high and extra high voltage powerlines ranging
from 69kv to 500kv. The extensive transmission powerline and corridor system is approximately
17,000 km long, ranges in width between 15 and 300m, and traverses some of the most rugged
topography found in North America (BC Hydro 1997B).

The corporation has always maintained its large transmission system with a single resource
management goal to provide "safe, efficient and reliable delivery of power from generating
stations to customers" (BC Hydro, 1997). As a result, management attention has been on
methods of guaranteeing vegetation remain a prescribed distance away from the overhead
powerlines (BC Hydro, 1997). Existing vegetation control techniques have allowed BC Hydro to
maintain a nearly uninterrupted flow of power.

2

In conjunction with public opinion and regulatory changes, research suggests corporations should
shift from maximizing short term financial returns to addressing longer term economic and
societal expectations (Alpert, 1995). Similarly, recognition has grown within BC Hydro, and the
utility industry as a whole, that resource management practices must change (Breece and Ward,
1996; Yeager, 1996; BC Hydro, 1997). BC Hydro's most recent vegetation management manual
(1997) reflects this increased awareness and states its new vegetation management strategy

(p.l.1):
One ofBC Hydro's objectives is to ensure the safe, secure and efficient supply of
electricity for its customers, while protecting public safety. At the same time,
BC Hydro's corporate policy emphasizes minimizing adverse effects on the
natural environment and promoting sustainable development to meet the needs of the
present, without jeopardizing the ability of future generations to meet their needs.

Riparian zones are one of the natural environments present on BC Hydro's transmission ROWs
that are increasingly being recognized as unique and important elements of the landscape. They
provide a critical link between terrestrial and aquatic ecosystems, leading to suggestions that
their name should be changed to the hydroriparian zone (to better reflect their role )(BC, 1995).
Regardless of nomenclature and classification schemes, riparian zones are moist areas adjacent to
water that are responsible for supporting terrestrial ecosystems that have high species densities
and diversities (BC, 1995). They are responsible for creating and then maintaining several
important features of the adjacent aquatic ecosystems. In particular, riparian zones moderate
solar energy inputs, stream production, morphology, habitat complexity and flow patterns
(Gregory et. al., 1991). When riparian areas are disturbed to the extent that ecosystem function is
reduced, adjacent streams often experience conditions less suitable for sustaining aquatic
ecosystems, that in turn, may impact fish populations.

3

BC Hydro ' s extensive transmission powerline system crosses thousands of streams each bounded
by a unique riparian zone. At point of powerline crossing, each riparian zone is influenced by the
vegetation maintenance techniques required to keep the vegetation well clear of the powerlines.
These techniques can have a wide range of influences, many of which may have adversely
impacted riparian ecosystems. However, only a few studies have concerned themselves with
these types of impacts (Peterson, 1993; Bunnell et al., 1995). Similarly highways, railways and
pipeline corridors have been poorly studied to determine their effects on riparian areas or
biodiversity (Bunnell et al. , 1995). No research concerning the effects of transmission powerline
vegetation management on riparian zones was discovered in the literature, or could be
established as having been completed in BC

As a result, there is very little information currently available to either: (1) confirm that current
ROW vegetation maintenance strategies are benign (in terms of riparian ecosystem function) ; or
(2) suggest the potential impacts of ROW maintenance on key riparian zone functions. Some of
the most recent riparian management strategies for ROWs recommend the preservation of tall
growing buffer strips (McLennan, 1996). This management approach originates from the
forestry-related research that deals with the impacts of harvest operations on the riparian zones. It
is a practice that may be more satisfactory for forestry and other linear projects but cannot work
for powerlines because of the necessity to restrict vegetation height. Therefore, there is a need to
evaluate the impacts of the vegetation management practices on riparian zones along ROWs and
use this information to suggest integrated management techniques.

During the planning stage of this project it was recognized that to meet the research goal, it was
critical that this study include information from a variety of sources. In this instance, both
4

quantitative and qualitative data including anecdotal information had to be collected and
analyzed to obtain an accurate description of the impact of vegetation management on riparian
ecosystem function. Although there are several research design options currently available to
handle both qualitative and quantitative information, the case study method was selected as the
most powerful design to accommodate this study ' s research problem (Yin, 1994; Zolman, 1995).
Moreover, a multiple case study method was applied using an experimental design that involves
each case being described individually but trends compared across case study sites.

Although it is the interaction of several parameters that ultimately defines an ecosystem's state,
for this study riparian ecosystem functions were broken into four separate but functionally
related categories. The four key functions are: (1) energy flow into a stream; (2) hydrology of the
stream; (3) bank stability; and (4) habitat complexity. Observations associated with these four
functions were collected at each of the case study sites. Analysis was completed by looking for
trends in each of the four key functions across the case study sites. The trends were then
compared to vegetation management history to correlate impacts on riparian ecosystem
functions. This information was used to develop opportunities and constraints, as well as,
conclusions and recommendations about integrating riparian zone function with current
vegetation management practices along electric transmission ROWs in British Columbia.

5

CHAPTER2
Managing Electric Transmission Righofways
And Riparian Zones
2.0 Introduction
Natural resource-based industries are increasingly being challenged to expand their management
goals and approaches to encompass many different issues. This section of the thesis considers the
now recognized dilemma concerning broadening the management scope for riparian zones
located along electric transmission ROWs. The review begins by presenting information about
ROW management, including a description of how and why maintenance occurs. Traditional
ROW management paradigms are then compared to strategies needed to protect riparian zones
including information and examples from other industries. The bodies of knowledge clearly
point to an apparent contradiction between management goals for ROWs and riparian zones.
Utilities manage ROWs by preventing the growth of tall growing vegetation thereby, ensuring an
uninterrupted flow of power. Conversely, in most other situations riparian zones are managed to
either restore or preserve tall growing trees and maintain ecosystem function. This apparent
conflict leads to a review of IRM, a prefe1Ted management approach that has been used
elsewhere to help integrate complex and seemingly contradictory issues.

2.1 Managing ROWs
A key component in the integrated electrical system is the transmission facility which links
generation of power with the substations and end users. This task is completed by high voltage
powerlines which are commonly grouped into three separate levels: high voltage (46-230 kV),
extra high voltage (231-765 kV), and extra extra high voltage (above 765 kV)(Randall, 1973).
Land based transmission facilities are most often found in one of two arrangements. The first is a
6

buried facility composed of metal power lines in large insulated and protected bundles below the
ground. While this system does have some advantages, mainly associated with aesthetics, it can
often be impractical due to cost, geography, public safety and involves significant environmental
disturbance. Therefore the second, and most commonly used arrangement, involves high voltage
powerlines suspended above the ground on large wooden or metal structures.

As stated, transmission powerlines and their ROWs are maintained to ensure consistent and
reliable movement of power, as well as to protect the public from the potentially lethal hazard of
contacting high voltage electricity. Maintenance of ROWs is generally broken into two separate
categories. Hardware maintenance involves all the tasks associated with ensuring the apparatus
directly related to moving power remains in good functioning order (e.g. powerlines, insulators,
support structures). The second category, landscape management, involves all the tasks
associated with the corridor through which the facility is located. One component of this entails
the need to ensure access to the whole line to respond to hardware maintenance and emergencies,
and generally involves the task of keeping rough roads along the ROW passable. The
significantly larger component of landscape management is the need to continually contend with
the tall growing vegetation located along the transmission system corridor.

When a transmission line is built, all vegetation within the construction corridor is usually cut
and removed (Nickerson and Thibodeau, 1984; Thibodeau and Nickerson, 1986). Attention
quickly turns to ongoing and routine maintenance along the ROW to keep vegetation at safe
distances (defined vertical distances) from the power lines (BC Hydro, 1997; Draxler, 1997).

7

2.1.1 Vegetation Management
Tall growing vegetation can affect powerlines in a variety of ways. Vegetation located adjacent
to the ROW poses a significant and ongoing threat to any electrical powerline because of the
potential for falling trees, or their branches, to strike the powerline. Most often this results in
power outages, fires , and damage to the apparatus. Another more persistent threat is the trees and
vegetation located directly under the wires that can grow up into them. Trees, which grow into
the wires, can, at the least, impair lines of sight (affecting hardware maintenance) and cause
power outages or fires. When trees come into contact with a transmission powerline they can
impose a potentially lethal hazard to the public by conducting high voltage electricity. Due to the
risks that vegetation poses to the maintenance of transmission systems, the industry standard in
North America has been the use of treatments, at the lowest costs available, to interrupt
vegetation succession and ensure a condition where vegetation is kept away (Egler, 1975; Luken,
1991). This has involved combining machine grooming, hand cutting, and the application of
herbicides (Egler, 1975 ; Luken, 1991).

Concurrent with public opinion and regulatory changes, recognition has grown within the utility
industry as a whole that resource management practices must change (Porteck et al. , 1995;
Breece and Ward, 1996; Yeager, 1996; BC Hydro, 1997). The modern transmission ROW
manager must address a variety of public concerns, including cost of power, environmental
quality, other uses along the ROW, and aesthetic values. This introduces the need for increasing
complexity into the planning of ROW maintenance (Porteck et al. , 1995), which can often
eliminate the use of many traditional vegetation control methods. Furthermore, it has been
suggested that to remain economically viable within the emerging deregulated business
environment, utilities must maintain consent to operate by meeting public and regulatory

8

demands (Yeager, 1996). Significant environmental impacts, at times acceptable for local
economic development, may not be acceptable to consumers who can purchase power from any
utility they choose in the emerging deregulated market (Yeager, 1996). Utility managers must
adopt broader multiple resource management plans that include integration of pertinent
environmental issues (BC Hydro, 1997; Breece and Ward, 1996). However, future viability of
the utility also demands that implementation of management techniques is affordable and ensures
safe, efficient and reliable power for customers (BC Hydro, 1997). As a result some researchers
suggest corporations must move from stressing short-term financial returns to establishing
longer-term economic and societal expectations (Alpert, 1995).

One significant aspect of an integrated approach involves developing explicit plans for managing
riparian zones along transmission ROWs. Historically, riparian zones were most often managed
in an identical manner as the rest of the ROW. It was not common practice to have specific
treatment prescriptions designed to help maintain ecosystem function on riparian sections that
intersect the ROW. However, there has been increasing awareness that areas located adjacent to
water require protection. As a result, some utilities are beginning to manage riparian issues to
meet ROW needs and reduce impacts to the affected ecosystem (Breece and Ward, 1996).

2.2 Riparian Zones
Riparian zones are increasingly being recognized as significant elements of the landscape,
providing meaningful three-dimensional links between terrestrial and aquatic ecosystems
(Gregory et al., 1991; BC, 1995). Moreover, as they are uniquely situated at the boundary
between different open systems, riparian zones have dynamic physical properties that vary with
climate, fluvial geomorphology and geologic history (Church, 1991 ; Leopold, 1994; BC, 1995).
9

Functionally, these areas create and maintain many key habitat parameters of freshwater stream
ecosystems (Gregory et al. , 1991). As a result, when riparian zones are disturbed, adjacent river
chmmels often undergo change that is difficult to predict and can lead to less stability and less
productivity or in some cases increased productivity (Hicks et al. , 1991 ; Li et al. , 1994).

2.2.1 Features of a Riparian Zone
Rivers are dynamic, open transport systems with complex physical properties which vary over
time and space (Knighton, 1984). Thus, riparian zones are not static but one of the most dynamic
areas of the landscape with properties which change according to fluvial and non-fluvial
disturbances (Gregory et al. , 1991). Moving downstream from a river' s headwaters the
morphology and properties of the system and its riparian zone depend on the complex interaction
of many factors. A small headwater stream, where the ratio of substrate size (em) to stream width
(m) is greater than 1, lacks the power to determine its own path. Rather, stream morphology (for
example cascade-pool, or riffle-pool) and the resulting riparian zone is determined by individual
roughness elements, valley gradient, and hydrology (Knighton, 1984; Church, 1991 ). In medium
size streams, where the ratio of substrate size to stream width is between 0.1 and 1, the river
system is able to complete more work and modify the landscape. These systems respond
morphologically to changes in gradient and hydrology, to maintain competence to move water
and sediment. In general, they have less severe gradients, mixed sediment composition, create
floodplains and modify the landscape they flow through (Knighton, 1984; Church, 1991). Finally
large rivers, where the ratio of substrate size to stream width is usually well below 0.1 , usually
display large meanders, low gradients and low velocities. Furthermore, they inevitably create
large floodplains where large quantities of fine sediments are alternately stored and eroded
(Knighton,1984; Church, 1991).
10

The morphology of the resulting riparian zone is also a function of these same processes. For
example, small high gradient streams have riparian areas composed of large and rough
sediments, mostly of a non-alluvial origin (Church, 1991 ). However, further downstream riparian
zones are predominantly composed of sediments alternately stored and transported within the
alluvial channel (Knighton, 1984; Leopold, 1994). The size and role ofthe riparian community is
determined by the interaction between soils, gradient, climate and hydrologic regime (BC 1995).
Species composition, density, diversity and habitat function are unique to each set of parameters.
As a result of this variability and the almost limitless combinations in turn confound any simple
spatial definition of the terrestrial riparian zone or description of its integration with the aquatic
ecosystem by separate criteria (BC 1993).
Regardless of size and function, most riparian zones are composed in a similar manner and have
cross-sections based on the amount of time an area is inundated with water (Gregory et al. ,
1991 ). Figure 1 is an illustration of a riparian zone. The most upslope community (including the
upper portions of the buffer zone in Figure 1) is generally unaffected by the stream other than by
increased groundwater availability. Typically it has a relatively stable vegetation community
composed of taller mature vegetation species (Gregory et al. , 1991). Downslope from this is the
floodplain, defined as the valley floor adjacent to a stream (including the lower sections of the
buffer zone in Figure 1) that is often inundated only during peak flows (Gordon et al. , 1993). The
floodplain has increased moisture and regular disturbance resulting in vegetation that is more
tolerant of moisture, higher species diversity and is dominated by low growing species (Gregory
et al., 1991). Next is the active channel, delineated by the annual high water mark (Gregory et al. ,
1991 ). This unit, is completed inundated for periods of each year and as a result does not support
terrestrial vegetation (Knighton, 1984, Gregory et al., 1991 ).
11

LEAF &
ORGANIC
LITTER ....' I
"/

\

I

I

~?l·~~~7l>::~

STABLE CHANNEL
BANK

RIPARIAN ZONE

RIPARIAN ZONE

(Figure from DFO and MoELP, Land Development Guidelines, 1992.)

Figure 1: The features and functions of a riparian zone.

12

2.2.2

Riparian Zones and Aquatic Ecosystems

Riparian zones are unique landscapes where the terrestrial environment helps create and maintain
aquatic habitat conditions required to support fish species. All ecosystems are functionally
defined by their access to external energy, their ability to capture it and the efficiency by which
they move it throughout the biological system (Odum, 1985; Gregory et al. , 1991 ). As a result,
riparian zones influence aquatic ecosystems by moderating energy exchange between terrestrial
and aquatic environments (BC, 1995). In the winter the riparian vegetation reduces backradiation, prevents the formation of anchor ice and preserves existing fish assemblages (Platts,
1991). Furthermore, they can directly control the aquatic environment's access to the most
important energy source, solar radiation (Gregory et al. , 1991)

During the warm summer months the riparian community provides shade and helps maintain
acceptable water temperature thereby determining fish presence, variety and density (Barton et
al. , 1985; Beschta et al. , 1987).

As all fish are poiklotherms (unable to regulate internal body temperatures), when the
temperature of the external environment moves beyond an acceptable range (either too hot or too
cold) the animals must move to other more suitable habitats, or perish (Beschta et al. , 1981 ;
Gregory et al. , 1991). In the case ofsalmonids, species specific and stock specific tolerances can
vary, but their clear, cool streams must remain absolutely below 24-26 degrees Celsius (Bjornn
and Reiser, 1991 ). As would be expected, the relevance of this temperature control function
varies according to season as well as geographical location (Beschta et al. , 1987). Accordingly, it
is the most critical factor for determining habitat suitability of streams located in warm and dry

13

climates (Platts and Nelson, 1989; Li et al. , 1994), but less relevant in cooler and wetter climates
(Murphy et al. , 1986; Beschta et al. , 1987).

Within the absolute realm of habitat suitability (lethal effects), riparian vegetation applies subtle
controls on biological processes through control of water temperature. Fish life processes are
affected by water temperature regimes. In the case of fall spawning salmon, logging activities
can increase the sunlight striking a stream and increase the intergravel water temperatures
(Ringler and Hall, 197 5). Increased incubation water temperatures can lead to premature
emergence and have a negative effect on juvenile survival (Beschta et al. , 1987; Hartman et al. ,
1987). In other situations increased water temperatures can lead to larger alevins and parr and
significantly increase their likelihood of success (Scrivener and Anderson, 1984; Beacham and
Murray, 1986). The riparian zone helps regulate annual water temperature regimes, thereby
affecting juvenile developmental processes and ultimately species survival.

Aside from developmental related sub-lethal impacts, water temperature changes also affect fish
behaviors. Research in the Yakima River demonstrated that spawning salmon will actively
pursue cool water refuges, associated with pools and ground water sources, during their
migration. The benefits to the animal are significant with each difference in 2.5 °C in water
temperature resulting in a 25% change in basal metabolic rate (Berman and Quinn, 1991 ). Other
research has suggested interesting interspecies aspects of water temperature changes. Reeves et
al. (1986), investigated the interaction of red side shiner and steelhead trout in a laboratory setting
and found that in cooler temperatures the trout dominated habitats and out competed the redside
shiners. As temperatures got closer to 19-22°C the shiners enjoyed a larger distribution, trout
production decreased and the shiners had the competitive advantage (Reeves et al. , 1986). In the
14

field setting, a change in species composition was also noted in high desert streams, as increased
water temperatures resulted in significantly lower densities of steelhead trout and sculpins (Tait
et al. , 1994; Li et al. , 1994). Generally non-sport fish are more tolerant ofhigher water
temperatures (Platts, 1991 ).

Riparian zone vegetation and its associated canopy control primary productivity by providing
shade. Autotrophic algae in freshwater streams depend on solar radiation to grow and reproduce
(Bilby and Bisson, 1992). As such, riparian vegetation communities help determine aquatic
ecosystem biomass and densities. For example, higher amounts of solar radiation entering a
stream invariably increase primary productivity, thereby potentially increasing the richness of
higher trophic invertebrate and vertebrate communities (Gregory et al. , 1991 ; Bilby and Bisson,
1992). Although increasing primary productivity in cooler, oligotrophic streams, invariably
benefit invertebrate and fish populations by creating more feed (Murphy et al. , 1986; Hartman et
al. , 1987; Bilby and Bisson, 1992), in warmer climates this must be tempered by the afore
mentioned need to moderate water temperatures (Li et al. , 1994).

In conjunction with affecting the amount of sunlight available to drive primary production, the
riparian community helps regulate the aquatic community by being a source of allochthonous
energy, nutrients and food (Gregory et al. , 1991). During the course of a year, vegetation in the
riparian zone grows leaves and fruit which over time fall from the plant and land in adjacent
streams. This material, most often in the form of leaves, sticks and berries provides nutrients and
energy to the invertebrate community, that in turn, fuel higher trophic levels (Gregory et al. ,
1991). In addition, terrestrial insects often fall from riparian vegetation into the adjacent water
and provide a vital food source for many aquatic animals. For example, it has been suggested that
15

in small streams flowing through large mature forests , up to 65% of the salmonid food and
organic matter available is of terrestrial origin (Bilby and Bisson, 1992). These inputs vary
seasonally.

In addition to water temperature and food availability, another key aquatic habitat parameter
largely controlled by riparian vegetation is water quality. As the roots and associated organisms
extract nutrients from the ground water to grow, respire and reproduce, they act as a filter
mechanism (Lowrance eta!. , 1984). This helps regulate the quality ofthe groundwater, which
slowly percolates into salmonid streams (Gregory eta!. , 1991 ). In some cases it removes
significant volumes of nitrates and other chemicals before they enter a stream (Lowrance eta!.,
1984). In ultraoligotrophic, cool water system the removal of nitrates can lead to reduced
productivity. Conversely in areas where water quality has been compromised, often near heavy
agricultural development, the filtering removes significant volumes of potentially harmful
compounds and ensures good water quality (Lowrance eta!., 1984; Osborne and Kovacic, 1993).
In summary, the riparian zone often plays a role in ensuring water quality remains within the
parameters required to maintain the current aquatic ecosystem (Gregory et a!. , 1991)

2.2.3 Riparian Zones and Morphological Processes
From a watershed perspective topography, climate and precipitation conditions invariably
determine stream networks, morphology, hydrology and water quality (Knighton, 1984; Leopold,
1994). However, from a site or reach specific perspective, riparian vegetation significantly
affects morphological processes and as a result also plays a key role in determining the suitability
of a water body as aquatic habitat (Gregory et 1991 ).

16

The first way riparian zones affect stream properties is by moderating hydrology through
attenuation of flow events related to precipitation (rain and snow melt) (Leopold, 1994). In areas
without significant vegetation, precipitation strikes the ground, causes rills and runs directly into
streams (Leopold, 1994). However, in areas with dense vegetation the precipitation strikes
foliage, where its kinetic energy is dissipated allowing it to more slowly flow into streams
(Leopold, 1994). Regardless of the climatic region, attenuation of flood events is beneficial to
streams because it reduces the likelihood of catastrophic pulse events and subsequent significant
damage to aquatic habitat (Leopold, 1994 ). The latter invariably occurring when a channel erodes
and responds morphologically, by either increasing width or gradient, to maintain competency
for peak flows (Leopold, 1994).

Interception also moderates hydrology by allowing more water to percolate into the earth and
enter the groundwater column (Knighton, 1984). Groundwater flow is more often the consistent
stream maintenance flow source, between precipitation events, and is another component of
hydrology affected by the structure of the riparian vegetation community. One of the reasons
heavily vegetated communities are able to hold more water for longer periods of time is due to
increased soil porosity and complexity created by roots and associated organic compounds
(Gregory et al. , 1991). As a result more vegetation ensures more consistent flows during low
flow periods (Leopold, 1994). This is especially important in dry arid regions where removal of
vegetated riparian zones, often through grazing, has driven perennial streams to intermittent
streams, eliminating them as potential aquatic habitat (Hicks et al. , 1991).

Erosion and the subsequent transport of sediment from landscapes are the next significant river
process, which to a degree are also regulated by riparian vegetation (Knighton, 1984). Peak flows
17

exert the highest shear forces on bed and bank, complete the greatest amount of work, and
ultimately determine a channel ' s shape and structure (Knighton, 1984). The riparian zone
moderates this process by providing roots and other organic compounds which armor the bank
and increase its resistance to erosion (Gregory et al. , 1991 ). This armoring works with site
roughness elements to reduces shear velocities and lateral erosion at peak flows. The extent of
armoring will moderate channel morphological response to changing hydrological variables, as
evidenced in vertical processes such as aggradation or degradation (Leopold, 1994).

Stream channels that scour and fill periodically are considered to be at grade. Decreased flows or
increased inputs of sediment can result in aggradation (a flow limited situation) (Knighton, 1984,
Church 1995). This response improves the flow effectiveness to transport sediment by reducing
depth, increasing gradient and thereby reducing the threshold for bed load transport (Lisle, 1982;
Gordon et al. , 1993). Some of the morphological indicators for these channels are a general
widening, large sediment bars, highly eroded banks, and decreased pool volume (Lisle, 1982). If
the channel aggrades the water table is raised, providing another mechanism by which to increase
groundwater flow (stream maintenance) (Elmore and Beschta, 1987). Increased flows or a
reduction in sediment input can lead to narrowing of the channel and degradation of the stream
(Church, 1995). Some of the indicators for these channels are a general narrowing, few sediment
bars, highly eroded banks and decreased pool volume (BCFPC, 1995). While degradation often
involves reduced habitat suitability, in some cases it can create more pools and beneficial
instream structures (Smith, 1990).

These physical processes are especially important when considering streams which in order to
support fish must exhibit clear, cool water and an array of morphological complexity (Murphy et
18

al. , 1986; Bjornn and Reiser, 1991; Fausch and Northcote, 1992). For some species, such as
salmonids, spawning and incubation requires riffles and runs composed predominantly of larger
sediment, with interstices free offine sediments (Bjornn and Reiser 1991). Rearing requires
deeper runs, a variety of pool types and off-channel areas. These are invariably filled and
subsequently eliminated from the stream when excessive fines sediments are deposited into a
stream. Without the resistance to lateral erosion many of these morphological forms would
disappear, diminishing the stream suitability as aquatic habitat (Heifetz et al. , 1986).

In larger river systems morphological complexity is determined by the larger watershed
characteristics, including form roughness and large debris jams (Leopold, 1994). However, in
smaller streams introduction of large woody debris (L WD) from the riparian zone is largely
responsible for creating complexity, and therefore salmonid suitability (Murphy et al. , 1986;
Robison and Beschta, 1990; Gregory et al. , 1991).

As a tree moves from the terrestrial riparian zone into the aquatic environment it becomes a new
roughness element of the stream channel that immediately impacts site morphology by reducing
and redirecting hydraulic forces (Keller and Swanson, 1979; Lisle, 1982). Because of its large
size (relative to small and medium size streams) at lower flows the L WD usually blocks a
. significant portion of the channel and a backwater pool is formed directly upstream of the
obstruction. The new pool then functions as a sediment trap and increases the residence time of
organic matter floating downstream (Bilby and Likens, 1980; Sedell and Swanson , 1984; Hicks
et al., 1991 b). At higher flows these areas upstream of the obstruction are scoured and depth is
increased. At sites where the L WD creates a small dam, the flowing water is forced to flow over
the object and thereby erodes downstream plunge pools.
19

In other situations where the L WD does not completely block flows water can erode around the
object, thereby creating undercut banks. Organic material at a meander bend will reduce
velocities and cause creation of a point bar (Knighton, 1984). The L WD may become further
embedded in the channel and become relatively stable control structures that can continue to
function for centuries (Toews and Moore, 1982; Sedell and Swanson , 1984).

In all streams the important positive effects (to fish habitat) ofL WD must be balanced by the
potential negative impacts of large debris jams which can destabilize stream banks (Bisson et al. ,
1982).These negative effects are most often the result of catastrophic events, such as mass
wastage or severe wind storms, that introduce large amounts of LWD into a stream and
significantly increase erosion and lateral movement (Robison and Beschta, 1990).

A key role of L WD in sustaining a rich aquatic population is creating and maintaining relatively
stable, complex microhabitat (Hicks et al. , 1991 b). Research into the relationship between
aquatic life, pools and L WD have found that pool volume is inversely related to stream gradient
and directly related to amount ofLWD in a stream (Carlson et al. , 1990; Hicks et al. , 1991b;
Bilby and Ward, 1991). Bilby and Likens (1980) found that in first and second order streams,
habitats associated with L WD contain between 58-75% of the streams standing organic matter.
Pools have more organic matter and result in higher macrobenthos densities, drift and food for
foraging fish (Schlosser, 1982; Elliot, 1986).

At higher levels in the trophic structure the interaction between pool and riffle habitat is critical
for many fish species to successfully conduct their life history processes (Bisson et al. , 1982;
Hicks et al. , 1991 b). Further, it is the diversity of microhabitat that creates conditions necessary
20

to allow the co-existence of multiple species commw1ities (Bisson et al., 1982; Hicks et al.,
1991 b). The microhabitat caused by L WD contributes to fish survival by providing quality
foraging areas, velocity refuges, increased depth and cover from predators (Toews and Moore,
1982; Elliot, 1986; Shirvell, 1990; McMahon and Holtby, 1992; Fausch and Northcote, 1992).
For some fish species, such as trout, pools are preferred habitats for conducting most of their life
history processes (Dolloff, 1986; Elliot, 1986; Fausch and Northcote, 1992). Whereas for some
Pacific salmon the volume of pool habitat and cover may only be important for a critical period
during one stage of their life history (Heifitz et al. , 1986; Shirvell, 1990; Berman and Quinn,
1991).

While the functions of the riparian community can vary over time, depending on climatic
conditions, they also vary with space. Again, based upon the paradigm that a biological
community within a stream conforms to kinetic energy dissipation patterns of the fluvial system
(Vannote et al., 1980), the role of riparian community stretches along a dynamic gradient. This
continuum begins at small heterotrophic headwater regimes, then moves through seasonal
autotrophic regimes (in the mid-reaches) and finally returns to large river heterotrophic processes
(Vannote et al. , 1980).

While this size gradient is analogous to the review of stream morphology presented earlier, this
paradigm suggests ecosystem function is governed by interaction between stream size and energy
availability. Where streams are small and their shape and form depend on the material and
gradient, they are often completely enclosed by canopy of the adjacent riparian vegetation
(Vannote, 1981 ; BC, 1993). As a result, habitat complexity, external energy entering the stream
(including temperature control and primary productivity), nutrients and feed inputs are directly
21

dependent upon the riparian community (Vannote et al. , 1981 ). As streams become wider and
more powerful, they are able to transport more material and modify the adjacent landscapes
(Church, 1991). In these wider streams that still have clear water, the riparian community ' s role
changes. Here, the vegetation canopy often covers less than half of the stream area and therefore,
instream autotrophic production becomes the mechanism which determines community structure
(Vannote et al. , 1980). At these sites vegetation takes on an increased role in providing bank
form resistance, site specific habitat diversity, and attenuating peak flow pulse events (Leopold,
1994). In larger rivers, water clarity is drastically reduced and correspondingly internal
production switches back to a heterotrophic driven ecosystem. In these systems, riparian
vegetation helps provide bank resistance, food sources and site specific complexity, but it is less
able to affect the quality of the fish habitat provided or stream morphology (Vannote, 1980;
Church 1991).

2.3 Managing Riparian Zones

Although the amount of interaction between terrestrial and aquatic ecosystems varies among
different riparian zones, disturbances of the terrestrial landscape often reduces stream
productivity (Barton et al. , 1985; Elmore and Beschta, 1987). As a result landscape management
has most often focused on strategies to help protect adequate riparian zones area and thereby
preserve stream productivity. More recently, researchers are suggesting that spatial criteria are
inadequate to protect ecosystem function. Rather new more integrated management parameters
criteria are required (Costanza, 1992). With riparian zones this includes expanding the
assessment from what they look like to what are the key functions .

22

Consistent with the previously described roles of riparian zones in maintaining aquatic habitat, in
general, when they are disturbed by land use activities, such as logging and agriculture, there is a
corresponding reduction in aquatic ecosystem productivity (Elmore and Beschta, 1987). Because
of the variability of riparian zone composition and function, the impacts of terrestrial
disturbances can vary with climate, topography and type of activity. For example, in wetter and
cooler climates, short term increases in primary productivity often occurs when the canopy is
thinned leading to higher juvenile fish populations (Hawkins et al. , 1983). But thinning could
also result in greater water temperature fluctuations, reduced L WD inputs and reduced habitat
complexity leading to decreased fish survival and densities (Heifetz et al. , 1986; Riehle and
Griffiths, 1993 ).

Effective riparian zone management involves integrating site and ecosystem specific limiting
factors with management strategies. In areas with suitable water temperature regimes and habitat
complexity, reducing the vegetation canopy removes a limiting factor and allows a system to
become more productive (Smith 1980, Peterson 1993). In fact some (Thedinga et al. , 1989) have
suggested that cutting vegetation to increase water temperature in streams that are cooler in the
summer than optimum, can increase productivity and should be assessed as an enhancement tool.
In warmer climates reducing the vegetation cover can lead to increased temperatures, introducing
a new limiting factor to stream production (Barton et al. , 1985; Li et al. , 1994; Tait et al. , 1994).

In order to reduce potential impacts of land management activities research has focused on
defining empirical criteria which describe the extent and type of riparian zone required to
preserve ecosystem function (Taylor and Biette, 1985 ; Gregory et al. , 1991; BC, 1995). This
work has generated several discrete criteria (Taylor et al 1985, BC Forest Practices Codes, 1995).

23

Single key criterion that have been used include measuring the largest trees and assessing either
their shading ability or potential for contributing L WD (Brazier and Brown, 1973 ; Mcdade,
1990). Other terrestrial indicators such as edaphic vegetation have been employed (Gregory et
al. , 1991; Millar et al. , 1996). In still other situations, professional and political judgment has
been used to place caveats around streams based on stream width, independent of a documented
scientific process of evaluation (Elmore and Beschta, 1987; Castelle, 1994). From a habitat
perspective other researchers have used water acidity as indicator criterion (Omerod et al. , 1993)
or the volume ofL WD (Fausch and Northcote, 1992). In addition to habitat suitability, actual
fish species and densities have often been used to describe the overall state of an ecosystem
(McMahon and Holtby, 1992; Peterson, 1993; Tait, 1994).

The most common management criterion used to identify and subsequently protect the function
of riparian zones has been width of pristine terrestrial area (Barton et al. , 1985; Castelle, 1994;
BC, 1995). Although this has occurred in large part because of the ecologically incomplete
perspectives provided by isolated criteria (Gregory et al., 1991 ), large terrestrial elements, such
as protected areas, have many very appealing qualities. The mature forest community: (1)
supports the climax community paradigm and represents the preferred structure of a healthy
ecosystem (Costanza, 1992); (2) involves a larger and more integrated unit which implicitly
provides greater biological diversity and resistance to incursion (Barton et al., 1985; Millar et al.,
1996); (3) represents a clearly defined spatial area, which is both quantifiable and easily
measured in the field (Platts et al., 1983 ; Oliver and Hinckley, 1987; Castelle, 1994); (4) is
assumed to be a composite indicator of many different parameters within the ecosystem
(Costanza, 1992); and (5) its linear properties facilitates relatively uncomplicated management
strategies (Castelle, 1994).
24

However, the consistent focus on the pristine buffer strip as the empirical and spatial unit of
assessment has been problematic and has lead to dubious management strategies (Rinne, 1990;
Castelle, 1994). The first and most pressing issue is the inability ofthis relatively simple measure
to account for function of the riparian zone within a highly variable natural system. According
to Oliver and Hinckley (p.260, 1987),
Riparian zones, particularly in upland regions, are not easily classified, because (1) the riparian
vegetation is not distinct from the upland vegetation, because (2) soils are not obviously different
nor is there a typical riparian zone soil, and (3) there is not always a topographical depression.
Although classification systems are useful in a court of law or for mapping similar units, they
may not be appropriate in defining the function of a riparian zone.
In addition, the application of a simple classification and protection scheme can often lead to
assessments which neglect the relative state of a site's aquatic habitat, focusing solely on
terrestrial areas (Castelle et al. , 1984). By establishing finite spatial boundaries instead of
functional criteria, the riparian zone is studied in isolation from the surrounding land-use
activities (Castelle et al. , 1994). This reduces the opportunity for new and more adaptive
protection strategies which integrate ecosystem function with change over both time and space
(Rinne, 1990; Costanza, 1992; Caste lie et al. , 1994).

More importantly, this approach often ignores the fact that aquatic ecosystems, including fish
species, do not absolutely depend on particular vegetation species or terrestrial landforms. Rather
it is the interaction of these that ultimately determines habitat suitability (Wilzbach, 1989;
Gregory et al. , 1991).

Recognizing the inherent problems with defining ecosystem spatial boundaries other researchers,
while not disagreeing with the need for buffer strips, suggest that buffer strip size should be
25

determined by four functional criteria: resource functional value, the intensity of the adjacent
land use, buffer characteristics and specific aquatic functions required (i.e. limiting
factors)(Castelle et al. , 1994). From a more biological perspective, others have suggested that
sediment composition, and invertebrate and vertebrate community structure should be used as
integrated assessment criteria (Rinne, 1990). In a recent controversial forestry application,
integration was fully recognized, resulting in a new title for the area (the hydroriparian zone),
recommendations for more qualitative functional criteria, and assessment periods of over 80
years (BC, 1995).

Calls for new and expanded criteria and less static concepts about riparian zone preservation
reflects the increasing understanding about the important role these areas play in the landscape
and their complex nature; many parameters need to be considered for effective management. The
new view of riparian zones have coincided with the redefinition of ecosystem health as an open
system that, "maintains its organization and autonomy over time and is resilient to stress"
(Costanza et al. , 1992). In this paradigm integrated indicators can be used to generate a broader
more comprehensive yet adaptable description of a healthy riparian zone (Costanza et al. , 1992).

2.3 .1 Setting Ecosystem Functions as Criteria for Managing Riparian Zones
As described within this review, isolated empirical assessment parameters cannot accurately
describe the health and function of a riparian zone and associated aquatic habitat. Even though
spatial preservation frameworks provide a standard and workable way to protect many stream
ecosystems, they are inadequate for accurately capturing and describing the functional
interactions of these dynamic zones. Notwithstanding, physical and biological features will

26

continue to serve as indicators of current watershed conditions (Rinne 1990). However, as
suggested by Rinne (p.375, 1990) to be meaningful they must accurately describe,
(1) the nature and the variability of stream habitat and biota under natural
(pristine) conditions, (2) the patterns of this variability through time, and (3)
both the relative information content and interactions of various features .

They must also be communicated into standard, understandable and effective management tools.

In order to accomplish these tasks certain points must be first recognized and then investigated.
Rather than using isolated key indicator species (vertebrate, invertebrate or vegetative) composite
functional criteria need to be identified. From a functional perspective it is the interaction of
several site specific variables, including biological factors, that ultimately defines a stream' s
productivity. Regardless, the roles of riparian vegetation in affecting aquatic habitat can be
grouped into four categories: (1) Energy Flow (the amount of solar energy entering a stream), (2)
Habitat Complexity (L WD controlled streams), (3) Stream Hydrology and (4) Bank Stability.
Some of the physical criteria which may be used to assess these processes are: water temperature,
primary productivity, bank stability, L WD, vegetation density, water flow, rates and timing.

There is a need for research that investigates methods of integrating traditional ecosystem
parameters with new more holistic measures, including anthropogenic effects on an ecosystem.
Broader ecosystem parameters should be studied from a habitat suitability perspective, allowing
for creation of new and more effective and adaptive management strategies; including guidelines
for managing different ecosystem habitats.

Riparian zones are extremely dynamic environments with physical and biological characteristics
which can change significantly over time and space. These areas are key links between terrestrial
27

and aquatic ecosystems, responsible in large measure for determining the suitability of many
aquatic habitats. While recognizing this variability, most research has focused on individual
ecosystem functions or key indicator species, in order to define ecosystem health. However, in
conjunction with expanded and functional views of ecosystems, has been increased recognition
that perspectives based on isolated components are ecologically incomplete. Rather, new more
robust and holistic criteria are required to accurately assess riparian zone condition. The literature
reviewed suggests that this can best be accomplished by combining many separate but
functionally related criteria. Furthermore, it suggests that future research must work within a
model that recognizes ecosystem constituents themselves do not ensure species presence. Rather,
it is the interaction of these criteria, which creates suitable habitat for both terrestrial and aquatic
species of plants and animal.

Given the critical role riparian zones play in maintaining both terrestrial and aquatic ecosystems,
it is important that new resource management methods are generated to better integrate riparian
zone ecosystem function with anthropogenic activities. For management of riparian zones on
ROWs this involves developing management goals, objectives and tools, such as guidelines, that
result in maintenance activities that address both utility and resource needs.

2.4 Integrated Resource Management

The two bodies of knowledge explored to this point in the thesis describe the dilemma facing
both regulators and the utility industry. The traditional paradigm of using severe physical and
chemical methods to achieve a single management goal (maintaining the safe and efficient
reliable flow along power ROW) is incompatible with maintaining riparian buffer strips. Equally
incompatible is the paradigm of using small and narrow prescribed and static buffer strips to

28

preserve stream function independent of existing and future landscape development, including
electric transmission powerlines and their associated ROW. Rather, new management methods
are required which better integrate ROW and riparian zone management. The literature suggests
that increased interest in managing riparian zones along ROWs is not an isolated issue.
Increasing attention reflects the ever increasing societal demand to obtain maximum benefits
from limited resources while satisfying concerns over their use (Lang, 1990).

The increasing demand, has in turn, demonstrated the shortcomings ofboth traditional
incremental and rational comprehensive approaches to planning and decision making (Lang,
1990). Current landscape planning approaches rely primarily on punitive regulations and
measures defined by acceptable limits of environmental impact (Montgomery, 1995). Some
scientists who share this criticism suggest that preserved areas are often insufficient to maintain
ecosystem integrity (Lajeunesse et al. , 1985 ; Brown and MacLeod, 1996). Rather, the preferred
process should involve identifying the effects of land use disturbances on natural processes in
advance, setting common management goals, and tailoring management strategies to attain them
(Montgomery, 1995).

It is increasingly being recognized that cross-disciplinary processes are required in order to

integrate anthropogenic items into ecosystem description. Other scientists have reviewed
management issues associated with controversial terrestrial resource allocation issues. When
reviewing the Northern Spotted Owl controversy in California, Roe (1996) proposes that social
science is more important than even ecology in making ecosystem management work. She
suggests that while several disciplines may be required to make a comprehensive management
decision, not all disciplines are equal. In particular, social sciences are offered as a preferred

29

process for reducing several issues as follows: conflicts between groups; inevitable confusion
with ecosystem interaction; and the red herring of setting artificial boundaries (arbitrary spatial
limits around natural processes). It is also proposed as a preferred method to initiate inside out
planning. Inside out planning refers to the planning process where all stakeholders participate at
the beginning when goals and objectives are being set. This early and comprehensive
participation ensures that all concerns are addressed in the resulting management strategies,
thereby reducing the likelihood of implementing management process which conflict with key
expectations. For example, with the Northern Spotted Owl example, inside out planning did not
occur, and as a result management strategies to preserve owl habitat appeared to clash with local
economic objectives concerning employment and economic prosperity.

While the desire for broader approaches to environmental management are not new and can be
traced through several fields of research (Mitchell, 1990; Burroughs and Clark, 1995; Margerum,
1997), they increasingly emphasize IRM as the preferred process (Lang, 1990). The literature
includes significant debate concerning methods of moving from a linear single resource focus
(often easily quantified) to a non-linear multiple resource use paradigm (Born and Sonzogi,
1995). This shift must account for the different needs of resource regulator, resource manager
and the general public. IRM must work within a framework which minimizes the impacts within
the broader context of societal objectives defined for a landscape (Montgomery, 1995).

Whereas the concept of integration is generally agreed upon, considerable debate still surrounds
the definition and preferred process of IRM. In their review of the Hunter Valley Conservation
Trust, Mitchell and Pi gram (p.21 0, 1989) state that, "there is no single method of implementing
IRM .... Rather there are a number of complimentary leverage points". To account for its inherent
30

complexity other researchers have suggested that the process must be coordinated, aim at specific
societal objectives and incorporate an inclusive strategic component (Born and Sonzogi, 1995).
More specifically an IRM process should be functionally defined by four essential components
as follows : comprehensive; interconnective; interactive/coordinative; and strategic (Born and
Sonzogi, 1995).

While the four essential components provide a conceptual framework for an IRM process, each
planning process is unique and will develop a unique set of methods to realize its goals.
Comprehensive refers to the need to include all the significant present and potential uses and
objectives for the system, as well as all the groups, that affect or can be affected by management
of a system. Interconnective refers to the dimension of IRM which involves addressing
interrelationships and linkages, including conflicting uses. The strategic dimension of the IRM
process is like a filtering process and involves focusing on key aspects of a problem and
selectively targeting those which are critical. Interactive/Coordinative indicate more of how IRM
should occur as a planning and decision making process. Specifically that an IRM approach must
be interactive and involve dispersal of information and shared decision making (Born and
Sonzogi, 1995). In this case the goal is to determine if it is possible to apply these elements and
integrate vegetation management along electric transmission ROWs with key riparian ecosystem
functions and as result progressively integrate the health of landscape and ecosystem with
societal and ecological factors (Samson and Knopf, 1996).

The actual application of these concepts has proved to be challenging as more failures than
preliminary successes have been reported (Walther, 1987; Born and Sonzogi, 1995). Hilborn
(1987) summarized weaknesses in IRM in dealing with three types of uncertainty: noise
31

(ongoing flux) , uncertain state of nature (dynamic equilibrium), and surprise (catastrophic
change). However, he further states knowledge and reactability are required in management,
undeniably demonstrating the support to continue refining the IRM process (Burroughs and
Clark, 1995).

As discussed previously, one implicit assumption with the current riparian zone management
paradigm is that any land disturbance within the riparian zone will compromise function. An
opportunity for shifting to an integrated management along ROWs lies in the fact that other
researchers do not support this assumption. Smith (1980) advises afforestation and subsequent
meadow creation in Scotland has significantly improved trout habitat in streams less than two
meters wide. Furthermore, Peterson (1993) proposes that ROW construction and subsequent
maintenance has increased habitat suitability and fish densities in the state of New York. These
studies indicate that, in some cases, limited disturbance and the introduction different physical
forms and energy types into an ecosystem may in fact increase stream' s productive capability.

Another opportunity for shifting to IRM stems from changes in ecosystem theory. The traditional
climax community paradigm of ecosystem progression has been challenged. Instead, this
normative view of community condition is being contested by the notion that disturbance is an
essential feature ofthe ecosystem process (Crossley, 1995). Moreover, it has been asserted that
an ecosystems condition should be judged functionally in terms of activity and a system' s ability
to maintain community organization, autonomy and resistance to stress (Costanza 1992). A
distressed ecosystem can display several symptoms, which can either increase or decrease
productivity, as follows (Crossley 1995):
1) changes in nutrient cycling;
32

2) changes in size of dominant species;
3) changes in species diversity ; or
4) a shift in species dominance to shorter lived forms .
As result, management structures should also be able to

~ between natural and

anthropogenic changes and be adaptable enough to respond when any of these changes are
observed. Further short-term changes may occur naturally and different ecosystem end states
may result from an environmental shift (Crossley, 1995).

The fundamental shift proposed by IRM is echoed in suggestions concerning setting ecosystem
based goals and objectives for the landscape management process (Slocombe, 1998). To date,
management has been conducted to maximize the volume of an item extracted, while still
maintaining a sustainable ecosystem. Ecosystem management proposes replacing this single
resource focus by maintaining the complete natural system (Alpert, 1995; Slocombe, 1998). The
emerging ecosystem services model supports and suggests that in order to ensure ongoing
delivery of the myriad of services and products we require from the natural environment, we
must maintain complete and functioning natural systems (Daily, 1997). Therefore, management
goals must shift from managing single resources and maximizing extraction to sustaining
complete ecosystems, including anthropogenic components. Some researchers suggest this can
be accomplished by setting explicit goals, objectives and targets defined to keep impacts within
acceptable bounds (Alpert, 1995 ; Slocombe, 1998).

Applying IRM within an ecosystem management framework provides a flexible structure where
scientific knowledge and complex sociopolitical concepts can be integrated towards a general
goal of protecting ecosystem integrity over the long term (Alpert, 1995). From an ecosystem
perspective it promotes more autonomous scientific bodies and a continuous process of
33

improvement and pursuit of understanding. In addition, it provides a process by which social
values and expectations are integrated with resource management decision making. This lends
support for its potential use for managing the increasing complex relationships involved in ROW
vegetation management

2.5 Summary
In summary the literature which has been reviewed for this research clearly points to the problem
which requires attention. Government and the utility industry perceive the potential need to
change traditional work practices in riparian zones. However it is unclear whether vegetation and
management can be integrated with riparian zone functions. In order to answer this question
information is required which helps determine the effect traditional ROW vegetation
maintenance techniques have had on riparian zone ecosystem functions. In addition, this
information can then be used to help identify key strategic issue and variables for developing
more holistic management goals, strategies and techniques.

i'

34

CHAPTER3
The Methods Used In This Study
3.0 Introduction
The previous chapter considered the gap in information currently exists about whether it is
possible to integrate vegetation management along ROWs with maintaining key riparian zone
functions . To help correct this situation and thereby increase the body of knowledge concerning
IRM this research project involved collecting, documenting and analyzing both quantitative and
qualitative data. This chapter describes the research design selected to accommodate the
objectives of this study. It then provides a detailed account of the research protocol used collect
the information presented later in the results chapter of the thesis.

In order for the project to reflect the diverse climate and topographies found in BC, sites were
located in a variety of different biogeoclimatic zones around the province. Recognizing time and
monetary constraints, a total of 12 separate case studies were selected across 5 separate major
biogeoclimatic zones throughout BC (Figure 2) and studied during summer and fall , 1998. Four
were located on Vancouver Island within Coastal Douglas Fir zones, three were located in the
Fraser Valley within coastal Western Hemlock zones, and five were located in the central interior
of the province within the Sub-Boreal Spruce zone, Interior Douglas Fir zone and Boreal White
and Black Spruce Zone (BC, 1991 ).

35

---

.

"'

- ---

f

..__ ...

_,

,

4!..4t llilft'M

,_

AlBERTA

1ACIFIC

0 C E J. N

•

WASHINGTON

BIOGEOCUMATIC ZONES:
i---- -- , AlPIN£ TUNDRA

~

-

~

BOREAL Vlt<I TENIO &Ar.KSPRUCE

l SUB-llQREAI. "fNE- SPRUCE
~

SUIJ-OOREAL SPRt.a!

. MOUNTAIN ..EIJLOCI<
~
l ~~

-·J ENGELIAANN SI'RUCE • SUBAlPINE FIR

\_

IDAHO

~

~ SPRUCE 'l\llLOW BIRCH
~

\

MONTANE SPRUCt:

OUNCHGRASS

E..-=:1 PCNOEROSI\ PINE
~

,..,.,

z.:J

C'ITeRIOR COUGIAS flR
~

l

INTeRIOR CCOAA HeMLOCK
~

HEII.LOCK

~

Figure 2: The Case Studies

36

'\

3.1 Research Design

The scientific process is the systematic collection of accurate observations to increase the body
of knowledge about a particular phenomenon (Babbie, 1995). The classic approach to this
procedure has involved the use of experimental or quasi-experimental research designs,
appropriate whenever the independent, dependent and confounding variables can be identified
and then controlled or explained (Babbie, 1995). These designs generally use a process of
falsification, through inferential analysis of larger samples of quantitative data, to help suggest
attributes about a population. However, many phenomena exist in terms of variables that cannot
be controlled or identified, and as such, require qualitative research designs (Zolman, 1993). In
these types of designs, emphasis is placed on gaining a better understanding of complex
relationships rather than on control and explanation (Zolman, 1993). Moreover, they are often
termed non-experimental by empiricists (Zolman, 1993 ), insinuating a hierarchical order of
investigative power (Yin, 1984). However, qualitative researchers continue to develop more
rigorous methods to ensure the validity and reliability of their work (Yin, 1994), thereby
increasing the investigative power of their research designs and progressively eliminating any
hierarchical comparisons. In addition, qualitative methods of research are increasingly being
recognized for the benefits inherent in their ability to study complex topics in great detail
(Babbie, 1995 ; Stake, 1995).

The research goal for this study was best met with the case study, a qualitative research approach
to examine the stated research questions. This approach maximizes internal validity, external
validity, reliability and power, when dealing with studies which involve: (1) contemporary
phenomena, (2) important contextual components (management direction), (3) confounding
37

variables (site interactions) which cannot be controlled, and (4) both quantitative and qualitative
information (Yin, 1994).
Within a broader case study strategy, this research was conducted with a multiple case study
method and applied using an experimental logic. This involved analyses of several individual
cases which were described and evaluated independently. Analyses were completed, within each
case by comparing empirical and qualitative site observations between a treatment and upstream
control site. Pattern matching was then conducted between sites and cross case comparisons were
compared to the current body of literature to answer the research questions.

Application of the case study method most often involves collecting a variety of data and
observations from different sources. This information is then analyzed to identify convergences,
divergences and trends. As a result, triangulation, of information form diverse sources is critical
to the validity of the research. The general protocol used to answer the main and secondary
research questions involved a three-part process. As presented in Figure 3, this first involved
using a multiple case method to determine the effects of current vegetation maintenance on
riparian zone function. The results of this case study were used, in conjunction with a literature
review to inform questions two and three. Finally all three answers and information were used to
inform question four and the primary research question (Figure 3).

38

Question 1
What are the current maintenance techniques for riparian zones along
transmission powerlines and what are their effects on riparian zones?
Case Study
- Site Analysis
- Lit. Review
-Interviews

Question 2
What are the constraints to managing for
riparian values along Rightofways?

Question 3
What are the opportunities for managing
for riparian values along Rightofways?
I

I
I
I

I
I
I
I
I
I
I
I

Question 4
What recommendations can be made concerning integrating riparian
zone health with Rightofway management strategies?

Figure 3: Mode of Triangulation and Analysis
39

3.2

Research Protocol

3 .2.1 Criteria Used to Select Case Sites
In addition to triangulation of information from different sources, documentation and consistent
application of a procedure is another means of increasing the power of the case study method.
The most significant threat identified, to both the validity and repeatability of this research, was
confounding variables potentially introduced from different watersheds located throughout the
province of BC In response to this potential problem sites were selected systematically based on
specific criteria which were chosen to ensure that a consistent type of stream (morphology) and
crossing were used in this study.

Although it was important that all study sites for this project were located along electric
transmission ROWs where vegetation management had occurred, it was also important that all
sites met parameters designed to ensure consistency of layout. Each study site was composed of:
(1) an upstream control segment (immediately upstream of the ROW);

(2) the ROW study segment; and
(3) a downstream assessment segment (immediately downstream of the ROW).

Furthermore, in order to ensure an adequate upstream control each site was to have a mature,
undisturbed control forested site (stretching at least one ROW width) immediately upstream of
the ROW. In addition, sites were only selected where streams cross the ROW within one span
(the distance between two support structures of an electric powerline ), thereby focusing
observations on the effect of vegetation management applied within that ROW span.

40

This project focused on collecting information on medium size (as described in the literature
review) L WD controlled, gravel and cobble streams, with a D/d ratio between 0.1 and 1.0
(B.C.E. 1996, Church, 1992, Knighton, 1984). Within this context, research sites were to be
selected partially on the basis of mean stream widths (bank to bank) between one to ten meters,
mean gradients less than less than 10%, and gravel or cobble topologies (B.C.E., 1995). To
eliminate any potentially significant confounding morphological variables like introduction of
sediment, sites were to be rejected if they have bridges or other road crossing built upstream of
the ROW test site. Hydrology, including, intermittent versus continuously flowing water was not
used a decision criterion.

As a precautionary item against uncontrolled anthrpogenic influences preference was given to
sites where minimal land use activity is present in the watershed upstream of the ROW.
Moreover potential sites were rejected if there was current activity immediately upstream of the
proposed site.

3 .2.2 Selecting the Case Sites
Locating sites that met the stated criteria proved to be one of most challenging aspects of this
research project, consuming significant time and energy. The first step in this process involved
obtaining all available ROW mapping including BC Hydro access maps, as well asl: 10,000 scale
and 1:20,000 scale topographical maps. In addition, where digital mapping existed, BC Hydro's
LapMap (a GIS type mapping and data tool) was also used. These sources identified where
transmission powerlines crossed streams. Preliminary investigations with available information
of site layout, fish presence, and morphological conditions were made to obtain a better
description of the potential sites and select good candidates. These were listed and local
41

BC Hydro staff were questioned about the potential sites. Finally, each site was visited and
assessed according to the stated criteria as to their suitability for this project.

The lengthy process described above involved an initial screening of approximately 1000
streams, subsequent visits to over 250 crossings throughout the province (often along very
difficult access roads in remote locations) and final selection of 12 final case study sites which
best fit the selection criteria. It should be noted that the original study proposal suggested using
16 case study sites. However, given the finite resources available and the difficulty in finding
sites which met the criteria, 12 sites were deemed adequate for this project.

In the urban and developed areas of Vancouver Island and the Fraser Valley the most common
reasons for rejecting potential sites was the lack of forested upstream controls, access roads
upstream of a potential site, upstream logging and development, and stream widths in excess of
those desired for the study. The latter was, provided the stream had a mean gradient of less than
10% and cobble or gravel topology, the variable for which maximum tolerance was given.

In less developed and rural areas, the most common reasons for rejecting streams was excessive
stream width, access roads upstream ofthe site, and significant site modifications. In numerous
cases, good potential sites had been recently converted to swamps, sloughs or fens, by beavers
and their dam construction activities. In addition, sites were selected if they met all appropriate
criteria except for possessing a downstream study section. In many cases, roads were located at
the downstream edge of the ROW, and as such introduced confounding variable which rendered
the downstream area invalid for comparison to the upstream control and the ROW sections.

42

As a result, the sites used in this study involve high and extra high voltage lines, ranging from 69
kV to 500 kV in a variety of configurations, including both wood and steel support structures.
There was diversity in the size of the corridor and transmission line arrangements from single
transmission powerline corridors 80 m wide, to triple system corridors (with mix of voltages) up
to 300 meters wide. In addition, all case study sites have been managed since construction of the
ROW. All the ROWs were built within the last 25 to 40 years .

3.2.3 Relevant Site Information
As discussed in the literature review, significant research has been completed to increase the
body of knowledge concerning measuring riparian zone function. The ecosystem functions of
riparian zones described by Gregory et al. (1991) can be grouped into four broader more
descriptive categories: (1) energy flow (the amount of solar energy entering a stream), (2) stream
hydrology, (3) bank stability and (4) habitat complexity. A variety of data collection techniques
were used at each site to collect integrated information that informed each of these categories.
Furthermore, this also involved collecting both empirical and nonempirical information to
suggest the effect of current riparian management techniques on key riparian ecosystem
functions. The information was then amalgamated and compared to more general ecosystem
criteria and information from the literature to suggest the relative state of function of the riparian
zone at each ROW. Each of the parameters will be further discussed according to the methods
employed in measuring ecosystem function.
Energy Flow

The first riparian zone function studied, energy flow, was investigated by using variables that
indicate the amount of solar energy striking the stream at each of the three segments of a case
study site. The first variable measured to represent this function was water temperature. Data was
43

collected using ONSET T-45 continuous temperature measurement and collection devices. All
units were deployed using a trigger start (on site) that recorded data in degrees Celsius at ISminute intervals, 24 hours a day. These data were then mathematically averaged to 4-hour
intervals, filtered and graphed in an X-Y scatter plot using MSExcel software to display the five
continuous warmest days of the data set. The data from the hottest day within that 5-day period
was then plotted and graphed using the original 15-minute increment data recordings. Trends
were suggested from both sets of graphs. In addition, trends results were compared to pertinent
corresponding air temperature information.

Solar energy input was also assessed by measuring Photosythentic Photonic Flux Density
(PPFD). As described by Messier and Puttonen (1995), instantaneous light measurements were
taken across each site by two researchers moving sequentially and in tandem upstream through a
site. The instantaneous readings were then pooled to calculate mean and range of the PPFD for
each of the three segments of the study site. Light was measured in flux density (micromolm-2 s1 ), using hand held digital read out Apogee Instruments Model QMSW quantum light meters.
The majority of data collection occurred in the summer, during the dry and hot time of the year.
However to be valid the light measurements as described, must be taken during dusk, dawn or
overcast conditions to ensure more consistent and diffuse photons of light (Messier and Puttonen,
1995). As a result light measurements were taken at each site in the autumn when the water
temperature meters were retrieved.
Stream Hydrology
. The second riparian zone function studied was the effect of vegetation management on stream
hydrology. This was investigated by measuring and describing three highly related variables.
Erosion was estimated by the presence or absence of rills in each segment of the case study site.
44

The density of tall growing tree species across each segment was also determined choosing one
stem as the center axis and measuring the distance from the center tree to the three closest tal I
trees by (Wells, 1998, pers. com.). In addition, the number of stems is documented for each tree,
including the center tree. Using a standard calculation sheet the number of stems/hectare is
calculated for the study area. It is critical that as many measurement plots are established as
required to be representative of the site. Lastly, dominant vegetation species were identified and
abundance estimates were made for each segment. The presence or absence of rills, vegetation
density and community description variables were used as surrogates for the ability of the
existing vegetation in intercepting precipitation and modifying hydrologic processes.
Bank Stability
The third riparian zone function studied was the effect of vegetation maintenance on stream bank
stability. The effect of reduced bank stability can be either aggradation or degradation of the
adjacent stream channel.

To assess the relative trends in the ability of the riparian zone across the segments of the case
study site to maintain bank stability the BC Channel Assessment Procedure (BCCAP) and
associated field handbook, including pertinent diagrams and charts, was employed (B.C.E. ,
1996B). This procedure involves a two-part process and calculates the relative level of
disturbance longitudinally along a stream. First, the researcher establishes five transects across
each stream segment and measures stream gradient between transects, using a hand held
clinometer. The preferred location for the transects is at the downstream edge of pools, where
thalweg depth is recorded. In addition five representative sediment items are selected at each
transect. The sediment items selected are those which the stream moves only at very high bank
maintenance flows and are recognized by features such as being the largest in the area without

45

moss and other organic matter growing on them. These are measured across the b-axis, averaged
and compared with the average thalweg depth and stream gradient through a series of
nomographs (in the BCCAP), to suggest the morphological description of the stream in question.
Next, the researcher moves upstream through the study segment, measures and documents, based
on stream type, the distance and level of aggradation and degradation observed. While the
minimum length measured to document different disturbance levels is determined by the
frequency with which conditions change, in uniform sections the maximum stream length
recommended is six mean bank widths (Hogan et al. , 1997). The resulting information describing
the relative amount of stream aggrading, remaining stable or degrading is then summed to
calculate the percentage of the study segment which is severely affected, moderately affected
and/or stable (Appendix 1).
Habitat Complexity

The fourth riparian zone function studied was the effect of vegetation maintenance on habitat
complexity, was determined by measuring the contributions ofLWD from the adjacent riparian
zone. In order to document the function of the L WD and the possible effect of vegetation
management on L WD recruitment across a case study site, three separate parameters were either
measured or described. First, each piece of L WD, defined as greater than 10 ern in diameter
(B.C.E. , 1996, B.C.E. , 1996B), was measured through each study area. The number of pieces
were then summed and averaged across the entire stream length through the study area, and
expressed as number of pieces per meter of length of stream. Photographs were taken of
representative reaches, habitats and associated L WD. The size and distribution of pools were also
documented in the research site, including specific descriptions of undercut banks and side pools.
Third, as the researchers moved through the site sketches were made of the stream condition
through each study area. These diagrams include general stream path, orientation of L WD and

46

associated pools, and significant morphological features including large boulders, braiding and
side channels.

While the presence of an adequate volume of functioning L WD is critical for maintaining habitat
complexity in L WD controlled streams, too much L WD can cause debris jams and become
detrimental to habitat forming processes. Windthrow (trees that are pushed over by the wind) can
form debris jams in streams and is often associated with streams located adjacent to cut blocks in
working forests (BC Forest Practices Code, 1996). This potential impact of vegetation
management activities was investigated by identifying if wind throw was present across a case
study site. If observed at a case site each piece was counted and measured (including diameter of
the pieces).

3 .2.4

Collecting Site Data

An identical data collection procedure was employed at each of the 12 case study sites used in
this study. The procedure involved obtaining information from three separate segments located
sequentially along the case study sites and then comparing the results amongst each site. While
the procedure employed in this work is similar to the work completed by Peterson in 1993 , this
project employed a downstream measurement site and focused on ecosystem function, rather
than fish densities.

In order to set consistent stream reaches, the length of the stream passing through the ROW site
was waded and measured. This was then designated as stream length, and colored flagging was
placed at both the upstream and downstream edge of the ROW. Next we measured and marked
one stream length downstream and one stream length upstream from the appropriate colored

47

flagging. Temperature meters were triggered and deployed at the downstream edge of the most
upstream study area, at the downstream edge of the ROW study area, and at the downstream
edge of the most study segment. They were submerged by attaching them to large boulders with
wire and marked with colored flagging to assist in retrieval. While not enclosed in any casing,
they were placed under the substrate element to ensure shading. Visual observations confirmed
that the case study site contained the same stream reach (B.C.E. ,1996).

With the case study site delineated and temperature meters deployed, researchers then moved to
the furthermost downstream edge of the case study site and applied the first step of BCCAP
procedure (as described earlier) to establish the morphological description of the stream.
Fallowing that, we started again at the downstream edge of the case study site, and began moving
upstream recording all data on separate data sheets for each of the three study segments. This
time researchers measured and characterized numerous parameters: (1) the length of stream (with
hipchain); (2) described and measured habitat units as well as pools and large woody debris ; (3)
sketched complete area (including habitat features and large woody debris) ; (4) documented the
level of disturbance as per the second part of the BCCAP; (5) completed vegetation density
measurements of all three study areas; (6) documented any evidence of rill erosion; (7) speciated
and described tall growing, shrub layer and understorry vegetation extending 100 m at right
angle; and (8) took representative photographs across the complete case study site.

3.2.5 Management Practices
The next component of the site evaluation was determining the actual vegetation management
practices used at each site. This was completed in two steps. An analysis of BC Hydro's inhouse document collection was conducted to provide work policies and practices and guided
48

telephone interviews were conducted with BC Hydro transmission powerline technicians and
vegetation biologists. Interviews were guided by an open-ended questionnaire (Appendix 3).The
questions were divided into a short list of technical items concerning the vegetation management
practices and maintenance cycles applied at a site.

Assessing the effect of documented management practices on the study sites completed final
analysis. First, each site was evaluated independently by comparing vegetation management
practices to similarities and differences among the variables representing ecosystem function.
Second, a summary description was completed for each case study site, including any data
suggesting a trend for an ecosystem function between the three case site segments. Third, the
data for each function was compared across all sites by using appropriate XY comparisons
including scatter plots and histograms. This process identified patterns among variables as well
as suggested trends in ecosystem functions and generated some key findings.

3.3 Summary
In order to determine if vegetation management along ROWs can be integrated with maintaining
functioning riparian zones the, case study method was applied in this research project. It was
applied with experimental logic and involved collecting information about twelve separate cases
study sites located throughout BC The resulting information about each site was used to provide
detailed case descriptions and compare trends, based on riparian zone functions, between cases.
The case study description and trends resulting from application of the methodology, are
presented in Chapter 4.

49

CHAPTER4
Case Study Results

4.0 Introduction

Case study data were collected, as per the methods described in Chapter 3, during the summer
and fall of 1998. The process involved visiting each site once to collect the required site
information and deploy the temperature meters. This was followed by a second trip later in the
year, when trees still had leaves, to collect the temperature meters and light measurements. While
the balance of the method worked as planned and was applied effectively, gathering water
temperature and light data proved to be the most challenging components of the fieldwork. Of
the twelve case study sites, two were dry when visited in the summer and thus had no water
temperature data collected. For the remaining ten sites, five had all three meters collect data, two
only had the upstream and ROW meter collect data and, the three remaining had only one meter
collect data. The reasons for lack of success were launch failure, wire corrosion and subsequent
breaking free of the meter, and internal battery failure. While the light meter procedure was
· effective for obtaining data, the warm sunny summer and fall enjoyed in 1998 made it difficult to
obtain completely overcast conditions at all sites. Hence light data was not obtained at two sites.

The twelve case study sites are spread throughout the province ofBC, as shown in Figure 2.
Table 1 provides a summary of information describing the Case Study sites and shows that four
cases are located on the east coast of Vancouver Island, three are located on the south coast of the
BC mainland and five are located in the north.

50

Table 1 also presents site similarities and further supports the assertion presented in Chapter 3,
that consistent site selection criteria were successfully applied to capture data from medium size
streams, with a D/d ratio between 0.1 and 1.0. As a result, ten of the streams studied are either
first or second order. Also they all have relatively short lengths, with seven of the streams
between zero and ten kilometers long and the remainder between ten and twenty kilometers long.
Although not presented in Table 1, because the criterion was not applied for site selection, most
of the streams, (including the intermittent streams at Case Study 2 and Case Study 10) support
fish populations.

To be relevant to this study, cases had to be located along electric transmission ROWs where
vegetation management has occurred. Subsequently, none of the resulting case study sites are
new electric transmission powerlines or corridors. The age of the sites used in the study ranged
from five years to thirty years. The five year old site (Case Study 10) actually involves a wide
and complex ROW that was first finished over twenty-five years ago but had a parallel
component cleared and constructed five years ago. The remainder of the sites have been managed
for a minimum of twenty years.

To reduce confounding variables, sites with any upstream bridge crossings were not selected.
Four of the sites selected have no bridge crossing, while eight of the sites have bridge crossings
located downstream of the ROW. Also nine of the twelve sites are in fairly broad and deep
gullies, while the other three sites have minor depression associated with the small creeks. This
is reasonable because larger gullies would make it more difficult to construct crossings and thus
bridges would be less common. They are accessed less frequently and towers can be reached as
effectively, and less costly, by using separate roads that end on either side of the gully.
51

Kelvin Creek

BC
Region
V.I.

Stream
Order
2

Stream
Length
10.4krn

Drainage
Area
25.3krn 2

Site
Age
25 yr

Gully
Present
Yes

2

Currie Creek

V.I.

2

9.45krn

11.6krn2

30 yr

No

3

Nile Creek

V.I.

2

16.65km

12.01krn2

25 yr

Yes

4

French Crk.Trib.

V.I.

1

3.2krn

2.1krn2

30 yr

Yes

5

Noons Creek

F.V.

0.8krn

0.35krn2

40 yr

No

6

Donegani Creek

F.V.

2

2.38krn

1.25krn2

35 yr

Yes

7

Mahood Creek

L.M.

4

19.88krn

19.43krn2

28 yr

Yes

8

Cluculz Creek

North

2

5.5krn

8.38krn2

25 yr

Yes

9

Sweden Creek

North

2

12.4krn

45.lkrn2

25 yr

Yes

10

S. Sisters Creek.

North

3

16.5krn

17krn2

5 yr

Yes

11

no name

North

1

Unknown

< 1 krn 2

20 yr

Yes

12

no name

North

1

Unknown

< 1 krn 2

20 yr

No

Case
Study
1

Stream Name

*V.I. = Vancouver Island; F.V . = Fraser Valley; L.M. = Lower Mainland

Table 1. Case Study Sites.

52

BC Hydro records were analyzed and the guided interviews were conducted during the spring
and early summer of 1999. Because of travel constraints, four interviews were completed over
the telephone, while one interview was conducted in person at a BC Hydro office. Record
analysis provided information about vegetation management policy and site specific
prescriptions. Interviews provided most of the practical site information including age,
maintenance cycle, techniques and secondary uses.

Record analysis and interviews indicate BC Hydro is completing inventories of all stream
crossings along all their electric transmission ROWs and placing that information into an
integrated mapping system called Lap Map. As of the spring of 1999, less than half of the
information has been collected and entered onto LapMap, hence it was not available during the
time of this study. Therefore it is impossible to quantify the representativeness of the study's
stream sites in terms of all crossings along the complete BC Hydro transmission facility. The
preliminary data shows that BC Hydro's 17,000 km of transmission lines crosses between 1750
and 2000 streams, of which the majority are in the same size range as the streams used in this
study. Thus, findings from this study appear to be applicable to a significant number of riparian
zones along BC Hydro ROWs.

This chapter presents the results obtained for the study. The results from record analysis and
interviews are imbedded in each case study description. First, a case by case description,
including vegetation management history, trends within the case, and photographs is provided.
Second, a cross case summary of vegetation management and trends for each of the ecosystem
functions is presented.

53

4.1 Case Studies

4.1.1 Case Study 1: Kelvin Creek
The first case study is located near Duncan on Vancouver Island and consists of an 85m wide
ROW that crosses Kelvin Creek (Photos 1&2). Site access is from the south and stops 25m from
the right bank with no bridge or other type of crossing. At the crossing, Kelvin Creek is a second
order stream with a total drainage area of 25 .3km 2, that flows through a broad, deep gully and is
located within the Coastal Douglas Fir biogeoclimatic zone. The transmission support structures
for the two 138kV circuits (one wood and one steel) are located on the gully crests and the
powerlines do not sag deeply into the gully, providing some room for the growth of vegetation.
The riparian vegetation across the ROW starts with a strip of topped red alder trees (on either
creek bank) then gives way to the groomed ROW. Other uses are intermittent livestock grazing
and motor biking.
Vegetation Management
The site has been managed every seven years since construction of the newer steel circuit in
1975. The predominant methods applied in the gully have been machine mowing and hand
slashing of tall growing target species such as broad-leaf maple and conifers. Traditionally,
riparian zone management included leaving the trees lining the stream bank. Over the last few
years a prescription has been applied that involves planting Western red cedar, willow, redelderberry, and red osier dogwood.
Riparian Ecosystem Function 1 - Energy Flow
The upstream control temperature meter was the only one successfully retrieved and
downloaded. The ROW temperature meter failed to launch and the downstream meter was not
found. The maximum diurnal water temperature range recorded was 17.0-19.25°C (July 17,

54

1998). The ROW allows more light to access the stream with mean PPFD light levels of
155.18 mols (upstream), 284 mols (ROW) and 203 .33 mols (downstream).
111

111

111

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated and display no signs of rill erosion anywhere inside the
gully. The densities of tall growing trees are 8000stems/ha (conifer) in the upstream section,
15,000 stems/ha (deciduous) at the ROW and 11 ,000 stems/ha (mixed) downstream. The
upstream and downstream sites have tall mature trees. Instead of tall trees the ROW is populated
by juvenile trees or older tree clumps with multiple stems. Also the ROW has a dense
understorey, described in Appendix 1, consisting of grasses, salmonberry, huckleberry, broom
and red elderberry.

Riparian Ecosystem Function 3 - Bank stability
The two trends observed related to bank stability are a progressive decrease in mean depth from
57cm upstream to 40.8cm at the ROW to 19.75cm downstream, and an increase in D60 from
13.38cm upstream, to 13.39cm at the ROW to 20.0cm downstream. Further, all 3 stream
segments had significantly eroded banks along their entire length.

Riparian Ecosystem Function 4 - Habitat Complexity
The trends for habitat complexity across the three stream segments is reduced pool volume from
60% deep pool in the upstream control, to 63% shallow pool (run) across the ROW, to 20% pool
in the downstream section. This trend is correlated to a decline in L WD from 0.17pieces/m
stream in the upstream section, to 0.05 pieces/m stream across the ROW, and 0.06pieces/m
stream downstream. The L WD in the upstream segment results in complexity including bars,
pools and undercut banks, but the ROW and downstream segments have less L WD, less
complexity and much longer riffle stretches.

55

Photograph 1.

Kelvin Creek and the Rightofway.

Photograph 2.

Looking upstream through the Rightofway.

56

4.1.2 Case Study 2: Currie Creek
The second case study is located approximately 15 km west of Duncan on Vancouver Island and
consists of a 185m wide, 238 kV ROW crossing Currie Creek (Photos 3&4) in the Coastal
Douglas Fir biogeoclimatic zone. At the site Currie Creek is a small intermittent second order
stream with a total drainage area of 11.6km2 spanned by one transmission powerline with steel
support structures providing little overhead room for vegetation to grow. Access is from the east
along with a bridge crossing at the downstream edge of the ROW. A decommissioned access
road and bridge are located at the middle ofthe ROW. The predominant land use is forestry and
active harvest sites are located by the site. Due to the presence of the bridge, and forest harvest
activities along the stream a downstream study section was not applied at this case. Also, the
pool distance and pieces ofL WD at the old bridge crossing (center of ROW) were omitted from
calculations. There is a large debris jam at the upstream edge of the ROW. Secondary uses are
indirect forest harvesting, recreational motor biking and hunting.

Vegetation Management
The site has been managed every five years since final construction in 1975. The predominant
methods have been machine mowing, hand slashing, and selective use of herbicides and girdling.
No specific plans or techniques were applied in the riparian zone, until preparation of a site
prescription in 1997. The prescription recommends girdling tall trees to encourage native low
growing shrubs. There is no windthrow at the site.

Riparian Ecosystem Function 1 - Energy Flow
No temperature meters were launched because the channel was dry when the site was visited on
July 22, 1998. The mean PPFD measurements were 16.64 mols upstream and 122 mols at the
111

111

ROW. These results suggest the shorter vegetation along the ROW allows more light to strike the
stream than the dense upstream vegetation canopy.
57

Riparian Ecosystem Function 2 - Stream Hydrology
Both sites are heavily vegetated and display no signs of rill erosion. Although the
decommissioned access road down the middle of the ROW has exposed mineral soils there were
no obvious signs of erosion. The upstream section has a mature second growth forest with a
dense canopy, tall conifer trees and dense understorey . The groomed ROW has numerous shrubs
(detailed in Appendix 1) no tall trees but several multiple coppice stems and juvenile young
trees. The densities calculated for tall growing tree species are 10,000 stems/ha (conifer)
upstream and 8000stems/ha (deciduous) across the ROW.

Riparian Ecosystem Function 3 - Bank stability
The data indicates that one trend in bank stability is that the ROW segment is two meters more
narrow than the upstream segment. This is misleading because the difference can be explained by
two measurements from the downstream edge of the segment where a large debris jam has
widened the channel. There were no trends in mean gradient, D60 or mean depth. Another trend
that was observed was an increase in amount of significant bank disturbance from 21% in the
upstream section to 47% across the ROW segment.

Riparian Ecosystem Function 4 - Habitat Complexity
One trend in habitat complexity observed across the two sections is an increase from 39% pool
habitat and no L WD in the upstream section (excluding debris jam) to 48% pool habitat and
0.05pieces L WD/m stream across the ROW. The increase in pool habitat through the ROW
stream segment is often associated with old-growth root wads but in some cases, it is associated
with undercut banks, covered by dense grasses and bushes.

58

Photograph 3.

Currie Creek and the Rightofway.

Photograph 4.

Looking upstream through the Rightofway.

59

4.1.3 Case Study 3: Nile Creek
The third case study is located near Qualicum Beach on Vancouver Island and consists of a 150m
wide, 238 kV ROW crossing Nile Creek (Photos 5&6). At the site, Nile Creek is a third order
stream with a drainage area of 12km2• (within seven km of Georgia Straight) flowing through an
irregular yet broad gully in the Coastal Douglas Fir biogeoclimatic zone. The metal support
structures are located on the gully crests and although the powerlines sag into the gully there is
room for trees to grow quite tall before being managed. Access is provided along an unpaved
road that parallels the right bank but ends 150m upstream of the ROW at a water intake structure
(upstream study segment). A portion of the upstream segment splits into two channels and those
data were grouped for relevant calculations. Other uses are angling, walking, and salmon
enhancement projects. There is no windthrow and the vegetation composition is presented in
Appendix 1.
Vegetation Management
Being in the Qualicum Water Board, increased site environmental concern and as a result
vegetation has been managed on a "as needed" basis since construction in the early 1980's. This
involved topping, hand slashing and girdling trees as they threatened the powerlines. Hence,
there are maple plants with multiple stems and hundreds of yet-to-fall girdled alder trees (10-15m
tall) across the ROW. The site prescription, prepared in 1997, recommends topping of conifers,
girdling and the planting of low growing species.
Riparian Ecosystem Function 1 - Energy Flow
There was a slight trend (0.5°C) towards warmer water temperatures as daily diurnal ranges
measured on July 28 were 12.25-13.75°C upstream and 12.5-14.25°C across the ROW. The
downstream meter had broken free and no results were obtained. More light was measured on the

60

ROW, as the mean PPFD light levels were 90.7111 mols in the upstream section 199.3111 mols across
the ROW and 75 .2\,mols downstream .

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated, as presented in Appendix 1, and display no signs of rill
erosion. The upstream section has mature second growth trees. The ROW is partially groomed
with numerous topped trees, multiple coppice stems or dense stands of red alder trees, 10-15m
tall. The downstream section has a mature second growth forest with a dense canopy, tall conifer
trees and dense understorey. The densities calculated for tall growing tree species are 257
stems/ha (conifer) in the upstream section, 29,700 stems/ha (mixed) across the ROW and 229
stems/ha (conifer) in the downstream section.

Riparian Ecosystem Function 3 - Bank stability
There were no trends suggested for stream width, mean depth, D60 or gradient. Although there is
a debris jam in the middle of the ROW stream segment and significant erosion of the right bank
the level of bank disturbance was lower in the ROW segment (31 %) than in the upstream section
(39%). The downstream segment had more highly eroded banks and 56% of its ' length
significantly disturbed.

Riparian Ecosystem Function 4 - Habitat Complexity
One trend in habitat complexity across the three segments is a steady reduction in pool habitat
from 54% in the upstream segment to 34% across the ROW to 31 % in the downstream section.
Despite reducing pools the amount of L WD stays relatively constant across all three sites and is
large old conifer trees . Although the LWD forming the debris jam in the middle ofthe ROW was
included in relevant calculations it would be inundated only at high flows . There are few pools
caused by undercut banks at the site.

61

Photograph 5.

Nile Creek and the Rightofway.

Photograph 6.

Looking upstream from the end of the ROW.

62

4.1.4 Case Study 4: French Creek Tributary
The fourth case study is located near Parksville on Vancouver Island and consists of a 125m
wide, 238 kV ROW that crosses a tributary of French Creek (Photos 7&8). At the crossing, the
creek is a small, shallow and continuously flowing first order stream (drainage area 2.1 km 2)
passing through a short, steep gully in a Coastal Western Hemlock biogeoclimatic zone. The
steel ROW transmission support structures for the single circuit are located on the crest of the
gully. The powerlines do not droop into the gully and trees can grow to a moderate height before
requiring management. Access is east along a forestry road that crosses the creek about five km
downstream of the ROW. The entire area was logged and natural regeneration has occurred
within the last 25 to 40 years. The riparian vegetation across the ROW begins with a narrow strip
oftrees between 10 and 15m tall that give way to the groomed ROW consisting of mixed
berries, shrubs, grasses and young trees as presented in Appendix 1. There are several debris
jams located along the creek. Other site uses include tree farming, hunting, motor biking and
secondary harvesting. There is no windthrow at the site.

Vegetation Management
ROW vegetation has been managed every five years since final construction in 1975. Above the
gully predominant methods have been machine mowing, slashing and selective application of
herbicides. In the gully, the riparian trees are girdled as they approach tolerance limits, while the
rest of the area has been slashed.

Riparian Ecosystem Function I - Energy Flow
Water moving through the site was subject to dramatic diurnal temperature fluctuations. The
water temperature range recorded on August 13 , 1998 was 14.0-16.0°C upstream, 13.00-19.5°C
across the ROW and 14.0-23.0°C downstream. The large increase in temperature was caused by
debris jams creating large shallow pools that were then exposed to direct sunlight. The mean
63

PPFD levels increased from 4.0mmols at the upstream section, to 24.0mmols at the ROW and
18.8mmols in the downstream section.

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated and display no signs of rill erosion or impervious soils. The
density of tall growing trees is 1283stems/ha (conifer) in the upstream section, 2459stems/ha
(deciduous) at the ROW and 2166stems/ha (mixed) downstream. Upstream and downstream sites
have densely spaced, moderately tall, second growth forests. All open spaces at the ROW are
entirely covered by a very dense understorey of berries, grasses and shrubs, and are presented in
more detail in Appendix 1.

Riparian Ecosystem Function 3 - Bank stability
There were no trends in mean width or mean gradient. One trend relative to bank stability that
was observed was a decrease in mean depth from 47cm in the upstream segment, to 40cm across
the ROW to 18cm downstream. D60 size did not follow this trend, but instead fluctuated from
17cm in upstream segment to 14cm at the ROW to 22cm downstream. The level of disturbance
progressively decreased from 46% in the upstream segment to 30% at the ROW to no (0%)
disturbance in the downstream segment.

Riparian Ecosystem Function 4 - Habitat Complexity
There is a trend for more pool habitat through the segments from 36% in the upstream site to
37% at the ROW to 53% in the downstream site. As alluded to, much of the downstream pools
were associated with debris leading to heating of the water; further, the functional L WD found at
all three sites is large and old.

64

Photograph 7. French Creek Tributary gully and vegetation downstream ofRightofway.

Photograph 8. Looking upstream through lower end of the ROW stream section.

65

4 .1. 5 Case Study 5: West Noons Creek
The fifth case study is directly north of Coquitlarn and consists of a narrow (65rn), 500kV ROW
that crosses West Noon Creek (Photos 9&10) in the Coastal Western Hemlock biogeoclimatic
zone. Access is from the east along a dirt road that crosses the creek downstream of the ROW. At
the crossing, West Noons Creek is a first order stream with a moderately high gradient, total
drainage area of 0.35krn 2 that runs along the side of a ridge. The metal support structures for the
two powerline are located back from the creek but provide little room for vertical growth of
vegetation. Culverts impact the downstream section, thus no morphological data was used. The
riparian community on the ROW is dense low growing species as well as tall growing species
with coppice sterns, as presented in Appendix 1. There is no windthrow but the upstream section
is braided through large old growth L WD and there is a debris jam at the upstream ROW edge.
Secondary uses are motor biking, walking and cycling along roads and paths.
Vegetation Management
The ROW has been managed every seven years since it was constructed in 1974. The
predominant vegetation management method has been hand slashing and girdling of tall growing
species. No management procedures have been applied explicitly to maintain the riparian zone.
Upstream of the ROW the site has an old growth forest composed of large conifers that are
estimated to be greater than 100 years old. The ROW section is groomed with shrubs, while the
downstream section has red alder between 30 and 50 years of age.
Riparian Ecosystem Function 1 - Energy Flow
There was a 0.5°C increase in temperature across the ROW but a recovery to above ROW
temperatures within 65m downstream. The maximum diurnal water temperature range recorded
on July 29, 1998 was 17.0-17.5°C (upstream), 17.0-18 .0°C (ROW) and 16.8-17.5°C

66

(downstream). The mean PPFD light levels increased from 3.0111 mols upstream to 29.0mmols at
the ROW and decreased back to 1.0111 mols at the downstream section.
Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated and display no signs of rill. There is a notable difference in
the observed densities of tall growing trees 1283 stems/ha (conifer) in the upstream section,
23,565 stems/ha (deciduous) at the ROW and 356 stems/ha (mixed) in the downstream sections.
The ROW also has a dense understorey of willow, salmonberry and huckleberry grasses as well
as modified cottonwood, red alder, maple and conifers.
Riparian Ecosystem Function 3 - Bank stability
The braided channels in the upstream site were combined for the following calculations: they
suggest gradient increase from 3.17% upstream to 5.75% across the ROW. D60 at the sites
increases from 0.14m upstream to 0.20m at the ROW. There is no trend in mean depth or width,
but reach disturbance did increase from 0% upstream (heavy-forested area) to 85% at the ROW
segment. Disturbance at the ROW is a function of degradation.
Riparian Ecosystem Function 4 - Habitat Complexity
With habitat complexity, the volume of pools drops from 46% in the upstream segment to 35%
across the ROW. This is accompanied by a reduction in L WD from 1.57pieces/m stream
upstream to 0.06pieces/m stream across the ROW. Upstream it is probable that there is too much
L WD and is impacting site morphology. Conversely, the ROW stream segment is wetted bank to

bank with only a few pieces of L WD at its most upstream end. Habitat complexity and pools in
this segment are most often associated with boulders, bedrock, and in a few cases, undercutting
of banks that are protected by willow trees.

67

Photograph 9.

Vegetation across Rightofway at Noons Creek

Photograph 10.

Looking upstream from the lower end of the ROW stream section.

68

4.1.6 Case Study 6: Donegani Creek
The sixth case study is located near Maple Ridge and consists of 85m wide 500kV
ROW (Photos 11&12). Access is from the northeast along an overgrown road and bridge at the
downstream edge of the ROW. At the crossing Donegani Creek is a second order stream with a
total drainage area of 1.25km2 zigzagging between towers, through a gentle gully in the Coastal
Western Hemlock biogeoclimatic zone. The steel support structures for the single circuit are on
the gully crests, but the powerlines restrict vertical growth of vegetation. There is a large boulder
in the ROW stream segment but it does not constitute a reach break. There is some windthrow at
the end ofthe downstream site and a debris jam at the upstream edge ofthe ROW. The riparian
vegetation across the ROW is composed of coppice stems, juvenile trees, dense understorey, and
has no secondary uses.
Vegetation Management

The site has been managed regularly every five years since final construction in 1973. The
predominant method applied across the ROW is hand slashing of tall growing target species such
as broad-leaf maple and selective use of herbicides. The site was last slashed in 1997 and debris
is evident throughout the ROW. No special efforts have been made to maintain riparian
ecosystem function. There are many multiple coppice stems of maple, cottonwood, red-alder and
conifers as well as understorey of willow, red elderberry, mixed berries and a dense ground layer
of grasses as presented in Appendix 1.
Riparian Ecosystem Function I - Energy Flow

The diurnal water temperature ranges recorded on July 29, 1998 were 17.75-22.0°C in the
upstream segment, 17.75-22.25°C on the ROW and 17.0-21.75°C downstream. They indicate a
minimal (0.5°C) increase in the diurnal temperature range through the ROW that is recovered to
above ROW water temperatures a relatively short distance (80m) downstream. The mean PPFD
69

results were 11.5mmols (upstream), 40.13mmols (ROW) and 44.5mmols (downstream). These
levels also suggests less sunlight is allowed to strike the upstream study segment than the ROW
or downstream segment.

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated and display no signs of rill. The observed densities of tall
growing trees are 1875 stems/ha (conifer) in the upstream section, 6833 stems/ha (mixed) along
the ROW and 3996 stems/ha (mixed) downstream. While the upstream site is composed of tall
mature trees the ROW has more multiple stems, shrubs and juvenile trees. The downstream
section has less of a gully, a vegetation community of red alder, cottonwood, maple and conifers
and ends 80m downstream at a copse (Appendix 1).

Riparian Ecosystem Function 3 - Bank stability
Although the stream passes under a large bridge located at the downstream edge of the ROW it
appears to have had minimal impact on stream morphology and as a result data from the
downstream segment was compared to the upstream segments. The only trend relative to bank
stability was a decrease in disturbance from 31% at the upstream segment to 0% at the ROW,
increasing again to 46% disturbance for the downstream segment.

Riparian Ecosystem Function 4 - Habitat Complexity
The results for habitat complexity demonstrate the close relationship between L WD and
complexity as pool area increases from 48% upstream, to 62% at the ROW and decreases to 46%
downstream. This is correlated to an increase in L WD from 0.043pieces/m stream upstream, to
0.12 pieces/m stream at the ROW and a decrease to 0.05pieces/m stream downstream. All L WD
is embedded and originated from an old growth conifer forest.

70

Photograph 11.

ROW and stream facing downstream section at Donegani Creek

Photograph 12.

Looking upstream in the middle of the ROW stream section.

71

4.1.7 Case Study 7: Mahood Creek
The seventh case study is located in Surrey and consists of a 130m wide, 500 kV ROW that
crosses Mahood Creek (Photos 13&14). The ROW land is privately owned and access is on foot
from either side of the stream. At the crossing Mahood Creek is a fourth order stream with a total
drainage area of 19.4km2 flowing through a broad gully in the Coastal Western Hemlock
biogeoclimatic zone. The creek forks into two channels upon reaching the ROW but returns to
one deeper channel near the downstream edge of the ROW. The steel structures for the three
powerlines are located on the gully crests and provide extensive room for vertical growth of
vegetation. Moving out from the edge of the stream, the riparian zone consists of a small forested
area of tall red-alder trees, willow and cottonwood. This extends for 20 m and gives way to the
groomed ROW composed of low growing grasses, hardhack and salmonberry as presented in
Appendix 1.
Vegetation Management

The ROW has been managed every seven years since construction in 1979. The methods used to
maintain vegetation have been machine mowing, slashing and girdling of tall growing target
species (such as broad-leaf maple, cottonwood, conifers). Traditionally trees adjacent to the
stream have been retained until they pose a hazard to the powerline before being topped or cut.
The site is in the second year of a plan to cut tall growing trees and plant low growing vegetation
such as willow, elderberry and red osier dogwood.
Riparian Ecosystem Function I - Energy Flow

The downstream control temperature meter was the only one successfully retrieved and
downloaded. The ROW temperature meter did not launch properly, while the battery failed in the
upstream temperature meter. The maximum water temperature range was 18.75-20.0°C, recorded

72

on July 28, 1999. The PPFD levels were of34.9 mols (upstream), 65.10mmols (ROW) and
111

52.8 mmols (downstream) indicating more light at the ROW.
111

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated and display no signs of rill. The observed densities of tall
growing trees are 2005 stems/ha (mixed) in the upstream segment, 15,000 stems/ha (deciduous)
across the ROW and 11,000 stems/ha (mixed) downstream. The upstream and downstream
communities are tall mature trees whereas the ROW has few trees. In an urban setting hydrology
is also impacted by development and impervious surfaces.

Riparian Ecosystem Function 3 - Bank stability
A large gravel bar has recently been deposited at the upstream edge of the ROW and while both
banks are experiencing lateral erosion, the right bank (no tall vegetation) appears to be more at
risk. Data for the two channels across the ROW were pooled and compared to the other
segments. The comparison reveals that while no significant disturbance was present in the
upstream or downstream stream segment, branching through the ROW has lead to significant
disturbance of 42% of the ROW segment.

Riparian Ecosystem Function 4 - Habitat Complexity
The trend in habitat complexity is for more pool habitat and more L WD upstream and
downstream of the ROW. The pool results are 82%(upstream), 55%(ROW) and 85%
downstream while L WD results are 0.04 pieces/m stream (upstream), 0.02 pieces/m stream
(ROW) and 0.08 pieces/m stream (downstream). Although the pools in the upstream and
downstream segments are deeper, the trend is confounded because flow through the ROW is
separated into two channels.

73

Photograph 13 .

East side of ROW with groomed section and riparian trees.

Photograph 14.

Looking upstream in the middle of the ROW stream section.

74

4.1.8 Case Study 8: Cluculz Creek
The eighth case study is located west of Prince George, in the Sub-Boreal Spruce biogeoclimatic
zone, and consists of lOOm wide, 500kV ROW crossing Cluculz Creek (Photos 15&16). Access
is west along a roadway that ends three quarters of the way down the gully. At the crossing,
Cluculz Creek is a second order stream with a total drainage area of 8.38km2 winding through a
complex gully with a very steep right bank and gentle left bank. The support structures for the
single transmission circuit are on the gully crest but provide little room for vegetation to grow
vertically. No windthrow or debris jams are at the site. The riparian vegetation community at the
ROW has tall growing trees and an understorey of willow, berries and salal (Appendix 1). Site
secondary uses are motor biking, hunting and intermittent livestock grazing.
Vegetation Management
The ROW, except for the gully, has been managed every 15 years, by mowing, slashing and
herbicide application, since construction in 1978. In the gully, vegetation is cut only when a tree
grows too close to the powerline. The upstream section has been harvested (selectively) within
the last 30 years but still has a mature riparian community of conifers and cottonwood trees.
Although the lower one-third of the right bank of the ROW is very steep and supports little
vegetation, the remainder of the ROW has a dense mixed community with trees up to 15m tall.
The downstream section has a gentle gradient and supports a mature riparian community
dominated by pine, spruce and cottonwood.
Riparian Ecosystem Function 1 - Energy Flow
The water temperature meter for the downstream section failed to launch properly. The other
two meters worked properly and recorded drastic temperature fluctuations. The diurnal water
temperature ranges recorded on August 13, were 12.25-21.75.0°C in the upstream section and
12.25-24.25°C across the ROW. The large increase in temperature is explained by large shallow
75

stretches flowing over bedrock with little shading. The PPFD levels 153.36 mols upstream,
111

284.73 mols at the ROW and 203.3 mols downstream, were collected during mixed overcast
111

111

skies and suggest more sun strikes the ROW.

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated, except where the steep slope prevents vegetation becoming
established. These steep banks of the gully at the ROW have signs of erosion and sloughing and
prevent vegetation from attaining a foothold. The densities of tall growing trees are 6833
stems/ha (conifer) in the upstream section, 23 ,565 stems/ha (mixed) across the ROW and 943
stems/ha (mixed) downstream. The upstream and downstream densities reflect tall mature trees
while the ROW has no tall trees.

Riparian Ecosystem Function 3 - Bank stability
One trend related to bank stability was that the ROW segment was 2m narrower than the
upstream or downstream segments. There was also a trend for an increase in gradient from 1.0%
upstream to 1.25% at the ROW to 1.5% downstream that matched an increase in stream
disturbance from 48% upstream to 63% at the ROW and 83% downstream.

Riparian Ecosystem Function 4 - Habitat Complexity
The information for the downstream section was accidentally destroyed. The other two segments
show a reduction from 50% pool habitat upstream to 34% pool habitat across the ROW.
Correspondingly L WD reduces from 0.05 pieces/m stream upstream to 0.01 across the ROW.
Anecdotally, the downstream section had similar morphology to the ROW including significant
stretches of exposed bedrock and little L WD.

76

Photograph 15.

The east side of ROW with access road and mixed vegetation.

Photograph 16.

Looking upstream in the middle of the ROW stream section.

77

4.1.9 Case Study 9: Sweden Creek
The ninth case study is located west ofPrince George and consists of a lOOm wide, 500kV ROW
that crosses Sweden Creek (Photo 17 & 18). Site access is from the west along a road that stops
about 1.5 km away from the crossing. At the crossing, Sweden Creek is a second order stream
with a total drainage area of 45.1 km 2 flowing through a large, broad gully in the Sub-Boreal
Spruce biogeoclimatic zone. The metal support structures for the transmission powerline extend
into the gully and provide little room for vegetation growth. The upstream section was
selectively logged between 10 and 25 years ago and the vegetation across the ROW, detailed in
Appendix 1, is sparse and provides no overhead cover to the shallow stream. Although BC
Hydro built a wood bridge at the site in 1996, it has since washed away. The transportation of
agricultural machinery, a secondary use of the site, is being accomplished by fording the stream,
leading to erosion and as a result, the downstream morphological data were not used in analysis.

Vegetation Management
The ROW has been maintained every 15 years since construction in 1978. The methods used
have been machine mowing and hand slashing of tall growing trees such as spruce and
cottonwood. To date these techniques have also been applied throughout the riparian zone. BC
Hydro staff now plan to change practices at the site by allowing trees in the gully to grow and
girdling them only when they come too close to the powerline.

Riparian Ecosystem Function I - Energy Flow
The water temperatures recorded moving downstream suggests a minimal (0.5°C) increase in the
diurnal temperature range through the ROW that is negated by traveling one study reach (330m)
downstream. The diurnal water temperature ranges recorded on August 13, 1998 were 12.020.50C in the upstream segment, 11.5-21.0°C across the ROW and 11.5-19.5°C downstream. The

78

PPFD levels were also higher on the ROW as the results were 51.33mmols upstream ROW,
69.5mmols across the ROW and 34.33mmols downstream.

Riparian Ecosystem Function 2 - Stream Hydrology
All three sites are heavily vegetated but the bridge crossing at the downstream edge of the ROW
show signs of rill erosion. The observed densities oftall growing trees are 28,512 stems/ha
(mixed) in the upstream section, 204,073 stems/ha (mixed) across the ROW and 8019 stems/ha
(conifer) downstream. The upstream site is composed of a mix of tall mature and juvenile trees
while the ROW has a number of plants with multiple stems. The ROW section has a very dense
covering of grasses and other low growing species.

Riparian Ecosystem Function 3 - Bank stability
There were no trends in mean depth, D60, gradient across the sites or level of disturbance. One
trend that was observed was mean width which increased from 3.8m in the upstream segment to
4.8m across the ROW. Also degradation is the dominant mode of disturbance in the bottom half
of the ROW segment and the downstream segment.

Riparian Ecosystem Function 4 - Habitat Complexity
There was no trend between the upstream segment and the ROW segment in terms of the amount
of pool habitat. However, there was a trend across all three of the sites for an increase in L WD
from 0.06 pieces/m stream in the upstream section to 0.08 pieces/m stream across the ROW to
0.12 pieces/m stream downstream . The LWD in the upstream segment and across the ROW was
composed of large old growth conifers well embedded in the banks. Although L WD in the
downstream segment often spanned across both banks and was associated with small woody
debris it did not create much pool habitat.

79

Photograph 17.

Photograph 18.

The vegetation, and stream across the ROW.

Looking downstream at the lower end of the ROW stream section.

80

4.1.1 0 Case Study 10: South Sisters Creek
The tenth case study is located near Quesnel and consists of a 300m wide, 500kV and
230 kV ROW that crosses Kelvin Creek (Photo 19&20). At the crossing, South Sisters Creek is a
third order intermittent stream with a total drainage area of 17km2, flowing through a deep gully,
in the Interior Douglas Fir biogeoclimatic zone. The corridor is occupied by three 500kV
powerlines on steel structures and one 230 kV powerline supported by wooden structures. The
gully provides moderate room for vegetation to grow before threatening the powerlines. The land
is privately owned, with approximately one third of the ROW used for cattle grazing, and access
is from the south. Because of cattle and road impacts, the bottom 70m of the ROW and the
downstream segment were not used in morphological analysis . The ROW riparian vegetation
community is presented in Appendix 1. The vegetation in the upper 200m of the ROW is dense
and diverse, whereas in the lower 1OOm it is sparse. There is no wind throw at the site.

Vegetation Management
Although, the majority of the circuits passing through this corridor were constructed between 20
and 25 years ago, the most recent addition was a 500kv powerline built along the downstream
side of the ROW in 1994. The ROW, to the upper edge of the gully, is mowed every ten years by
BC Hydro. Vegetation in the gully is either maintained by private landowners, or BC Hydro
girdles and cuts trees as they approach the powerlines.

Riparian Ecosystem Function 1 - Energy Flow
No temperature meters were launched because the channel was dry when the site was visited on
August 16, 1998. The mean PPFD levels were 61.67 mols at the upstream section, 53 .92 mols at
111

the ROW and increased to 92.42 mols at the downstream section.
111

81

111

Riparian Ecosystem Function 2 - Stream Hydrology
Although all three sites are heavily vegetated, the area associated with the access road and
bridge crossing at the downstream edge of the ROW show signs of rill erosion. The observed
densities oftall growing trees are 1708 stems/ha (conifer) in the upstream section, 18,042
stems/ha (mixed) along the ROW and 891 stems/ha (conifer) downstream. The upstream site is
composed of a mix of tall mature trees. The ROW is densely vegetated with many coppice stems
and has a dense understorey. The downstream site supports spruce, pine and deciduous trees and
a dense understorey.

Riparian Ecosystem Function 2 - Bank Stability
There are no trends between the upstream and ROW stream segments in mean width, mean
depth, mean gradient or D60. One trend that was observed was an increase from 0% significant
disturbance in the upstream section to 19% disturbance across the ROW (excluding habitat
below the bridge crossing) and both sections have sound stream banks.

Riparian Ecosystem Function 4 - Habitat Complexity
There was no trend in habitat distribution (amount of pools) between the upstream and the ROW.
However, when the data from all three segments is used there is a increase in L WD from
0.16pieces/m in the upstream section and a similar amount of 0.13pieces/m stream across the
ROW up to 0.56pieces/m in the downstream section. The L WD upstream and across the ROW is
composed mostly of large old conifer debris that is functioning and well embedded in undercut
banks. It should be noted that some potential L WD in the upstream section has been cut by
chainsaw and removed thereby reducing the amounts potentially observed. Downstream, the

L WD was smaller (1 0-20cm), accompanied accumulations of small debris and did not often
contribute to forming pools.

82

Photograph 19.

The ROW, creek and vegetation looking north.

Photograph 20.

Looking upstream through the middle of the ROW stream section.

83

4.1.11 Case Study 11: no name creek
The eleventh case study is located between Chetwynd and Tumbler Ridge and
consists of a 60m wide, 238 kV ROW that crosses a no name creek on Elephant Ridge (Photo 21
& 22). Access is obtained along aBC Hydro access road that has a bridge crossing at the lower

end of the ROW and parallels the electric transmission corridor. No name creek is a small
shallow perennial first order stream with a small gentle gully that occurs in the Northern White
Spruce biogeoclimatic zone. The creek is spanned by one powerline with wooden support
structures and provides very little room for vegetation to grow before it becomes a safety
problem. The riparian vegetation across the ROW is described in Appendix 1 and consists of a
dense understorey, composed almost exclusively of grasses, with a few taller shrub and tree
species. While the predominant land use is forestry, there are no active harvest sites near the
ROW. Due to the presence of the bridge and a steep reach break downstream of the ROW a
downstream study section was not applied at this case, leaving two 60m long research segments
to compare data. There is no windthrow at the site but there is a debris jam at the upstrean1 edge
of the ROW. The site is located in a remote location and is used for hunting and trapping.

Vegetation Management
The site has been managed every 15 years since final construction 30 years ago. Traditionally the
ROW was machine mowed, and in some cases this has left portions of the corridor in an almost
tree free condition. More recently certain areas, including around riparian areas, have been cut at
waist height in order to create winter browse for large ungulates. These animals now maintain the
vegetation in these areas by continually eating trees and bushes, thereby pruning the vegetation
and keeping it at a safe height.

84

Riparian Ecosystem Function I - Energy Flow
The upstream temperature meter worked properly but the ROW meter failed to launch properly.
The maximum diurnal water temperature range recorded at the upstream site occurred on August
18, 1998 and was 7.5-11.0°C. Poor light conditions (sunny and scattered clouds) at both site
visits prevented the collection of sunlight data.

Riparian Ecosystem Function 2 - Stream Hydrology
Both sites are heavily vegetated but exposed soils at the downstream edge of the ROW could
lead to rill erosion. The upstream section has a small, incised gully but has smaller second
growth spruce forest above the gully. The ROW is groomed with some multiple coppice stems
and some young trees. The densities calculated for tall growing tree species are 74,735 stems/ha
(conifer) in the upstream control and 4395 stems/ha (deciduous) across the ROW.

Riparian Ecosystem Function 3 - Bank stability
The mean width of the upstream section is 1.77m while the ROW segment is much wider at
2.93m. There are no trends apparent between mean depth, D60 or reach disturbance. The upper
section has a gradient of7.33% while the ROW is gentler at 5.67%.

Riparian Ecosystem Function 4 - Habitat Complexity
One trend across the two stream segments is a reduction in pools from 25% upstream to only
13% pool habitat across the ROW stream segment. In addition, the ROW is dominated by a long
continuous riffle while the upstream section has more complexity and alternating habitats. L WD
also decreases moving downstream (excluding the debris jam) from 0.20 pieces/m stream
upstream to 0.02 pieces/m stream across the ROW and in both cases invariably involves pieces
of conifer between 10 to 30cm in diameter.

85

Photograph 21.

The ROW looking south from the left bank of the creek.

Photograph 22.

Looking upstream from the middle of the ROW.

86

4.1.12 Case Study #12: no name creek
The twelfth case study is located between Chewtynd and Tumbler Ridge on and consists of a
60m wide, 238 kV ROW that crosses a no name creek on Elephant Ridge (Photo 23&24). It is
very close in distance and similar in size to Case Study 11 , but also has many different attributes.
Access is obtained along a BC Hydro access road that has a small, rarely used ford crossing at
the upper end of the ROW and parallels the electric transmission corridor. No name creek is a
small perennial first order stream in a small gentle gully that occurs in the Northern White
Spruce biogeoclimatic zone. The creek is spanned by one powerline with wood support
structures that prevents trees from growing very tall. Riparian vegetation across the ROW is
described in Appendix 1 and consists of bunches of red alder and willow that line the creek and
an understorey composed almost exclusively of grasses. Due to the presence of a large beaver
dam at the downstream edge of the ROW a downstream study section was not applied at this
case, leaving an upstream segment 42m long and a 72m long ROW stream segment. There is no
windthrow at the site but there are debris jams upstream ofthe ROW. The site is located in a
remote location and other uses include hunting and trapping.
Vegetation Management
As with Case Study 11 this site is managed every 15 years and was constructed 30 years ago . As
an alternative to traditional machine mowing, which has left large portions of the corridor in an
almost tree free condition, this site has also more recently been managed to integrate the needs of
large ungulates with the needs ofBC Hydro electrical transmission facility. Vegetation is cut at
waist height to allow the foraging and eating activities of moose and elk to prune the vegetation
and maintain it at safe limits from the powerline.

87

Riparian Ecosystem Function 1 - Energy Flow
The temperature meters recorded an increase in water temperature as it moved downstream
through the ROW stream segment. On August 18, 1998 the maximum diurnal water temperature
range recorded upstream of the ROW was 9.5-15.0°C, while across the ROW the water
temperature range recorded was 9.5-18.5°C. Poor light conditions (sunny and scattered clouds)
on both visits prevented light data collection.

Riparian Ecosystem Function 2 - Stream Hydrology
Both sites are heavily vegetated and display no signs of rill erosion. The upstream section has a
small encised gully but has a second growth spruce forest above the gully. The densities
calculated for tall growing tree species are 8000stems/ha (conifer) in the upstream control but
very few young deciduous stems across the ROW. Although, the ROW has no tall trees, the
riparian zone is heavily vegetated with lower growing species.

Riparian Ecosystem Function 3 - Bank stability
There are no trends between mean width, mean depth or D60. The upstream section has a higher
gradient at 5.25% than the section through the ROW at 4.42%. One large difference was while
71% of the upstream section was significantly disturbed only 10% of the ROW segment was
significantly disturbed. Upstream disturbances are most often due to boulders, which block the
narrow gully and deflect water against either bank.

Riparian Ecosystem Function 4 - Habitat Complexity
While there is no trend involving pool habitat the lower section has moreL WD. The ROW
section has 0.07 pieces/m stream whereas the upstream section has 0.02 pieces/m stream. The
upstream section ended at a large debris jam 42m upstream ofthe ROW.

88

Photograph 23 .

The ROW and crossing looking north along the corridor.

Photograph 24.

Looking upstream from the middle of the ROW.

89

4.2 Case Summaries
Although each case study site has a unique set of parameters such as topography, location in the
province, powerline configuration, growth rates, and stream size there are some common themes
concerning the impacts of vegetation management on the riparian zone ecosystem. A summary of
information about vegetation management and ecosystem function is presented Table 2. This
section of the thesis elaborates on the information presented in Table 2 by identifying patterns
that are common across the case studies.

4.2.1 Vegetation Management
The interviews and record analysis completed for this study, revealed that a limited number of
vegetation maintenance teclmiques are used across the BC Hydro transmission facility. At all
sites vegetation management occurs to prevent the growth of tall growing tree species into the
overhead powerlines. The methods which are applied can be grouped according to two different
themes: (1) cut the vegetation when it is young and small, where re-sprout often occurs or, (2)
wait and cut it when it becomes larger, taller and less likely to re-sprout.

In most cases the vegetation management targets are tall growing species. While all coniferous
tree species are managed, there are also many quickly growing deciduous target tree species
including black cottonwood (Populus trichcarpa) , big-leaf maple (Acer macrophylum ), red alder

(Alnus rubra) and paper birch (Betula papyrifera) .

90

Case
Study
1

2
,..,

.)

4

5
6
7
8

9
10
11

12

Vegetation
Management
-mowed, cut
-leave strip
-mowed, cut
-no leave strip
-girdle, cut, top
-tall,dense,veg.
-slash, girdle
-leave strip
-mow,cut,girdle
-no leave strip
-slash
-no leave strip
-top,cut,slash
-leave strip
-girdle,slash
-mixed veg.

-girdle,slash
-mixed veg.
-girdle,slash
-tall,dense, veg.
-mow, cut
-no leave strip
-mow, cut
-no leave strip

Trends for Ecosystem Functions (across the ROW)
Hydrology
Bank Stability
Complexity
Energy Flow
-decrease depth -decrease pools
-no trends
-increase light
-increase D60
-decrease L WD
-increase width -increase pool
-increase light
-no trends
.
. .
-mcrease m s1g. -increase L WD
Disturbance
-no trends
-decrease sig.
-decrease pool
-increase temp
Disturbance
-increase light
-no trends
-decrease depth -increase pool
-increase temp
-increase light
-decrease sig.
Disturbance
-increase temp
-no trends
-increase slope
-decrease pool
-increase light
-decrease L WD
.
.
-increase temp
-no trends
-mcrease s1g.
-increase pool
-increase light
-increase L WD
Disturbance
.
.
-increase light
-no trends
-mcrease s1g.
-decrease pool
Disturbance
-decrease L WD
-increase temp
-no trends
-decrease width -decrease pool
-increase light
-increase slope
-decrease L WD
.
.
-mcrease s1g.
Disturbance
-increase temp
-no trends
-increase width -increase L WD
-increase light
.
.
-increase light
-no trends
-mcrease s1g.
-no trends
Disturbance
-no data
-no trends
-increase width -decrease pool
-decrease slope -decrease L WD
-increase temp
-no trends
-decrease slope -increase L WD
-decrease sig.
Disturbance

Table 2. Vegetation Management And Ecosystem Function Trends.

91

The frequency of vegetation maintenance differs according to the growth rates of a particular
area. In some southern and northern coastal areas aggressive tree species can grow up to six m
per year and maintenance occurs every two years. In the north and southern interior areas even
trees with aggressive growth require a fraction of maintenance used on the coast and are cut
every fifteen to twenty years.

At sites with more room for vegetation to grow before it threatens powerlines, such as Nile Creek
(Case Study 3), BC Hydro maintenance staff groom to the edge of the gully by cutting trees
when they are young and low to the ground. Within the gully, trees are often allowed to grow
until they threaten a powerline before being cut. At five of the twelve sites the riparian vegetation
along the ROW included narrow strips of trees running along the sides of the creek. The
increased tall tree canopy at these sites provides some shade and can, if left long enough, provide
some smaller pieces ofL WD.

In some cases herbicides are sometimes applied to control target vegetation. But herbicide use is
limited to tree specific application either as an adjunct to slashing or girdling, or independently
by capsule injection or foliar spray. Broadcast herbicide use is not applied along any BC Hydro
powerlines. According to BC regulations governing the use of pesticides, herbicide usage is
limited to 10m away from standing water (BC Hydro 1997a).

The interviews also suggest that there is increased recognition of the need to reduce frequency
and magnitude of incursions into the riparian zone. The preferred method now selected to reduce
impacts is girdling, which involves waiting for trees to approach tolerance limits and then cutting

92

a continuous strip through the bark, around the tree . When done properly girdling kills the tree
and it then falls to the ground.

Tree topping is another method which has been used to manage tall trees in riparian zones. As
the name indicates, this involves simply cutting the top of a tree off and allowing re-sprout.
While this method has many short term advantages; it can sometimes cause increased risk to a
powerline (quick regrowth) . Topped trees have a higher potential of failure because re-growth is
not well attached and increases the risk falling limbs and debris. Maintenance staff use this
method only after assessing the risks (to the public and the powerline) associated with a site.

In the past vegetation maintenance methods were selected for given stretches of powerline and
then applied according to a schedule determined by prior experience. For example, a section of
powerline would be mowed or slashed from point a to point b, every five years. In this process
work was accomplished according to tried and true past practices and schedules.

In 1997 BC Hydro began changing its electric transmission powerline vegetation maintenance
approach and processes. This is being done to be more selective in treatments and focus more
resources at problem areas while shifting resources away from areas that pose less of a threat to
the powerlines (BC Hydro 1997a). The new approach to vegetation management also provides a
vehicle that allows for site sensitivities to be integrated with site work plans.

BC Hydro's new vegetation management process depends on improved mapping, computer
technology and staff visits to complete a site inventory, define work requirements (by species,
93

growth rate and topography) and site sensitivities. These factors are then integrated to prepare a
site specific work plan, called a prescription. In many cases riparian zones have different
sensitivities and therefore their prescriptions are different than adjacent areas on the corridor. An
example of this is in northern BC, near Case Study sites 11 and 12, where areas along the electric
transmission have been managed to create wildlife browse (Stacey, 1998).

4.2.2 Ecosystem Function 1: Energy Flow
The methods applied in this study assured that the temperature data used was from the hottest
day recorded. The summer of 1998 was extremely warm for extended periods of time, with no
precipitation. As a result, the water temperature data reflects extreme and almost worst-case
conditions.

The first trend observed at the case studies was for more sunlight to strike the ROW study
section than either the upstream section or the downstream. At all sites where light measurements
were taken, more light was measured across the ROW than at the upstream section. At eight of
the ten sites where light measurements were collected light measurements were higher along the
ROW than the downstream section.

The second trend observed at the 7 case studies, where sufficient data was collected to compare
above ROW to ROW, water temperatures increased by 0.0 to 3.5°C across the ROW. Further, of
the four sites where data was also collected below ROW, three sites had streams cool to or near
to upstream temperature levels within one stream segment length downstream (Table 3). Of the
sites that recorded increases, Cases 4 and 8 experienced the most dramatic temperature changes
and Case 8 was the only site where water temperatures approached levels lethal to fish (24.25°C
94

was recorded on August 13, 1998). At Case Study 8 temperature increases were due to the
presence of very shallow pools and riffle flowing (for long stretches) over fully exposed bedrock
through the ROW stream section. At Case Study 4 increases in temperature were caused by
broad, shallow pools exposed to direct sunlight.

Site

Upstream
ROW
Downstream max. change
diurnal range diurnal range diurnal range at ROW

*difference
downstream

3
4
5
6
8
9
10

12.25-13.75
15.0-16.0
17.0-17.5
17.5-22.0
12.5-22.0
11.5-20.5
9.5-15.0

NIA

12.5-14.25
13.0-19.5
17.0-18.0
17.0-22.0
12.5-24.25
11.5-21.0
95-18.0

N/A
14.0-22.0
16.5-17.5
17.0-21.5
N/A
11.5-19.5
N/A

+0.5
+3.5
+0.5
0.0
+2.5
+0.5
+3.0

+6.0
0.0
-0.5

NIA
-1.0

NIA

*=difference between maximum temperature upstream of ROW and maximum
temperature for segment downstream of ROW

Table 3: Diurnal Temperatures
4.2.3 Ecosystem Function 2: Hydrology
The trends observed among parameters selected to describe hydrology suggest this function has
not been compromised at any of the Case Study sites. Rill erosion was not encountered at any of
the sites, except at some bridge crossings downstream of the ROW. Vegetation densities varied
dramatically, with ROW sections sometimes having higher stem densities than the adjacent study
sections. The upstream section invariably had a vegetation community of single stem tall
95

growing trees . The ROW often involved younger trees with multiple stems and wider
interspersed spaces between them. Also, the small trees that were present on the ROW often had
several, if not hundreds, of stems from repeated cuttings that have occurred since the electric
transmission powerline was constructed.

All the case studies had a denser and more mixed understorey community across the ROW
section. The constant mowing and cutting of tall growing trees has allowed other species, such as
willows and mixed berries, to flourish and dominate the ground cover. In addition, grass cover
was dense at all case study sites. The lack of obvious signs of erosion or impervious surfaces
indicates suggests the vegetation management activities at the sites studied has established
vegetation communities that are able to attenuate precipitation inflow into the adjacent streams.

4.2.4 Ecosystem Function 3: Bank Stability
There were no trends across the cases with regards to bank stability. This was because no pattern
was noted between bank stability and the level of significant disturbance. As presented in Figure
4 there was also no trend concerning processes of disturbance, for example, degradation did not
outweigh aggradation as the most dominant form of disturbance across the sites or between
biogeoclimatic zones.

4.2.5 Ecosystem Function 4: Habitat Complexity
Each of the stream morphologies used in this study were controlled by volume and function of
L WD. As a result, the volume and function ofL WD determines the in-stream habitat complexity
across stream reaches. In general, the amount of pool habitat in the streams studied was most
often associated with, and created by, individual pieces ofLWD. Across the ROW stream

96

Percent ci Stream Dsturmoce ll.Je to PgJ-adation
1CD%

l

ro>/o
BJ'/o

7fY/o
W/o
4CJ%

I

0

00'/o

~

•

JJ>/o

-

•

1fY/o

0 D:wrstrea

3

1---

1

0

4

-

fY/o
2

0 RJ./\1
[j]

[j]

1

• Ltstrean

[j]

-

2CWo

•

[j]

5

A

6

7

8

9

10

...-

11

12

Figure 4: Distribution of Aggradation Across the Case Study Sites.

segments pools were also found in association with boulders and undercut banks covered with
grasses, berry bushes and willows trees.

Two separate, yet highly related trends that were observed suggest vegetation management at the
case studies will, overtime, reduce habitat complexity in the ROW stream segment. First, pool
habitat in the ROW segment decreased at 50% of the case study sites and was not related to the
presence or absence of a leave strip. Second, the amount of L WD also decreased at 50% of the
case study sites and again did not correlate to the presence of a leave strip. All the L WD located
on the ROWs was large, old and well embedded in the banks, therefore represents contributions

97

from past vegetation communities. There are no sites where ROW vegetation will generate large
riparian trees that will eventually grow, fall and replace the L WD.

4.3 Summary

Management of vegetation by cutting tall growing trees increases stream exposure to solar
energy, and reduces habitat complexity. On the other hand, vegetation management activities
appear to have minimal effect on the variables measured as indicators of bank stability or
hydrology. These trends, the magnitude of impact and implications to BC Hydro's vegetation
management strategies, are discussed in the next chapter.

98

CHAPTERS
Analysis
5.0

Introduction

While direct statistical comparison of data describing each ecosystem function is not valid
because of the uncontrolled confounding variables at each site, it is valid to indicate prevailing
patterns. This chapter begins by exploring the key findings concerning vegetation management
along BC Hydro electric transmission ROWs. Then the results concerning each of the four
ecosystem functions studied were analyzed to determine the impact of vegetation management,
potential negative and positive impacts, and important confounding variables that should be
taken into consideration.
5.1 Vegetation Management

The data collected in the field support the trends about historical and current vegetation
management practices indicated by both the interviews and record analysis. This portion of the
discussion explores the triangulation between the three separate information sources.

In the past vegetation management at riparian zones located along BC Hydro ROWs most often
involved machine mowing or hand slashing of target trees . Cut stumps and multiple coppice
stems are common at the case study sites and attest to the vegetation management technique
used. In some cases these techniques were accompanied by back-pack spray or capsule injection
application of herbicides, as evidenced in areas with a noticeable lack of multiple coppice stems
or girdled trees. Interviewees indicated that mowing no longer occurs within riparian zones of
the case study sites. Instead, riparian vegetation is now hand slashed, girdled or topped as it
approaches the limits of tolerance. According to the data collected the presence or absence of a
gully contributes to determining both the frequency and method of vegetation management

99

applied in a riparian zone. In sites with steeper and deeper gullies it is more difficult to operate
machinery and trees can be allowed to grow higher. For example 75% of the case study sites
have some type of gully associated with the crossing. Of these gullied sites three had leave strips
of trees running along the stream and the other four sites had riparian vegetation with mixed
heights that extended well back from the bank of the stream.

The remaining sites provide additional confirmation that gully depth affects vegetation
maintenance activities. At Donegani Creek (Case Study 6), the complete riparian zone had been
slashed the previous year, making it impossible to assess if target trees had reached tolerance
limits. Regardless, short growing species such as willow have been left undamaged by the
previous year's work. In the last case with a gully (Case Study 11), the gully is very shallow and
the powerline support structures provide very little vertical growth tolerances. The remaining
three sites that did not have gullies Currie Creek, West Noons Creek and no name creek (Cases
2, 5, and 12), have been managed (cut) up to the stream and have few tall growing trees.

The information collected also supports the assertion that BC Hydro is implementing a new
vegetation management processes for integrating site sensitivities with vegetation management
plans. Ofthe twelve case study sites visited in this study six have riparian zone prescriptions that
were completed since the new process was introduced in 1997. At Kelvin Creek (Case study 1)
the prescription involves establishing a more diverse riparian community by planting low
growing species and western red cedar. Eventually the strip of red alder trees at the site will be
cut to release the younger vegetation. For Nile Creek (Case Study 3) the prescription involves
maintaining the current type of community by girdling deciduous trees, topping target conifers
trees and planting native low growing stock. At Mahood Creek (Case Study 7) the prescription
100

involves transforming the site to a more stable low growing community that requires less
frequent and drastic maintenance from BC Hydro. Over a period of 3 years the prescription calls
for all tall trees to be cut and removed. The prescription for French Creek Tributary (Case Study
2), is very similar to Kelvin Creek. The other two prescriptions, Currie Creek (Case Study 2) and
West Noons Creek (Case Study 5) are nearly identical (no gully exists at either site) and involve
the removal of all tall trees and establishing dense low growing vegetation communities.

The goal of these prescriptions is to maintain, to the extent possible, stream bank stability and
shading (Appendix 1). Rather than pioneering new vegetation management techniques these
prescriptions involve different combinations of existing tools. They assume that by establishing a
relatively stable lower growing riparian vegetation community (that requires less frequent
incursions for management) the riparian ecosystem will function more effectively, providing
increased benefits to the stream. They do not identify hydrology or L WD inputs as key riparian
functions and do not involve ongoing monitoring or field validation at test sites. Further, they do
not enroll stakeholders or interested parties in helping set goals. Instead, BC Hydro technical
staff interacts with resource regulators to define work methods that satisfy their respective
interests.

Other information that supports the prescription process as an effective platform for combining
site maintenance and environmental needs stems from interviewees suggesting that prescriptions
allowed for more effective relationships with regulators and for better internal work planning.

Analysis indicates that in the past, BC Hydro managed riparian zones no differently than the rest
of the ROW. The utility has subsequently changed vegetation work practices in riparian zones in
101

an effort to reduce impacts on stream ecosystems. It is now implementing a system which
appears to be a standard, effective method for integrating varied technical information into
practical more holistic vegetation management work plans.

5 .1.1 Ecosystem Function 1: Energy Flow
The data collected at the case study sites confirm that vegetation management at each site has
helped increase stream temperature and sunlight striking streams. This section analyses the
increases in stream temperature, temperature recovery, impacts observed relative to watershed
level thermal regulation and impacts of increased sunlight on stream productivity.

The energy flow trend was investigated by exploring the relationship between light and change in
temperature. Increases in water temperature are correlated to amount of light allowed to access a
stream (Figure 5). But the variance of the data also suggest that other factors help determine
stream susceptibility to increases in water temperature. The extreme light measurements in
Figure 5 were collected during partly cloudy skies, allowing sunshine to break through.
Regardless, the light data indicates that more energy strikes the ROW stream segment than either
upstream or downstream segments. This can lead to increases in water temperatures.
Stream Heating
On the warmest day of the collection period the maximum increase in water temperature adjacent
to the ROW ranged between 0.0 and 3.5°C. These increases are smaller than those observed
elsewhere in BC. Brownlee (1988) found the maximum water temperatures in some smaller
streams flowing through logged areas near Prince George, BC increased between 5.5 and 9 °C.
Holtby and Newcombe (1982) found mean water temperatures in Carnation Creek increased by
7°C when 39% of the watershed had been logged. Still others have documented 15°C
102

•

12

10

11

..."'
Ql

E
Ql

I-

11

8

~

....::J

•

~
1/)

~

1/)

c:Qi

•

•

•

6

+Upstream

. ROW
11Downstream

·- l~
0
1/)

"'~

.=
0

4 ·

•

•
•
t
oI
2

0

11

•

•

•

-t--

50

100

150

200

250

300

Light Measurement

Figure 5. Correlation Between Light Levels and Increases in Water Temperatures.

increases after logging (Beschta.et al. , 1987). Similarly, the increases in temperature are smaller
than those observed in several streams flowing through logged areas elsewhere in the Pacific
Northwest (Beschta et al. , 1987; Scrivener and Anderson, 1994; Macdonald et al. , 1998; DFO
unpublished data). In most of these other studies the mean temperature values are consistent with
the data collected at the BC Hydro sites, while maximum increases (used in calculating the mean
value) were higher than those obtained in this study. These temperature findings are also
consistent with work done by Peterson (1993) on ROWs crossing small streams in New York.

103

Given these other results it is reasonable to suggest that the vegetation management along the
ROWs is maintaining a canopy that provides varying amounts of shade to the stream. At sites
susceptible to increases in water temperature, shade is a critical and a substantial ROW riparian
community may moderate water temperature. This will only be effective at stream sites where
gully morphology or powerline clearances allows for vegetation to grow to sufficient height to
shade a stream. It is also possible that temperature changes may have been more extreme in the
first few years after clearing when very little shade would be provided to a stream.

The data indicates that warm water temperatures were experienced for longer periods of time at
ROW stream segments than at the other segments analyzed (Appendix 1). Barton et al. (1985)
also observed this relationship and concluded that unshaded streams reach their maximum
temperatures earlier in the day and show greater daily variation than shaded streams. As a result,
the partially shaded ROW sections experience a longer duration of higher temperatures than the
shaded adjacent sections.

Conversely, the lack of water temperature change at some sites with very little shade (Case Study
6) affirms that vegetation canopy is one of several important thermal regulation variables. Water
temperatures depend on the influence of many variables including: headwater lakes, watershed
orientation, channel morphology, stream depth, ambient air temperatures, flow levels, ground
water contributions and length of time exposed (Beschta et al. , 1987; Scrivener and Anderson,
1994). An example of the interaction of these temperature control variables is Clucluz
Creek (Case Study 8) where the minimum to maximum water temperatures range was

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12.5-24.25°C on August 13, 1998. At this site the ROW site supports more tall trees than most of
the other study sites and they partially shade the stream. The large diurnal ranges and near lethal
temperatures can be attributed to riverbed erosion and degradation at the sites, that have created
long stretches of shallow water flowing over bedrock. Bedrock is more efficient than gravels at
accepting and conducting heat (Beschta et al. , 1987). Erosion results in shallow morphology and
acts in synergy with increased sunlight to increase water temperatures.

None of the other sites had water temperatures that approached lethal levels for fish. This finding
supports the assertion presented in Beschta et al. (1987) that in general stream temperatures in
deforested Pacific Northwest watersheds, are invariably warmer than when in a forested state, but
they rarely approach the tolerance limits of resident fish species. However, as discussed in
Chapter 2, small but long term changes in temperature regimes can also have sub lethal but
significant affects on fish populations. Recent work on streams in North Central BC suggests that
forestry operations can change summer and winter water temperature regimes and affect the
timing of fry emergence and the probability of successful outmigration (Macdonald et al. , 1998).
Temperature Recovery
At most of the sites where data were collected at all 3 monitoring stations the increase in water
temperature was most often cooled to pre-ROW levels within one study segment distance
downstream of the ROW (Table 3). In fact some of the sites actually cooled to temperatures
lower than those observed prior to entering the ROW stream segment.

When working on streams in California, McGurk (1989) observed that stream waters were
cooled by 1.0 to 1.5°C within a distance of 130 m downstream. Temperature recovery is a
phenomenon associated with the balance and transference of energy between air and water
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(Beschta, 1987; Teti, 1998). Water is warmed when passing through an exposed area but then
loses thermal energy when flowing in cooler forested areas. The exception to a quick recovery in
water temperature was French Creek Tributary on Vancouver Island (Case Study 4). At this site
water temperatures increased by 3 °C across the ROW site and then increased a further 4.0°C
downstream of the ROW. The progressive increase was attributed to the presence of small
shallow pools that had access to direct sunlight through openings in the sparser downstream
canopy. Further, the small stream flows north to south and is situated on a south-facing slope,
providing conditions for intercepting direct sunlight during the warmest periods of the day.

These results again emphasize that each is unique with respect to temperature fluctuation. The
interaction of several potential variables such as morphology, bedrock, groundwater inflows,
orientation, shade and area hydrology above, at and below the ROW affect fluctuation. For this
study ground water contributions on maintaining water temperature were not considered and it is
assumed they do not play a role at the case sites.

The temperature recovery results indicate that incremental increases in water temperature across
the ROW stream segment do not constitute a significant impact when an appropriate mix of
conditions exist conditions, such as ample shade in the downstream section, for water
temperature recovery to occur.
Watershed Level Processes
In investigating vegetation removal and water temperature there is a direct relationship between
the amount of watershed logged and impact (increase) in mean stream temperatures (Holtby and
Newcombe, 1982; Beschta et al. , 1987). Because no information was collected on percentage of
a watershed impacted by transmission ROWs, this study cannot be used to assess the potential
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role of vegetation management at the case study sites on cumulative impacts in their respective
watersheds.

From a stream network perspective, research has been completed on the relative impact of
tributary inflow on the water temperature regimes of larger streams. Independent of the
importance of the smaller streams to life histories of species found in a watershed, studies
suggest that first through third order streams do not have significant impact on the water
temperatures of fourth or higher order stream temperatures (Beschta et al. , 1987; Teti, 1998).
Temperature Trends
In general, the results from this study suggest that vegetation management can be designed to
maintain some shade but allows enough sunlight through to cause a moderate increase in water
temperatures at many of the ROW stream crossings. Where an increase in water temperature
does occur it is often reduced or eliminated within a short distance past the ROW. It is doubtful
that the majority of streams used in this study (first through third order) contribute to water
temperature changes in receiving streams.
Increased Exposure to Sunlight
While the effects of increased sunlight suggest that the vegetation maintenance may increase
water temperatures, the increase in sunlight striking a stream may also have the effect of
increasing overall productivity. Several researchers have found that removing the canopy above
small and medium streams dramatically increases a stream' s primary productivity and carrying
capacity (Murphy and Hall, 1980; Newbold et al. , 1980; Murphy et al. , 1986; Gregory et al. ,
1987; Feminella et al. , 1989; Keith et al. , 1998). These results are not independent but based on
vegetation removal activities not affecting habitat complexity, cover and other key channel
features (Gregory et al. , 1987; Carslon et al. , 1990, Keith et al. , 1998). In other work, a team of
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researchers removed riparian canopy from two streams and documented an increase in sunlight
striking the stream resulting in, significantly higher accrual rates of chlorophyll a and higher
densities of benthic invertebrates in the open areas (Hetrick et al. , 1998a; Hetrick et al. , 1998b).

Increased sunlight does not in itself have a negative effect on fish foraging activities (Keith et al. ,
1998). It is the interaction of factors including habitat complexity, cover, food availability and
water temperatures that determine foraging activities (Bilby and Bisson, 1987; Gregory et al. ,
1987; Keith et al. , 1998). When increased sunlight is a product of land disturbances that also
effects other riparian factors stream productivity is often reduced. Other recent research proposes
that increased solar radiation may affect development and reduce juvenile fish survival in fresh
water habitats; however this has not been widely investigated (Walters and Ward, 1998).

5.1.2 Ecosystem Function 2: Hydrology
This section analyzes the trends relative to stream hydrology, compares findings to the literature
and identifies potential confounding variables.
Site Hydrology
The data demonstrates that although the ROW have fewer tall trees present they often have
higher stem densities and are completely covered by an extremely dense lower canopy composed
of willows, miscellaneous berry species and numerous different shrubs and grasses. Vegetation
diversity also is higher in groomed areas than in the forested areas. These variables represent
hydrological function because they describe vegetation communities continue to effectively
intercept precipitation and allow percolation into the groundwater because. While no direct
hydrological variables were measured such as precipitation, ground water flow or soil moisture
these variables suggest ROW management does not affect key hydrologic functions .
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A riparian ecosystem ' s ability to intercept and help infiltrate precipitation into the groundwater
table is critical for maintaining a stream's ability to support a wide variety of aquatic life
(Gregory et al. , 1991 ). The presence of dense vegetation communities along the ROW
significantly reduces the probability that the ROW sites contribute to flashier stream flows. In
investigating the effects of urbanization on a watersheds ability to attenuate flows , Honer et al
(1994) found that the steepest rate of decline in biological functioning of streams occurs as the
amount of impervious land cover increases from zero to six percent of a watershed. Hetherington
(1982) found that extensively logged areas of Carnation Creek increased flows and caused
increased erosion. While it is possible that this study was confounded by climate change issues
Castelle et al. (1994) describe other research hat concluded forest vegetation and litter lowered
one stream' s one hundred-year flood stage from 9.9 m to 5.3 m. These findings support the
hypothesis that the vegetation community plays a large role hydrological function.

Impervious surfaces in BC are most often associated with urban areas, but at many locations with
little moisture, susceptible soil compositions and no vegetation, exposed soils not in developed
areas can quickly become impervious surfaces. While none of the study sites had impervious
soils, except along access roads, in many semi-arid areas of the southern United States of
America, bare exposed ground acts as an impervious layer. Hence, major precipitation events are
not intercepted or attenuated and instead can cause flash floods (Leopold 1994).

The lack of rill erosion at any of the case study sites can also support the hypothesis that the
riparian zones along the ROWs is intercepting precipitation and providing conditions for the rain
to infiltrate into the ground water table . Conversely, the presence of rills (numerous small
eroding channels) could be an indicator either that the soils are, or are not, impervious and that a
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significant amount of precipitation is not being intercepted, but instead flows unabated into the
stream.

Watershed Hydrology
Although this study did not focus on watershed level hydrologic processes, the information that
was collected can help point to potential impacts of ROW vegetation maintenance on some
broader scale functions, such as the relationship between snow accumulations and water yield .

In colder climates such as the northern sites (Case Study 8 through Case Study 12), riparian
vegetation plays a major role in maintaining hydrology by intercepting snow. Snow strikes the
vegetation and often is melted or evaporates before striking the ground. When the tall tree crown
cover is reduced there are greater snow accumulations and increases in the amount of sunlight
that strikes the ground which can result in quicker melts and increased peak flows (Beaudry,
1998; Heinonen, 1998). In discussing the effects of snow on stream hydrology, Beaudry (1998)
proposed that riparian areas are often considered to be of disproportionality high importance to
peak-flow runoff. Oppositely, when investigating the effects of logging in the Bowron watershed
(central BC) Wei and Davidson (1998) found no significant impacts on spring snow melt or
winter base-flow. This suggests that watershed specific features must be identified and
understood to predict the cumulative impacts of forest removal in a given watershed (Hogan et
al. , 1998).

There are few tall trees at any of the northern ROW sites and it is difficult to propose a
mechanism where the low growing vegetation species help reduce snow accumulations or
prolong snow melt.

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Evaporation

Evaporation and evapotranspiration are two different yet highly related processes also connected
to riparian vegetation. In this context evaporation refers to the rate of water loss from sunlight
striking an exposed stream surface and vaporizing the water, thereby removing it from the stream
(Mitsch and Gosselink, 1993). This effect can be moderated by shade. Evapotranspiration on the
other hand involves the water that vaporizes from the soil or water together with the moisture
that passes through vascular plants to the atmosphere (transpiration).

There are many empirical calculations to estimate rates of evapotranspiration but none are
entirely satisfactory because they can not account for the host of meteorological and biological
factors associated with a site specific situation (Mitsch and Gosselink, 1993 ). Most models
require rooting depth, leaf area index and soil moisture data. These data were not collected as
part of this study hence it is impossible to quantify the difference in evaporation between the
three study segments at each case study site.

Still, general conclusions can be drawn about a ROW community' s composition and ability to
help regulate general evaporation processes based on research done in forestry. In a mature
forest, clear cutting immediately reduces the rate of evapotranspiration by 30-70% (Swanson et
al. , 1998). However when cover density returns to approximately 50% of pre-harvest conditions
evapotranspiration returns to pre-harvest levels. Because of their quicker growth rates and leaf
shape deciduous stands recover quicker (Swanson et al. , 1998). Since the ROW communities
often resemble naturally regenerating cut blocks it seems reasonable that one effect of ROW
vegetation management is reduced rates of evapotranspiration.

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Conversely, when reviewing work on wetlands Mitsch and Gosselink (1993) suggested that
vegetation has a minimal impact but rather it is the interaction of features, such as size of the
waterbody, topography and soil composition which determines the net impact of riparian
vegetation on site hydrology. It is assumed that this hypothesis is confined to smaller scale sites
as opposed to watershed level processes where vegetation clearly impacts hydrology

The delicate balance between hydrology, morphology and evapotranspiration can be found in the
management of riparian zones in the southern USA. In arid areas it has been a long-standing
agricultural practice to cut riparian vegetation in the belief that transpiration is reduced thus
conserving water for irrigation purposes (Mitsch and Gosselink, 1993). Ironically, researchers
have found that dense stream bank vegetation prevents erosion and often results in stream
aggradation (Li et al. , 1994; Elmore and Beschta, 1987). As the stream aggrades and "rises" in
the channel the groundwater level also rises. In these situations restoring the riparian zone can
transform streams from intermittent to continuously flowing (Elmore and Beschta, 1987; Li et
al. , 1994).

Hicks et al. , (1991) found that forest harvesting increased annual water yield. Increased snow
accumulation occurs in clear cuts and in the absence of transpiration, more water moves into the
ground and into streams, especially in upslope areas (Macdonald et al. , 1998; Swanson et al. ,
1998). As this is largely a cumulative impact correlated to the amount of vegetation removed and
the percent of watershed dedicated to roads if a ROW has only small impact on vegetation it can
be speculated that these activities do not cause large hydrological disruption. However, ROW
access roads must be factored into any assessments about potential impacts.

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Ecosystem Function 3: Bank Stability
A stream's bank stability is largely controlled by the grain size of the bank material, the amount
of bed material carried in the channel and the riparian vegetation cover (Sullivan et al. , 1997). It
appears that vegetation management on the ROWs is maintaining bank stability. Analysis
includes comparing these observations with the literature and a discussion about confounding
variables and alternative explanations
Form Resistance

All riparian zones in this research project were heavily vegetated with a dense, mixed vegetation
community sometimes associated with undercut stream banks and associated pool habitat. An
indicator of recent disturbance and the resulting processes to help return bank stability is the
presence of pioneer species such as alder and willow.

Riparian vegetation contributes to bank stability by establishing dense root systems that increase
channel form flow resistance (Wilzbach, 1989; Huang and Nanson, 1996). Removal of the
riparian vegetation reduces bank stability and may lead to changes the hydraulic geometry of the
channel (Elmore and Beschta, 1987). As a result, disturbances often lead to increased erosion
which introduces more sediment, reduces the volume of pools, and widens the stream (Hawkins
et al. , 1983 ; Beschta and Platts, 1986). Huang and Nanson (p.241 , 1996) found that, "channels
which possess non vegetated banks can be roughly two to three times wider than those with
banks that are densely vegetated".

The process to re-stabilize eroded banks begins with the germination of tough, quick growing
pioneer vegetation species such as willow, birch, maple and alder. These species establish
themselves and reduce water velocities along the stream banks, leading to sediment deposition
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and accretion of the stream banks (Hupp, 1992; Church, 1995). As pioneer species mature, other
succession vegetation species grow in the recently colonized areas and establish larger deep root
systems. The bank continues to move inwards until the stream reaches a new equilibrium that
balances grade with sediment transfer and flow regime (Elmore and Beschta, 1987; Hupp, 1992;
Church, 1995).

Recognizing the ability of riparian vegetation to affect bank stability, some researchers suggest
that removing tall growing trees and replacing the trees with low growing vegetation can quickly
improve bank stability and increase fish densities (Smith, 1980; Wilzbach, 1989, Peterson 1991).
Peterson (1991) also found that vegetation management along ROWs promoted dense vegetation
along streams crossing ROWs and concluded that bank stability had in fact been improved by
construction and management of the ROWs. These conclusions need to be balanced by the need
for larger root systems during extreme high water events (Wilzbach, 198 8; Gregory et al. , 1991).

The results from this study suggest that there is no direct correlation between the ROW
vegetation management and bank disturbance, aggradation or degradation. The presence of dense
vegetation communities composed of pioneer species supports the hypothesis that sites were
impacted when the ROW was constructed and that the current vegetation community contributes
to bank stability by propagating lower growing pioneer species. ROW vegetation management
activities at case study sites are not having an impact on bank stability.
Confounding Variables
If vegetation management appears to be having no impact on bank stability the focus then turns

to the other fluvial factors that affect bank stability: (1) the grain size of the bank material, and
(2) the amount of bed material carried in the channel. Knighton (1984) reviewed the relative role
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of each in maintaining bank stability and suggested that although the role of vegetation is
important it is highly variable and difficult to quantify. Richards (1976) investigated the
oscillation in channel width between riffles and pools and although it did not explore the role of
vegetation the study found that channel width is determined by the capacity of the stream to
erode its bank (a function of flow and sediment).

More recent research proposes that riparian vegetation is less important to bank stability than
individual roughness elements (Huang and Nanson, 1997). Instead, Huang and Nanson (p. 245 ,
1996) suggest that, "the influence of bank vegetation on channel width can be overridden by the
effect of roughness elements". These studies suggest that the cumulative impacts associated with
development and watershed differences in variables such as flow, climatic events, L WD
functions, gradient, bank composition and the resulting changes changes to flow or sediment
characteristics ultimately drive the stream' s capacity to erode bank material. It is possible that the
impact of ROW vegetation on site bank stability is being overwhelmed by larger influences.

The BCCAP used in this study is intended to identify disturbances relative to watershed level
impacts such as forestry and slope failures (BCFPC, 1995). This is accomplished by determining
the level of disturbance in a reach and then comparing the results to other reaches of the same
river system. In this study the BCCAP was modified to delineate differences between sites,
sometimes less than 100 m in length, within the same stream reach. Therefore, the method may
not have been able to detect small scale impacts of vegetation management on bank stability
across shorter lengths of stream. It is also possible that the method worked well but the impacts
at the stream segments were too small to be detected relative to the effects of disturbances in the
upstream watershed or that pre ROW activities have influenced site morphology.
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5.1.4 Ecosystem Function 4: Habitat Complexity
A none of the case study sites can BC Hydro allow tall riparian communities to develop. None of
the ROW riparian zones will produce the L WD that is required for watershed level habitat
complexity. Riparian leave strips observed during the study were too narrow to contribute
adequate L WD to maintain site habitat complexity. L WD contributes to establishing the long
profile and helps determine the riffle pool sequences (Sedell and Swanson, 1984; Bisson et al. ,
1987; Hogan et al., 1998). In the Pacific Northwest, McDade et al. (1990) found that 11% of
L WD originated from within 1 m of the stream while 70% originated from within 20 m. Other
researchers also looking at streams throughout the Pacific Northwest found that riparian trees at
least 50 years old are required to provide an adequate source ofLWD (Andrus et al. , 1988 ; Bragg
et al., 1998). Small riparian leave strips were inadequate for providing sufficient L WD to
maintain stream complexity.

At Kelvin Creek (Case Study 1) ample L WD exists upstream of the ROW, but few pieces exist
across the ROW segment. The upstream segment has habitat complexity and some very deep
pools associated with L WD. There are fewer pools adjacent to the ROW and little other habitat
complexity.

Bilby and Ward (p.2505 , 1991) predict "a decrease in L WD over time as a result of decay of
wood present in the channel prior to disturbance coupled with decreased input from the riparian
area." These researchers found that the volume ofL WD decreased by 22% from old growth
levels 5 years after harvest and 35% after 50 years in streams 5 m wide. Peterson (1991) who
found considerably less L WD across ROW stream sections than upstream control sites also

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observed a reduction. In a worst case scenario, there maybe more than one hundred times more
L WD in small coastal streams before forest harvesting (Sedell et al. , 1988).

Although all research sites for this project are at least 5 years old there wasn't a trend for less
L WD at the ROW stream segments sites. The difference in these finding from the literature cited
above can be attributed to different clearing practices during ROW construction. Harvesting
often involved salvage, stream cleaning (for culverts) and yarding (Sedell et al. , 1988; Bilby and
Ward, 1991 ; Bilby and Beschta, 1991) whereas some ROW construction projects may have
involved less salvage and less stream cleaning. Another reason could be that original
construction activities actually contributed L WD to the BC Hydro ROW stream crossings by
increasing blowdown immediately following construction (Sedell, 1988). These hypotheses are
supported by the presence of several large debris jams immediately upstream of the ROW that
could be accumulations of blowdown. At all sites trends with L WD can be confounded with
other roughness elements such as boulders or exposed bedrock.

Both the Bilby and Beschta ( 1991 ), and Peterson ( 1991) suggest that decreasing inputs of L WD
is indicated by the absence of newer less imbedded L WD. Similarly, all the L WD found along
the ROW stream segments used in this study were well embedded structures from older preconstruction vegetation communities. At Donegani Creek (Case Study 6) more pool habitat and
L WD are found along the ROW stream segment even though no tall trees are present anywhere
on the ROW.

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The results and the literature support the hypothesis that over time the amount of L WD will
progressively decrease with an accompanying decrease in habitat complexity and reduced
abundance of aquatic life across ROW stream segments.

5.2 Summary
A comparison of these results with the literature has supported several key findings. BC Hydro
has created a process whereby site sensitivities can be incorporated into work plans. Current
vegetation activities are having a minimal impact on water temperature and are probably
increasing primary productivity of stream segment flowing through ROWs. While site hydrology
is largely unaffected by vegetation maintenance, it is possible that in some instances ROW
maintenance affects watershed level processes. Bank stability appears to be unaffected by
vegetation activities relative to larger stream capacity processes. Vegetation management is
negatively impacting habitat complexity and over time, as wood decays, it is expected that the
volume of pools at and immediately downstream of the ROW will progressively decrease. This
will lead to reduced stream productivity and carrying capacity levels. The next chapter uses these
findings to propose opportunities and constraints to integrating vegetation management with
ecosystem function.

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CHAPTER6
Conclusions and Recommendations
6.0 Conclusions

This chapter presents the key findings from this study. It begins by drawing conclusions about
the opportunities and constraints for managing for riparian values at streams located along
ROWs. This is accomplished by summarizing the impact of vegetation maintenance activities on
the four riparian ecosystem functions that were studied, and conclusions are presented about the
management process used by BC Hydro for riparian zones located on its transmission facility.
These findings lead to a final conclusion about the possibility of integrating the management of
riparian zone function with ROW vegetation management, as well as recommendations for
activities that support opportunities, mitigate constraints and identify information gaps requiring
more study.

6.0.1 Ecosystem Function
Vegetation maintenance at the case study sites has had minimal impact on two of the riparian
ecosystem functions studied. The dense lower growing vegetation communities found on ROWs
continue to intercept precipitation and help regulate site hydrology. They appear also to maintain
stream bank stability; this latter finding is tied to the presence of hardy pioneer vegetation
species which are known for their ability to protect bank stability. Further, there was no
consistent difference between the amount of stream disturbance calculated for the ROW sites and
the control sites.

These findings suggest vegetation maintenance techniques have, and will continue to transform
the vegetation community to dense low growing communities but this does not impact the
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variables studied to describe the riparian ability to regulate hydrology or bank stability.
The conclusion about bank stability must be tempered by the fact that it is possible that the
assessment method used in this study may have been unable to detect changes within the stream
study reach. Further, ROW crossings create smaller scale exposures that may have negligible
impact on stream disturbance relative to larger scale watershed disturbances and processes. Also,
site specific roughness features may be exerting more influence on stream morphology than the
channel roughness of the stream bank at the study sites.

The research does indicate that vegetation management does impact energy flow processes.
Increased exposure to solar energy may provide both opportunities and constraints to managing
for riparian zones along transmission ROWs.

Vegetation management at the case study sites reduces shading across the ROW and allows more
sunlight to strike the stream than in forested areas. The increased exposure to sunlight resulted in
increases in water temperature of between 0 and 3.5°C. Temperature increases of this magnitude
are smaller than those that have been measured in BC or elsewhere in the Pacific Northwest.
None of the increases resulted in water temperatures lethal to the fish present in the streams
visited. Also, the majority of streams experienced a rapid cooling in water temperatures to above
ROW conditions, after flowing a relatively short distance downstream of the ROW. Where
recovery does not occur, the literature indicates that smaller order streams have a negligible
impact on the temperature regime of larger receiving streams.

These findings support the hypothesis that while vegetation cover does play a significant role in
thermal regulation it is the interaction of a variety of factors (including size of clearing, stream
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depth, morphology, site topography and orientation) that regulate stream water temperatures.
Some sites are more susceptible to temperature increase impacts than others but most sites in this
study experienced minimal temperature increases. Most of the factors identified are not directly
impacted by ROW vegetation management activities. However, efforts must be made to maintain
shade at sites with a high sensitivity to increases in water temperature.

Increased access to sunlight has an impact on water temperatures and also represents a significant
opportunity for improving stream productivity and potential carrying capacity. By increasing the
sun energy in a stream, ecosystem primary productivity improves significantly. In streams where
habitat complexity is maintained, this will result in more productive ecosystems than those in
shaded forested areas.

Opportunities arise because vegetation management on electric transmission ROWs appears to
have limited impacts on energy flow processes into a stream, that are restricted to relatively short
distance ofthe ROW stream segment. While temperature increases are usually minor, where
increases are more drastic and recovery does not occur impacts are restricted to smaller order
streams. Conversely, increased access to sunlight potentially improves stream productivity.

While there are opportunities inherent in the increase access to solar energy, there are also
constraints associated with the impacts. The reduction of shade and increase in water temperature
may contribute to more subtle site specific sub-lethal temperature impacts such as changes in
winter temperature regimes, small scale changes in species behavior and reductions in juvenile
survival. Further, constraining this impact is that the sub-lethal impact on fish species, especially
winter temperatures is poorly understood (Macdonald et al. , 1998). Also, there are no tools
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currently in use to identify sites more at risk for temperature increases in order to factor this risk
into site vegetation management activities. The opportunity that increased access to sunlight may
be benign or potentially benefit the stream ecosystem must be compared to the potential for
vegetation management to result in more subtle chronic impacts from sub-lethal temperature
changes.

Although there are positive and negative aspects to moderating access to sunlight, there is no
doubt that a constraint to integrating riparian zones with ROW management is that maintenance
impacts stream habitat complexity. Cutting vegetation on ROWs will continue to avoid
threatening electric transmission powerlines. Further, areas without gullies will continue to
require more frequent cutting than gullied areas . As a result, most ROWs will be managed to
support vegetation communities that are dominated by young trees, cut stumps and a dense
understorey. While large old pieces of L WD were present in equal proportion at most case study
sites it is very likely that continued cutting will prevent future recruitment of L WD into ROW
stream segments and progressively reduce habitat complexity. In small and medium sized
streams, less L WD will change the riffle-pool morphology and lead to reduced habitat
complexity, retention time and fish carrying capacity.

For cleared forested areas it takes a minimum of 50 years for a riparian area to re-grow and begin
contributing L WD to streams. At ROW sites the riparian zones will not be provided that time
and without a change in management practice the stream segment flowing through ROWs will
become less productive. Fortunately there are many existing enhancement and management
methods, including L WD placement, debris catchers and placing logs along banks, to mitigate
the situation at ROW stream crossings when problems occur.
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6.0.2 Integrated Resource Management
An opportunity for managing riparian values along ROWs is provided by BC Hydro ' s new
(1997) vegetation management prescription process for its electric transmission facility. The
process is being progressively implemented and half of the study sites are now being managed
under unique riparian prescriptions. While the range of available techniques for vegetation
management are relatively unchanged, the prescriptions are created by multidisciplinary teams
composed of vegetation biologists, fisheries biologists and transmission maintenance staff. This
approach appears to be having an impact on riparian ecosystem function. For example, at sites on
small streams vegetation communities can be transformed to more stable low growing
communities that require less frequent incursion. At larger gullies, the intervals between working
at sites can be extended to allow trees to grow, and then they are either girdled or topped,
providing for more stream shade, a source of litter input and SWD. The prescription process is
significant as a management approach because it is an effective approach for integrating complex
issues into a practical work plan.

Integrated management approaches are increasingly being recognized as a preferred method for
combining the management of several different, and at times, conflicting resource management
issues (Lang, 1990). The BC Hydro vegetation management process satisfies three of the four
IRM components identified by Born and Sonzogi (1995) as critical for a successful IRM process.
First, it is comprehensive in scope. This means that is applicable for all riparian zones at all
transmission powerline stream crossings in the BC Hydro electric transmission facility. Second,
it is interconnective and uses new mapping technology to capture and present site specific
topographical, anthropogenic and bio-physical parameters. Third, the process is strategic; it
reduces and aggregates the multitude of concerns possible for each ROW stream crossing site
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into a smaller more workable set of concerns, goals and objectives. In practice, the new
BC Hydro prescription process has modified work practices at case study sites to consider key
ecosystem functions.

The new BC Hydro prescription process not interactive/coordinative (Born and Sonzogi, 1995)
as it does not engage interested parties and complete a process of shared goal setting and decision
making. Without this component it is very difficult to address key societal values, emoll key
parties or build a broader vision of desired outcomes or mutual accountabilities for the vegetation
management process.

Although the prescription process has the ability to integrate ROW and ecosystem issues, it has
not yet been completely implemented throughout system. Ongoing cost constraints, especially
those associated with company restructuring and anticipated market deregulation, combined with
the remoteness of many of the sites and the practical challenges of implementing large
operational changes may limit the practicality of implementing other, potentially more
expensive, operational processes. As all field vegetation work on BC Hydro transmission ROWs
is completed by contract staff, another challenge is training and providing contract specifications
that ensure the terms of the prescription are implemented effectively and are cost effective. A
confounding variable is although BC Hydro has easements that provide access to the ROWs, the
utility does not own the majority of the land along its electric transmission facility. Therefore the
interaction of key parties, such as First Nations and land owners, is critical to implementing
different management paradigms at many ROW stream crossings.

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6.0.3 Summary
The findings indicate that it is possible to integrate riparian zone function with current vegetation
management practices along electric transmission ROWs in BC. BC Hydro is committed to
design management systems for ROWs that consider riparian zones function. Traditional
vegetation management for ROWs look to be compatible with newer management strategies as
they do not appear to have a significant impact on most riparian ecosystem functions. Also,
where impacts do occur they can be mitigated by applying existing vegetation maintenance and
stream enhancement techniques. Beyond ecosystem level issues an IRM approach to vegetation
management can be accomplished by expanding the prescription process to include other key
parties affected by landscape management of ROWs.

6.1 Recommendations
The opportunities identified by the analysis represent the elements supporting the possibility of
managing electric transmission ROWs for riparian values. However, to accomplish an integrated
resource management approach to this issue the constraints must also be addressed. In order to
achieve IRM the following must also occur:
1) ecosystem functions should be used as assessment criteria for determining the impact of
electric transmission ROW vegetation maintenance on riparian zones;
2) guidelines should be developed for assessing stream sensitivity to impacts on energy flow
based on depth, width, morphology, orientation and potential for water temperature recovery;
3) guidelines should be developed for evaluating, contributing and monitoring L WD in streams
at ROW crossings;

125

4) the ROW vegetation management process should proactively engage and address key parties
with regards to riparian zone management goal setting and work practices;
5) BC Hydro must be prepared to change practices, including reviewing the options for higher
towers and changing ROW routes, in the face of public scrutiny; and
6) a commitment is necessary for completing stream inventories and prescriptions for all
riparian sites along the transmission facility .

As resource managers are increasingly pressured to develop new management models that
integrate anthropogenic and biophysical issues, research into different practical applications is
critical. This study contributes to the riparian ecosystem body of knowledge by testing and
confirming the value of using functional assessment criteria to evaluate the impact of landscape
management activities on riparian zones. From a technical aspect, key information gaps exist and
more research is required into (1) the chronic impacts of sub-lethal changes in water
temperatures on fish, and (2) different methods for detecting site specific morphological trends.
This study also contributes to the IRM body of knowledge by confirming an integrated approach
is appropriate (and provides a description of necessary conditions) for successful management of
environmentally sensitive areas also critical for the electric utility industry. This is important
because there are few studies that compare current IRM theory to field situations and affirm that
different and apparently mutually exclusive management objectives can be combined into
compatible elements of managing a landscape.

126

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Yeager, K.E. 1996. The exuberant planet: A global look at the role of utilities in
protecting biodiversity. Environmental Management 29(6):967-971.
Yin, R. 1994. Case Study Research: Designs and Methods, 2"d edition. Sage
Publications: 1000 Oaks, Ca..
Zolman, J. 1995. Biostatistics: Experimental Design And Statistical Inference. Oxford
University Press: New York, N.Y..
137

Appendix 1

The Case Study Data.

138

1 -

l

. -

~
·

1

I
[o7:oo -12:o0
[1. 1-24

. ...
1 Stream Name
Orientation of Crossing

- - - · · - - ·. . · - - - · - - ... _. · - .,

~
·
Time
Crew
General photograph roll ID and #'s

Direction of Flow

Location

I

Crossing:

None

N/A

Condition

N/A

Page 1 of 3

N/A

Comments:
This site involves a relatively narrow Righofway, occupied by 1 wood pole 138 kv circuit and 1steel
tower 138 kV structure. This stream is located in fairly deep gully While not very steep the transmission structures are loca!ed
on the top of the gully, therefore the span is very long. There is floodplain at the foot of the gully. The area is only accessible along
a rough 4•4 gated road . There is thin strip of topped alder tree (about 15m tall), 1-3 trees deep beside the stream through the ROW.
The stream section passing through the Righofway is wetted from bank to bank, with no exposed bars. In the upstream stretch there
is significant bars, pools are formed by LWD. All 3 segments display degradation with various levels of aggradation .

,,,

27/4E
w
w

Kelvin Creek
Right angle

Region of BC
Biogeoclimatic Zone
lCoastal Douglas Fir
Transmission Line ld
to
Tower Numbers (as power flows)
27/3D
170m jStream segment length Iss M
Width of rightofway
I Sideslope angles (%) In 45% S 25% e
Vertical distance from nearest stream bankfull w1idth to top of gully (morN/A)
In 60 m s 50m e
Landuse immediately upstream
!Dormant
Predominant type of watershed land use
!Farming, Residential (very low density), private logging
Distance from closest tower to nearest stream b ank full width
RIGHT 150m
LEFTI100m I
Fish Present
IYes
I
Species
!Co, Cm, Ch, St,Ct
I

Site Description:

Date
Weather

30, 1998

I #f -1

General Information:

Case Number

Riparian Research Project... .Case Study #1

I

~~~~
Treated Section

15,000 stemslha (deciduous)
10% conifer, 10% red alder, 60% maple (clumps),
10% willow, 10% cottonwood
Dense 30% salmonberry, 20% huckleberry
40% broom, 10% elderberry

Bankfull Width (Wb)
Thalweg Depth
Mean Depth (d)
D60 (D)
Gradient(%)
D!Wo
Did
(Did)(D/Wb)
Stream Type
Importance of LWD
Reach Disturbance

Transect

Upstream Control Section

8,000 stemslha (conifer)
10% red alder, 5% willow, 80% conifer (large
and tall), 5% cottonwood (mature)
Dense 30% bracken fern, 30% sa/a/, 40%
1
(huckleberry and red elderberry)

Usptream Control Section

17.0-19.25
155.18

Page 2 of 3

I

Downstream Section

~~~~

Downstream Section

'\

9.60
55.00
20 .00
0.17
1.50
2.08
0.02
0.0358
RPc

3

~~~~ ~~~

8.85
65.00
19.75
0 .20
1.33
2.23
0.02
0.0495
RPc
~: ::~ ~ :: ·~~ ~ ~: :

8.40
75.00
17.00
0.21
1.00
2.02
0.03
0.0506
RPc

4 Mean

Downstream Section

~: ·.l·:·.• ~ : · : :~· ;:;:::· : ~ ·:~~ ~~

2
8.90
80.00
18.00
0.24
1.50
2.02
0.03
0.0545
RPc

11,000 stems/ha (coniferous)
10% cottownwood, 40% red alder, 10% willow,
40% conifer
Sparse 40% brackenfern, 30% mixed berry,
20% Salal, 10% Willow

Treated Section
Upstream Control Section
2
3
4
5 Mean
5 Mean
2
3
4
14.10
11.68
8.85
8.60
7.10
7.20
8.30
8.50
11 .90
12.80
8.01
9.90
9.70
50.00
48.00
64.00
80.00 48 .00
13.00
60.00 40.49
1.47
53.70
52.50
62.00 42.00
50.00
18.00
20.00
57 .00
35.00 46.00 45.00
38.00 40.00
24 .00
40.80
70.00 127.00
13.25
16.00
15.10
14.10
9.60
12.10 13.38
0.17
12.00
12.50
15.10
14.10
13.39
0.9
0.86
1.18
0 .78
0.79
0.87
1.23
1.23
0.02
0.96
0.86
1.4
0.90
1.62
1.18
0.75
0.86
2.82
1.36
1.54
1.76
2.10
1.70
1.67
1.56
1.19
0.34
0.02
1.62
1.56
1.18
0.00
0.02
0.88
0.29
0.28
0.40
0.02
0.26
0.4649 0.4438 0.4890 0.8334 0.0320 0.4429 2.6120 2.4233 1.4039 0.0013 0.0137
1.29
0.0565
RPc-g
Rpg
RPc
RPc
RPg
Rpg
RPc
RPc
RPc
RPc
RPc
Rpc
RPc
Controlled
Controlled
Controlled
.. ~ . .~~ · ~ ~ ~:~: : ~ ~ ~· ~ -~~ ~:~~~ : · ~ ~ · ~ ~ :
~
, r.·;, - ·:~ ·~?: ·: :
~~~ · ·
· : : ~: :
~

Riparian Ecosystem Function 3 - Bank Stability:

Understory

Vegetation Density
Vegetation Diversity

I

Treated Section

Riparian Ecosystem 2 -Stream Hydrology:

Temperature (Diurnal range)
Light (mean PPFD)

Riparian Ecosystem Function 1 - Energy flow:

Riparian Research Project... .Case Study #1

Treated Section
None observed
N/A
N/A
N/A
N/A
N/A
Upstream Control Section
None Observed
N/A
N/A
N/A
N/A
N/A
'----

Page 3 of 3

,

Vegetation Management:
Observations
The vegetation on the left bank (facing downstream) has been aggressively managed to create an almost
The vegetation on the left bank (facing downstream) has been aggressively managed to create an almost field like condition
field like condition, there are very few tall growing species other than a few maple tree clumps, in addition grasses are the dominant
ground cover and there is no sign of rill erosion or surface flow. The right side has been less aggressively managed
and as such there are many more clumps of tall growing maples and as well as naturally occurring coniferous trees .
This side has also been planted out with cedars . The left side has dense pockets o! scotch broom .

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roiiiD and #'s

Windthrow

Length distribution of habitat (m)
Total Length Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Ecosystem Function 4 - Habitat Complexity

Riparian Research Project. ... Case Study #1

Downstream Section
None observed
N/A
N/A
N/A
N/A
N/A

~ ·······

~

~

~ 14

E

c.

Gl

~

2:24

~

35993.5

...

35993

2! 16

~

E

~
Gl
c.

•

~

•

35994.5

~

..

... .• •

Date and Time

35995.5

~

4:48

7:12

~

35996

9:36

~

Time of Day

12:00

35996.5

~~

14:24

~

~
~

16:48

••••••••••••••

Upstream Case 1, July 18, 1998

35995

• • •

................................. .

"'

35994

• •

••

•

19:12

~~

35997

~
~

21 :36

~

35997.5

•

0:00

~

~

~

35998

~

~

•

18.------------------------------------------------------------------------------------------------.

2! 161

~

Upstream, Case 1 July17-21, 1998

Riparian Prescription
Stream Narne:

Kelvin Creek

Circuit:

1L10-11-14 (7/3-7/4)

Prescription
The following prescription is designed to ensure transmission powerline security while
maintaining riparian zone ecosystem function. The uninterrupted transfer of power
demanded by communities can only be achieved by keeping vegetation from growing
within tolerable limits of approach. In addition, riparian zones are some of the most vital
ecosystems to both aquatic and terrestrial habitats. Therefore, prescription will be
designed as per the riparian management process to integrate operational and
environmental needs.
Firstly, to protect aquatic habitat vegetation, work will be executed in a manner which
prevents bank disturbance and increased erosion.
Secondly, to ensure shade and bank stability and reduce the need for future incursions
into the area, vegetation control inethods will be applied which encourage the native low
growing community on the site.
Thirdly, where possible, safe and practical, tall growing trees will be topped and/or
girdled and only felled when necessary.
Lastly, in cases where tree removal negatively impacts the site replanting will occur as
per the attached planting standard.

Site Characteristics
..

This stream has a 50m wide shallow, braided channel with riffle run sequences and
provides habitat to coho, chum, chinook, cutthroat, and steelhead.
~

,.

Maintenance Plan

1. Selectively top conifers as they grow into the limits of approach.
2. Girdle or remove tall growing deciduous species as they grow into the limits of
approach.
3. Encourage low growing species.

I

#2

June 10/98; Jul
Overcast; Sunn

I
1

···~
,....

I

l

:

~ ~l

[foll#2, 1-2.lfu- •

1 Stream Name
Orientation of Crossing

I
Time
Crew [JS, JM
General photograph roiiiD and #'s

1

1 _._.,,, .... -'"'"""'

----- -

Page 1 of 3

l

,,'

-

2.20

Crossing:
~l : :
:
: ::
l
!Dismantled
!Age
I> 20 years
I
Specifications fN/A
Type
Comments:
There is an old timber crib bridge which wood have spanned the middle Righofway. All that is left are a few
timber logs, which would have formed the cribbing. The deck of the bridge has been removed from the site It appears
a few of the large logs from the bridge have moved up to 30 m downstream. A pool has formed where the crossing used to exist,
and is not included in the habitat descriptions/calculations.The old access road is well vegetated and there are no signs of rill erosion.

!Vancouver Island
Biogeoclimatic Zone !Coastal Dougals Fir
I
2.10
to
I2L 170/126
Tower Numbers {as power flows)
I
w
e
1185 m I Stream segment length 1195 m
Sideslope angles {%)In 2.5% s 5%
w
In 20m s 10m e
ulated from nearest stream bankf full width to top of gully {m or N/A)
upstream
!Logging
vatershed land use
I Logging
RIGHT 30m .
tower to nearest stream bank full width
LEFT I
l
.......................... ,
!Yes
Species utlizing stream !Ct
I
I
Comments:
This is a wide Rightofway for 2 separate steel structure 238 kV circuits. Currie Creek passes at right angles
to the Rightofway. It crosses under a large access road bridge on the downstream side of the Righofway. The stream supports fish
but is also intermittent. There's a narrow band, 1-3 trees wide, of riparian vegetation composed of willows and red alder. T;he
Righofway has relatively few large coppice root wads, suggesting selective use of herbicide. In addition an old decommissioned
bridge is located in the middle of the Rightofway {see below). The entire Righofway is low gradient and exhibits relatively no gully.
When visited the stream was dry downstream of the ROW. Therefore no data were collected for the downstream section.

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project....Case Study #2

I

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 {D)
Gradient (%)
0/Wb
D/d
(D/d)(D/Wb)
Stream Type
Importance of LWD
Reach Disturbance

3

4

Treated Section

2.80
3.30
2.90
3.00
50.00 48.00 42.00 42.00
15.00
16.00
14.00 13.00
3.75
3
4.25
4.12
5.36
4.85
4.33
4.83
0.30
0.33
0.33
0.31
1.6071 1.6162 1.6092 1.3413
RPg
RPg
RPg
RPg
Controlled
47. percent · · . :-'"1.:' '· · ::~?: ~ l: ~:.. ~

2

Riparian Ecosystem Function 3 - Bank Stability:

: ~

··r-,.: :~· : ~:
:: ~

·

5 Mean
3.20
3.04
42.00 44.80
15.00
14.60
1.66
3.36
4.69
4.80
0.36 . 0.33
1.6741 1.5651
RPg
RPg

Treated Section
Vegetation Density
8,500 stemslha (decidous)
Vegetation Diversity 10%conifer, 90% deciduous {red alder,willow)
Understory
20% bracken fern , 10% salal, 15% huckleberry
10% red elderberry, 5% goose berry, 40% broom

Riparian Ecosystem 2- Stream Hydrology:

~~~~

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
Light (mean PPFD)(micro mols)

Page 2 of 3

I

' \\

Upstream Control Section
. 2
3
4
8.50
5.30
4.50
4.40
35 .00
50.00
30.00
50.00
13.00
14.00
14.00
18.00
2.5
3.50
; 5 .00
3.00
1.53
2.64
3.11
4.09
0.37
0.28
0.47
0.36
0.5681 0.7396 1.4519
1.4727
RPg
RPg
RPg
RPg
Controlled
~ ~~~ ~·: ·· ~· ~ · l >?~~ · ·
21 percent ··

.

~ : ~·~ ~

: : ~~ ~~~ ~~

5 Mean
5.52
4.90
57.00
44.40
18.00
15.40
4.00
3.60
3.67
2.79
0.32
0.35
1.1600
0.9677
RPg
RPg

Upstream Control Section
10,000 stems/ha (coniferouS)
10% decidous, 90% conifer (tall), 60-80 vears old.
70% salal, 15% red elderberry, 15 mixed broad leaf shrub

~~~~

Upstream Control Section

Riparian Research Project. ... Case Study #2

Treated Section
None observed
N/A
N/A
N/A
N/A
N/A

Upstream Control Section
None observed
N/A
N/A
N/A
N/A
N/A

0 :::~~~~7~ :: :~ •·...~ · ~

Upstream Control Section

Page 3 of 3

Veaetatlon Management:
Observations:
This site appears to have been managed aggressively over the years. The lack of tall growing
trees/saplings along the wide Rightofway suggests herbicides have been used. This is further substantiated by the 2-3 deep band
of deciduous trees which compose the riparian vegetation and coincide with a 10m pesticide free zone . In addition it appears that
vegetation work has been completed at the site within the least 2 year. Some of the young deciduous trees have coppice
and put on between 2 to 4 meters of growth, well within annual growth yields for these species within these
l
~ zones.
There is a significant debris jam at the upstream edge of the Righfofway, the material was either been placed there, during
construction or it has been brought downstream and collected there. The material is mostly compose off large coniferous trees and
associated smaller deciduous trees caught in the debris jam. This has lead to significant upstream aggradation .

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roiiiD and #'s

Windthrow

Riparian Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
Total Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Research Project.. .. Case Study #2

.,,

Riparian Prescription
Stream Name:

Currie Creek

Circuit:

2L 126/170 (2/2-3/1)

Prescription
The following prescription is designed to ensure transmission powerline security while
maintaining riparian zone ecosystem function. The uninterrupted transfer of power
demanded by communities can only be achieved by keeping vegetation from growing
within tolerable limits of approach. In addition, riparian zones are some of the most vital
ecosystems to both aquatic and terrestrial habitats. Therefore, prescription will be :
designed as per the riparian management process to integrate operational and
environmental needs.
Firstly, to protect aquatic hal;>itat vegetation, work will be executed in a manner which
prevents bank disturbance and increased erosion.
Secondly, to ensure shade and bank stability and reduce the need for future incursions
into the area, vegetation control methods will be applied which encourage the native low
growing community on the site.
Thirdly, where possible, safe and practical, tall growing trees will be topped and/or girdled
and only felled when necessary.
Lastly, in cases where tree removal negatively impacts the site replanting will occur as per
the attached planting standard.
Site Characteristics

This stream provides habitat to cutthroat. The streambed consists of incised bedrock, and
the stream channel has a significant amount of LOD. There is an abundance of shrub
streamside understory namely salmonberry, oceanspray, wild rose, stika willow on this site
therefore planting is not required.
Maintenance Plan

1. Girdle all Red alder, Cottonwood trees greater than 4cm at girdle height on
streamside to release understory in 1998.
2. The bridge will be replaced in 1998, a Q1 00 has been completed and a Section 9
permit has been applied for to complete in stream works
3. Girdle rem?ining alder and maple as their stems grow to the specific girdle width.
4. Encourage all low growing species. See diagram in field notes for details.

I

I

I

~

-- -]

Stream Name (Nile Creek
45 degrees

111:1 oam -3 :1op_rn_
12, 11-24

Orientation of Crossing

Crew IJS, AP
I
Time
General photograph roiiiD and #'s

Direction of Flow

Location

I

Page 1 of 3

,,,,

None
!Condition
IN/A
IAae
IN/A
Specifications IN/A
Comments:
There is crossing at this site but a waterboard access road parallels the right bank of the Creek. It remains at least 80 m from the stream
at ail times across the Rightofway.The road is gated and receives very little use.

Crossing:

LVancouver Island
Biogeoclimatic Zone
!Coastal Douglas Fir
I
65/1
64/3
to
I2L1231128
Tower Numbers (as power flows)
I
w
1150 m !Stream segment length 1261 m
Sideslope angles
ln25% s30% e
w
ulated from nearest stream bankfull width to top of gully (morN/A)
In 30m s 45 m e
upstream
I Domestic Watershed, Dormant
vatershed land use
!Limited logging and farming
;t tower to nearest stream bank full width
RIGHT
LEFT I30m
I
IYes
Species utilizing stream ICm, Ctt, Pnk, Rbt,Std
--I
I
I
Comments:
This is a wide Rightofway with 2 steel structure 238 kV circuits. Nile Creek passes through the ROW at 45% angle and is in a fairly deep, broad gully.
The site is located within 5 km of the streams confluence with the ocean, and has noroad crossing. It is low gradient and has many enhancement groups.
activities. There are no signs of erosion although the area is heavily used by local residents as a greenway for walking and fishing .
While there is no debris jam usptream, the Rightfway has a debris jam in the middle casuing significant lateral movement of the stream. The upstream section is 150 m long
ending at an area manipulated by the waterboard, thereby reducing confounding variables . The upstream section is composed of two channels, data was collected for both .

I

#3-l

'July 16198
Cloudy, overcast

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project... .Case Study #3

I

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 (D)
Gradient (%)
DNVb
D/d
(D/d)(DNVb)
Stream Type
Importance of LWD
Reach Disturbance

14.80 14.00
0.40
0.90
0.22
0.21
1.5
2.00
0.02
0.01
0.55
0.23
0.0082 0.0035
RPc
RPc
Controlled
31 percent

2

I

Upstream Control Section
257 stem/ha, conifer (large >60ft mature conifer}
596 stem/ha , deciduous
60% cedar, 30% hemlock, 10% fir, conifer red alder,
deciduous (near open areas near the road beside Nile Crk)
very little, sword fern , salmon berry (where light allows},
thimbleberry

~~~:~ _ 14.25

Upstream Control Section

I

70% salmonberry, 10% swordfern ,
10% th imble berry, 10% mixed
herbacious ,where the canopy is open

Downstream Section
229 stems/ha, conifer (trees,> 70ft}
523 stem/ha, deciduous (>50ft large,)
70% hemlock, 20% cedar, 10% fir

~~~~

Downstream Section

3

Page 2 of 3

'"

Upstream Control Section
Downstream Section
5 Mean
1 (l)
2(L)
3
4 (R)
5(R} Mean
2
3
4 Mean
. 9.74
9.60
5.80
16.00 10.80 12.30 13.58
11 .80
12.40 14.00
14.20 13.10
10.90 13.80
8.60
0.78 66.00 60.00 54.00
0.72
0.86
0.73
0.85
0.75
0.85
60.00 60.00
0.81
0.85
0.65
0.16
0.11
0.16
0.18 20.00
17.00 21.00
0.24
0.22
0.21
19.75
0.24
0.17
0.23
21.00
2.00
1.90
4.00
2.00
2.40
2.5
1.00
2.00
2.50
2.00
2.00
2.00
2
1.50
2.50
0.01
0.03
0 .02
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.02
0.01
0.03
0.02
0.01
0.15
0.19
0 .23
0.30
0.28
0.39
0.35
0.33
0.19
0.28
0.26
0.28
0.33
0.26
0.28
0.01
0.0019 0.0073 0.0046 0.0043 0.0062 0.0032 0.0076 0.0018 0.0052 0 .0044 0.0051 0.0039 0.0058 0.0052
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
Controlled
Controlled
. !: .:-:: ·
. ·J:.--:. 56 percent ·
<-t . .~ · :
:
~~ ~ . .·:;.;; ~ :
~ ~:~
~· -- '~· ..· · ~~~: : .... ~
: ~ ~ ~ ·_·}_
·_ 39 percent ;-,·- ', : . .' ·.. ·, . _:• ....~ '· . ~ '.i i' .• ..

Treated Section

4

60% red alder, 30% big leaf maple,
10% coniferous
50% salmonberry,30% thimbleberry,
10% brackenfern,1 0"/omixed herbacious

Treated Section
29,700 stem/ha (predominantly decidous}

Riparian Ecosystem Function 3 - Bank Stability:

Understory

Vegetation Diversity

Vegetation Density

Riparian Ecosystem 2 - Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range}
12.00- 13.75
Light (mean PPFD}(micro mols}
199.3

Riparian Research Project.. .. Case Study #3

l

Treated Section

. . ....

-. 1

N/A
N/A
N/A
N/A
N/A

None

Treated Section

0.08 '.<·<:•,·. ~: :~~ ~:

261 M

34 percent pool, 66 percent riffle

N/A
N/A
N/A
N/A
N/A

None

Upstream Control Section

N/A
N/A
N/A
N/A
N/A

None

Downstream Section

ercent riffle

Downstream Section

Page 3 of 3

.,.,

Observations:
The site, except for the gully with the riparian zone has been managed aggressively over the past 10 to 20 years. There is a lack of tall growing spp.
Instead the Righofway vegetation is dominated by low growing shrub species, broom and mixed berry species. Nile Creek crosses the Rightofway at approximately a
45 degrees through a shallow yet morphologically complex gully. The creek is part of the local waterboard water source. Little vegetation work seems to have occurred
,except for selective slashing since the line was built 25 yrs ago. The vegetation of the site is composed of massive maple root wads with up 200 stems per wad, tall conifer
trees and red alders with DBH's up to 60 em . A significant portion of the vegetation is now threatening the powerline, alm<;>st all existing alders have been girdled and will fall.
Maple root wads have been slashed again and where appropriate it appears conifer species have been topped . While there is significant conifer recruitment in the . ,
mixed stands. In the areas composed of red alder {@70% of the right bank) , the understorry is predominantly composed of thick salmonberry bushes, el iminating
the opportunity for young conifer species to get established it appears that as the area is opened to light {as girdled trees fall) the potential for tall growing trees will be
significantly reduced.The clearances in this gully would allow the growth of conifers species which could be topped on 20 to 25 year cycles.

Vegetation Manl!IJ!!ment:

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Wjndthrow

Distribution of habitat
Total Reach Length{Thalweg)
Volume of LWD {Pieces/m stream)

Riparian Ecosystem Function 4 - Habitat Complexity

Riparian Research Project....Case Study #3

10

12

14

~ ·

14

16

7-25-98
12:00AM

10
0:00

E
~ 12

c.

Q)

~

::I

~

..

~

c.
E

~Q)

::I

~

16

2:24

7-25-98
12:00 PM

' .·

••

-

4:48

7-26-98
12:00AM

'
....

7:12

7-26-98
12:00 PM

' -• ,--,

9:36

••
lil

7-28-98
12:00 AM

''

Time of Day

12:00

14:24

Case 3, July 28, 1998

DatefTime

7-27-98
12:00 PM

'I :

7-27-98
12:00AM

• I '

Case 3, July 25-30, 1999

••

16:48

7-28-98
12:00 PM

ij

•

I

19:12

•

• I

21 :36

7-29-98
12:00 PM

u• :

7-29-98
12:00AM

.-,
i

0:00

7-30-98
12:00AM

~

l

lI

Appro1·ed Work Practices for 1'vlanaging Riparian Vegetation

Appendix 3 Examples of Implemented Site-Specific Prescriptions for
Management of Riparian Vegetation in Transmission ROWs
Location:

Nile Creek

Power Line:

5L29/31

Setting:

The stream side vegetation surrounding the 185 m section of Nile Creek, near Qualicum
Beach B.C., where it crosses underneath power line 5L29/31, is a productive riparian
ecosystem. However, it is also an area where vegetation must be maintained to ensure
the flow of power to Vancouver Island is never interrupted. At this crossing site, tall
growing vegetation is dominated by deciduous species including big leaf maple, red alder
and black cottonwood. In addition, the site has tall coniferous species which include
hemlock, western red cedar and Douglas fir. Currently, the tallest of the red alder, black
cottonwood, hemlock and Douglas fir are reaching heights of between 10 to 15 m,
bringing some within the transmission line's limit of approach. The dense lower canopy
of the site is dorr¥nated by salmonberry, elderberry, bitter cherry, ferns and other berry
species.
Nile Creek is classified as a S2 stream, utilized by coho and chum salmon as well
as resident trout species. The section of creek flowing through this site, has a gradient
of <2.0%, exhibits predominantly run-riffle habitat (with few pools) and
substrate
dominated by large gravel and cobble. In the upstream 90 m of the crossing the stream
demonstrates multiple channels and good habitat complexity. However, the remaining
95 m of the crossing the creek remains in a single channel, has ample shading but lacks
habitat complexity. To compensate for this, enhancement activities have involved
placing large organic debris (LOD) within the stream or cabling it to the stream bank.
Nile Creek has significant social value. This area is readily accessible and heavily
utilized by both sport fishers and hikers. The crossing lies within the traditional lands of
the Qualicum Indian Band Habitat. In addition habitat conservation is also a major
concern of the Nile Creek Hatchery
~

Rationale:
:

The following work is planned for the area which falls within the 50 m riparian zone
around this S2 stream. Over a 8 year (figure 1) period the current tall growing largely
deciduous riparian community will be altered into a mixed low growing deciduous and
taller growing coniferous community. This plan will maintain the current functions of
the riparian conununity but will lead to less frequent and drastic incursions into the area.
In addition, developing the largely coniferous stream side community will contribute to
hydraulic stability and habitat complexity (through the natural addition of LOD). In the
future , riparian zone vegetation management will involve removal of hazard trees from
the site rather than major site disturbance.

Procedure: 1 Prepare a site work plan including access, planting strategies and goals for the site, which
is discussed with work crews during all tailboard meetings.
2 .Girdle 113 of tallest deciduous trees throughout the site with priority given to the tallest
and those clumps which provide the best natural regeneration.
DRAFT 1.1- February 11, 1999
RVMS 99.doc

Appro•·ed Work Practices for Managing Riparian Vegetation

3 Selectively crown reduce (by up to 1/2) all coniferous trees, >20m tall.
4 Do not modify species which will not grow tall enough to enter limits of approach.
5 Prepare and implement plan a which maintains biodiversity at the site including;
a) Enhancing willow, red elderberry, Indian plum and other native low to medium
height deciduous species found at the site,
b) Where appropriate and beginning directly adjacent to the high water mark of the
stream plant minimum 1 m tall acceptable conifer species.
c) Monitor site and ensure good survivals
6 Ensure no machinery enters stream or damages banks.
7 Selectively create wildlife trees where safe, practical and effective.

Year 1

1) Girdle ~ of riparian deciduous trees
2) crown reduce coniferous trees (>20m)
3) selective planting where required

Year2

1) Girdle 113 of riparian deciduous trees

Year3

1) Girdle 1/3 of riparian deciduous trees

Year4

1) Monitor planted site
2) Girdle selected vegetation

Year 5

1) Monitor site

Year7

1) Monitor site

Year 8

1) Girdle selected vegetation
2) Monitor site

Proposed Schedule for Vegetation Management in the Riparian Area of Nile Creek
;

~

DRAFT 1.1- February 11, 1999
RVMS 99.doc

33

[

'July 1iT98
Sunny

~

I

I

I

Page 1 of 3

IN/A!Age
IN/A
!Specifications IN/A
I
Type
!None
!Condition
Comments:
There is no crossing a this steep little gully, rather access to each tower on the other side of gully is
accomplished by using a crossing approximately 2 km downstream of the site and then back tracking along existing roads.

Crossing:

,,.,

48/2
w
w

French Cr. Trib.5
Right Angle

Coastal Western Hemlock
Biogeoclimatic Zone
48/1
to
Tower Numbers {as power flows)
slideslope angles
n 120% s 130% e
:::: : 7 ~ morN/A
n 45 m s 40 m e

1O:OOam - 2:00
3, 1-24, 4,

Stream Name
Orientation of Crossing

Crew IJS, AP
I
Time
General photograph roll ID and #'s

Location
Direction of Flow

Species utilizin
unknown____ _ _ _.......
Comments:
The crossing includes a small stream at the bottom of a relatively short yet very steep gully. The gully is
crossed by one span to span length of the wood pole structures and hardware. As such the line itself does not enter the gully but
rather stretches across it. The riparian vegattaion is composed of bushes and shorter species, except for a band of decidous
trees 1-5 individuals deep, adjacent to the stream. The site is relatively remote and the access road would be predominantly
used by_llunters and logging companies . There are debris jams located at several points along the study area.

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project... .Case Study 4

Treated Section
2459 stemslha
90% red alder, 10% cedar
40% willow sp., 20% huckleberry,
30% salmonberry, 10% salal

16.00

I

Upstream Control Section
1283 stems/ha
40% cedar, 30% hemlock, 30% red alder
20% berry, 40% brackenfern,
2_§"{o willow sp. , 15% salal

l ~~

Upstream Control Section

Page 2 of 3

Downstream Section
14.00 - 23.00
I
118.80

Downstream Section
2166 stems/ha
40% red alder, 30% cedar, 30% hemlock
30% mixed berry,available light near ROW edge
30 willow sp._30% brackenfern, 10% salal

!,.,

Treated Section
Downstream Section
Upstream Control Section
Transect
2
3
4
2
3 Mean
5 Mean
1
2
3 Mean
Bankfull Width {Wb)
4.00
4.00
3.47
4.10
2.80
5.10
4.00
2.70
3.10
4.30
2.50
4.20
3.70
3.62
Mean Depth (d)
0.35
0.42
0.47
0.29
0.17
0.07
0.18
0.37
0.44
0.44
0.44
0.52
0.43
0.40
D60 (D)
0.10
0.16
0.17
0.12 ; . 0.13
0.12
0.10
0.14
0.42
0.22
0.21
0.18
0.16
0.16
Gradient(%)
1
5
6
4.10
5.17
5
10
4
6.33
3.5
5
5
5.5
5
D/Wb
0.03
0.03
0.04
0.13
0.07
0.07
0.04
0.04
0.07
0.04
0.04
0.06
0.01
0.04
D/d
0.29
0.27
0.29
0.36
0.41
0.76
6.00
1.26
0.34
0.49
0.36
0.41
0.36
0.31
(D/d)(D/Wb)
0 .0071 0.0086 0.0100 0.0331 0.0135 0.0131 0.0295 0.0139 0.0133 0.0481 0.0293 0.0464
0.0824
0.0558
Stream Type
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
RPc
Importance of LWD Controlled
Controlled
Controlled
..... : ~ -:: . ·... : ~
:·. ,~· 1§_p_ercent •'' · . · _.· · ·: : :: ~ ~ : ~ 0 percent"·: : ·: ·: : : 7 ~ ~~ ·~· : :.' -- •· . ; ; ...! . ....
Reach Disturbance 30 percent

Riparian Ecosystem Function 3 - Bank Stability:

Vegetation Density
Vegetation Diversity
Understory

Riparian Ecosystem 2- Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
13.00 - 19.50
Light (mean PPFD)(micro mols)
24.00

Riparian Research Project. ... Case Study 4

~

Treated Section
None
N/A
N/A
N/A
N/A
______

36

Control Section
None
N/A
N/A
N/A
N/A
N/A
L___

~~ ~

Page 3 of 3

.,,

J

Downstream Section
None
N/A
N/A
N/A
N/A
N/A

' ,. ,

Downstream Section
53 percent poooll 47 percent riffle

Vegetation Management:
Observations:
The vegetation along the ROW, except for the riparian gully has been managed aggressively. The right bank,
above the gully has numerous conifers and seems to be either a Christmas tree farm or managed wood lot. The left side
of the gully has been managed more extensively and there is very few tall growing stems. The gully has bee slashed
and managed except for a stretch of trees adjacent to the stream. This combined with the noticeable presence of tall trees, except
for the strip next to the stream , suggests slashing and treating has been accomplished to the 10m pesticide free zone. ;.
This has resulted in a very dense layer of berry {salmonberry) plants and other mixed shrub layer. There is a dense and
diverse tall growing deciduous strip through the Righofway but a noticeable lack of opportunity for conifer recruitment.
The clearances at this site seem to suggest conifers could be topped ever 10 to 20 years and not effect line safety.

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Wjndthrow

Riparian Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
ercent riffle
Total Beach Length{Thalweg)
Volume of LWD {Pieces/m stream)

Riparian Research Project.. .. Case Study 4

I

22

~

7:12

36019.5

36020.5
Date/Time

36021

9:36

12:00

Case 4, August 13, 1998

36020

14:24

36021 .5

16:48

~
~

36022

'

.
..t.

36022.5

19:12

I

A

.. -u-

36023

..,

21 :36

'

•

.. _lilt

0:00

Upstream

• Righofway

+ downstream

18.00

1-

10.00
0:00

12.00

14.00

§ 16.00

c.

Cll

Time of Day
~

Downstream

• Righofway

4:48

36019

*

..

•

+ Upstream

2:24

36018.5

• ...
u

•• •

• •

• ••
~~
•
• ....
.. .. ~ ii(it-=FJ·
.
•
•
-=
.
.
u
"'
•
0 Q
~
•

•

~

22 .00

24 .00

26.00

.a.

~·

~

10
36018

12

14

•

• • •

...

....

~ 20.00

Cll

...

~

E 16

c.

:D 18

(II

...~ 20

Cll

24

26

CASE 4, Agust 11-16,1998

vuly 21/98
Sunny, hot

I

Location
1

[ 10:30 - 2:30-l
[4, 1-24

Stream Name INoons Creek
Orientation of Crossing
Right angle

Crew [JS, JM
[
Time
General photograph roiiiD and #'s

1

1 . - r -· .. - - · · · - - - . · - · - - - · - - . , - · .. - · .. - · - · 1

Page 1 of 3

[Goodu
IAQe
IN/A
!Specifications [3 of 1.0 m
I
Type
!Culverts (3) ·- · u!Condition
Comments:
The culverts are located at the downstream edge of the ROW. They pass under the gated Rightofway
access road . It is heavily used by recreation enthusiasts and in good condition .

Crossing:

,,.,

!Coastal Western Hemlock
I Lower Mainland I
Biogeoclimatic Zone
N/A
to
N/A
Tower Numbers (as power flows)
I5L45
I
165m Istream segment length [65 m
[
slideslope angles In
s
e 5% w5%
e 10m w 10m
s
ulated from nearest stream bankfull width to top of Qully (morN/A)
In
upstream
I Dormant (hill above development)
vatershed land use
!The watershed is predominantly used for residential development
;t tower to nearest stream bank full width
LEFT 142m
RIGHT
I
..........................
Sp_ecies utilizing stream !Yes, unknown
I Yes
I
I
Comments:
This site is located at Noons Creek above Westwood Plateau, near Meridian Substation, in Coquitlam B.C..
The site involves a narrow Righofway and single steel238 kv circuit. There is a large debris jam at the upstream edge of the ROW.
The stream has a fairly high gradient, however the site is not located in a gully, rather it flows down the is of the mountairn.There is a well used Rightofway access at the downstream edge of the Rightofway. There are 3, 1 m diameter culverts
which pass under the road . The downstream section of the case study site is significantly higher gradient. A large barrier (falls) is
located 67 m downstream of the Righofway. The upstream section is composed of large conifers which appear t()be >_1_0Q_yr. old .

Site Description:

Date
Weather

I

I #D

General Information:

Case Number

Riparian Research Project....Case Study #5

~

I

-

- - - --- ---

-------

---

Upstream Control Section
1,283 stems/ha (conifer)
90% conifer (tall),60-100 yrs old.,10% decidous
!(red alder and cottonwood) at edQe of ROW's
Minimal shrub .

~~~ ~ 17.5

Upstream Control Section

----

. .. .

I

: •,•

Page 2 of 3

~~~~ -17.5

I

Downstream Section

''

,.

Mean
6.70
0.51
0.20
7.75
0.08
0.03
0.0022:
APe

Downstream Section
356 stems/ha (decidous)
5% cottownwood, 5% hemlock, 90% red alder.
the alder are of uniform heiQht and spacinQ
Sparse of brackenfern, few salmonberries.

Treated Section
Upstream Control Section
Downstream Section
Transect
2
3
4 Mean
1
2
3 Mean
4
2
3
Bankfull Width (Wb)
3.70
3.85
3.80
3.90
4.00
2.40
2.10
3.40
2.63
5.70
6.60
8.60
5.90
Mean Depth (d)
0.40
0.68
0.66
0.50
0.56
0.49
0.46
0.52
0.35
0.70
0.36
0.45
0.67
D60 (D)
0.19
0.23
0.22
0.16
0.20
0.16
0.12
0.14
0.14
0.17
0.24 ~ 0.17
0.21
Gradient(%)
4
3
8
8
5.75
4.00
2.5
3.17
11
3.00
7.00
10.00
3.00
DfWb
0.05
0.06
0.06
0.04
0.05
0.08
0.04
0.12
0.04
0.19
0.08
0.07
0.06
Did
0.48
0.34
0.37
0.02
0.04
0.33
0.32
0.07
0.06
0.04
0.05
0.03
0.04
(D/d)(DfWb}
0.0244 0.0205 0.0188 0.0128 0.0190 0.0044 0.0033 0.0017 0.0100 0.0024 0.0029 0.0008
0.0042
Stream Type
APe
APe
RPc-g
APe
CP-RPc
APe
APe
APe
APe
APe
APe
APe
RPQ
Importance of LWD controlled
controlled
controlled
. ·'
~
l ·~
~~~ :· ~ ~··~ : ~··: • 0 perc·ent ~ ~ · ·
100 (:lercent ~ ::>> .·. ;> \t!··· · . .•.·
Reach Disturbance 85 percent ·

Riparian Ecosystem Function 3 - Bank Stability:

Treated Section
Vegetation Density 23,565 stemslha (deciduous}
Vegetation Diversity 5% other, 5% cottonwood, 20% willow species,
70% red alder.
Understory
~~l
45% huckleberry, 50% salmonberry.

Riparian Ecosystem 2- Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
17.0-18.0
I
Light (mean PPFD)
129.00

Riparian Research Project....Case Study #5

~

~

~

~

~

20.00

....

2:24

., ...

-

T'

7-26-98
12:00 PM

-----------

14.00
0:00

c.
E
~ 16.00

Cl)

~

z

~

7-26-98
12:00AM

16 -1

18

l!! 18.00

~

E

c.

~Cl)

~

Cl)

.. ..
;&,

4:48

7-27-98
12:00 AM

~

.,..;
~

7:12

7-28-98
12:00AM

9:36

7-28-98
12:00 PM

~

-

7-29-98
12:00AM

~

Time of Day

12:00

14:24

16:48

...

7-29-98
12:00 PM

~~

.....~
....

Case 5, July 29, 1998

Date and Time

...................,

.....

7-27-98
12:00 PM

>

A

. - a - D -H --A-· - ±

. ..

~·

T

19:12

7-30-98
12:00AM

21:36

,.,.,.,.,

7-30-98
12:00 PM

~

0:00

~

7-31-98
12:00AM

~

20.----------------------------------------------------------------------------------.

Case 5, July 26-31, 1998

+ Upstream

Downstream

• ROW

+ Upstream

Downstream

• ROW

I

#6

Psuly 22198
]unny, very hot

I

I

I

: ~
u

~

I

General photograph roiiiD and #'s

Crew

Time

Location
·--- ··----·-..
· -·--·····-r·-·
.. - 3 -- - ·- ·
1--..
I
Direction of Flow

11 o:ooam-3:oopm __ __j
14, 1-24,5, 1-24

, Stream Name

ml

Crossing:

Page 1 of 3

.,.,

!Coastal Western Hemlock
I Lower Mainland I
Biogeoclimatic Zone
141/3
141/2
to
Tower Numbers (as power flows)
ISL82
I
w
slideslope
l ~ n 10% s 15% e
I
!Stream segment length 1175 m
w
ulated from nearest stream bankfull width to top of gully (morN/A)
In 15m s 15m e
upstream
I None
vatershed land use
IResearch into forestry and logging practices
tower to nearest stream bank full width
RIGHT
LEFT 156m
I
I Yes
Species utilizing stream !Yes, Unknown
I
I
Comments:
The site. involves a wide Righofway, single steel 500 kv circuit and a salmonid stream which meanders between towers in a
zigzag manner, but crosses at about 45 degrees. The stream flows out of the UBC research forest hills and then meanders through the bottom of
forest across the case site . There is a large rock, and step falls in the latter end of the ROW, however it does not consti!l,Jte a reach break.
The stream passes under a very large bridge located at the downstream edge of the Righofway. The stream does not appear to be affected by the
large bridge.The site is very remote, with a very overgrown access raod . A large debris jam is loacted at the suptream edge of the rightofway.
Through the Rightofway, there is no riparian strip of tall trees, rather dense understorry growth. All functioning LWD is old grow1h conifer.

Site Pescrlption:

Date
Weather

General Information:

Case Number

Riparian Research Project.. .. Case Study #6

!
I

Treated Section
6,833 stems/ha (Tall growing)
20% maple/cottonwood, 10% hemlock
20% Fir, 10% cedar, 40% red alder
20% red elderberry, 20% willow,
20% mixed berries, 40% salmon berry

(D/d)(DfiNb)
Stream Type
Importance of LWD
Reach Disturbance

Did

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 (D)
Gradient(%)
DfiNb

~

Dense in pockets, 40% red elderberry, 30 salal,
10% thimble berry, 10% huckleberyy, !0% mixed

Upstream Control Section
1875 stems/ha
10% cottonwood, 40% alder, 50% conifer.

Upstream Control Section
17.75-22.0
I
111 .50

Very dense understory, 5% brackenfern,
5% thimble berry, 90% salmonberry.

Downstream Section
3,996 stems/ha
5% cottonwood, 80% red alder, 15% cedar

Downstream Section
17.0 _ 21 .75
I
144.50

Page 2 of 3

.,.,

Treated Section
Upstream Control Section
Downstream Section
2
3
4 Mean
2
3
4
2
3
4
5 Mean
5 Mean
4.10
5.80
3.50
4.75
4.20
5.00
2.90
3.60
3.90
3.90
5.70
4.00
5.20
5.30
4.50
4.64
4.00
0.52
0.60
0.35
0.46
0.55
0.46
0.63
0.59
0.57
0.55
0.09
0.18
0.47
0.49
0.40
0.47
0.50
0.14
0.17
0.12
0.08
0.11
0.33 :. 0.18
0.14
0.12
0.14
0.18
0.14
0.20
0.18
0.18
0.61
0.51
3.00
2.00
2.00
2.38
0
4.00
1.00
3.00
4.00
2.40
2.3
3
1
1
2.06
2.5
3
0.01
0.03
0.07
0.05
0.04
0.05
0.13
0.11
0.03
0.04
0.04
0.04
0.04
0.02
0.04
0.03
0.04
0.18
0.94
3.39
0.15
0.39
0.33
0.30
0.41
0.45
0.37
0.37
0.24
0.25
0.22
0.24
0.21
5 .67
0.0153 0.0058 0.0107 0.0092 0.0065 0.0089 0 .7225 0.3627 0.0021 0.0058 0.0650 0.0176 0.0140 0.0080 0.0154 0.0180 0.0141
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
controlled
controlled
controlled
..
·.: . ~~ :: :
.' ·
·:-;: 46 p'e"rC.ent ~ ~~ ~~~ ;~~· ~ ::~ : ~~~ · ~ ~ ~~ · :: ~~: ~7 : ..:··7~~
..... ~~ · ~ ~~~. : ~~ > : '..: : .': ::;<:'. 31
~ · ·. • · ·.'
0 percent ·

Riparian Ecosystem Function 3 - Bank Stability;

Understory

Vegetation Density
Vegetation Diversity

Riparian Ecosystem 2- Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
17.5-22.25
I
Light (mean PPFD)
140.13

Riparian Research Project .. .. Case Study 1/G

I

I

I

I

I

I

N/A
N/A
N/A
N/A
N/A

Treated Section
None

N/A
N/A
N/A
N/A
N/A

Upstream Control Section
None

Upstream Control Section
ercent riffle

Page 3 of 3

Downstream Section

.,,

Downstream Section
Yes
Youna trees bent over, roots intact
red alder
Over and in stream
@2.5 oercent
Photo 3

Veaetatlon Manaaement:
Observations:
Very dense vegetation in ROW area, has been slashed recently. The ROW crossing appears to have
been managed within the last 2 years. This is suggested by the fact all tall trees species have been slashed and lie horizontal on
the ground. The usptream community is composed of mature second growth forest in a braod gully, the
Righofway is composed of low growing species in high densities, the Downstream section is mature and composed of mixed
conifer and deciduus species.

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Windthrow

Riparian Ecosystem Function 4 - Habitat Complexity
Treated Section
Distribution of habitat
ercent riffle
Total Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Research Project.. .. Case Study #6

~

1-

----

:~

~~

~

~

-

~ ~· . ~ . ~

- -fl-

Case 6, July 29, 1998

7-30-9812:00 AM

17 _,__________

~

~

4:48

~

2:24

T-------

0:00

16

~

7:12

~

:::

9:36

~

~::~

12:00

~

Time of Day

~

~

~

16:48

~

14:24

19:12

~

21:36

0:00

----=l

j

7-31 -98 12:00 AM

-----------1

-

-----

r -----n---

- o----------· -{}--

7-29-98 12:00 AM

..

Date and Time

7-28-98 12:00 AM

~

~ _ _.__n__________

7-27-98 12:00 AM

~

__ ,. __i!l ___ - - - - ---'=--_9-

~~~

~~ -----------22 -'-----------·----------..aar '1144i .1m,;- - - 21 -·- - - - -- - - - - - -- - - - - - - - - - - - - - - - - - - - -

~ 18 ~

Q.

Ill

~

~~

16

~:

19

~ ~~~~~

7-26-98 12:00 AM

.a 2.o

Ill

.

1-

Ill

c.
E

Ill

~

....::l

:

Case 6, July 26-1,1998

Downstream

-----

• Rightofway

+ Upstream~

------

Downstream

• Rightofway

[

-

+ Upstream

C#7:J

'July 23/98
~
Sunny, very hot

I

I

1

-

1

I

]11 :00 -14:00
]1, 1-24

-l

1 Stream Name
Orientation of Crossing

- - · · - , . · - · -.. - - . _ , _ - - ·. . . . . _ .. __

Crew IJS, JM
--]
Time
General photograph roll ID and #'s

Location
1
Direction of Flow

--)

Crossing:

None

Condition

N/A

Page 1 of 3

N/A

Comments:
This site is located in the middle of Surrey, B.C. and is composed of a tributary of Bear Creek, in a gentle
gully, and crosses at right angles to the double steal structure, 500 kV transmission circuit. There is no debris jam or roac;! .crossing.
'
Residential development stops well back from the gully which runs along the stream. Instead the gully is occupied
by large lots and hobby farms. Bear Creek is a quality Lower mainland salmon stream. Bear Creek is wide and displays
a large deep run before entering the ROW, where it breaks into 2 channels, before returning to 1 channel near the end of ROW.

' \'

Region of BC
rcoastal Western Hemlock
Biogeoclimatic Zone
to
Transmission Line ld
Tower Numbers (as power flows)
e35% w20%
Width of rightofway
I130m I Stream segment length 1140 m
Sideslope angles In
s
[n
e20 m w 14m
s
Vertical distance calculated from nearest stream1 bankfull width to too of oullv (morN/A)
Landuse immediately upstream
!Residential development,2 km upstream fo the site
Predominant type of watershed land use
I Residential development
RIGHT 68 m .
Distance from closest tower to nearest stream b mk full width
LEFT I
I
Fish Present
!Yes
I
Species
!Co, Cm, Rbt, Cit
I

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project....Case Study #7

I

~

'

I

Upstream Control Section
2,005 stemslha
10% cottonwood, 10% maple, 80% red alder.
10% hardhack, 40% willow species,
50% mixed berry (salmon, red elderberry, thimble) .

~~~~

Upstream Control Section

Page 2 of 3

~~~~

I

Downstream Section

Downstream Section
1,848 stemslha
40% conifer (cedar, douglas fir) , 60% deciduous
20% cottonwood, 30% alder, 50% maple).
20% mixed berries, 20% willow species ,
50% Hardhack

,,

Downstream Section
Treated Section
Upstream Control Section
Transect
2
3
4 Mean
2
3
4
5 Mean
1
2 Mean
Bankfull Width (Wb)
9.35
8.50
7.50
3.50
7.00
4.00
9.75
11.40
10.00
8.00
5.50
5.60
9.50
10.00
Mean Depth (d)
0.52
0.45
0.51
;· 0.48
0.60
0.51
0.43
0.33
0.45
0.53
0.30
0.42
0.50
0.51
D60 (D)
0.14
0.10
0.10
0.09
0.08
0.07
0.09
0.07
0.08
0.07
0.10
0.08
0.09
0.05
Gradient(%)
1.00
3.00
0.50
0.50
2.50
1.50
0.50
0.50
0.50
1
0.50
0.75
0.5
0.00
DNJb
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0.01
0.01
D/d
0.27
0.19
0.17
0.20
0.18
0.16
0.10
0.16
0.24
0.17
0.27 0.2169
0.16
0.19
(D/d)(DNJb)
0.0031 0.0007 0.0020 0.0021 0.0048 0.0024 0.0020 0.0021 0.0020 0.0011 0.0038 0.0020 0.0022 0.0022
Stream Type
RPg
RP_g_
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
RPQ
RPg
RPg
Importance of LWD controlled
controlled
controlled
. ·.:
. ·. ~ :-=: ~
:··::·.'-: ·
:~~:·
'···. .. . - 0 percent _,, ... · ... ··.. ·:·.·-'·· 0 percent · · · ·
·:
:? ~· ·
'.
Reach Disturbance 42percent

.

Treated Section
149 stemslha (con), 1,848 stemslha (decid)
90% red alder, 10% young cedar
25% red elderberry, 30% hardhack,
20% salmonberry, 10% thimbleberry, 15% willow

Riparian Ecosystem Function 3 - Bank Stability:

Vegetation Density
Vegetation Diversity
Understory

Riparian Ecosystem 2 - Stream Hydrology;

~~~~

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
Light (mean PPFD)

Riparian Research Project....Case Study #7

!

None
N/A
N/A
N/A
N/A
N/A

Treated Section

ercent riffle

None
N/A
N/A
N/A
N/A
N/A

Upstream Control Section

Upstream Control Section

Page 3 of 3

'\ \

None
N/A
N/A
N/A
N/A
N/A

Downstream Section

Downstream Section

Vegetation Management:
Observations:
The Rightofway has been managed very aggressively and there is berry little evidence of tall growing species
except in the gully where Bear Creek crosses the Righolway. This area is very moist and has dense skunk cabbage pockets.
The Rightolway crossing site appears not to have been managed for over 10 years. the site is dominated by tall mature alders .
The process for the site appears to involve waiting for the trees to mature and pose a line hazard, then coming in and removing
them, like a small logging operation. The site is currently in the second of a 3 year plan to cut or top all tall growing trees. :.
During 1997 a mis-communication resulted in almost all vegetation being removed on the left bank. Both banks are
suffering from significant lateral erosion, however the right bank, now devoid of tall vegetation appears to be moving more
quickly. The site morphology also changes significantly though the site with energy being expended on eroding laterally
as a result a large gravel bar has been deposited on the most upstream edge of the Righofway crossing.

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Windthrow

Riparian Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
Total Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Research Project... .Case Study #7

l

a.

~

....

E

12:00AM

16.00

36003

•

••

36005
Date and Time

.....

Downstream Case 7, July 28, 1998

36004

....

2:24AM

4:48AM

~

7:12AM

9:36AM

Time of Day

12:00 PM

2:24PM

~

.....

~

36006

•
T

•
•

.. ~~~~~ ~
36007

4:48PM

7:12PM

~

36008

9:36PM

~

12:00 AM

~

..........
. . . . . . . . . . . . . . . . . . . . . . . .. . .

.....
..........
. ............. ·····················~

•

.
.
.
.
• •-~~•
~ :~:

~

20.00 .

22.00

36002

~

16.00 -l-

Q3 18.00 .

(Q

~

...

...:::J

~

.... 18.00

e~

~I!!

~
•

22.00.-----------------------------------------------------------------------------------------------.

. . ••. ••

Downstream, Case 7, July 26-Aug 01, 1998

I #8 I

'August 8/98 - ~
Sunny and warm

I

Location

I

I

Crew
~
I
Time
General photograph roll ID and #'s
l10:30am-

Iroll 1, 1-37

:

Hwy 17

~

I

Crossing:

None

Page 1 of 3

Condition
NIA
While no formal crossing is present the stream could be forded at low flow.

N/A

'"

[Northern Interior[
[Sub-Boreal Spruce
Biogeoclimatic Zone
to
43 I 1
42 I 5
Tower Numbers (as power flows)
I 5L61
I
e 40% w10%
s
1100 m !Stream segment length
334m
sideslope angles In
e 28m w 15m
s
Jlated from nearest stream bankfull width to top of gully (morN/A)
In
upstream
!Spot was selectively logged within 30yrs, no other intrusions (roads, etc.)
vatershed land use
[Farming and logging
LEFT [28m I
RIGHT
tower to nearest stream bank full width
[Yes
Species utilizing stream !unknown
I
I
Comments:
This site is complex, involving a creek meandering through a wide, single steel structure, 500 kV circuit Righofway,
morphologically complex gully with a right bank which is steep (sheer in some places) but more gentle left bank. There is no crossing ,
the creek crosses the Rightofway at@ 450 angle. In many places the banks of the gully are composed of highly erodible ;sand
deposits, , where it is impossible for vegetation to become established. As a result in many places the stream has degraded
to bedrock. In still other aggradation has occurred leading to large sediment bars. While ATV tracks were seen around the site
it is fairly remote along a rugged 4*4 road, and would be visited by hunters, and farmers only. There is no debris jam upstream of the ROW
Being fairly deep in a gully there is no riparian leave strip, rather the entire riparian area is fairly heavily vegetated with a mix of species.

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project. ...Case Study #8

Treated Section
23,565 stems/ha
10% red alder, 10% birch , 30% cottonwood,
40% spruce .
10% salal, 10% mixed berries, 80% willow
Upstream Control Section
6,833 stems/ha
10% cottonwood, 10% aider, 10% birch ,
70% spruce .
20% mixed berries, 80% willow species .

Upstream Control Section
12.25-21.75
153.36

I

Downstream Section
943 stems/ha
10% cottonwood, 10% red alder, 20% birch,
60% spruce.
5% cow parsley, 45% mixed berries , 50% willow

~~~~

Downstream Section

Page 2 of 3

.,,

Treated Section
Upstream Control Section
Downstream Section
Transect
2
3
4 Mean
2
3
4 Mean
3
4
5 Mean
2
Bankfull Width (Wb)
7.50
7.70
5.90
8.60
9.42
9.20
10.80
8.00
8.90
9.23
10.80
6.20
10.00 10.20
9.90
7.43
Mean Depth (d)
0.65
0.88
0.69
0.85
0.74
0.73
0.71
0.73
0.73
0.65
0.86
0.76
0.80
0.65
0.55
0.61
D60 (D)
0.14
0.19
0.14
0.20
0.17
0.14
0.18
0.20 :· 0.20
0.21
0.15
0.19
0.13
0.13
0.15
0.17
Gradient (%)
1
1
2
1
1.25
1.50
0.5
0.50
0.25
1.00
0.56
0.5
2.00
1.50
1.00
2.50
DN/b
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.01
0.02
0.02
0.02
0.02
0.02
0.02
0.03
0.02
D/d
0.22
0.22
0.20
0.28
0.23
0.16
0.24
0.17
0.18
0.31
0.36
0.29
0.28
0.21 0.2886
0.15
(D/d)(DN/b)
0.0040 0.0053 0.0048 0.0066 0.0052 0.0025 0.0041 0.0025 0.0025
0.00 0.0057 0.0117 0.0060 0.0046 0.0031 0.0060
Stream Type
APg
APg
APg
RPg
APg
APe
APe
APe
APe
APe
APe
APe
APe
APe
APe
APe
Importance of LWD Controlled
Controlled
Controlled
.. ..
~~:~ ·· ~ · · ~ ~~~ ~
·.Y ·
.. . .
48 percen(:;;;;:: · ~~ ~ ·· __.., ,;,. · · · . : · ~· ~:·:
Reach Disturbance
63 percent
~ :l· : ~ · i \1;· , _:_ __ ~

Riparian Ecosystem Function 3 - Bank Stability:

Understory

Vegetation Density
Vegetation Diversity

Riparian Ecosystem 2- Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
12.25 - 24.25
Light (mean PPFD)
284.73

Riparian Research Project... .Case Study #8

N/A
N/A
N/A
N/A

Treated Section
None

N/A
N/A
N/A
N/A

Upstream Control Section
None

Page 3 of 3

·n

N/A
N/A
N/A
N/A

.,.j

Downstream Section
None

~~~~

Downstream Section

Vegetation Management:
Observations:
The non riparian sections of the Righofway, up to the edge of the gully, appear to have been managed
aggressively, either through mowing or mowing and herbicide application. From the top of the gully on either bank it appears that
the management strategy has been slashing vegetation as it becomes a problem . While the right bank provides little habitat for
vegetation, due to the screef slope, the left bank provides ideal growing conditions .. The vegetation community shows significant
diversity, with both tall growing coniferous vegetation and deciduous species present. The left bank also appears appears to be
a part of a farmers' operation, which may prohibit routine cutting of trees. Upstream of the site it appears that selective removal
has occurred within the last 30 years. However significant riparian community is still present along the shallow valley, through
which the passes There are many pieces of large functioning LWD in the upstream reach, but it is much less common
later in the stream. There is no potential LWD sources in the treated section .

Present
Type
Species
Distance From Stream
% riparian zone vegetation

Wjndthrow

Rioarjan Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
ercent riffle
Total Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Research Project....Case Study #8

I

22

24

26

~c. 18

~ 20

2:24

•• ••

--------------------

10
0:00

12

14

~ 16

E

-• • ••

10
36016

12

c. 16
E
Cll
~ 14

...Cll:J 20
iQ 18
...Cll

22

24

.•

...

•

7:12

36018

9:36

• • ••

•

14:24

• •
••

16:48

36020

iii

•

'•
36021

19:12

•

••

------------- --------------- ----

Time of Day

12:00

Case 8, August 13, 1998

Date and Time

36019

•
~

'
•--..--'

.

4:48

36017

• ll

-

• II

Case 8, August 9-14, 1998

21:36

.'

0:00

36022

I

•• '=

I

I

INorth East

~

I

I

111:00 am ·2:30pm
··
· · · ·· ·

Stream Name ISweden Creek
1
Orientation of Crossing
·- aegrees
·
4!:>

Crew
~
Time
General photograph roll ID and #'s

· -·

Page 1 of 3

Crossing:
Type
.-IF-o-rd_(_b-rid_g_e_)---.I condition
]Very Poor
]Age
]U/A
]Specifications 17-m-wide by 7m long
Comments:
At the downstream edge of the Righofway a relatively new wood bridge, without timber cribbing,
has been eroded and washed, resulting in a ford crossing. It appears a local farmer has used machinery to improve the ford.
However this also exposed significant soils and continues to introduce significant volumes of fine grained sediments to the
stream,. Fine sediments are very visible downstream of the crossing but not upstream. Much of the downstream substrate has
been covered by a film of fine sediment. Thje right bank is much worse (more exposed soils) than the left.

I

""

Biogeoclimatic Zone
!Sub-Boreal Spruce
LNorthern Interior!
19/1
I5L61
J
Tower Numbers (as power flows)
18/5
to
e10% w6%
11 OOm I Stream segment length 1160 m
sideslope angles
s
In
lated from nearest stream bankfull width to top_ of gully(m or N/A)
e40 m w45m
s
In
;pstream
I Dormant
atershed land use
!Agricultural, logging
tower to nearest stream bank full width
RIGHT 65 m
LEFT I
I
Species utilizinQ stream I unknown
- .IYes
I
I
Comments:
This site is composed of wide, single steel structure, 500 kV circuit Righofway, which passes across
a small stream which traverses the bottom of very large and broad but gentle gully. Rather the stream transects the rolling hills
on which the transmission facility is built. There is no riparian leave strip and no debris jam at the uspttream ede of the ROW. The stream
crosses approximately a 45 degree angle to the ROW with minimal meandering. The Righofway site is composed predominantly of red alder
clumps, mixed shrub species and grasses. The old, out of commission crossing {discussed below) contributes significant line
sediments to the stream and may reduce the quality of downstream habitat. There is significant SWD downstream of the site
There is no tall growing riparian vegetation leave strip, rather only young small trees, which provide no cover to the shallow stream.

Site Description:

I

,-#0

General Information:
fAuQ.-7198
Date
Weather Sunny, warm

Case Number

Riparian Research Project....Case Study #9

Treated Section
204,073 stemslha (short (young) decidous stems)
25% total: 40% cottonwood,
50% aspen, 10% spruce
75% of total: 40% red alder, 30%mixed berries,
30% Will\ow
~

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 (D)
Gradient (%)
D/Wb
D/d
(D/d)(D/Wb)
Stream Type
Importance of LWD
Reach Disturbance

Treated Section
2
3 Mean
. 2.90
5.70
5.80
4.80
0.60
0.62
0.66
0.63
0.20
0.20
0.20
0.19
1.00
1.00
1.50
1.17
0.04
0.03
0.07
0.05
0.30
0.31
0.33
0.31
0.0117 0.0100 0.0209
O.Q1
APe
APe
APe
APe
Controlled
29 percent'/" : :>· : ~ ~ ~l
~

Riparian Ecosystem Function 3 - Bank Stability:

Understory

Vegetation Density
Vegetation Diversity

Riparian Ecosystem 2- Stream Hydrology:

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
11.50- 21 .00
Light (mean PPFD(micro mols)
69.50

Page 2 of 3

Upstream Control Section
1
2
3 Mean
3.50
4.40
3.50
3.80j
0.58
0.62
0.60!
0.60
0.16
0.17
0.17
0.18
1.00
1
0.50
1.50
0.05
0.05
0.05
0.05
0.30
0.30
0.30
0.30
0.02
0.0154
0.02
0.02
APe
APe
APe
APe
Controlled
·.. ·.....
25 percent : ·
· : : ~ ~ :l ~

Upstream Control Section
28,512 stems/ha (deciduous) , 2,183 (coniferous)
60% of total: of that: 20% spruce, 20%
cottonwood, 60% birch.
40% of total, of that: 20% mixed berries,
30% willow, 60% red alder.

Upstream Control Section
12.00 - 20.50
51.33

Riparian Research Project.. .. Case Study #9

'.,

Downstream Section
4 Mean
1
2
3
3.50
3.40
3.45
3.70
3.20
0.53
0.51
0.51
0.46
0.52
0.16
0.18
0.12
0.16
0.17
0.88
1.00
1.50
0.00
1
0.04
0.05
0.04
0.05
0.05
0.31
0.23
0.37
0.35
0.31
0.01
0.0136 0.0196 0.0178 0.0080
APe
APe
APe
APe
APe
Controlled
:~ : ~ ~~ l
·35;percentr..tr.< : ~~~:~· :: :·l~~~

Downstream Section
8,019 stemslha (coniferous and decidous)
5% birch, 15% aspen, 20% cottonwood,
60% spruce.
10% mixed shrubs, 10% salal berries, 20% mixed
berries, 20% red <!lder, 30% willow species.

Downstream Section
11 .50-19.50
I
134.33

Treated Section
None
None
None
None
None
None

~·

·· ~

Upstream Control Section
None
None
None
None
None
None

0.06 'f;; ·

Upstream Control Section

!

0.12 : ~

Downstream Section
None
None
None
None
None
None

~ :~ >:: _
:

Downstream Section

Page 3 of 3

·n

Vegetation Management:
Observations:
It appears that vegetation has been slashed and mowed. The sides of the creek have been ~
aggressively.
There is minimal overhang for the stream, mostly grasses and very few individuals form tall species around the stream. The· upstream
section is not densely vegetated (a 2nd growth forest), appears as though selective logging may have occurred within the last 30 years.
The downstream section very densely covered by spruce forest. It appears the land has been largely left undisturbed for a
significant period of time. The vegetation managemnt at the site has resulted in multiple coppice red alder bushes and aspen
stands (both sinqle and multiple coppice) , quite heavy in some spots persisit throughout the broad gully at the site.
·

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Windthrow

Riparian Ecosystem Function 4 - Habitat Complexity
Treated Section
Distribution of habitat (m)
Total Reach Length(Thalweg)
0.08 .; .-,_.. .
Volume of LWD (Pieceslm stream)

Riparian Research Project....Case Study #9

t--

~~

20

22

24 -

:; 18 -

~ ..

2:24

4:48

J==--=-===--=====

0:00

8

10

~ ••

-

- ------- - - -- -

1-

12

~~~
~ 14 - -

10
-t 16 . - -

Q.

~

8 1 - - - - - - - -··- - - ----"- 36017
36018

10

12

~

------.

- -

· ~

1-

~ 14

tQ. 16

cu

...~ 18

20

22

24

•

-

-

7:12

36019

I)

-0-

~

•

9:36

!
•"'
t-

36020

....

Time of Day

12:00

~

14:24

~

16:48

36021

·

-

~

.

•

·----1

---------------.~·
,., o

~

Date and Time

u

Case 9, August 13, 1998

~

0

_ _ _ __ _ ____j_ __ _ _

1.-"

"
•

....

Case 9, August 10-15, 1998

~

"'

<

- - --

...

.a.

21 :36

0:00

,_ ..

36023

~~ : ~

36022

19:12

..

--

+ Upstream

Rightofway

L Downstream

:+
Upotre:J
i•

, · • Rightofway
Downstream

,-run

~
Cloudy, very warm

I

I

Crew IJS, JM
Time
General photograph roiiiD and #'s
114:30- 18:30-1
1, 1-24

,----· -· ____ .._. -·-·· _.. ---·-·-·. ·--- , Stream Name
1
• ·
I . -Orientation of Crossing
45 degrees

Comments:
by cattle grazing.

Page 1 of 3

Condition
IGood
IAae
IU/A
ISoecifications IU/A
The timber bridge, without cribbing, is located on the downstream edge of ROW and has been disturbed

!\ .,

!Central Interior I
I Suboreal Spruce
Biogeoclimatic Zone
244/1
to
244/2
I5L11t12
Tower
Numbers
(as
power
flows)
I
w
1300 m I Stream segment length 1314 m I
sideslope angles
In 10% s20% e
w
e
;lated from nearest stream bankfull width to top of gully (morN/A)
InN/A s N/A
upstream
I Dormant
vatershed land use
!Grazing (cattle)
RIGHT 38m ·
tower to nearest stream bank full width
LEFT I
I
IYes
Species utilizing stream Junknown
- - . --- . ·I
I
Comments:
This site is composed of a small intermittent stream which crosses a very wide Rightofway with
2 steel structure 500 kV's circuits. The stream was dry upon entering, showing predominant gravel, riffle-pool morphology. The
The stream is located in a fairly deep gully with pole structures on top of the gully on the right and but only 1/2 way up th& gully on the other.
Banks exhibit some significant degradation from free range cattle grazing which is allowed by the farmer on the lower 1/3 of the Righofway.
The farmer has also placed a road crossing on the bottom edge of the Rightofway. These stream sections were not factored into habitat.
calculations. All procedures except for a diagram, and pool-riffle analysis, were completed on August 16/98. The remainder of the
procedural tasks were completed in early fall1999.

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project... .Case Study #10

(D/d)(D/Wb)
Stream Type
Importance of LWD
Reach Disturbance

Did

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 (D)
Gradient (%)
D/Wb

I

~

I

Upstream Control Section
1,708 stems/ha
10% cottonwood, 20% birch , 30% aspen,
40% spruce .
10% brackenfern, 30% mixed berries,
30% cow parsley, 30% red alder.

l~ 7

Upstream Control Section

I

Downstream Section
891 stems/ha
10% cottonwood, 1O%birch, 40% aspen,
40% spruce.
5% brackenfern, 20% red alder, 20% willow
species, 25% mixed berries, 30% cow parsley.

~~~~

Downstream Section

Page 2 of 3

,,.,

Treated Section
Upstream Control Section
Downstream Section
2
3
4
2
3
4
5 Mean
2
3
4
5 Mean
5 Mean
3.60
2.40
3.00
2.80
3.40
2.80
4.00
3.24
3.00
2.30
3.10
4.40
3.36
3.00
3.00
3.00
2.30
2.62
0.50
0.45
0.71
0.49
0.55 :. 0.54
0.59
0.50
0.32
0.47
0 .58
0.49
0.48
0.49
0.40
0.48
0.49
0.55
0.19
0.11
0.19
0.15
0.17
0.17
0.17
0.19
0.15
0.18
0.12
0.13
0 .16
0.14
0.18
0.18
0.19
0.18
2.00
2.00
2.25
2.05
1.50
1.75
2.00
1.75
2.50
1.50
2.00
2.50
2.50
0.50
2.00
1.90
2.00
1.50
0.04
0.07
0.05
0.07
0.00
0.05
0.05
0.04
0 .07
0 .04
0.05
0.06
0.07
0.03
0.05
0.05
0.11
0.06
0.21
0.31 0.3380
0.31
0.38
0.31
0.37
0.48
0.37
0.24
0.34
0.28
0.28 0.2883
0.38
0.39
0.40
0.33
0.0201 0.0214 0.0263 0.0251 0.0104 0.0203 0.0179 0.0420 0.0335 0.0113 0.0131 0.0236 0.0011 0.0125 0.0164 0.0116 0.0184 0.0120
RPg
RPg
RPg
RPg
APg
RPg
RPg
RPg
APg
RPg
RPg
RPg
RPg
RPg
RPg
RPg
APe
RPg
Controlled
Controlled
Controlled
. , :,
... . · None \.', ·.
.., .
·..~ ~ . _. .. ~ ~ · ·::·~~ :.. : ~.._. ~:~ :· ..
~.. ., :... ·:: ~~
: .... :; •:
19 percent .
.. 4percent · .'·f?-: ·:,·· . : ·~ ::
~:

Treated Section
18,042 stems/ha
10% red alder, 10% cottonwood, 20% spruce,
50% aspen.
10% grasses, 10% red alder, 20% willow species,
20% mixed berries, 40% cow parsley.

Riparian Ecosystem Function 3 - Bank Stability:

Understory

Vegetation Density
Vegetation Diversity

Riparian Ecosystem 2 - Stream Hydrology:

~~~~

Rioarlan Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
Light (mean PPFD)(micro mols)

Riparian Research Project. ... Case Study #10

Treated Section
None
N/A
N/A
N/A
N/A
N/A

l

Upstream Control Section
None
N/A
N/A
N/A
N/A
N/A

Page 3 of 3

'\ '\

Vegetation Management:
mowing
Observations:
The vegetation along this Righofway has been managed but it appears this involves slashing ~
at long intervals. The vegetation on the Right bank is mixed and heavily composed of conifers. On the left bank there are very
dense aspen patches, most with multiple coppices. As noted earlier the lower 1/3 of the Rightofway is used for free range cattle
grazing. The riparian community through this section is often limited to a strip of vegetation alone the stream. In the upper section of
the Righofway there is a fairly dense and diverse riparian zone. The upstream section has a mature and well developed
riparian community. The area seems to have been untouched for over 60 to 70 years. The downstream section is young'e.r,
appears to be less than 40 years, and composed of a mixed species, with conifer emerging as dominant individuals.

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll ID and #'s

Wjndthrow

~ ~~

Riparian Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
19.5 percent pool,81 .5 percent riffle
Total Reach Length{Thalweg)
c•:.l
. .. ..·;:'·'·"···.
. ·'-;' · .......
Volume of LWD {Pieceslm stream)

Riparian Research Project....Case Study #10

Downstream Section
None
N/A
N/A
N/A
N/A
N/A

Downstream Section
ercent riffle

I

I

I

f13:3o=1s:oo

lroll2, 15-37

Orientation of Crossing

Crew IJS, JM
]
Time
General photograph roll ID and #'s

Location
Direction of Flow

to
e2%
N/A

1

Crossing:

Culvert

Condition
Good

Page 1 of 3

90cm culvert

Comments:
This site is composed of a 2 pole wood structure and Righofway which passes along the front
of Elephant Ridge on its way to Tumbler Ridge. The stream crossing site is small shallow creek which flows down the hillside
and across the Righofway. No gully is present, rather the site, like the Righotway is a series of low rolling hills. There are
numerous small alders (<2.5 m tall), which , because of the small size of the stream, do provide some overhang and cover.
The site ends at the downstream edge of the Righofway because culverts are present, but then the gradient also increases to
over 25%. There is a debris jam immediately upstream of the Righofway which appears to have occurred during construction .

Region of BC
Biogeoclimatic Zone
LNorthern White Spruce
Transmission Line ld
88/3
Tower Numbers (as power flows)
]
Width of rightofway
160m
!Stream segment length so m
I
sideslope angles In
s
Vertical distance calculated from nearest stream bankfull width to top of gully (m or N/A}
s
In
Landuse immediately upstream
[Logged, 25-50years ago., riJ)arian zone mature
Predominant type of watershed land use
[Logging, however mostly unlogged.
Distance from closest tower to nearest stream ba
LEFT [58m
RIGHT
I
No
I
Species
Fish Present
IN/A
I

I

I #f!J

fAu!ff7t98
Sunny, warm

Site Description:

Date
Weather

General Information:

Case Number

Riparian Research Project....Case Study #11

., '

88/4
w4%
N/A

I

INo name

)

I

Treated Section
Transect
1
2
Bankfull Width (Wb)
3.20
2.90
Mean Depth (d)
0.60
0.42
D60 (D)
0.16
0.11
Gradient (%)
6.00
6.00
D/Wb
0.05
0.04
D/d
0.27
0.27
(D/d)(D/Wb)
O.Q1
0.01
Stream Type
APe
APe
Importance of LWD
Controlled
~
Reach Disturbance
: :~ ~·
: ~ :

~

:

3 Mean
2.70
2.93
0.30
0.44
0.12
0.13
5.00
5.67
0.04
0.04
0.27
0.27
O.Q1
0.01
APe
APe

Page 2 of 3

Treated Section
4,395 stemslha
No tall QrowinQ present.
5% cottonwood, 15% young spruce, 25% willow, 55% red alder.

Riparian Ecosystem Function 3 - Bank Stability:

Vegetation Density
Vegetation Diversity
Understory

RiParian Ecosystem 2- Stream Hydrology:

~~~~

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
Light (mean PPFD)(micro mols)

l~·~

I

Upstream Control Section

~~~

:

: ·

::? ~:

,,.,

~

~

Upstream Control Section
1
2
3 Mean
1.77
2.20
1.40
1.70
0.38
0.39
0.48
0.30
0.13
0.12
0.16 :. 0.12
8.00
5.00
7.33
9.00
0.07
0.08
0.11
0.05
0.25
0.53
0.32
0.37
0.06
0.02
0.03
0.01
APe
APe
APe
CPe
Controlled

Control Section
74,735 stems/ha
60% spruce-(25-30yrs), 40% cottonwood. Sparsely vegetated above gully
5% spruce , 10% Pine, 15% berries, 70% red alder.

Riparian Research Project.... Case Study #11

Treated Section

None
N/A
N/A
N/A
N/A
N/A

None
N/A
N/A
N/A
N/A
N/A

Upstream Control Section

Upstream Control Section
ercent riffle

Page 3 of 3

,,,,

Vegetation Management:
Observations:
This Righofway, including the riparian zone has been heavily managed. The area appears to have been
mowed in some areas but slashed in others. The remaining vegetation's composed of bundles of red alder and miscellaneous
broad leaf shrubs, (predominantly willow species). The area is also part of test site where vegetation is cut at waist height so
winter forage activity by ungulates keep tall growing species under control. The remaining vegetation is well away from tolerance limits.

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roll 10 and #'s

Windthrow

Riparian Ecosystem Function 4- Habitat Complexity
Treated Section
Distribution of habitat
ercent riffle
Total Reach Length(Thalweg)
Volume of LWD (Pieceslm stream)

Riparian Research Project. ... Case Study #11

I

J

I

Location

I

Crew IJS, JM
I
Time
General photograph roiiiD and #'s

l : ~ :
1Roll3, 1-24

Orientation of Crossing

l

IRight Angle

Along Elephant Ridge, 1/2 way between Chetwynd and Tumbler Ridge

Ford

Page 1 of 3

Condition
Good
The ford is not often used; it is heavily vegetated, and contains gravel.

N/A

., .,

Biogeoclimatic Zone
I Northern White Spruce
I
I2L12113
Tower Numbers (as power flows)
85/6
to
85/2
160m
!Stream segment length 172m
sideslope angles
s
eN/A wNIA
In
ulated from nearest stream bankfull width to top of gully (morN/A)
eN/A wN/A
s
In
upstream
IDormant
vatershed land use
I Logging, dormant
it tower to nearest stream bank full width
RIGHT 38m
LEFTJ
J
Species utilizing stream IN/A
!No
.. _. ... ·---··.
I
I
Comments:
This site is composed of a 2 pole wood structure and Righofway which passes along the front
of Elephant Ridge on its way to Tumbler Ridge. The stream crossing site is a small shallow creek which flows down the hillside
and across the Righofway. No gully is present, rather the site, like the Righofway is a series of low rolling hills. There are
numerous small alders (<2.5 m tall) and willows, which do provide some overhang and cover. A beaver has created
a dam which backs up the downstream edge of the ROW. Therefore this site is does not have a downstream section.
There is a debris jam immediately upstream of the Righofway which appears to have occurred during construction.
The vegetation along the Righofway is well away from tolerances and managed for ungulates.

INorth

fAug.T?/98
Sunny, warm

Site Description:

Date
Weather

General Information:

South

I

r-#11

Case Number
Direction of Flow

Riparian Research Project....Case Study #12

I

Transect
Bankfull Width (Wb)
Mean Depth (d)
D60 (D)
Gradient (%)
D/Wb
Did
(D/d)(D/Wb)
Stream Type
Importance of LWD
Reach Disturbance

I

~

· ~:: ·

~ ·~

~

Treated Section
2
3 Mean
0.70
1.00
1.10
1.60
0.27
0.19
0.21
0.18
0.12
0.06
0.09
0.08
4.00
5.50
3.75
4.42
0.17
0.06
0.05
0.09
0.44
0.44
0.44
0.44
0.03
0.02
0.04
0.08
RPg
RPg
RPg
RPg
controlled

Page 2 of 3

Treated Section
no tall trees species,
40% red alder, 40% willow sp., 10% cottonwood, 10% aspen
30% Cow Parsely, 40% mixed berries, 20% grasses, 10% broad leaf shrub

Rioarian Ecosystem Function 3 - Bank Stability:

Vegetation Density
Vegetation Diversity
Understory

Riparian Ecosystem 2 - Stream Hydrology:

~~~~

Riparian Ecosystem Function 1 - Energy flow:
Treated Section
Temperature (Diurnal range)
-18.25
Light (mean PPFD)(micro mols)
I

Upstream Control Section

~ ~ - 15.00

Upstream Control Section

., '

Upstream Control Section
1
2 Mean
1.00
1.80
1.40
0.30
0.20
0.25
0.10 : 0 .06
0.08
4.00 ' 6.50
5.25
0.07
0.10
0.03
0.33
0.30
0.32
0.01
0.02
0.03
RPg
RPg
RPg
controlled
7..Hpei'C::'eht · :~ · ~~

100% spruce
50% red alder, 40% mixed berry, 10% willow sp.

Riparian Research Project....Case Study #12

Treated Section

None
N/A
N/A
N/A
N/A
N/A

Treated Section

--

--

- - - -- -

None
N/A
N/A
N/A
N/A
N/A

Upstream Control Section

Upstream Control Section

Page 3 of 3

.,.,

Observations:
This Righofway, including the riparian zone has been heavily managed. The area appears to have been
mowed in some areas but slashed in others. The remaining vegetation's composed of bundles of red alder and miscellaneous
broad leaf shrubs, (predominantly willow species). The area is also part of test situation where vegetation is cut at waist height so
winter forage activity by ungulates keep tall growing species under control. The remaining vegetation is well away from tolerance limits.

Vegetation Management:

Present
Type
Species
Distance From Stream
% riparian zone vegetation
Photographs roiiiD and #'s

Wlndthrow

Distribution of habitat (m)
Total Reach Length(Thalweg)
Volume of LWD (Pieces/m stream)

Riparian Ecosystem Function 4 - Habitat ComPlexity

Riparian Research Project. ...Case Study #12

~

::s

~

6.00 0:00

8.00

.... 10.00

Cll

e~ 12.00

'lV 14.00

16.00

18.00

20.00

•

•

2:24

•

4:48

..

•
:A:

1998-08-21
0:00

7:12

.....

•

~

• •
•

.....

_,

9:36

.....

1998-08-22
0:00

... ...

..JIT"

12:00
Time of Day

14:24

.....

.JIIIII"'" --...

1998-08-22
12:00

16:48

19:12

21 :36

---....
.........................--......

1998-08-21
12:00

--........._
-....
..................... ..............._
...,....

Case 12, August 18, 1998

Date and Time

1998-08-20
12:00

•
... ...

• -

·~
~

0:00

1998-08-23
0:00

.
.. - - . .
.• - .
•. • •••

1998-08-20
0:00

•

•

••••
.....
,,..., ----...........

1998-08-19
12:00

-• •

1998-08-19
0:00

•

• .....

•

1998-08-18
12:00

. ..-

6.00
1998-08-18
0:00

8.00

.... 10.00

Cll

~ 12.00

Gl

...::s 16.00
'lV
...Cll 14.00

18.00

20.00

Case 12, August 18-23, 1998

~

t-RaWl

Appendix 2

The Questionnaire Used in this Study.

187

Riparian Zone Management on Electric Transmission Rightofways
QUESTIONNAIRE
(BCHYDRO ROW MANAGEMNT STAFF)
Optional information:
Respondent Name:
Job Title:
Daytime Telephone Number: (

)-

Site Description
l) Are you familiar with the Rightofway (line ID) crossing of (stream name) near
(location)?

1.

#

2)

What is the composition of the powerline (i.e. double, 238 kv, wood-pole
structures)

3)

What is the age of the transmission line?

4)

Does heavy machinery pass across this site?

5)

How is that accomplished (ford, bridge, culvert, other)?

11. Vegetation j\;fanagement
What is the vegetation management cycle frequency, applied for this section of
transmission line ()?
1 year
2 year
...
3 year
4 year
5 year
6 year
7 year
8 year
9 year
10 year
15 year
20 year
other

•
•
•
•
•
•
•
•
•
•
•
•
•

7)

Which of the following methods does B.C.Hydro use to manage vegetation?
along this Rightofway, at this site?
- broadcast herbicide application (aerial or ground spraying)
- selective herbicide application (i.e. baseline thinline, basal streamline
or backpack foliar
- capsule injection
- non-selective mowing
- selective mowing
-high table mowing (cutting at waist level)
-topping
- selective hand cutting (i.e. chainsaw, brush saw, hand slash)
- forestry type operations (large scale cutting, clearing, widening)
- cut and treat (i.e. cover surface of fresh stump with herbicide)
-girdling
- controlled burning
- sheep grazing
- cattle grazing
- allelopathy
-other

------------------------------------------------------------

8)

What is the goal of the vegetation maintenance program across this site?

9)

To your knowledge, does B.C.Hydro actively employ any form of Riparian
Zone Management strategies or techniques along its Rightofways?

I 0)

To your knowledge have any special conditions or work plans been
considered or applied at this stream-crossing site?

ll)

What was the goal of any such conditions or work plans?

12)
Do you anticipate applying any new or additional special conditions or work plans
at this or other stream crossing sites in the future?

III. Other Factors
Are there other additional considerations, other than routine maintenance can require
significant work at a stream crossing (i.e.
~ hardware maintenance, marking ball
replacement etc.)

14)
Do you anticipate applying any new or additional special conditions or work plans
at this or other stream crossing sites ~ the future in conjunction with the items identified
in the previous question ( 13 )?

IV Secondary uses
15)

•
•
•
•
•
•
•
•
•

16)
•
•
•
•
•
•
•
•
•

Are there any other work related activities that have been conducted at or near this
site by members ofthe public, private landowners, municipal governments, First
nations or other corporations/utilities including,
tree farming
gravel removal
road construction
landscape management
livestock grazing
forestry operations
vegetation harvesting (salal, berries, etc.)
trapping
other

Are there any other recreation activities that are or have been conducted at or near
this site including,
snow mobiling
hiking
motor-cross
4*4 operation
hunting
fishing
skiing
nature walks
other