cowichan lake shoreline habitat...

BRITISH COLUMBIA CONSERVATION FOUNDATION

Cowichan Lake Shoreline Habitat Assessment

Foreshore Inventory and Mapping Project

Volume I - Report

October 2012

Cowichan Lake Shoreline Habitat Assessment October 2012

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Prepared for:

Fisheries and Oceans Canada

3225 Stephenson Point Road

Nanaimo BC

V9T 1K3

Prepared by:

BC Conservation Foundation

#3 - 1200 Princess Royal Ave.

Nanaimo, BC

V9S 3Z7

October, 2012

Report Background:

This report was prepared in fulfillment of a contract (F1481-110011) between Fisheries and Oceans

Canada and the BC Conservation Foundation.

The report was authored by Peter Law, Chantal Nessman, Michelle Kehler and Gary Horncastle.

Acknowledgements: The following people contributed time and energy to development of the

project and report, and we wish to thank them.

Tracy Michalski, Steve Baillie, Kate Lindsay, Gerald Thom, George deLure, Jean Atkinson, Kai

Rietzel , Jen Morgan, Lovena Morton, Bryce McLean, Ted Burns, Eric Morris, Craig Wightman,

Brad Mason, Nick Leone, Mark Kissinger and Lisa Christensen.

Front Cover: Cowichan Lake looking east from the hills above Caycuse.

Photo Credit: Cowichan Lake & River Stewardship Society.


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Executive Summary

Over the past decade Cowichan Lake has undergone significant growth of new "part time" summer

residents, who are attracted by the area’s natural aesthetics and recreational potential. There is a growing

demand for new recreational real estate (and amenities) that has prompted a dramatic increase in

lakeshore residential development. Planning for future land development at Cowichan Lake is a complex

challenge and balance between public demand for housing, economic realities of the region, and

established social and cultural traditions of the affected communities. To ensure the planning process is

well informed, a solid understanding of the lake’s aquatic riparian resources and values is essential.

The Cowichan watershed supports anadromous (sea-run) and resident fish species/stocks, which in

aggregate contribute to significant First Nations, commercial and sport fisheries (Westland, 2005).

Cowichan Lake serves as a licenced water supply for the Catalyst pulp mill (in Crofton), and as a source

of drinking water for residents of the Town of Lake Cowichan, Crofton and smaller lakeside

communities. The watershed also provides critical habitats for many important wildlife species. For all

of these reasons, local residents have expressed a strong desire to preserve and protect the watershed’s

natural capital for future generations.

The main objective of this report is to provide a baseline overview of the shoreline habitat attributes of

Cowichan Lake. Methods employed are discussed in detail, and are now a standard being used to map

other large lake shorelines throughout the Province. The mapping protocol should allow stakeholders to

understand current shoreline conditions, and measure and monitor changes in the future. Some success is

being reported in the Okanagan and the Kootenay regions, where a three step process has been adopted to

help integrate environmental data with land use planning. The process involves the following steps:

1. Foreshore Inventory and Mapping (FIM) is a protocol being used to collect baseline

biophysical data about current habitat conditions of a shoreline. The FIM uses a map-based

approach to describe the shoreline. Data is compiled on shore types, substrates, land use and

habitat modifications that are geo referenced and uploaded into a Geographic Information

System (GIS). This information is then combined with fish population and other environmental

inventories to enhance its interpretive value for land use planning decisions.

2. An Aquatic Habitat Index (AHI) is generated using FIM data to determine the

relative/comparative habitat value of shoreline segments. This index follows similar methods

that were developed for lakes in the BC Interior. The AHI integrates features such as substrate

composition, shore spawning use, presence of aquatic vegetation and alike to estimate the habitat

value of a particular shoreline segment.

3. Shoreline Management Guidelines are prepared to identify “Shoreline Vulnerability.”

Shoreline vulnerability is based on the AHI (step 2 above) and is a risk-based approach to better

protect ecologically sensitive shoreline features.


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This report represents Step 1 in this three-tiered process. Data has been compiled from field surveys

including assessment of biophysical conditions of Cowichan Lake’s shoreline (October 2010); fish

abundance sampling at representative shoreline index sites in July 2011 and September 2011; assessment

of unmapped inlet streams to determine potential fish use; assessment of important shoreline segments for

reproduction of the SARA-listed Vancouver Lamprey (Lampetra macrostoma; Fundy Aqua Services

2011); and, Cowichan Lake Erosion Assessment by Kerr Wood Leidal Assoc. Ltd. (2011).

These data have been linked to native fish species and their seasonal dependence on the lake’s shoreline

ecosystems. Results provide valuable guidance to land and water use planners concerning critical

features, habitats and related resources for the shorelines of Cowichan Lake. A brief summary of results

include the following:

Impacts to the shoreline were determined from categorical descriptions of the level/types of

disturbance observed around the lake. It is estimated that 25% of the shoreline has a high level of

impact (> 40% disturbance), which accounts for 25.3km of shoreline. Areas of low impact (less

than 10% disturbance), or no impact, account for 55% (55km) of the shoreline. Impacts include

lakebed substrate modification, riparian vegetation removal, retaining walls, docks, beach

grooming and similar riparian incursions. In total, it is estimated that 29.4% or 29.5km of the

shore length is disturbed while 70.5% or 70.6km remains in a natural state.

The most dominant land use around the lake is forestry (48%), followed by single family

developments (30.5%), and industrial/park lands (6%-7%). Disturbance was highest along

shorelines where single family housing is the dominate use (64%).

Wetlands and stream mouths are the most rare shore types, accounting for 0.5% and 4.6% of the

total shore length, respectively. The most common shore type is gravel beach, dominating 72%

of the lake's shoreline perimeter. Gravel shorelines also account for 92% of shoreline

disturbances on the lake.

Aquatic vegetation occurs along 21% of the shoreline and is important habitat for juvenile

salmonids. Most (20%) of this vegetation was classed as emergent (hydrophilic shrubs such as

Myrica Gale and willow spp.), while submergent vegetation was rare, and only abundant in the

lake's outlet and some inlet stream mouths. The recent discovery of the aquatic invasive plant,

Eurasian Water Milfoil, may change this scenario in future (should it become well-established).

In an effort to relate the condition of shoreline riparian vegetation to adjacent land use, the FIM

rated shoreline vegetation as either "patchy" or "continuous". Single family land use once again

had the highest occurrence of impacted vegetation.

The following summarizes Cowichan foreshore modifications observed:

Docks were the most common structural modification observed, with a total of 596 counted.

Both pile-supported and floating docks were observed. Often accompanying docks are floating

log boom-stick structures designed to “dampen” the height of waves. These are becoming a

common feature in association with docks, and are now found on 12.5% of the lake’s shoreline.

Retaining walls were the second most common structural modification, with 360 observed. Many

walls are constructed of cement, and are often associated with a modified beach. Walls occupy

9% of the shoreline, or 9km.


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Rock groynes and beach modifications are becoming common along the most developed arms of

the lake, now accounting for 17% of the shoreline, or 17 km.

In a companion report entitled, Cowichan Lake Erosion Assessment (KWL Assoc. Ltd. 2011), natural and

man-made causes of erosion on the lakeshore were reviewed. The report identified that over decadal

time, gravity, friction, waves and human activity are the dominant forces that have shaped the lake’s

shoreline. The most dominant erosive force on the shoreline is waves, which are generated both by winds

and large power boats. The degree of subsequent shoreline impacts from waves largely depends on the

shoreline’s exposure to wave energy, degree of human disturbance and associated disruption of natural

sediment transport, substrate composition and the integrity of natural riparian vegetation communities.

Shorelines generally are classified according to their composition (KWL Assoc. Ltd. 2011). The main

categories are

1. Cohesive (e.g. bedrock, clay, vegetated)

2. Non-cohesive; and

3. Man-made.

The FIM shoreline analysis (2010) indicated over 72% of substrates which characterize the majority of

the lake's shorelines are composed of gravel and cobble beaches. Up until 50 years ago, these beaches

were "naturally vegetated" by hydrophilic plants and shrubs which provide cohesive strength to a beach

from erosion forces. Such vegetated shorelines are considered to be in "equilibrium". However, the FIM

also indicated that gravel shorelines are increasingly being "disturbed," particularly by owners of single

family residences, who are clearing their waterfronts for “improved” views and recreational purposes.

The conversion of gravel beaches from vegetated (cohesive) conditions to man-made states continues to

take place, resulting in greater erosion pressures on shorelines.

Development of retaining walls and groynes, or removal of riparian vegetation below the 164 m elev. will

disrupt natural shoreline erosion processes and lead to instability, especially in local areas where

modifications have occurred (KWL Assoc. Ltd. 2011). The report also identifies that certain lake

shorelines are more vulnerable to wind-driven wave energy, with the most exposed areas being Youbou

Lands (Cottonwood Creek fan), Youbou, west side of Sa-Seen-Os Point, and the west shore of Bald

Mountain. The North and South Arms of the lake are subject to medium levels of wind-related wave

energy.

For this report, a video comparison was made of development along three shoreline reaches of Cowichan

Lake. The videos provided an opportunity to compare and estimate percent area changes to the following

categories:

Riparian tree and shrub modification - the percent of a property's total shoreline where riparian

tree and/or shrub modifications have occurred between 2006 and 2010.

Erosion protection – percent of a property's total shoreline where erosion works have been

installed between 2006 and 2010.


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Beach creation/shoreline clearing – percent of a property's total shoreline where changes have

occurred between 2006 and 2010.

Docks - Number of new docks and ramps installed between 2006 and 2010.

The first shoreline assessed was the development known as "Creekside." It is located on the North Arm

of Cowichan Lake. As part of the (2005/06) subdivision approval of 75 shoreline lots, this development

was subject to Cowichan Valley Regional District (CVRD) bylaws, designed to protect the riparian area

of the lake. In comparing the shorelines of fifty properties (developed to date), 26 properties (52%) have

undergone changes to the shoreline between 2006 and 2010. Thinning of riparian vegetation and trees

inside the Streamside Protection and Enhancement Area (SPEA) has occurred on 19 properties. Clearing

of shrub vegetation, to make a "beach" appears to be limited. Fifteen new docks were installed, most with

aluminum gangways that appear to be anchored properly to shore.

The second shoreline assessed was the community of Youbou. The video comparison looked at whether

property redevelopment is resulting in further shoreline modification. From the video comparison, a total

of 34 shoreline properties (24%) have undergone some development between 2006 and 2010. Overall,

the rate of change to the Youbou shoreline was less than 10%, with very few properties undergoing tree

and shrub removal, or shoreline clearing. This result was expected, as the Youbou waterfront underwent

significant shoreline change several decades ago. What was striking was the number of new retaining

walls (N=16). Many of these walls could be replacements for aging or failing original structures. It is

interesting to note there is a high likelihood that none of the retaining walls were permitted by the

Province of BC.

The third shoreline assessed was the Walton Road’s area, a small community of residences and

commercial RV Parks, west of the village of Honeymoon Bay. Many of the 41 properties have been

developed as seasonal cottages or year-round single family residences. Most buildings appear to have

been built 40+ years ago (Fig. 24). There are two commercial campsites located in this area. Between

2006 and 2010, the video comparison identified only two of the 41 properties (5%) with a change to

shoreline conditions. One of the properties had rebuilt a retaining wall, and one property was cleared and

undergoing house construction.

Fish population sampling was the largest component of the 2011 field work program, with a total of 26

different sites located along the shoreline. These index sites were selected to represent a range of

different shore types (e.g. gravel beach, stream mouth, etc.), with different levels of development.

Snorkel surveys, beach seining and minnow trapping were used to sample fish populations residing along

or near the shoreline, so that relative abundance of each species could be obtained for each shore type.

Sampling took place in summer (late June/July) and fall (mid-September) in 2011. An attempt to sample

fish in winter (January 2012) was abandoned due to difficult weather and lake travelling conditions.

In general, the fish assemblage in Cowichan Lake showed a diversity of species inhabiting the foreshore,

including seven native species. . No invasive fish species were captured in the sampling. Based on a

literature review and archival files, as well as interviews of agency biologists and local anglers, only one

native species (Dolly Varden char) was not sampled in the 2011 field survey. Fish species whose life

histories (and spawning locations) are least understood, are the Vancouver Lamprey and Kokanee salmon.


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A separate sampling program, focused on the SARA-listed Vancouver Lamprey, was attempted in fall

2011, however, it was abandoned due to inclement field conditions.

In a review of fish abundance by shore types, the "stream mouth" shore type had the highest percentage of

all fish sampled in both sampling seasons. In summer, stream mouth areas around the lake accounted for

over 50% of all fish sampled, more than all other shore types combined. The largest "stream mouth"

shore type segment in the lake is the lake outlet /Catalyst weir area, where high densities of juvenile Coho

were sampled. Large numbers of Coho fry from the upper Cowichan River are known to migrate to the

lake in the spring to rear, before migrating downstream as smolts the following spring.

Rocky shore types are also important in the summer and fall months, accounting for approximately 20%

of fish abundance in the lake. Rocky shore types typically display a bathymetry that drops steeply away

from the shoreline. In Cowichan Lake, these steep drop-off zones are often covered in logs and fallen

trees. During fall snorkel observations, schools of Coho juveniles were observed in these cooler, deeper

waters (4 - 6 m) under submerged large woody debris (LWD). Gravel and sandy shore types account for

15% of total fish abundance in the lake in both surveys. The majority of fish sampled in these shore types

were Three-Spined Stickleback and Prickly Sculpins.

When comparing the FIM shore types found around the lake with high fish abundance ratings, stream-

mouths have very high fish abundance, yet represent only 4.6% of the lake's total shoreline, while rocky-

shores represent 17%. The wetland shore type is very rare on Cowichan Lake (0.5%), but supports a

moderate fish abundance rating. Stream-mouths are also recognized for their high biological productivity

for lamprey spawning and ammocoete (larvae) habitat. This underscores the importance of this

combination of shore types (i.e., stream-mouth/rocky/wetland), representing 22% of the lake's shoreline,

to wild fish productivity in the lake.

When looking at the dominate fish species sampled in the 2011 field program, juvenile Coho and Three-

Spined Stickleback were most abundant (97%) along the lake’s shoreline in summer. The importance of

gravel shore types for fish and fish habitat during the winter and spring seasons (featuring high water

levels) is not well understood at this time, and further field investigations will be necessary in the future.

A final field investigation in the fall of 2011 was launched to determine the importance of 17 small 1st

order streams for fish and fish habitat. These streams were not mapped in 1:20,000 TRIM map sheets and

their status was unknown to DFO Habitat Management staff in Nanaimo. In September 2011, a field

investigation of these sites identified only 14 streams, with 10 having a dry channel at the time of survey.

For the purpose of summarizing whether these streams "contribute" to fish habitat, we must understand

how fish in Cowichan Lake use the stream(s) during their species-specific life histories.

Small inlet streams provide salmonids with spawning and early rearing habitats essential to species

recruitment in the long-term (millennia). Fish have adapted to the seasonal hydrology of these streams, so

the fact that 72% are dry by early fall is a natural phenomenon and not necessarily deleterious to species

sustainability. In aggregate, these streams can support significant numbers of juvenile salmonids when

suitable flows exist, so they should not be ignored or diminished in terms of habitat protection in land use

planning processes.


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In 2011, a total of five watercourses were found to be highly "modified" by human developments. These

were heavily impacted by ditching and drainage management from adjacent roadways or land use. The

remaining nine streams had channel conditions identified as "natural," with no measurable human

encroachments in the reaches assessed. The majority of stream channels were dry at the time of field

observations. These watercourses drain small forested basins (Figure. 44). Three streams had wetted

channels at the time of survey. Two streams had confirmed fish presence. Of the 14 streams assessed, 9

were judged to support viable fish habitats.

Based on results from 2010/11 Cowichan Lake field investigations, this report recommends actions that

will support lake shoreline and fish habitat protection, as well as future biophysical inventory needs and

priorities.

DISCLAIMER Results in this report are largely based on biophysical data collected during field surveys from a single year (2011). It is understood that ecosystems respond differently in both time and space to variable

environmental conditions, even inter-annually. Hence, conservative assumptions underlie the report’s

current conclusions and recommendations, and these may be subject to change based on new information becoming available in future.

Data in this assessment were not analyzed statistically and no inferences about statistical significance

should be made when the term “significant” is used to describe field observations or conditions. Citing of

the report’s conclusions and recommendations is the responsibility of parties using the information, and should be prefaced by the caveats expressed above.

The BC Conservation Foundation, Fisheries and Oceans Canada and the report’s authors should not be held responsible for errors of omission or interpretation given best efforts were made to verify the

accuracy and completeness of field data collected and presented in this technical document.


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Table of Contents 1.0 Introduction .................................................................................................................................... 1

1.1 Significance of the Foreshore Environment to Fish and Wildlife ................................................. 1

2.0 Project Overview............................................................................................................................. 2

2.1 Project Partners .......................................................................................................................... 3

2.2 Objectives ................................................................................................................................... 3

2.3 Description of the Cowichan Lake Watershed ............................................................................ 4

2.5 Important Fisheries Resource Information ................................................................................. 5

2.6 Foreshore Management Overview.............................................................................................. 6

3.0 Methods.......................................................................................................................................... 7

3.1 Foreshore Inventory and Mapping Methodology ....................................................................... 7

3.1.1 Biophysical Assessment of Shoreline Condition .................................................................. 7

3.1.2 FIM Data Analysis ............................................................................................................... 8

3.2 Foreshore Modifications on Cowichan Lake.............................................................................. 10

3.2.1 How Lakeshore Erosion Processes are Influenced by Development ................................. 10

3.2.2 A Comparison of Lake Shoreline Development between 2006 and 2010......................... 10

3.3 Fisheries Sampling .................................................................................................................... 13

3.4 Fisheries Data Analysis .............................................................................................................. 15

3.5 Fish Species of Cowichan Lake .................................................................................................. 15

3.6 Assessment of Fish Habitat Potential in Unmapped Inlet Streams (Fall 2011) ......................... 15

4.0 Results........................................................................................................................................... 16

4.1 Foreshore Inventory: Biophysical and Shoreline Characteristics of the Lake ........................... 16

4.2 Foreshore Modifications on Lake Cowichan............................................................................. 23

4.2.1 Shoreline Erosion and Effective Shoreline Protection ....................................................... 23

4.2.2 Shoreline Development Comparison: 2006 and 2010 ...................................................... 26

4.3 Fish Sampling ............................................................................................................................ 32

4.4 Lamprey Sampling ..................................................................................................................... 35

4.5 Fish Results................................................................................................................................ 36

4.5.1 Fish Abundance by Shore Type.......................................................................................... 38

4.5.2 Fish Species by Shore Type ................................................................................................ 41


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4.6 Fish Species of Cowichan Lake ...................................................................................................... 44

Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) ...................................................................... 44

Coho Salmon (Oncorhynchus kistch) ................................................................................................. 45

Rainbow Trout (Oncorhynchus mykiss) ............................................................................................. 46

Chinook Salmon. (Oncorhynchus tshawytscha) ................................................................................ 47

Kokanee (Oncorhynchus nerka) ........................................................................................................ 48

Dolly Varden (Salvelinus malma) ...................................................................................................... 49

Three-Spined Stickleback ( Gasterosteus aculeatus) ......................................................................... 50

Prickly Sculpin (Cottus Asper) ............................................................................................................ 51

Vancouver Lamprey (Lampetra macrostoma)................................................................................... 52

4.7 Assessment of Fish Habitat Potential in Unmapped Inlet Streams (Fall 2011) ......................... 53

5.0 Discussion and Recommendations................................................................................................ 58

References ................................................................................................................................................ 65

GLOSSARY OF TERMS AND ACRONYMS .................................................................................................... 69

Figures

Figure 1. Overview Map of Cowichan Lake ................................................................................................ 4

Figure 2. Arms of Cowichan Lake: A-South Arm; B-North Arm; C-Main Arm ............................................. 9

Figure 3. Creekside Subdivision Video Track ............................................................................................. 11

Figure 4. Youbou Townsite Video Track .................................................................................................... 11

Figure 5. Walton Road Video Track ........................................................................................................... 12

Figure 6. Shoreline Elements Used in Video Comparison between 2006 and 2010 .................................. 13

Figure 7. Seining a Sandy Beach and Snorkelling to Assess Fish Abundance............................................. 14

Figure 8. The total shoreline length rated Natural or Disturbed on Cowichan Lake ................................. 17

Figure 9. Length of Disturbed and Natural Shoreline within the different Arms of Cowichan Lake .......... 17

Figure 10. Length of Natural and Disturbed Shoreline by Land Use Types................................................ 18

Figure 11. Length of Natural and Disturbed Shoreline by Local Government Zoning ............................... 19

Figure 12. Length of Natural and Disturbed Shorelines Observed Within the Different Shoretypes ........ 19

Figure 13. Map of Cowichan Lake Showing Shoreline Substrates ........................................................... 20

Figure 14. Total Shoreline Length by Type of Aquatic Vegetation ............................................................ 21

Figure 15. Total Number of Different Shoreline Modifications Identified on Cowichan Lake ................... 21

Figure 16. Total Shoreline Length Physically Altered by Development ..................................................... 22

Figure 17. Condition of Riparian Vegetation by Land Use Type ................................................................ 23

Figure 18. Rating of Development Impacts to the Shoreline of Cowichan Lake ........................................ 23

Figure 19. Wave Energy Map of Cowichan Lake ...................................................................................... 25


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Figure 20. Number, Type of Modifications and Impact Identified along Creekside (2006-2010) .............. 27

Figure 21. Example of Shoreline Changes to a Creeksde Property -.......................................................... 28

Figure 22. Number, Type of Modifications and Impact Identified along Youbou (2006-2010) ................. 29

Figure 23. Example of House Re-Development in Youbou ...................................................................... 30

Figure 24. Example of Cottage Housing in Walton Road Area .................................................................. 31

Figure 25. Number, Type of Modifications and Impact Identified in Walton Road Area (2006-2010) ...... 31

Figure 26. Recorded Daily Water Levels for Cowichan Lake in 2010, with Max and Min Water levels

Observed (1913-2010) ............................................................................................................................. 32

Figure 27. Photo Comparison of Fish Fish Sample Sites - Winter vs Summer Water levels ...................... 34

Figure 28. Percent of Fish Sampled by Shoretype - Summer and Fall 2011 .............................................. 39

Figure 29. Mean Number of Coho Sampled in Each Shoretype in 2011.................................................... 42

Figure 30. Common Emergent Plant Association (Myrica Gale spp) Prefered by Coho for Escape Cover 42

Figure 31. Woody Debris - Important Escape Cover for Fish in Cowichan Lake ........................................ 43

Figure 32. Submerged Aquatic Plants - Important Escape Cover for Fish ................................................. 43

Figure 33. Trout Parr Captured by Minnow Trapping (Sept. 2011) ........................................................... 44

Figure 34. Adult Cutthroat Tout Sampled in Lake Sport Fishery. Note Lamprey Scar. ............................. 45

Figure 35. Juvenile Coho Sampled in September 2011 ............................................................................. 46

Figure 36 Rainbow Trout Sampled in Summer 2011 ................................................................................. 47

Figure 37. Chinook Salmon Juvenile Sampled in July 2011. ...................................................................... 48

Figure 38. Adult Kokanee Salmon Sampled in July 2011 ........................................................................... 49

Figure 39. Juvenile (left) and Adult (right) Dolly Varden Char. ................................................................. 50

Figure 40. Adult Threespine Stickleback. ................................................................................................. 51

Figure 41. Adult Prickly Sculpin ................................................................................................................ 51

Figure 42. Cowichan Lake Lamprey Ammocoete, Sampled at Meades Creek North, Oct 2010 ............... 52

Figure 43. Example of Modified (Ditched) Stream Channel ..................................................................... 56

Figure 44. Example of Dry "Natural" Stream Channel ............................................................................... 57

Tables Table 1. Method and Number of Capture Attempts in Sampling Fish Abundance in 2011 ....................... 32

Table 2. Description of Fish Sample Index Sites 2011 ............................................................................... 35

Table 3. Number and Relative Abundance (%) of Fish Observed/Sampled at each Sample Site............... 37

Table 4. Rating of Shoretypes as Measured by Fish Abundance in 2011 .................................................. 40

Table 5. Potential Locations for Ammocoete or Lamprey Spawning in Cowichan Lake (2011)* ............... 53

Table 6. Locations of Streams Field Checked in September 2011 ............................................................. 54

Table 7. Summary of Fish Habitat Conditions in Modified Streams .......................................................... 55

Table 8. Summary of Fish Habitat Conditions in Natural Streams............................................................. 56


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List of Appendices

Appendix A - Foreshore Inventory and Field Mapping detailed methodology (FIM)

Appendix B - Foreshore Inventory Methodology - Raw Data for Cowichan Lake from October 2010

Survey.

Appendix C - Fisheries Field Sampling 2011

Appendix C1 - Summary of Fish Sampling Site Descriptions 2011

Appendix C2 - Fish Sampling Results of Index Sites -Summer 2011

Appendix C3 - Fish Sampling Results of Index Sites -Fall 2011

Appendix C4 - Detailed Fish Sampling Index Site Descriptions - September 2011

Appendix D - Cowichan Lake - Stream Assessments 2011

Appendix D1 - Summary of the Streams Surveyed in September 2011

Appendix D2 - Stream Inventory Data Sheets - 2011

Appendix E- Shoreline Development Video Comparison Tables - 2006 compared to 2010 Video

E1 - Creekside - North Arm

E2 - Walton Road - South Arm

E3 - Youbou - Main Lake

Appendix F – Vancouver (Cowichan Lake) Lamprey

F1 – Vancouver Lamprey Recovery Strategy (2007)

F2 – Vancouver Lamprey Field Report (Fundy Aqua Services, 2012)


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1.0 Introduction In 1884, William Forrest, one of the first Europeans to see Cowichan Lake, described it "as the most

beautiful spot he had ever seen." Upon his return to Victoria, he set out to encourage the Premier of the

Province to build a road and encourage settlement at the lake. A few years later, the road was completed,

and the settlement of Cowichan Lake began, with a focus on logging the area's magnificent forests. For

the next 100 years, forestry was king in Cowichan Lake (and valley), with logging operations supporting

three sawmills and shipping an estimated 400,000 railway cars of logs to other local mills for processing.

Today, the mills are gone, and the forest resource no longer provides economic support to local

communities the way it once did.

More recently, however, there is a new sense of optimism surrounding "Kaatza" or "the Big Lake," as

new people arrive and the economy shifts gears to one which emphasizes retirement living and eco-

tourism more prominently. Over the past decade, Cowichan Lake has undergone significant growth of

new "part time" summer residents who see the beauty of the area for its recreational potential. There is

demand for new recreational real estate (and amenities) that has fuelled a dramatic increase in lakeshore

residential development.

To meet this growing demand, local governments have been updating their Official Community Plans.

The Cowichan Valley Regional District (CVRD) has updated Official Community Plans (OCP’s) for

Area I (2005) and Area F (1999), to better manage growth. The Town of Lake Cowichan recently (2011)

completed an OCP review. With these land use plans, local communities have introduced policies to

manage future growth to accommodate new development (e.g., Youbou Lands). The question many

residents have is whether these plans will be effective in sustaining the lake's environmental health.

The Cowichan watershed supports many anadromous (sea-run) and resident fish stocks, which support

valuable First Nations, commercial and sport fisheries (Westland, 2005; Burt and Wightman 1997). The

lake is also an important water supply for the region’s pulp mill (in Crofton), and as a source of drinking

water for the Town of Lake Cowichan, Village of Crofton and surrounding area residents. The watershed

provides critical habitats for many indigenous wildlife species which support recreational hunting and

viewing opportunities. For these reasons, local residents have expressed a strong desire to preserve and

protect the watershed’s aquatic and terrestrial ecosystems.

Planning for future land development is a complex relationship between the public’s demand for housing,

prevailing economic realities, along with social and cultural values of affected communities. To ensure

land use planning is well informed, a solid understanding of aquatic riparian resources is essential.

1.1 Significance of the Foreshore Environment to Fish and Wildlife Why should local residents be concerned about Lake Cowichan's riparian foreshore ecosystems?

Lakeshores form a transitional ecological community between aquatic and terrestrial habitats, referred to

as an “ecotone.” Ecotones are important for fish and wildlife species since they provide the benefits of


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differing habitats in close proximity to each other. Lakeshore habitats are important for a wide range of

invertebrates and vertebrates for reproduction, feeding, resting and protection from the elements and

predators. Vegetated foreshores help to reduce erosion through soil stabilization and through a reduction

in the erosional energy of rainfall and wave action. Leaf litter and fallen branches/trees provide food

and/or habitat for aquatic organisms, including fish spawning and rearing sites. Riparian vegetation is

distinct from upland habitats due to the close presence of water, and in ecological terms is considered

more productive than much drier or wetter habitats. Many habitat attributes associated with lake

shoreline ecosystems play important roles in the life cycles of fish and wildlife species, including

amphibians (Holmes 2008). These can be divided into three general zones around the lakeshore - open

water, littoral and upland.

Habitat complexity in the littoral zone is particularly important to fish productivity. Coarse woody debris

(CWD), aquatic macrophytes (emergent/submergent plants) and substrate composition are examples of

habitats important to fish that are often compromised as a result of foreshore residential development.

These habitats provide many functions including refugia from predation, foraging substrates, spawning or

nesting habitat, cover from the sun and nutrient cycling (Schindler et al. 2000 and Engel 1990). The

littoral zone is also particularly important for early life-history stages of many fish species (Radomski and

Goeman 2001). Residential developments can impact these habitats through direct removal of vegetation,

construction of built-structures (such as piers, docks and marinas), and alteration of the shoreline with

riprap or concrete (e.g., like retaining walls and groynes).

Overall, empirical studies indicate that human activity can promote significant changes in the physical

structure of lake environments, and that impacts to natural habitats are a significant management concern.

Further, when impacts are considered cumulatively for an area, they interact in complex ways to alter fish

and wildlife growth and reproduction rates. Jennings et al. (2003) found that cumulative changes to

watersheds and riparian zones were associated with measurable differences in littoral habitats that may

not be detectable at smaller scales. Radomski and Goeman (2001) suggested that shoreline management,

which is often conducted through site-specific regulations and permits, frequently fails to address

cumulative effects on aquatic habitats.

In 2010, a report by the BC Ministry of Environment indicated that land development practices on lakes

in British Columbia are resulting in negative impacts to fish and wildlife habitats due to the cumulative

loss of foreshore habitats (Anonymous, 2010). The report further indicated that many landowners were

non-compliant within existing "rules" governing land development along lakeshores. How to effectively

deal with the growing issue of unauthorized development and environmental impacts is one of the

greatest compliance challenges now facing BC’s regulatory agencies.

This report has been prepared based on the belief that it is possible to properly manage lake shoreline

environments, and their related ecosystem assets, in a sustainable manner.

2.0 Project Overview Fisheries and Oceans Canada (DFO) Ecosystem Management Branch (EMB) has been working closely

with Provincial and local government agencies, and non-government organizations, to complete foreshore


3

inventories and mapping (FIM), fish inventories and Shoreline Management Guidance Documents

(SMGD) for priority lakes and streams throughout BC. FIM and SMGD assist DFO with its objectives of

restoring and protecting fish habitat, promoting public education and awareness programs, and developing

environmental partnerships with external parties. These activities support commitments to Canadians for

maintaining “Healthy and diverse salmon populations that support harvest opportunities and contribute to

sustainable marine and freshwater ecosystems.”

The primary objective of this report is to provide a baseline overview of the shoreline conditions of

Cowichan Lake. Methods employed are discussed in detail and are now a provincial standard being used

to map lake shorelines throughout BC. The mapping protocol will allow stakeholders to understand

current conditions of a given shoreline, and subsequently measure and monitor changes in the future.

In this report, foreshore and shoreline are used synonymously. The shoreline zone is defined as the

terrestrial (riparian) lands adjacent to the lake (e.g. within 30 meters of the 164 meter elevation contour).

Riparian ecosystems are directly influenced by typical water levels in the lake, influencing the soil

moisture regime. The foreshore zone is that portion of the lake between the winter high water mark and

the summer/fall low water level. This shallow aquatic zone is highly productive, and therefore extremely

important to the health of aquatic species in the lake. This will be explained in greater detail below.

2.1 Project Partners A number of local organizations have contributed to the success of this project to date, including:

1. Cowichan Valley Regional District

2. Fisheries and Ocean Canada

3. Ministry of Forests, Lands and Natural Resource Operations

4. Ministry of Environment

5. Cowichan Tribes

6. Cowichan Watershed Board

7. BC Conservation Foundation and Living Rivers Trust Fund

8. Cowichan Lake and River Stewardship Society

2.2 Objectives The Cowichan Lake FIM project is intended to both assist and support regional land use planning

objectives by:

Supporting local governments’ OCP planning that integrates aquatic information with upland

development planning, to ensure protection of sensitive lake foreshore areas;

Providing ongoing environmental public awareness and education;

Supporting lake management plans;

Acquiring detailed sensitive area mapping;

Ensuring appropriate zoning of shoreline properties that respects biophysical conditions and

environmental sensitivities of the site; and


4

Providing digitally accurate video coverage of the lake shoreline with access to the video and

associated GIS database through the Community Mapping Network.

This (Step 1) FIM report is organized in three parts with the following objectives:

Part 1. Assessment of Cowichan Lake's Biophysical Conditions and Foreshore Modifications:

1. Compile and summarize the Foreshore Inventory Mapping data (shoreline morphology, land use,

riparian conditions and anthropogenic alterations) for Cowichan Lake using the FIM database

generated in October 2010.

2. Compare shoreline development on three representative shoreline reaches between 2006 and

2010.

3. Highlight lake foreshore modifications common to Cowichan Lake and assess how they impact

natural processes and habitats.

Part 2. Assessment of Fish Species of Cowichan Lake

4. Summarize native fish assemblages using the shoreline of Cowichan Lake.

5. Provide an index of fish abundance that identifies preferred shore types by season.

6. Assess the fish use potential of 17 small streams that have not been previously mapped.

Part 3. Discussion and Recommendations

7. Identify key issues and recommend next steps in the Lake Cowichan FIM.

2.3 Description of the Cowichan Lake Watershed The study area for this project encompasses the foreshore of Cowichan Lake (Figure. 1.)

Figure 1. Overview Map of Cowichan Lake (source: CVRD).


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Cowichan Lake is located 30 km west of the City of Duncan. It is the second largest lake on Vancouver

Island (6,360 ha.) and is approximately 31 km in length. The lake sits at 164m (average high water level)

in elevation above sea level and empties into the Cowichan River which flows 47km east to Cowichan

Bay. Like many large coastal lakes in British Columbia, Cowichan Lake is characterized by bathymetry

that is very deep, with a mean depth of 50m and a maximum depth of 152m. For the most part, the lake

drops quickly from shore except for some isolated embayment’s formed by tributary streams.

The surrounding drainage area to the lake is 616.6 square kilometers, with more than 53 inlet streams and

rivers. Griffith (1989) noted there are numerous secondary tributaries to these streams, as well as many

smaller 1st and 2

nd order streams that flow into the lake. Rainfall averages 2,800 mm of precipitation a

year, which provides the lake with an enormous inflow volume which completely replenishes every 2.2

years. In winter, the weather is influenced by strong frontal storms moving eastward from the Pacific

Ocean. Often these systems arrive in a series, bringing periods of sustained rainfall to the lake basin.

Approximately 80% of annual basin inflows occur from September to March (Westland 2005). Flows

into the lake can vary dramatically in relatively short periods, literally changing from extended fall

droughts to floods in a matter of a few days.

The entire "lake" watershed is dominated by the Coastal Western Hemlock biogeoclimatic zone that is

held as private managed forest lands.

About 6,000 residents live and work in close proximity to the lake, with many thousands more in the

summer that come to enjoy a recreational experience that includes camping, swimming, boating and

fishing.

At the outlet to the lake, a flow control weir owned by Catalyst Paper Corp., regulates flows downstream

in the river typically between the months of May to October. Water released to the river must meet

fisheries conservation flow requirements and supply the pulp mill operation at Crofton. During winter

months, the weir’s gates and boat lock are fully opened and lake levels rise in response to a natural river

channel constriction in vicinity of the Greendale Trestle (Sutherland, 2010), approximately 2km

downstream.

2.5 Important Fisheries Resource Information Cowichan Lake contributes significantly to production of wild salmon and trout in the Cowichan River

basin. The lake and its tributaries support important populations of adult fall Chinook (Oncorhynchus

tshawytscha) and Coho salmon (O. kisutch), that annually migrate to the lake from September to

December to spawn. In spring, after fry emergence, many juvenile Coho migrate to the lake and rear for a

year before smolting to the ocean. It is estimated that over 75% of Coho smolt production (for the entire

watershed) rear in the lake (S. Baillie, DFO, pers comm.). Extensive studies of these populations have

been ongoing for over 40 years by DFO research staff, Cowichan Tribes and community stewardship

groups (S. Baillie, DFO, pers comm.). Salmon stocks are extremely important to local First Nations and

contribute substantially to First Nations’ food, social and ceremonial values.

Coupled with valuable salmon populations are small and discrete populations of Winter Steelhead

(O.mykiss) that enter the lake and spawn in four inlet tributaries.


6

The lake also provides habitat for resident populations of Coastal Cutthroat trout (O. clarki clarki),

Rainbow trout (O. mykiss), Kokanee salmon (O. nerka) and Dolly Varden char (Salvelinus malma). A

sport fishery, targeting resident trout, is estimated to account for over 15,000 angler days annually (T.

Michalski, MFLNRO, pers. comm.).

Also found in Cowichan Lake are some non-salmonid species, common to south coastal BC lakes,

including Three-Spined Stickleback (Gasterosteus aculeatus) and Prickly Sculpin (Cottus asper).

A species that is "Red Listed" by the Province of BC is the Vancouver lamprey (Lampetra macrostoma).

In 2000 and 2008, Vancouver Lamprey was designated as "Threatened" by the Committee on the Status

of Endangered Wildlife in Canada (COSEWIC), and is currently protected under the Federal Species at

Risk Act (SARA). Very little is presently known about the biology, population status or habitat

requirements of this species in Cowichan Lake. Consequently, an important inventory project was

launched in September 2011 to identify critical habitats used by L. macrostoma to aid future management

and protection of critical lake shore and stream habitats of the species.

The lake’s shoreline is an important component of the life history of all salmonid and non-salmonid

species in the lake. For example, there are numerous shoreline areas where Kokanee are known to

annually spawn. Young Coho fry emerge from tributary streams and many move to shallow shoal areas

of the lake where they rear for a year before smolting. Cutthroat trout fry also are highly dependent on

the lake shoreline and associated littoral area for rearing for the first two to three years of their life

history. Adult Cutthroat also depend on shoreline environments for food organisms.

It is recognized that salmon are a "keystone species" in the Cowichan watershed. Adult salmon are a

staple source of food for bears, eagles and other native species, with carcasses of spawned adults

providing a source of marine nutrients (N, P, C) for both terrestrial and aquatic ecosystems. Salmon also

act as an indicator species for the health of the Cowichan ecosystem as a whole, because they are highly

sensitive to changes in freshwater habitat and water quality (Cowichan Water Board, 2012).

2.6 Foreshore Management Overview A three step process being used in the province as a template for shoreline management generally

proceeds through the following steps:

4. Foreshore Inventory and Mapping (FIM) is a protocol used to collect baseline biophysical

information on current lakeshore conditions. The FIM uses a map-based approach to

characterize shorelines. The inventory includes data like shore type, substrates, land use and

habitat modifications that are geo-referenced and uploaded into a Geographic Information

System (GIS). Information is subsequently combined with fish population and other

environmental inventories to help develop a hierarchical picture of shoreline habitat values.

5. An Aquatic Habitat Index (AHI) is generated using the FIM data to determine the relative habitat

value of the shore. This index follows similar methods that were developed for lakes in the


7

Interior of BC. The Habitat Index combines many different criteria, such as substrates, shore

spawning locations, presence of aquatic vegetation, etc. to estimate the habitat value of a

shoreline segment.

6. Shoreline Management Guidelines are prepared to identify Shoreline Vulnerability. Shoreline

vulnerability is based on the AHI (in step 2 above) and is a risk-based approach to shoreline

management, assessing the potential risks of different activities for specific shoreline segments.

This report represents Step 1 in the foreshore management process. The primary goal is to analyze

available aquatic environmental data (both quantitative and qualitative) for Cowichan Lake, in relation to

existing land uses, and to facilitate better decisions in land use planning by all levels of government.

The Cowichan Valley Regional District (CVRD) encompasses almost the entire Cowichan Lake

watershed, except the lake outlet area, which is within the Town of Lake Cowichan's jurisdiction.

3.0 Methods

3.1 Foreshore Inventory and Mapping Methodology The Foreshore Inventory and Field Mapping (FIM) detailed methodology is presented in Appendix A.

This inventory is based on mapping standards developed for Sensitive Habitat Inventory and Mapping

(SHIM; Mason and Knight, 2001) and Coastal Shoreline Inventory and Mapping (CSIM; Mason and

Booth, 2004). Mapping and video for the Cowichan Lake FIM can be accessed through the Community

Mapping Network (CMN) website (http://www.cmnmaps.ca/cvrd/).

3.1.1 Biophysical Assessment of Shoreline Conditions

FIM field surveys were conducted by DFO over a four day period between October 20 and 27, 2010. The

assessment used 2006 colour ortho-photos obtained from CVRD, printed on 2'x3' sheets with legal

cadastre to assist with location of property boundaries on the lake. A Trimble GPS unit, equipped with a

Hurricane antenna, was loaded with a data dictionary (SHIM v. 2.6) to collect FIM data. The GPS was

also linked to the HD Video for tracking of video footage along the entire lake shoreline. Daily

information was downloaded to a laptop computer as a backup.

The following additional data fields were added to the FIM data dictionary:

1. For purposes of this assessment, "aquatic" vegetation includes any plant life occurring below the

high water level of the lake. This included plants that are not truly aquatic, however, all are

hydrophilic (water-loving) and contribute to fish habitat. Efforts were also made to map

overhanging (riparian) vegetation. The spatial extent of aquatic vegetation was classified into the

following groups:


8

Emergent - generally refers to native riparian plants that are tolerant of flooding for

short time periods (<4 months) and included trees (e.g., Red Alder), shrubs (e.g., Sweet

Gale), Reeds (e.g., Thule) and grasses (e.g., Equisetum spp.). Coverage within these

polygons needed to be consistent and well established. These areas were generally not

dominated by true aquatic macrophytes and occur in steeper shoreline areas.

Submergent - these submerged areas of vegetation (that do not break the water surface

for most of the growing season) were generally found in shallow bays on the lake.

Floating - included species such as native Potamogeton spp , pond lilies and other types

of vegetation that float.

2. Small stream confluences and seepage areas entering the lake. These streams were not identified

on existing 1:20,000 BC TRIM maps, so further field work was initiated to assess fish use.

3. The placement of log booms and associated pilings to protect docks from high waves is common

on Cowichan Lake. The locations and lineal lengths of "dock protection booms" were captured.

3.1.2 FIM Data Analysis General data analysis was completed from the FIM database. Data were collected with the goal of

analyzing each shore segment. For definitions and descriptions of the categories, refer to Appendix

A. The following summaries were completed using the FIM database for Cowichan Lake:

1. Percent distribution of natural and disturbed shoreline;

2. Total shoreline length that remains natural or disturbed for each land use identified

along the shoreline;

3. Total shoreline length that remains natural or disturbed for each (local government)

zoning category, and by geographic sections of the lake;

4. Total shoreline lengths that remain natural or disturbed for each shore type that

occurs along the shoreline;

5. Total length of shoreline that contained aquatic vegetation, including emergent,

floating or submergent plants;

6. Total number of shoreline modification features recorded;

7. Total shoreline length with different shoreline modifiers; and,

8. Level of Impact "Rating.”

The level of impact rating (#8 above) is a categorical description used to portray the general

disturbance observed along the shoreline. Disturbances are considered to be any changes to the


9

natural condition, caused by humans. Field assessors must be trained professionals and be

consistent in their site-specific determinations. Disturbance categories include:

a. Low - Segments that show little or limited signs of foreshore disturbance

and impacts. These segments exhibit healthy, functioning riparian

vegetation. They have substrates that are largely undisturbed, limited beach

grooming activities, and few-to-no modifications.

b. Moderate - Segments that show moderate signs of foreshore disturbance and

impacts. These segments exhibit isolated, intact, functioning riparian areas

(often between residences). Substrates (where disturbed) exhibit signs of

isolated beach grooming activities. Retaining walls (where present) are

generally discontinuous. General modifications are well spaced and do not

impact the majority of the foreshore segment.

c. High - Segments that show extensive signs of disturbance and impacts.

These segments exhibit heavily disturbed riparian vegetation, often

completely removed or replaced with non-native species. Modifications to

the foreshore are extensive and likely continuous or include a large number

of docks. Generally, residential development is high intensity. Modifications

often impact a majority of the foreshore segment.

For purposes of identifying the spatial distribution of development impacts on Lake Cowichan, the lake

has been organized into "arms," to allow communities and local residents to better grasp/understand the

findings (Figure. 2).

Figure 2. Arms of Cowichan Lake: A-South Arm; B-North Arm; C-Main Arm (source: T. Michalski,

MFLNRO, Nanaimo).


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3.2 Foreshore Modifications on Cowichan Lake In the Cowichan Lake FIM, the level and types of disturbance are summarized. What is missing from the

analysis is a better understanding of the "scope" of foreshore modifications compared to the natural

Cowichan Lake shoreline. For this report, the following questions were posed:

1. What are the natural erosion processes that influence shoreline stability on Cowichan Lake and

how are shoreline modifications impacting these processes?

2. What is the rate of change or shoreline conversion from undeveloped to developed (on

representative shoreline reaches) over the past four years?

To answer these questions, a review of existing reports and files was undertaken.

3.2.1 How Lakeshore Erosion Processes are Influenced by Development A report recently completed for the BC Conservation Foundation entitled "Cowichan Lake Erosion

Assessment" (KWL Assoc. Ltd. 2011) addressed the issue of shoreline erosion, including causes and

effects. The principal author, Eric Morris (M.Sc., P.Eng.), a Shoreline Erosion Specialist, was

interviewed to provide further clarity concerning several of his report's findings. Outcomes from the

KWL report were compared with Cowichan Lake FIM results.

3.2.2 A Comparison of Lake Shoreline Development between 2006 and 2010 To provide a measure of the changes resulting from land development along Cowichan Lake’s shoreline,

a comparison of "sample" shorelines, using videos taken in different years, was undertaken.

Under field direction of DFO, a video of the entire shoreline of Cowichan Lake was captured on

September 9, 2006 by members of the Lake Cowichan Salmon Enhancement Society. In 2010, as part of

the FIM project, DFO staff, with assistance from the (South Island District) Conservation Officer Service

and members of the Cowichan Lake and River Stewardship Society, completed a second video taping of

the lake shoreline between October 20 and October 27, 2010. The videos are available at the CMN

website (http://www.cmnmaps.ca/cvrd/).

To complete the comparison of shoreline development between 2006 and 2010, three representative

shoreline segments were selected with the assistance of the CVRD’s Development Services Department.

The locations selected were as follows:

1. All waterfront properties along the North Arm - accessed by Creekside Drive (Figure 3).

2. All waterfront properties along the Youbou waterfront (including Saseenos Point) from

Swordfern Park to the Youbou Lands development entrance (Figure 4).

3. All waterfront properties on Walton Road, from Sutton Creek to the entrance of Gordon Bay

Provincial Park (Figure 5).


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Figure 3. Creekside Subdivision video track.

Figure 4. Youbou Townsite video track.


12

Figure 5. Walton Road video track.

The CMN website has a video tracking module, showing the exact GPS location of the observer. This

was useful in aligning each video to show the same location along the shoreline. Videos were run on

separate (side by side) computer screens to allow for comparison of each property's development status.

A cross-check was made (at regular intervals) with the Cowichan Valley Regional District website, where

a mapping portal was accessed to allow for legal lot cadastre and "Property Identifier" (PID) tags to be

visible on a map. For the development review, each property was assessed as follows:

Riparian tree and shrub modification - the percent of a property's total shoreline where riparian

tree and or shrub modification has occurred between 2006 and 2010.

Erosion protection - a percent of a property's total shoreline where erosion works have been

installed between 2006 and 2010.

Beach creation/shoreline clearing - a percent of a property's total shoreline where changes have

occurred between 2006 and 2010.

Docks - Number of new docks and ramps installed between 2006 and 2010.


13

Figure 6. Shoreline elements used in video comparison between 2006 and 2010.

These parameters were observed in a manner that allowed the videos to be compared in a frame-by-frame

view of similar properties, so that a "percent of change in shoreline condition" can be ascribed to the site

(Figure 6). For example, if a property in 2006 showed no dock on the video and in 2010 a dock appeared,

then a new dock is identified in the table. For properties where modifications were visible between years

(e.g. riparian trees were thinned to promote views of the lake), then an estimate of area changed was

provided.

For purposes of summarizing the impacts to shorelines in the three study areas, a "level of impact" rating

was determined using the following criteria:

Low - where a "change" has been identified (between 2006 and 2010) that occurs on <30% of the

shoreline length of the property.

Medium - where a "change" has been identified (between 2006 and 2010) that occurs on >30%

but <60% of the shoreline length of the property.

High - where a "change" has been identified (between 2006 and 2010) that occurs on >60% of

the shoreline length of the property.

3.3 Fish Population Sampling A number of fish population assessments were completed at pre-selected shoreline locations during the

summer and fall of 2011 on Cowichan Lake, using a range of sample techniques. Sites were selected based on their representation of the shoreline segment's shore type, level of disturbance, slope and

suitability to quantitatively sample fish.


14

The method used to sample fish at each site depended on the site's physical habitat conditions. Beach

seine netting was the preferred method used where a gravel beach provided excellent opportunities to capture fish over a (shallow) shoal area (Figure 7). A 30m long seine net with 5 mm stretch mesh was

dropped into the water by boat, as it made a semi-circle set around the sampling area. The target netting area was determined on-site, and depended on specific physical characteristics (i.e., presence of netting

obstructions like large rocks or woody debris). The net was drawn onto the exposed shoreline with care

to ensure the lead line stayed tight on the bottom. Fish were collected from the net, identified to species, and returned live to the same area where they were captured. All salmonids were measured to fork length

and released.

Figure 7. Seining a sandy beach and snorkelling to assess local fish abundance.

Snorkelling was a preferred technique in locations where depth was greater than 3 meters and biophysical conditions made netting difficult (i.e., macrophytes or woody debris were present). Snorkel surveys were

carried out during daylight hours, using three observers abreast, along a 200 m x 30 m transect that followed the contours of the shoreline. All personnel were equipped with a drysuit, hood, gloves and

mask/snorkel. All fish species observed were noted. Observers discussed their individual counts before

determining a final fish tally, to ensure double counting was minimized. Snorkel surveys were used more in the fall assessment season, sometimes in combination with netting (Figure 7).

Minnow trapping was used in combination with snorkel surveys or netting, to confirm fish identification

and fish size. To improve fish capture results in the fall, we increased the number of traps used (from 4 to 20/site), changed bait (from canned cat food to salmon roe), and allowed traps to soak for longer time

periods (from 2 to 20 hours).

The influence of high lake water levels on the behaviour of juvenile fish using the shoreline in winter was

added to the scope of the project in January 2012. Due to limited time and funding, a reconnaissance of

previously sampled sites was planned, to confirm fish presence using snorkel observations. Other

methods for sampling (seining, minnow trapping) were ruled out as having very limited utility in flooded

shorelines. A snorkel survey was attempted on January 5, 2012 to determine the efficacy of this

approach.

In September 2011, a field assessment of adult lamprey spawning and ammocoete (larvae) rearing habitat was undertaken using electrofishing techniques in streams and creek mouths on the lake. Results are

outlined in a report submitted to DFO (Appendix F2).


15

3.4 Fish Data Analysis An important component in defining the "importance" of different shore-types to fish productivity

required an analysis of the fisheries index site sampling data. Data analysis followed protocols used in

the Windermere Lake study (McPherson, 2008). Summer and fall data were analysed and presented

separately to provide seasonal reference to fish use of the various shoreline habitat types. Data was not

analysed using statistical methods, as Cowichan data collection was designed to allow for simple

calculations – i.e., presence/absence and relative abundance of species in the various lakeshore habitat

types. Relative abundance was calculated using grouped data across similar shore types. For each

season, all fish sampled/observed (using netting and snorkel surveys) from a particular shore type were

pooled and the relative abundance for the particular shore type was calculated, by species. The

assumption is that if fish are sampled in a particular shore type, utilization of that shore type would be

comparable in similar shore types around the lake.

3.5 Fish Species of Cowichan Lake A literature review on the ecology and life history of each fish species known to inhabit Cowichan Lake

was completed. This resulted in a one-page summary defining important characteristics of the species

and their relationship to shoreline habitats. It was assumed that all fish that reside in Cowichan Lake

utilize the foreshore for a portion of their life history. The literature review provides a brief description of

the importance of shoreline environments and the lake foreshore ecosystem in meeting native fish species

habitat needs. The Ministry of Forests, Lands and Natural Resource Operations (MFLNRO) in Nanaimo

provided fish inventory files for review, as well as unpublished reports. A draft report entitled, "Lake

Management Plan for Cowichan Lake" by Tracy Michalski, RPBio., was also reviewed.

Fish Information Summary System (FISS) databases were accessed to confirm fish species known to exist

in the lake. Cowplan 2002 (Burns 2002) was also referenced for fish habitat restoration and enhancement

projects. Steve Baillie of DFO (Stock Assessment Unit, South Coast Area, Nanaimo) was interviewed

about historical salmon research that has been ongoing on the lake for the past 30 years.

The SARA-listed Vancouver Lamprey was the subject of a SARA Recovery Strategy report that was

published in September 2007. This document has a detailed account of life history information for the

species and has been appended to this report as Appendix F1.

It is well known by anglers and (long time) local residents that Kokanee spawn on the shorelines of

Cowichan Lake, however, there have been no records kept by agencies of these locations or numbers of

fish using them over time. Recording traditional spawning locations is important for future protection of

critical shoreline habitats. For this project, a number of local anglers were contacted regarding their

knowledge of Kokanee spawning locations and timing.

3.6 Assessment of Fish Habitat Potential in Unmapped Inlet Streams (Fall

2011) During the FIM assessment in October 2010, several small streams were identified by the surveyors

that were not previously mapped on (Provincial Standard) TRIM stream layers for Cowichan Lake.


16

In the fall of 2011, in association with shoreline fisheries assessments, a total of 17 streams were

assessed using a modified Level 1 Habitat Survey Data Form (Johnston 1996). GPS coordinates were

used to locate where each stream discharged into the lake. The general survey approach was to walk

the stream channel for at least 100 meters upstream from the lake, to gauge stream size, habitat

conditions and barriers to fish upstream migration. Many of these site visits involved walking up-

stream to a main road crossing (North or South Shore Roads). No fish sampling was attempted,

however, if the channel was wetted fish observations were made. Upon completion of the survey

form, professional judgement was exercised on whether a stream represented viable salmonid fish

habitat (embracing some or all phases of a “typical” salmonid life history). A rating of "good" or

"poor" was used. Professional opinion was based on the following considerations:

Level of human disturbance to stream;

Stream slope/gradient - gradients>15% = poor/gradients <15% = good;

Channel Substrates - no moss on substrates = poor/ moss on substrates = good;

Channel morphology - no stable LWD present = poor/stable LWD present = good

Presence/absence of barriers to fish migration upstream.

This commentary must be viewed with caution, as this was not based on an extensive fish and habitat

inventory of each stream, but rather on a "snapshot" of the lowest reach in time and place. A file

search of stream surveys in the Lake Cowichan area was conducted to determine whether any of the

streams had been subject to previous field investigations. Locations of the 17 small inlet streams can

be found on the CMN website (http://www.cmnmaps.ca/cvrd/).

4.0 Results

4.1 Foreshore Inventory: Biophysical and Shoreline Characteristics of the

Lake

The following section provides an overview of the Cowichan Lake system. Data is presented graphically

for ease of interpretation. Cowichan Lake FIM data is available in Appendix B.

Foreshore inventory and mapping was completed on 100,111m (100.1 km) of shoreline on Cowichan

Lake. This represents 100% of the lake's "outside" perimeter. Small islands in the lake, representing 6.7

km of shoreline, were not assessed using FIM. The total length of disturbed shoreline was 29,505m

(29.5km), which represents 29.4% of the shoreline (Figure 8). The total length of shoreline in a natual

condition was 70,607 m (70.6 km), which represents 70.5% of the shoreline.


17

Figure 8. The total shoreline length rated “natural” or “disturbed” on Cowichan Lake.

When looking at the spatial distribution of developments on the lake (refer to Figure 2), the FIM rated

76% of Main Arm’s shoreline as being in a natural state (Figure 9). Within the Main arm, 24% of the

shoreline is rated as disturbed, with the Village of Youbou accounting for 6% of the disturbance. The

remaining 20% of shoreline disturbance is linked to old log dumps or recent campground developments.

Along the South Arm, the disturbed shorelines are primarily located adjacent to the Town of Lake

Cowichan (29%), and along the Honeymoon Bay waterfront (20%). The North Arm displays a lineal

disturbance of shoreline associated with residential development along the Youbou Road, while the Bald

Mountain shoreline remains in a natural state.

Figure 9. Length of disturbed and natural shorelines within the different arms of Cowichan Lake.

The Cowichan Lake FIM identified that 48% of the shoreline is presently dedicated to forestry use. These

forestry-based lands provide a healthy riparian buffer, with 85% of the shoreline classified as being in a

natural state (Figure 10). Forests surrounding the lake’s shoreline are now in a second growth phase (80+

years old) and are managed to protect riparian function with setbacks from streams and lakes (PMFL

2012). The next most dominate land use is single family, which accounts for 30.5% (30.6 km) of the total

0.00 20000.00 40000.00 60000.00 80000.00

Disturbed

Natural

Shoreline Length (m)

Nat

ura

l vs

. Dis

turb

ed

Sh

ore

line

0% 20% 40% 60% 80% 100%

North Arm

South Arm

Main Lake

Percent of Shoreline Length

Arm

s o

f C

ow

ich

an L

ake

Disturbed

Natural


18

shoreline. Disturbance of shorelines was greatest in this land use type, with 64% of lakeside homes and

cottages having either removed riparian vegetation, constructed retaining walls or modified substrates

(sometimes in combination). Industrial lands identified in the FIM were either old mill sites or log dumps

that are no longer used for fibre processing. Many of these sites have, or are currently undergoing, local

government rezoning for conversion to residential use.

Figure 10. Length of disturbed and natural shoreline by land use types.

It is important to understand the FIM is a "field-based" attempt to categorize existing land use. To ensure

this is placed in the context of current zoning, shoreline segments were compared to local government

(CVRD and Town of Lake Cowichan) zoning maps available at the following websites:

http://www.cvrd.bc.ca

http://www.town.lakecowichan.bc.ca/bylaw%20land.shtm

When FIM data is compared to zoning maps, forestry zoned lands represent the largest shoreline segment

on the lake (54%). Residential (Single Family) zoned lands account for 26% of the total shoreline length.

Shorelines with residential zoning were the most disturbed (65%) on the lake (Figure 11). It is interesting

to note that a large tract of land, east of Honeymoon Bay, is zoned "Agricultural," yet remains in a natural

(forested) state. Commercially zoned properties appear to be used for RV camping and marinas.

Although this zoning represents a small area on the lake, they are subject to intensive shoreline

disturbance. Several existing sites zoned industrial, where wood manufacturing (sawmilling) was

previously dominate, are today presented as large "clearings" beside the lake. Some of these sites are

now being rezoned to allow for re-development (e.g., Youbou Lands).

0 20000 40000 60000

Forestry

Industrial

Natural Areas

Park

Recreation

Single Family


Lan

nd

Use

Typ

es

Disturbed

Natural


19

Figure 11. Length of disturbed and natural shoreline by CDRD zoning.

Gravel shorelines dominate (72%) the physical composition of shore types observed (Figure 12). This

was confirmed in a recent report on lakeshore erosion by KWL Assoc. Ltd. (2011), where moderately

sloped (5-20 degrees) shorelines with cobble, gravel or sand substrate are distributed throughout the lake

(Figure 13). Gravel shorelines are subject to the majority of all shoreline disturbances (92%). FIM data

showed that only 4.6% (4,600m) of the shoreline is classified as having “stream mouth” characteristics,

with wetland shore types accounting for only 0.5% (455m). No major disturbances were measured at

these highly ‘fish-sensitive’ shore types, except at the Catalyst weir (lake outlet), where a marina and

residential development are changing shoreline conditions.

Figure 12. Length of disturbed and natural shorelines observed within the different shore types.

0 20000 40000 60000 80000

Agriculture

Commercial

Forestry

Industrial

Indian Reserve

Parks

Residential


Loca

l G

ove

rnm

en

t Zo

nin

g Disturbed

Natural

0 20000 40000 60000 80000

Cliff/Bluff

Gravel

Rocky Shore

Sand

Stream Mouth

Wetland

Shore Length (m)

Sho

re T

ype

Disturbed

Natural


20

Figure 13. Predominant shoreline substrates of Cowichan Lake (KWL Assoc. Ltd. 2011).

The definition of aquatic vegetation used in the FIM is defined as any type of vegetation (emergent,

submergent or floating) that occurs below the lake's average high water level (164.0m elev.). The aquatic

vegetation analysis includes true macrophytes (submerged in water) and those plants that are hydrophilic

or tolerant of periods of inundation during high water levels.

The FIM identified approximately 20 km (21%) of the shoreline with aquatic vegetation present (Figure

14). Most vegetation observed was classified as emergent, with hydrophilic shrub species (e.g., Myrica

Gale spp.) occurring along 20% of the entire lake shoreline. Areas of submergent (e.g., Thule spp.) and

floating vegetation (e.g., Potamogeton spp.) were rare in the lake, observed in only 3 km of shoreline

length. In the lake outlet area, a dense mat of Eurasian water-milfoil (Myriophyllum spicatum) has

established itself near the public boat ramp. Only a limited assessment has been done to date to assess the

movement of this invasive plant species into other areas of the lake (MoE files, Nanaimo).


21

Figure 14. Total shoreline length by major type of aquatic vegetation.

Docks are the most common shoreline "structural" modification observed (n=596) on the lake (Figure

15). Retaining walls are the next most numerous shoreline modification feature (n=360). Both types of

structures can have significant impacts on shorelines, contributing to serious erosion and instability to

natural shoreline processes, depending on how and where they are installed (KWL Assoc. Ltd. 2011). In

the past, docks were installed without regard to shoreline impacts, however, today the use of properly

installed gangways with anchored dock flotation systems on pilings is more common. Concrete boat

launches were identified in 119 different locations on the lake and rock groynes at 52 locations. All of

these structures, if installed on gravel beaches below the high water mark, can disrupt sediment transport

and cause erosion.

Figure 15. Total number of different shoreline modifications identified on Cowichan Lake.

0 5000 10000 15000 20000 25000

AquaticVegetation

SubmergentVegetation

EmergentVegetation

FloatingVegetation

Shoreline Length

Aq

uat

ic V

ege

tati

on

0 100 200 300 400 500 600 700

Retaining Wall

Docks

Boat Houses

Groynes

Boat Launch

Marine Rails

Marinas

Number of Structures

Typ

e o

f St

ruct

ue


22

Length of shoreline impacted by major developments such as roads, retaining walls, dock protection

boom-sticks and substrate modification, was recorded. In summary, 17% or 17 km of shoreline have had

some form of substrate modification (e.g., rock groynes) and 9% or 9 km have been impacted by retaining

walls (Figure 16). Floating boom-sticks (i.e., floating logs located in front of docks) are becoming

common, representing 12.5% or 12.5 km of the shoreline. They are popular with boat owners who see

them as effective in dampening waves from passing water craft and/or strong winds. The impacts they

have on shoreline conditions are discussed in Section 4.2.

Figure 16. Total shoreline length physically altered by development.

Removal of shoreline vegetation around the lake is difficult to quantify in a FIM study like this. It is

difficult to determine whether emergent vegetation has been removed, or whether it ever existed at

specific locations historically. The FIM does rate the "condition" of riparian vegetation as "patchy" or

"continuous," which are indicators of human-related impacts. In a review of riparian vegetation

conditions in relation to land use, the highest impacts occurred along shorelines where single family

developments exist (Figure 17).

0 50000 100000 150000

Total Shoreline Length

Substrate Modification

Roadway

Retaining Walls

Protection Booms


Mo

dif

icat

ion

Typ

e


23

Figure 17. Condition of riparian vegetation by land use type.

Ranking of shoreline impacts identified 25% (25.3 km) of the lakeshore as being highly impacted (Figure

18). This corresponds with high levels of disturbance from residential (single family) land developments

on the lake. Commercial and industrial lands also account for high impacts. Moderate impacts were

assigned to 20% of the shoreline, with 55% (55 km) of the shore having either low or no impacts

observed.

Figure 18. Ranking of development impacts to the shoreline of Cowichan Lake.

4.2 Foreshore Modifications on Lake Cowichan

4.2.1 Shoreline Erosion and Effective Shoreline Protection In his 2011 report entitled, "Cowichan Lake Erosion Assessment," Eric Morris, P.Eng., of KWL Assoc.

Ltd. provided a concise outline of shoreline erosion processes. Erosion forces are caused by gravity,

0 5 10 15 20 25

Forestry

Single Family

Park

Natural

Industrial

Recreation

Number of Shoreline Segments

Lan

d U

Se T

ype

Patchy

Continuous

0

5000

10000

15000

20000

25000

30000

35000

40000

High Medium Low None

Sho

relin

e L

en

gth

Level of Impact

High

Medium

Low

None


24

waves, wind friction, cohesion, water currents and human activity. Erosion forces can be divided into

"constructive forces" that build up a shoreline, and "destructive forces" which erode them.

Over time, gravity, friction, waves and human activity have been dominate forces that have shaped the

lake’s shoreline. The major destructive force is caused by waves, which are generated by both wind and

boat traffic. The force of waves can vary and depends on many factors. Generally, they are divided into

two components: long shore and cross shore. Beaches on Cowichan Lake are subject to waves of

different heights and directions throughout the year, and waves generated by local wind conditions tend to

be steep and destructive. Erosion impacts from these waves will largely depend on the substrate

composition of shorelines.

Shorelines generally are classified according to their composition (KWL Assoc. Ltd. 2011). The main

categories are:

1. Cohesive (e.g. bedrock, clay, vegetated)

2. Non-cohesive; and

3. Man-made.

Cohesive shorelines are composed of materials such as bedrock and clay. Vegetated shorelines are also

in this category, as there is a high degree of erosion resistance due to root strength of native riparian plant

species. Riparian vegetation also can diminish wave energy.

Non-cohesive shorelines consist of beaches made of sand or gavels. Erosion resistance increases with

the size of particles and decreases with increasing steepness of the slope. The slope profile of non-

cohesive beach sediments eventually reaches a stable angle of repose as determined by various

geomorphological processes at work (Guthrie 2005).

Man-made shorelines include many retaining walls constructed of rip rap or cement. Erosion resistance

is highly localized and these structures tend to transfer impacts to adjacent unprotected properties/areas

(i.e., “collateral damage”).

FIM shoreline analysis indicates >72% of substrates that characterize the lake's shorelines are gravel and

cobble beaches. Up until 50 years ago, these beaches were "naturally vegetated" and consisted of

hydrophilic plants and shrubs which provide beaches with cohesive strength to resist erosion. These

vegetated shorelines are considered to be in "equilibrium" with the lake’s wave energy dynamics.

However, the FIM also indicates that gravel shorelines are increasingly being "disturbed," particularly by

owners of single family residences who are clearing waterfronts for improved views and recreational

purposes. Conversion of gravel beaches from cohesive to non-cohesive, man-made conditions is

accelerating, resulting in greater erosion pressures on the lake’s shoreline.

Stability or equilibrium of the shoreline is dictated by the sediment budget and wave energy in the lake.

A shoreline is said to be in long term equilibrium when the edge of the shore does not shift (for a given

water level) over long time periods (KWL Assoc. Ltd. 2011). This does not mean there is no erosion and

resulting sediments, but there is a natural balance of sediments flowing onto a beach and sediments

flowing off-shore or along a beach. If a beach is cut off from sediment sources, for example by building a

retaining wall, then the shoreline equilibrium is disturbed and more erosion will likely occur. Eric Morris

noted that waves are particularly destructive at high lake water levels. His report described how many


25

retaining walls he observed were not properly designed/engineered, making them ineffective in the face

of major storms, especially when lake levels rise above 164m elevation.

Construction of retaining walls and groynes, or the removal of riparian vegetation below the 164m elev.

will, he concluded, disrupt natural shoreline erosion processes and lead to shoreline instability, especially

in specific areas where modifications have occurred. More recent development of floating docks on the

lake, using pilings or anchors to position the floats, coupled with an access gangway (to minimize impacts

on gravel beaches and riparian vegetation), do not typically create unstable shorelines. Use of "boom-

stick" wave attenuation structures to protect docks and boats (a now common practice on the lake) were

not fully assessed in the KWL Assoc. Ltd. (2011) study.

Certain lake shorelines are more vulnerable to wind-driven wave energy (Figure 19). The most exposed

areas include Youbou Lands (Cottonwood Creek fan), Youbou, Sa-Seen-Os Point and Bald Mountain.

Figure 19. Wind/wave energy map of Cowichan Lake (KWL Assoc. Ltd. 2011).

In comparing Figure 19 with the FIM, much of the Youbou shoreline (FIM Segment 20) is dominated by

gravel beaches that have undergone significant changes over the years with construction of retaining

walls. Youbou Lands (FIM Segment 22-24) are composed of (vegetated) gravel beaches, and do not

appear to be subject to erosion at this time; however, this could change with future land development


26

plans. Shorelines along the south and north arms of the lake are rated as having a moderate vulnerability

to wave erosion from prevailing winds, however, waves from high boating activity (vessel wake wave

energy) are identified as a source of erosion at specific locations.

4.2.2 Shoreline Development Comparison: 2006 versus 2010 The video comparison provides a unique snapshot of the impacts experienced along "sample" shorelines

over a four year time period. The video quality for 2006 was poor due to light conditions (overcast) on

the day of filming, making identification of objects smaller than 1 square meter difficult. For new docks,

it was difficult to identify an "impact" to the shoreline from video coverage. The potential for negative

impacts would be in their siting over aquatic plant communities, or a dock with improper separation

between the shore and float. In such cases, a dock may be "dragging" along the shoreline and causing

local erosion. So, in this analysis, a "new" dock, with a "gangway" was identified as having low impact,

as docks are designed to sit in deeper water, with shoreline vegetation remaining intact. There were no

"new" docks identified in study areas that did not have gangways.

Video comparison data tables are available for Creekside in Appendix F1, Walton Road in Appendix F2

and Youbou in Appendix F3.

4.2.2.1 "Creekside" Shoreline Development (2006-2010) Development of the subdivision known as "Creekside" is located along the North Arm of

Cowichan Lake. As part of the (2005/06) subdivision approval of 75 shoreline lots, the

development was subject to CVRD bylaws, designed to protect the riparian area of the lake. A

Riparian Areas Regulation detailed assessment report was completed and registered with the

Ministry of Environment in 2006, that described how the development would protect riparian

setbacks and allow for limited landowner access/use of the shoreline. The CVRD also

implemented zoning on the lake to minimize shoreline impacts from docks. This "dock strategy"

involved permitting a single dock for every two houses through zoning of the lake to limit

shoreline disturbance.

In comparing the shorelines of fifty properties (developed to date), 26 properties (52%) have

undergone changes to the shoreline between 2006 and 2010 (Figure 20).


27

*One property can have up to 4 impacts identified

Figure 20. Number, type of modifications and impacts identified along Creekside (2006-2010).

Between 2006 and 2010, construction of new homes has mushroomed. Videos show that tree and

shrub removal has occurred on half of the developed properties along this shoreline. This is

interesting, as the shore is protected by local government bylaw. All house construction

"envelopes" are located outside of the Development Permit Area (SPEA). Modifications within

the DPA require an on-site assessment. Video comparison shows a majority of thinning has been

limited to less than 50% of existing vegetation, and appears related to improved views from the

home and not part of widespread clearing of riparian vegetation on individual lots (Figure 21).

Clearing to make a "beach" has occurred on 19 properties, however, the scope of clearing appears

limited.

Results of the video comparison for Creekside are encouraging, especially with regard to erosion

protection, with no construction of retaining walls identified. The only structures placed within

the shoreline were dock gangways anchored to a small concrete slab for durability and stability.

The near absence of retaining walls along this shoreline is very good news, as these properties do

have a significant slope and potential erosion risks.

Between 2006 and 2010, fifteen new docks were installed. It is not known whether these docks

followed CVRD guidelines for docks, or BMP's for installation. In reviewing the 2010 video,

general dock placement and construction practices appear to be effective in limiting riparian

vegetation removal and associated modifications to the shoreline area. Most docks were installed

with aluminum gangways that appear to be anchored properly to shore.

0

2

4

6

8

10

12

14

16

Tree andShrub

RemovalN=23

ShorelineClearing

N=19

ErosionProtection

N=0

New DocksN=15

Creekside - North Arm*

Low (10% - 30%)

Medium (40% - 50%)

High (>60%)


28

Figure 21. Example of shoreline changes to a Creeksde property - Left -July 2007; Right- Oct 2010.

In a recent conversation (Feb. 2010) with an area resident, he indicated the CVRD "dock

strategy" policy was not going to remain a requirement of future development permitting of

Creekside properties. If this is correct, then all properties will have an opportunity to build a

dock. This will result in significant impacts to the shoreline. With no control on the number of

docks or appropriate designs, there are likely to be significant changes to riparian vegetation in

coming years.

4.2.2.2 Youbou Shoreline Development (2006-2010) The Village of Youbou began as a small, forest-dependent community on the shore of Cowichan

Lake in 1907. The village was established as a residential community to support the Cottonwood

sawmill and logging operations on the lake’s north shore. In the past 20 years, the town has

changed from an industrial hub for sawmilling, to a "retirement" and "recreational" community.

Properties on the waterfront were developed many years ago, with little regard to shoreline

impacts. Many of the large (acreage) properties west of town were cleared in the 1920's from

Youbou Road down to the lake, with no original riparian vegetation remaining. In the town area,

west of Sa-Seen-Os Point, homes were built close to the lake with cement retaining walls

commonly used to buttress properties from winter storms and high lake levels. Further west of

the town centre, a recent development (Youbou Lands) has been approved on the old sawmill

site.

The video comparison looked at whether re-development is resulting in further shoreline

modifications. From the video comparison, a total of 34 shoreline properties (24%) have

undergone some development between 2006 and 2010 (Figure 22).


29

* One property can have up to 4 impacts

Figure 22. Number, type of modifications and impacts Identified along Youbou (2006-2010).

Certain commercial properties were difficult to assess shoreline changes over time (e.g., Ben’s

Marina), due to the small area and many modifications to docks and campsites. Overall, the rate

of change to the Youbou shoreline was less than 10%, with very few properties undergoing tree

and shrub removal, or shoreline clearing. This result was expected, as the Youbou waterfront

underwent significant shoreline change several decades ago. What was striking, were the number

of new retaining walls (n=16). Many of these could be replacements for aging or failing original

structures.

Noteworthy, is the likelihood that none of these walls were formally permitted by the Province of

BC. This was supported through a request to the Ministry of Forests, Lands and Natural

Resource Operations concerning the number of Section 9 (Water Act) Authorization Permits

issued to construct retaining walls on Cowichan Lake in the past 6 years. To wit, only one permit

has been issued.

As discussed above, the Youbou shoreline has undergone significant alteration over the past 100

years. Many of the new changes taking place are "retrofits," where older homes are either

remodelled or demolished and new homes built on existing foundations (Figure 23). Often these

retrofit homes include an amenity such as a private boat launch, which adds to the hardening of

the lake shoreline.

0

5

10

15

20

25

Tree andShrub

RemovalN=13

ShorelineClearing

N=12

ErosionProtection

N=16

New DocksN=20

Youbou - Main Arm*

Low (10% - 30%)

Medium (40% - 50%)

High (>60%)


30

Figure 23. Example of house re-development in Youbou (MoE - 2007).

4.2.2.3 Walton Road Shoreline Development (2006-2010) The Walton Road study area is a small community of residences and Commercial RV Parks, west

of the Village of Honeymoon Bay. Many of the 41 properties have been developed for use as

seasonal cottages or year-round single family residences. Most buildings appear to have been

built 40+ years ago (Figure 24). There are two commercial campsites located in this area.

Much of the natural shoreline has been highly disturbed, a result of many decades of

cottage/residential development. The beach consists of small gravels with sand. The prevailing

beach profile is low gradient (<5%), with housing located on a low elevation bench next to the

lake. In a review of CMN mapping of the lake, land elevation contours derived from LIDAR

show many homes along Walton Road are constructed between 164m and 167m elevation. This

indicates that homes in the area were constructed prior to the CVRD's building bylaws for new

house construction, that now require a house to be built above the lake's 200 year flood elevation

level (167.33 m elev.).

In comparing the videos, it appears that many of the developed properties have existing retaining

walls (constructed prior to 2006). Retaining walls are constructed of cement, and allow for

backfilling in front of the residence, to offer protection from high winter water levels. Retaining

walls are also common in the RV parks, where campsites are located adjacent to the lake. Most

properties in the Walton Road study area have a dock or float in front of the residence, however,

most docks are old and do not have a fixed gangway from the shoreline for access. Docks are

partially protected along the shoreline by a continuous boom-stick, deployed by property owners

over the years. Pilings are used to anchor many of the docks and associated wave protection

booms.


31

Figure 24. Example of cottage housing in Walton Road area (MoE -2007).

Between 2006 and 2010, the video comparison identified only two properties of the 41 (5%) with

a change to shoreline conditions (Figure 25). One of the properties had rebuilt a retaining wall,

and one property was cleared and undergoing house construction.

Figure 25. Number, type of modifications and impacts identified in Walton Road area (2006-2010).

0

1

2

3

4

5

Tree andShrub

Removal N=2

ShorelineClearing N=1

ErosionProtection

N=0

New DocksN=0

Walton Road - South Arm*

Low (10% - 30%)

Medium (40% - 50%)

High (>60%)


32

4.3 Fish Sampling Table 1 provides a summary of the number of index sites sampled for fish abundance and methods used

for fish capture in 2011. A summary of site descriptions is provided in Appendix C1. Site sample

locations can be viewed on the Cowichan Valley Watershed Atlas at the CMN website

(http://www.cmnmaps.ca/cvrd/).

Table 1. Method and number of capture attempts in sampling Cowichan Lake fish abundance in 2011.

Summer (June/July) Fall (Sept)

Number

of Sites

Sampled

Number of

Fish

Capture

Attempts

Snorkel Seine Minnow

Trap

Number

of Sites

Sampled

Number of

Fish

Capture

Attempts

Snorkel Seine Minnow

Trap

26 26 5 17 4 25 31 13 16 3

To ensure an adequate sample of the fish community at each site, some sampling technique(s) were

changed in the fall field sampling, due to physical variability in sites caused by changing lake water

levels. In the summer field assessment, mean lake level was 1.46m elev., while in the fall assessment

(September), the mean lake level was 0.96m elev. as determined by Water Survey Canada (WSC Station

08HA009). This ‘phenomenon’ of decreasing lake water levels during summer months is a result of flow

regulation at the Catalyst weir, where discharge to the Cowichan River is managed (Figure. 26). This

~0.5m drop in lake level had an effect on shoreline conditions for some sites which influenced sampling

protocols. For the fall sampling, site #16 was dropped from the list due to an abundance of woody debris

in the area. Snorkel surveys were used more in the fall, as water clarity was excellent (5m+), and

submerged woody debris lying on the gravel shoals made seine netting difficult.

Figure 26. Recorded daily water levels for Cowichan Lake in 2010, with max. and min. water levels observed (1913-2010) Source: Water Survey of Canada.


33

An attempt to sample fish in "high" lake water conditions was done on January 5, 2012. Water levels

were monitored, and after several large storm events in late December 2011, the lake level was recorded

at 2.5m (WSC Station 08HA009). Snorkel techniques were used to assess fish abundance in three

representative shoreline sites. Results were disappointing, with only one unidentified juvenile fish seen.

There are a number of reasons for these poor results:

Poor water clarity. This was the biggest factor that reduced daytime snorkel observation's sampling effectiveness. In response to heavy rains, sediment inputs from inlet streams and

flooded lands draining into the lake reduced visibility to <2 m.

Poor daylight conditions. Coupled with suspended sediment in the water, the low winter sunlight and cloudy conditions weaken an observer’s ability to "see" in flooded riparian

vegetation where (we believe) fish were hiding.

Cold water temperatures. Temperature of lake surface water was 6.5˚C on Jan.5th. Fisheries scientific literature indicates that salmonids are much less active in cold winter water

temperatures. Winter snorkel surveys, completed by BCCF to assess fish use of LWD habitat in rivers, indicate that juveniles "emerge" at night to opportunistically feed (C. Wightman, RPBio.,

pers. comm.). Night snorkel assessments have been previously done successfully in Okanagan

Lake (Schleppe 2006).

Safety of Observers. Cowichan Lake, at higher winter water levels is not a safe environment for

boating due to floating logs and debris. Hypothermia of surveyors, caused by exposure to cold air temperatures during transport in an open boat, is a serious crew safety concern.

Complexity of flooded riparian areas, and the exponential increase in "available area" for salmonids to hide. With an additional 1.6 meters of water covering the shoreline (from observed summer low levels), the riparian cover available for fish multiplied significantly, presumably

allowing fish to widely disperse.

Comparisons of how site conditions change due to lake water levels in the winter, compared to fall, are

demonstrated in the photos below (Figure 27).

Site 11 January 5, 2012; Elev. 2.5m Site 11 September 14, 2011; Elev. 0.9m


34

Site 19 January 5, 2012; Elev. 2.5m Site 19 September 14, 2011; Elev. 0.9m

Site 14B January 5, 2012; Elev. 2.5m Site 14B September 14, 2011; Elev. 0.9m

Figure 27. Comparison of Cowichan Lake fish sample sites - winter vs. summer water levels.

Table 2 provides a summary of index site general locations, FIM segments, shore types and levels of

disturbance. Site numbering followed sampling order, which started at Gordon Bay Provincial Park and

proceeded west into the Main Arm, then North Arm and South Arm. Sites were distributed

geographically around the lake as follows:

Main Arm = 11 index sites

North Arm = 4 index sites

South Arm = 11 index sites

Sample sites represented the dominate foreshore conditions in the area, with the Main Lake having the

most sites characterized as low/no impact, while the South Arm had the most medium/high impacted

sites.


35

Table 2. Description of Cowichan Lake fish sample index sites, 2011.

Site Number

Foreshore Segment

#

(FIM Report)

Shore Type Level of

Disturbance

Location

1A 35 Rocky Shore None Narrows north of Gordon Bay

1B 35 Rocky Shore None South Shore -Opposite Youbou

2 36 Gravel Beach Low Cove Opposite Sa-Seen-Os Point

(Youbou)

3 22 Gravel Beach Medium Youbou Mill

4 40 Rocky Shore High South Shore Road

5 47 Stream Mouth Low Mouth of Shaw Creek

6A 49 Gravel Beach Low South Shore of Hawes Bay

6B 49 Gravel Beach Low Hawes Bay

7 53 Wetland None Wetland/Shoal area along North Shore

Road

8 24 Gravel Beach None Youbou Lands

9 23 Stream Mouth None Mouth of Cottonwood Creek

10A 18 Gravel Beach High Miracle Way waterfront

10B 18 Gravel Beach High North Shore Road

11 15 Cliff/Bluff None Bald Mountain

12 16 Rocky Shore Low North Shore of the Bald Mountain

Peninsula

13 34 Sandy Beach Medium Gordon Bay Park Beach

14A 33 Gravel Beach High Walton Road Area- Honeymoon Bay

14B 33 Gravel Beach High Honeymoon Bay

15 32 Gravel Beach High Hancock Lands near Bear Lake

16 28 Gravel Beach Low Forest Research Area

17 29 Gravel Beach Low Forest Research Area

18 12 Gravel Beach Medium Marble Bay

19 27 Gravel Beach Medium Point Ideal

20 25 Stream Mouth Medium Weir at Lake Outlet

21 1 Stream Mouth High Boat Launch adjacent lake outlet

22 4 Rocky Shore High Town Water Intake area

4.4 Lamprey Sampling On October 7, 2011, an electrofishing survey was attempted on Cowichan Lake with a specific focus on

creek mouth habitats. Unfortunately, the survey was abandoned due to high lake levels and turbid inlet

streams. A large rainstorm (100mm+), just days prior to the survey, created the poor field sampling

conditions. A boat survey of potential Vancouver Lamprey spawning sites is described in Section 4.4 of

this report, with the full report found in Appendix F1. In the fall of 2012, a follow-up field investigation


36

was completed under separate contract to DFO Biologist, Warren McConnachie. A report, will be

completed in the near future, and added to this report as an addendum.

4.5 Fish Sampling Results A summary of fish sampling results from the summer (June/July) of 2011 is found in Appendix C2. A

summary of fish sampling results from the fall (September) of 2011 is presented in Appendix C3. A

detailed record of each Index Site sampling results appears in Appendix C4.

As outlined in the Methods (Section 3.4), fish sampling data was not analysed using conventional

statistical treatments, as the field survey design was only intended to produce species presence/absence

and relative abundance in the various lakeshore habitat types (McPherson, 2008). Relative abundance

was calculated using grouped data across similar shore types. For each season, all fish sampled/observed

(using netting and snorkel surveys) from a particular shore type were pooled and the relative abundance

for the particular shore type calculated. The assumption is that if fish were sampled in a particular shore

type, utilization of that shore type would be comparable elsewhere in the lake.

Sampling techniques were not viewed as being "selective" for certain species, therefore, fish captures (by

species) for each site were combined (i.e., if two methods were used to sample the same site - e.g.,

snorkel counts and seine netting), and then divided by the number of samples for that habitat type.

Table 3 outlines results of the fish sampling completed in the summer and fall of 2011, and resulting

average fish abundance for each shore type in Cowichan Lake.

In reviewing the total number of fish sampled in the summer versus the fall of 2011, fall sampling

resulted in over twice as many fish being captured or observed. It is important to note there were

additional attempts made to capture fish in the fall period. At several sites, snorkel observations were

combined with netting. One other reason for the higher rate of capture of fish in the fall was the

improved "efficiency" of capture, due to lower lake water levels. As discussed in Section 4.3.1, water

levels are typically higher in the early summer, dropping by late fall. Gravel beaches can be partially

submerged, making the deployment of a seine net difficult and leading to fish avoidance of capture

attempts. In September, the sampling was done at water levels approximately 50cm lower, when

shorelines have wide gravel bars for setting the net more effectively, resulting in more efficient fish

capture results.

An inconsistency in sampling data is noted in summer sampling of Site 7. In the summer sampling,

minnow trapping was used as the capture method, with only two Sticklebacks captured. In the fall,

minnow trapping was the primary capture method, however, fish were visually much more abundant in

this area than trapping results indicated. A snorkel transect was used confirming the presence of several

schools of Coho juveniles (in submerged vegetation in the area). This modification to the sampling

regime resulted in a significant increase (700%) in fish observed at this site. Poor fish capture results at

Site 7 in summer were likely a result of less efficient capture techniques being used, as it is unusual to see

such a significant difference in fish abundance in a three month time span.


37

Table 3. Number and relative abundance (%) of fish observed/sampled at each Cowichan Lake sample site.

Season Common

Name

Species Rocky

Shore

(N=5)

Gravel Beach

(N=14)

Stream Mouth

(N=4)

Cliff/Bluff

(N=1)

Sandy

Beach

(N=1)

Wetland

(N=1)

Total # of

Fish

Percent of

each species

sampled Summer Coho O.kisutch 84.6 27.3 67.5 69.7 1870 60.3

Chinook O. tsha-wytscha

0.2 2 0.1

Kokanee O.nerka 1.4 0.6 0.1 17 0.5

Rainbow O.

Mykiss

0.4 0.1 0.2 3.3 8 0.3

Cuttthroat O. clarkii

clarkii

2.0 0.4 4.5 3.3 24 0.8

Unk Trout 2.9 0.2 0.2 22.7 44 1.4

Three-Spined

Stickleback

G.

aculeatus

8.5 68.2 31.1 3.0 86.6 100 1147 35.3

Sculpin C. asper 0.2 3.4 0.5 6.8 40 1.3

Total # of

Fish 773 819 1401 66 30 2 3091 100

Mean Fish

Abundance 154.6 58.5 350.3 66 30 2

%

Abundance 23.0 9.0 53.0 10.0 5.0 0.1

Fall Common

Name

Species Rocky

Shore

(N=6)

Gravel Beach

(N=16)

Stream Mouth

(N=5)

Cliff/Bluff

(N=1)

Sandy

Beach

(N=1)

Wetland

(N=2)

Total # of

Fish

Percent of

each species

sampled Coho O.kisutch 64.3 5.7 59.7 39.2 3612 45.3

Chinook O. .tsha-wytscha

Rainbow O.

Mykiss

0.1 16.7 2 0.1

Cuttthroat O. clarkii

clarkii

0.2 0.1 0.2 0.7 0.1 15 0.2

Unk Trout 0.1 0.6 2 0.1

Three-Spined

Stickleback

G.

aculeatus

35.0 90.9 39.6 83.3 98.0 60.1 4251 53.4

Sculpin C. asper 0.1 3.3 0.4 1.3 81 1.0

Total # of

Fish 1731 1828 3534 6 148 716 7963 100

Mean Fish

Abundance 288.5 114.25 706.8 6 148 358

%

Abundance 18.0 7.0 44.0 0.1 9.0 22.0


38

“N” is the number of fish capture attempts completed in each shore type. Overall, "all" shore types were

found to be utilized by fish during both summer and fall field investigations.

4.5.1 Fish Abundance by Shore Type

Both the summer and fall fish sampling surveys identified the importance of "stream mouth" shore types

(Figure 28). The largest "stream mouth" segment in the lake is the lake outlet /Catalyst weir area, where

high densities of juvenile Coho were sampled. Large numbers of Coho fry from the upper Cowichan

River are known to migrate to the lake from the river in the spring to rear, before migrating downstream

as smolts the following spring (S. Baillie, DFO, pers. comm.). The suspected primary reason for this

‘mass’ migration to the lake is avoidance of high water temperatures (>21˚ C) in the upper river in the

summer/fall period (S. Baillie, DFO, pers. comm.). Several "stream mouth" shore types in the lake

exhibit habitat attributes that make them highly "complex" (aka desirable) sites for fish. For example,

submerged aquatic plants, along with abundant riparian shrub communities, were observed in Shaw Creek

and Bear Lake outlets.

Rocky shore types are also important in the summer and fall months, accounting for approximately 20%

of fish abundance in the lake. Rocky shore types typically have a bathymetry that drops steeply away

from the shoreline. In Cowichan Lake, these steep drop-off zones are often covered in logs and fallen

trees. During fall snorkel observations, schools of Coho juveniles were observed in these cooler, deeper

waters (4-6 m) under submerged large woody debris (LWD). Abundance of submerged LWD in the

lake's littoral zone is believed to be a result of both natural and man-made events (e.g., past log booming),

that have created a complex network of wood structures used by fish as escape cover.

Gravel and sandy shore types accounted for 15% of total fish abundance in both surveys. The majority of

fish sampled in these shore types were Three-Spined Sticklebacks and Prickly Sculpins. The reason is

believed to be high ambient water temperatures (>21˚C) which discouraged salmonid presence.

Substrates are suitable for nest building and reproduction, a common behaviour of both species during

summer/fall periods (Scott 1998). Index sample sites, where submerged vegetation or LWD provided

enhanced habitat complexity, often had higher Coho fry densities (e.g., Site 14B). Gravel shoreline sites

where Myrica Gale shrubs were present and partially submerged, were also well correlated with juvenile

Coho use (e.g., Site 10B).

Wetland shore types, as previously stated, were not consistently sampled in this study between seasons,

but fall sampling(only) provided a strong indication of the importance of this habitat for juvenile Coho.


39

Figure 28. Percent of fish sampled by Cowichan Lake shore type - Summer and Fall 2011.

In the Schleppe and Arsenault (2006) report on Okanagan Lake, the environmental sensitivity or

biological value of a shoreline is described using an Aquatic Habitat Index (AHI). The AHI methodology

provides a ranking of each habitat along a shoreline, based on a review of the following parameters:

Biophysical;

Fish populations;

Shoreline vegetation;

Terrestrial; and

Shoreline modifications

The AHI as a metric of shoreline habitat sensitivity has been employed on several large lakes in the

Interior of BC, like Shuswap, Mabel, Okanagan and Windermere.

For this report, the AHI methodology was not used due to the limited time and budget available. The

concept of rating shorelines for biological significance involves a very complicated analysis of the above

parameters. In contrast, we used a simple approach for rating the importance of Cowichan Lake shore

types for the summer/fall seasons, based on seasonal abundance of fish expressed in the following

categories:

23%

9%

53%

10%

5% 0%

Summer

Rocky Shore (N=5)

Gravel Beach (N=14)

Stream Mouth (N=4)

Cliff/Bluff (N=1)

Sandy Beach (N=1)

Wetland (N=1)

18%

7%

44% 0%

9%

22%

Fall

Rocky Shore (N=6)

Gravel Beach (N=16)

Stream Mouth (N=5)

Cliff/Bluff (N=1)

Sandy Beach (N=1)

Wetland (N=2)


40

Shore Type Rating

(based on Fish Abundance)

Summer Assessment

Fish Abundance (from Table 3)

Fall Assessment

Fish Abundance (from Table 3)

Low < 50 fish/site < 100 fish/site

Moderate 50 - 150 fish/site 100 - 200 fish/site

High >150 fish/site >200 fish/site

Due to extra efforts made to capture fish at many of these sites in the fall, the mean fish abundance was

increased by 50 fish to allow us to compare and "rate" shore types between seasons.

In Table 4, a rating of fish abundance by shore types and by season is outlined. The table provides a

simple overview of the importance of various shore types as fish habitat in the summer/fall seasons of

2011. This rating does not include a detailed analysis of how existing shoreline developments and habitat

alterations have had either negative or positive impacts on fish abundance. To accomplish this would

require a more rigorous statistical design of the field sampling program, with a significant increase in the

number and distribution of sites sampled.

Fish abundance did not shift significantly from one shore type to another between seasons. Stream-mouth

and rocky-shore types had the highest relative abundance of juvenile fish, while cliff/bluff and sandy-

beach types produced moderate to low fish abundance. Gravel beaches had moderate fish abundance

densities, while wetland types supported a similar "moderate" abundance in this analysis.

Table 4. Rating of Cowichan Lake shore types as measured by observed fish abundance in summer/fall 2011.

Season Fish Abundance Rating by Shore Type (2011)

Rocky

Shore

Gravel

Beach

Stream

Mouth

Cliff/

Bluff

Sandy

Beach

Wetland

Summer H M H M L L*

Fall H M H L M H

Average Rating H M H L-M L-M M

Total Shore Length

(lineal m)

16,912 72,028 4,603 5,591 520 456

*Poor sample methods

While this is admittedly a very simple association tool, and is only meant to provide a general sense of

how juvenile fish respond to shoreline conditions, we can estimate how fish might be distributed along


41

shorelines during the summer/fall seasons. In evaluating shoreline length (Table 4), approximately 72%

of the lake's total shoreline is rated as “moderate fish abundance,” as the dominate shore type is gravel-

beach.

When comparing the FIM shore types found around the lake with high fish abundance ratings, stream-

mouths have very high fish abundance, yet represent only 4.6% of the lake's total shoreline, while rocky-

shores represent just 17%. The wetland shore type is very rare on Cowichan Lake (0.5%), but has a

moderate fish abundance rating. When adding the importance of stream-mouths as critical habitat for

lamprey spawning and ammocoete (larvae) rearing, we begin to better appreciate the importance of this

combination of shore types (stream-mouth, rocky and wetland), representing just 22% of the lake's total

shoreline, as simply irreplaceable.

Despite an attempt to assess fish abundance in January 2012, the 2011 fish Cowichan Lake sampling

program does not provide clear insight on the distribution of fish in different shore types in the winter or

spring seasons. In the past, fish population and habitat investigations completed in winter and spring

indicate that gravel beach shore types may have increased importance in higher winter and spring lake

levels. Fish sampling, using electrofishing, have revealed Coho juveniles seeking refuge in shorelines

with flooded hydrophilic riparian vegetation (MoE files, Nanaimo). Net trapping on gravel shorelines in

the South Arm in the 1990's indicated Coho smolt migration occurs during the months of April and May,

with juveniles migrating along gravel shores towards the lake outlet (S. Baillie, DFO, pers. comm.).

4.5.2 Cowichan Lake Fish Species by Shore Type

Table 3 identifies fish species present in summer and fall sampling periods (live captures and

observations). Data show juvenile Coho and Three-Spined Stickleback dominate (97%) collective fish

biomass along the lake shore. It is noteworthy that no invasive (non-native) fish species were captured in

2011.

In comparing summer versus fall fish sampling results, there is a shift in species dominance from juvenile

Coho (summer) to Three-Spined stickleback (fall). Probable reasons for this are associated with lake

water conditions. Sticklebacks and Sculpins prefer gravel and sandy shorelines for reproductive purposes

as water temperatures rise. Escape cover from predators is not a primary concern in this period. Nest

building occurs in shallow (<2m depth) shoal areas, with warm surface water temperatures stimulating

spawning behaviour (measured at 21˚C in September 2011). Coho, are impacted negatively by warmer

surface water temperatures and will move into deeper, cooler water.

The abundance of "other" species accounted for only 3% of total fish captured/observed in 2011. Presence

of other species seems to be dependent on the physical and biological attributes of a site being sampled.

In a review of the life history of Coho in lakes, there is a strong dependence of juveniles on "escape"

cover from predators (McPhail 2007). Common types of cover include submerged macrophytes,

emergent riparian vegetation and large woody debris. These attributes are commonly found in wetland,

stream-mouth and rocky-shore types on Cowichan Lake. Figure 29 confirms higher Coho abundance

associated with these more complex habitat shore types.


42

Figure 29. Mean Number of Coho Sampled in Each Shoretype in 2011.

Figure 30. Common emergent plants (Myrica gale spp.) prefered by juvenile Coho as escape cover.

In gravel beach shore types, presence of emergent vegetation was particularly important in providing

juvenile Coho with cover. Coho abundance was often associated with a common hydrophilic shrub,

Sweet Gale or Bog Myrtle (Myrica gale), found on most gravel shores of the lake. These plants have a

very robust stem and root system. Plants are often submerged (or partially) during the year, so that fish

hide under the stems/roots for cover (Figure 30). The index sites on the lake, where the plants were

partially submerged, had high juvenile Coho abundance (e.g., Site 7, Segment 52).

16

46

236

0

130.8

0

Gravel Beaches

Cliff/Bluff

Stream Mouth

Wetland

Rocky Shore

Sandy Beach

Summer 2011

6.56

0

422.6

140.5

185.5

0

Gravel Beach

Cliff/Bluff

Stream Mouth

Wetland

Rocky Shore

Sandy Beach

Fall 2011


43

In rocky shore types, Coho preferred cover around submerged large woody debris (Figure 31). During

snorkel observations at these sites, schools of Coho were observed in 3-5m of water, swimming close to

log debris. Another reason for Coho to occupy deeper water is to avoid warm surface water temperatures

(e.g., September 2011 - 21˚C).

Figure 31. Woody Debris - Important escape cover for juvenile fish in Cowichan Lake.

In stream-mouth shore types, macrophytes such as Large Leaved Pondweed (Potamogeton amplifolius),

Pondweed, (Potamogeton spp), Water Milfoil (Myriophyllum spp.) and Eurasian Water Milfoil

(Myriophyllum spicatum) provided the dominate cover used by Coho (Figure. 32). This was especially

true in the generally shallow lake outlet area, where macrophytes (especially Eurasian Water Milfoil)

flourished in large mats. A reason for the abundance of this invasive milfoil is likely related to a nearby

boat launch where unknowing boat owner/operators inadvertently transported root fragments on boat

trailers and outboard motors from ‘infested’ lakes elsewhere.

Figure 32. Submerged aquatic plants - Important escape cover for juvenile fish.


44

4.6 Fish Species of Cowichan Lake Following is a brief summary of the life history of native fish species that reside in Cowichan Lake, with

reference to local knowledge of how populations use the lake's littoral/shoreline habitats.

Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) Coastal Cutthroat trout belong to the Salmonidae Family. Coastal Cutthroat are found on the entire BC

coast (McPhail 2007). Based on patterns of migration, three general life history forms are commonly

recognized; a non-migratory freshwater resident form, a migratory (adfluvial) freshwater resident form

and a sea run (anadromous) form. In Cowichan Lake, the adfluvial population dominates life history of

the species. Spawning generally takes place between mid-March and late May every year (Lough 2011).

Cutthroat trout escapement estimates in the spring of 2011 in four tributary streams totalled 1,272

spawners (Lough 2011). Cutthroat fry emergence occurred between June 15th

and July 15th

in the same

tributaries studied (Lough 2011). In Cowichan Lake, a large number of fry migrate to the lake due to

limited rearing habitat availability in streams (Lough 2011). In the lake, fry reside primarily in the littoral

zone of the lake, close to cover, feeding on surface insects and zooplankton. As they mature into their

second and third years, they prey on a wider variety of food sources, including Three-Spined Stickbacks

and Prickly sculpins (MoE, Gillnet record files, Nanaimo). Larger Cutthroat in the lake become more

aggressive in foraging on other fish, especially Kokanee, growing in size to over 60cm and up to 3kg.

The largest Cutthroat measured in the 2010/2011 sport fishery was 65cm and over 7 years old (T.

Michalski, MFLNRO, pers. comm.).

A study began in 2010, in cooperation with the Cowichan Valley Fish and Game Club, to monitor the

Cowichan Lake sport fishery. Anglers are being interviewed about their effort and catch. The sport

fishery on the lake is presently estimated at 15,000 angler days, with approximately 5,000 fish caught in

2010. Cutthroat trout make up 73% of the total catch of sport fish in the lake. This work is leading to

development of a Large Lake Management Plan for all Cowichan sport caught fish in the lake (T.

Michalski, in prep., 2012).

During index site sampling in fall 2011, five cutthroat trout juveniles were captured and measured for

fork length, with a mean of 185.0mm (Figure 33). Lamprey-scarred Cutthroat adults are commonly

caught in the sport fishery (Figure 34).

Figure 33. Cutthroat trout parr captured by minnow trapping in Cowichan Lake (Sept. 2011).


45

Figure 34. Adult Cutthroat trout sampled in Cowichan Lake sport fishery. Note lamprey scars (T. Michalski, MFLNRO, Nanaimo).

Coho Salmon (Oncorhynchus kisutch)

Coho at one time were the major recreational sport fishing species in the Strait of Georgia, but in recent

years there has been a precipitous decline in their numbers (McPhail 2007). There are over 2,600 Coho

salmon stocks in BC (Slaney 2006). Of these, 214 stocks are considered at high conservation risk. These

high risk stocks are a result of historic overfishing and freshwater habitat degradation. Cowichan River

Coho have been monitored by DFO staff at the Pacific Biological Station as part of the Pacific Salmon

Treaty, over many years. Historical adult escapements of Coho averaged 20,000 spawners, annually. The

upper Cowichan River and tributaries to the lake are very important spawning areas. The run size

declined about ten years ago, with spawning escapements in the past few years ranging from 4,000 to

8,000 (S. Baillie, DFO, pers. comm.).

In the Cowichan River, adult Coho enter the river to spawn from mid-October through early December.

Coho are the most secretive of the Pacific Salmon, with most reproduction occurring in small streams and

at night. Fry emerge about three months after spawning. Growth rates are sensitive to water temperature,

food abundance and fry density. Irving and Johnston (1992) reported that fry migrate to the lake where

they distribute along the littoral zone and form schools (Swain and Holtby, 1989). After years of

monitoring by DFO Stock Assessment, Baillie (pers. comm.) concluded that most fry from the upper

Cowichan River and lake tributaries migrate to the lake to rear. Over 75% of all Coho smolts produced in

the Cowichan watershed reside, for at least part of their early life history, in the lake. Most Coho migrate

to sea in the spring after approximately one year in the lake. Baillie estimated that over the past 25 years,

smolt yields have ranged from 70,000 - 250,000 annually from the lake (with a mean of 150,000).

Through the years, DFO has operated several Coho monitoring projects on the lake including the

following (data filed at Pacific Biological Station, Nanaimo - S. Baillie, DFO, pers comm.):

:Smolt net trap at the Lake Cowichan Education Centre between May and July in 1997, 1999-

2003 and 2005-2007. This trap captured tens of thousands of wild Coho smolts migrating along

the shore of the lake to confirm smolt population size estimates.

Downstream smolt fence from 1985-1995 in Mesachie Creek.


46

Coho adult escapement counts from 1989-2008 in Robertson River, Patricia Creek, Shaw Creek

and Mesachie Creek.

Coho fry density surveys from 1990-2004 in Lakehead Creek, Patricia Creek, Halfway Creek and

Oliver Creek.

During fish sampling in fall 2011, a total of 76 Coho were measured for length at eight index sites. Mean

length of Coho was 61.0mm (Figure 35).

Figure 35. Juvenile Coho sampled in Cowichan Lake in September 2011.

Rainbow Trout (Oncorhynchus mykiss)

In BC, rainbow trout occur as both freshwater resident and anadromous (Steelhead) forms (McPhail

2007). In Cowichan Lake, both Steelhead and lake residents are present. Steelhead are a winter-run

ecotype, and enter lake tributaries in January and February to spawn (Lough 2011). The lake resident

rainbow population is an adfluvial ecotype, and spawn in upper reaches of the Cowichan River from

February to April (MoE files, Nanaimo). Fry emerge from June to early July. Typically, rainbow and

steelhead will attain a length of 60mm (+/-20mm) in their first year of growth, however, water

temperature, food availability, population density, stream flows and interactions with co-habiting species

all influence inter-annual growth rates (Post and Parkinson 2001; K. Pellett, BCCF, pers. comm.).

In Cowichan Lake, a majority of steelhead progeny migrate through the lake and down to sea as spring

smolts at age 2(+). Progeny of lake resident rainbow trout can reside in the upper Cowichan River for 1-2

years before migrating to the lake, or they can move into the lake as fall fry. Fry that enter the lake likely

remain in shallow shoreline waters, typically 2-5m deep, where they grow for another 1-2 years. During

the day they are often associated with cover (woody debris) and emerge to actively forage at night

(McPhail 2007).

Samples of mature rainbow show an average length of 330mm (age 4+), with some samples as large as

600mm (age 7+) (MoE files, Nanaimo). Stomach samples reveal rainbow feed heavily in the lake on

terrestrial insects.


47

Lake dwelling rainbow prefer to reside in water temperatures below 18˚C, where dissolved oxygen

concentrations are well above 3.0mg/l (McPhail 2007). Rainbow trout feed primarily in shallow littoral

areas of the lake, often associated with cover such as large woody debris. They are rarely found feeding

in deep pelagic lake habitats and usually remain within 50 meters of the shore to feed (Luecke and

Teuscher 1994). Rainbow typically feed before dawn and are most active at dusk. Over 90% of their

behavioural activity occurs within surface waters of the lake (to 3m depth).

A total of 10 rainbow parr were captured in the summer/fall field surveys on Cowichan Lake in 2011

(Figure 36).

Figure 36 Rainbow Trout sampled in Cowichan Lake in summer 2011.

Chinook Salmon. (Oncorhynchus tshawytscha) Chinook salmon are indigenous to larger rivers on the Pacific Coast, and are found in over 250 rivers and

streams in BC (McPhail 2007). Cowichan Chinook escapement estimates ranged from 1,200 - 10,000

fish over the past 20 years (Nagtegaal, 2006). The population of early fall Cowichan spawners has been

the subject of intense monitoring for more than 20 years as part of the Canada/US Pacific Salmon Treaty.

Monitoring of tributaries to the lake has been ongoing during this same time period, with only a small

number of spawning Chinook observed in Robertson River, Meade Creek and Shaw Creek (N=100; S.

Baillie, DFO, pers. comm.; Burns 2000). Local First Nation elders have also described an early (May)

run of Chinook that once migrated to Cowichan Lake. These adults held in deep waters of the lake until

the first rains when they would spawn in the lake outlet and inflowing tributaries (S. Baillie, DFO, pers.

comm.). There is no indication this unique stock persists today at more than remnant numbers (i.e., <50).

Chinook fry emigrate from lake inlets and travel through the lake, on their way to sea. Chinook smolts

have been captured during DFO’s April-June net trap operations in the lake, however, the number

captured drops significantly by June of each year (S. Baillie, DFO, pers. comm.). In the 2011 shoreline

fish sampling assessment, a pair of Chinook smolts were captured by seine netting in July, however, none

were sampled in fall surveys (Figure 37). Chinook likely spend a few days to a few months feeding in the

lake before they move downstream as smolts in late spring or early summer. This differs from Shuswap


48

Lake, where Chinook juveniles spend their first spring and summer in shallow shoal areas feeding and

residing in the lake for a full year before migrating to the ocean as smolts (Brown, 2004).

Figure 37. Chinook salmon juvenile sampled in Cowichan Lake in July 2011.

Kokanee (Oncorhynchus nerka)

Three forms of Sockeye have been identified in BC including the andromous form (Sockeye), the

permanent lake-dwelling form (Kokanee) and non-anadromous progeny of Sockeye (residual Sockeye)

(Rutherford, 1988). In Cowichan Lake, a large population of kokanee, estimated at up to 5.1 million,

have evolved without migrating to sea (Rutherford, 1988).

Kokanee spawn in the fall, usually when lake temperatures fall below 7˚C (Rutherford 1988). Timing of

spawning is described as late November to mid-December (T. Burns, pers. comm.). McPhail (2007)

identified Kokanee spawning in streams or lakeshore areas where upwelling (artesian) flows exist, or

where there are subsurface flows like gravel bars at stream mouths. Burns (pers. comm.) indicates that

Kokanee in Cowichan Lake are limited in spawning locations, as their small average size at maturity

(165mm) precludes them from spawning in streams or shorelines with large gravels and cobbles. This

limits spawning to lakeshore locations where ‘pea-sized’ gravel dominates beach substrates. The

presence of small gravel on a shoreline depends on the fluctuation of water levels and movement of

sediment and gravel by lakeshore currents. Shore spawning of Kokanee in Cowichan Lake appears to be

"opportunistic," as fish seek preferred conditions. Spawning takes place in the wash of waves or at depth

in upwelling areas up to 10m below the lake surface (McPhail, 2007).

Areas where Kokanee have been reported to have spawned include the following:

North Arm: Spring Beach (Forest Service Campground).

Main Arm: Heather Campsite, Hawes Bay, MacKay Beach, Gravel Bars off Shaw Creek,

Cottonwood Creek, MacKay Creek, Wardroper Creek.

South Arm: Walton Road gravel bar (Gordon Bay Campsite boat launch to Sutton Creek

confluence).

Fry emergence timing is dependent on water temperatures in the lake. It is assumed that fry migrate

immediately into the pelagic (deep water) zone to escape predators and begin feeding on very small

zooplankton organisms. However, this has not been substantiated by empirical evidence. A study is now


49

underway to re-assess Kokanee population dynamics in Cowichan Lake as part of a Large Lake

Management Plan (T. Michalski, MFLNRO, pers. comm.).

The health of the lake’s Kokanee population is integral to Cutthroat trout in Cowichan Lake, as they are

the primary prey species once Cutthroat have attained a size of 30cm. In spring and summer months,

Kokanee have extensive daily vertical and onshore-offshore movements in search of preferred

zooplankton food. Schools of Kokanee are known to move into littoral - shoreline areas of the lake at

night to feed on zooplankton and aquatic insects (Scott and Crossman 1998). Net trapping at the Lake

Cowichan Education Centre in spring (May to July in 1997, 1999-2003, 2005-2007) and fall (November

1996) captured up to 20 Kokanee every night of trap operations. In summer of 2011, fish sampling by

BCCF captured 17 Kokanee (Figure 38).

Figure 38. Adult Kokanee salmon sampled in Cowichan Lake in July 2011.

Dolly Varden (Salvelinus malma)

In BC, Dolly Varden char display three predominant life histories including an anadromous form that

migrates from freshwater to the sea and back; a stream resident form that spends its entire life in rivers

and streams; and, an adfluvial form that lives most of its adult life in lakes and spawns in streams

(McPhail 2007). In Cowichan Lake, there is an adfluvial stock. Dolly Varden spawn in the fall, although

the exact time varies with watershed latitude, stream temperature regime and related life history traits.

Several inlets to Cowichan Lake are known to be important spawning and rearing areas for Dolly Varden

(Griffith 1989). Eggs incubate in gravel and take about 3 months to hatch. Fry emerge in streams in

May/June and usually remain there for up to two years before migrating to the lake. Habitat use in lakes

by Dolly Varden is influenced by the life history and presence of other fish species. For example, in

Cowichan Lake, Cutthroat and Rainbow trout co-exist and use littoral areas for early rearing, so Dolly

Varden appear to favour offshore/deeper habitats for rearing.

In 2011, gill netting off Nixon Creek’s mouth resulted in 16 Dolly Varden captured, with a mean size of

306 mm and 300 grams. Stomach contents were dominated by clams, showing a preference for bottom

feeding (MoE files, Nanaimo). Dolly Varden have also been captured in trap net operations in November

1996, so they do move into shallow lake shore areas when preparing to spawn. Dolly Varden have been


50

observed spawning in Shaw Creek during salmon spawning escapement counts (1989-2008; S. Baillie,

DFO, pers. comm.).

No Dolly Varden were sampled in the index 2011 surveys. Examples of juvenile and adult char are

presented in Figure 39.

Figure 39. Juvenile (left) and adult (right) Dolly Varden char (Mike Lough & Assoc.).

Three-Spined Stickleback ( Gasterosteus aculeatus) Three-Spined Stickleback is a coastal species that has marine, anadromous and freshwater resident life-

histories. In Cowichan Lake, the species life history can be diverse, however, there are periods when the

lake shoreline is critical for reproduction and recruitment. Breeding male Sticklebacks are territorial and

nest builders (McPhail 2007). Nests are generally built in shallow water (<1m) in muddy and sandy

substrates with some rock outcrops or submerged logs. They can nest in open areas, or under dense

cover. When a male builds a nest on an open sandy beach, they usually cover it with sands or silts to

hide it. Males spawn with several females before they switch to nest-guarding parental behaviour.

Females can spawn up to 29 times over a 3 month period (in summer). Eggs hatch about 5 days after

being laid (depending on water temperatures). Stickleback lifespan can range from 1 - 5 years. They are

carnivorous and in lakes feed primarily on zooplankton in the water column, however, they will also

forage on bottom organisms like amphipods, ostracods, and aquatic insect larvae. When they are not

breeding, adult Stickleback may forage in pelagic areas of a lake, beyond immediate protection of

shoreline/littoral vegetation. Juvenile Stickleback are generally closely associated with shoreline

vegetation or LWD for cover.

In the 2011 fish sampling program, Three-Spined Stickleback were a dominant species sampled in four of

the seven shoreline habitat types (Figure 40). A total of 5,398 Stickleback were captured in both summer

and fall surveys. Stickleback dominated the sampled fish biomass on gravel and sandy beaches, where

shallow shorelines were ideal for nest building and foraging. Habitat types where they were present in

lower abundance were steep, rocky shorelines that dropped to depths >5m within a short distance (10

m+/-) of shore.


51

Sticklebacks are a key prey species for Cutthoat trout. In August 2011, over 50% of Cutthroat trout

sampled by gillnets had Stickleback in their stomachs (MoE files, 2011).

Figure 40. Adult Three-Spined Stickleback (Google images).

Prickly Sculpin (Cottus asper)

Two forms of Prickly Sculpin occur in BC; a coastal and an inland form (McPhail 2007). In Cowichan

Lake, the coastal form is present and has evolved to spend its entire life history in the lakeshore

environment (Figure 41). Adult Prickly Sculpins are usually found in littoral (shallow) zones where there

is good cover from cobbles, boulders or woody debris. During the day they remain close to cover, but at

night forage in the open. They feed on micro plankton, but can shift to benthic prey such as nymphs and

larvae of aquatic insects. Larger individuals can prey on other fishes such as Three-Spined Stickleback

and salmon fry. Prickly Sculpins spawn in the spring when water temperatures rise above 6°C and

continue to spawn until water temperatures exceed 16°C. Males build nests in shallow margins of the

lake, usually associated with wood debris, and court females into sharing nests. Eggs are laid and take 15

days to incubate at 12°C. Eggs then hatch into larvae which remain planktonic for 30 to 35 days before

transforming into small sculpins which reside in shallow areas of the lakeshore. Generally these fish have

a life expectancy of 2 - 5 years (McPhail 2007).

Figure 41. Adult Prickly Sculpin (Google Images).


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Vancouver (aka Cowichan Lake) Lamprey (Lampetra macrostoma) Vancouver lamprey are known only in Mesachie Lake and Cowichan Lake, BC. In 2000 and 2008, this

species was designated as Threatened by COSEWIC and is currently protected under the Species at Risk Act (Vancouver Lamprey Recovery Team, 2007). Very little is known about the species’ biology,

population status or specific habitat requirements (Fundy Aqua Services, 2011). The species was first

described by Beamish (1982) as a freshwater parasitic derivative of Lampetra tridentata. There are many morphological differences between the two species, including a significant meristic difference. L.

macrostoma can remain wholly in freshwater and feed prior to spawning at a significantly smaller size than L. tridentata (Beamish, 1982).

L. macrostoma has been shown to utilize shallow areas with small gravel near mouths of creeks/rivers, and these areas have been identified as essential for the successful recruitment of the species (Beamish

and Wade, 2008). In the 1980’s, ammocoetes (or metamorphosing juvenile lampreys) were collected

from small gravel areas at the mouths of Shaw Creek, Nixon Creek, Cottonwood Creek and Meade’s Creek, where they enter Cowichan Lake. All lampreys which had completed metamorphosis were

subsequently identified as L. macrostoma (Beamish 1982).

Habitats suspected to be used by L. macrostoma in Cowichan Lake were inventoried in 2011 in order to

enhance their protection, which is crucial to future conservation of the species. Adults (non-spawning)

appear to use the main body of lake where they can parasitize larger salmonids like adult Cutthroat trout.

Ammocoetes have been known to use creek mouths, as described previously, however, this information is

now dated from the late 1980’s and needs reaffirmation.

Identification and description of habitat and/or potential habitat by spawning lamprey and ammocoetes in

Cowichan Lake and tributaries was the focus of a field investigation and by report by Fundy Aqua

Services (Appendix F1). Poor field conditions on October 7, 2011, following heavy rain and flooding,

resulted in limited catches of ammocoetes (Figure 42), so this phase of the investigation may have to be

repeated. A boat survey of the lake resulted in a list of future sites for further lamprey assessments (Table

5).

Figure 42. Vancouver Lamprey ammocoete, sampled at Meades Creek North, Oct 2010 (Fundy Aqua Services).


53

Table 5. Potential locations of ammocoetes or Vancouver Lamprey spawning sites in Cowichan Lake (2011).*

Meade’s Creek (N) 48˚50.707’N 124˚07.074’W Mud, silt Ammocoete

Miracle Creek 48˚51.591’N 124˚09.188’W Mud, silt Ammocoete

Swordfern (Youbou) Gordon Bay

(location 1)

48˚50.122’N 124˚11.657’W Clay Ammocoete

Gordon Bay

(location 2)

48˚50.188’N 124˚11.730’W Gravel Spawning

Sutton Creek 48˚49.383’N 124˚10.861’W Gravel, rock None

Ashburn 48˚49.268’N 124˚10.620’W Gravel, rock None

Robertson Creek 48˚48.194’N 124˚08.091’W Submerged,

undetermined

Unknown

Bear Lake 48˚48.926’N 124˚07.814’W Gravel, rock None

Unnamed (1) stream from Mesachie into Bear Lake

Marble Bay 48˚50.089’N 124˚07.435’W Silt and clay Ammocoete Meade’s Creek (S) 48˚49.812’N 124˚06.391’W Small gravel, hard

packed

Spawning

Unnamed (2) (by

the cross)

48˚51.479’N 124˚11.046’W Silt/clay Ammocoete

Ben’s marina 48˚52.203’N 124˚11.719’W Muddy Ammocoete

Old motel 48˚52.192’N 124˚11.688’W Short vegetation None

Coon Creek 48˚52.425’N 124˚12.606’W Gravel, sand Spawning

Arbutus Creek 48˚52.558’N 124˚13.243’W Gravel, sand Spawning Mill pond area 48˚52.634’N 124˚13.343’W Gravel None

Cottonwood 48˚52.473’N 124˚14.165’W Gravel, fine

sediment

Ammocoete

Campsite (from here A)

48˚53.568’N 124˚17.045’W Sand, silt Ammocoete

Campsite (to here

B)

48˚53.613’N 124˚17.222’W Sand, silt Ammocoete

Wardroper Creek 48˚54.281’N 124˚18.725’W Rock, gravel None McKay Creek 48˚54.335’N 124˚19.646’W Rock, gravel None

Hawes Bay 48˚55.285’N 124˚22.624’W Sand Ammocoete,

spawning

Shaw Creek 48˚55.045’N 124˚24.530’W Sand, clay Ammocoete *From Cowichan Lake Lamprey Habitat Study. Field Survey Final Report. Fundy Aqua Services (2011).

Note: In the fall of 2012, a follow-up field investigation of Vancouver Lamprey was completed under

contract to DFO Biologist, Warren McConnachie. A report, under separate cover, will be completed in

the near future, and will be added to this report as an addendum.

4.7 Assessment of Fish Habitat Potential in Unmapped Inlet Streams (Fall

2011) During the FIM assessment in October 2010, GPS coordinates were generated for 17 small streams on the

lake shoreline, that were not previously identified on 1:20,000 BC TRIM mapping (Table 6).


54

Table 6. Locations of small streams field checked in September 2011.

Lat/Long

Shore Segment

Number.

Stream

Number.

48˚49'12.82" 124˚04'10.52" 26 1

48˚48'55.47" 124˚09'49.67" 32 2

48˚52'16.83" 124˚17'38.64" 36 3

48˚54'06.52" 124˚23'29.61" 39 4

48˚54'20.40 124˚24'24/94" 41 5

48˚54'25.89" 124˚24'50.42" 41 6

48˚54'31.68" 124˚25'30.77" 41 7

48˚54'52.12 124˚26'14.64" 43 8

48˚54'57.19" 124˚26'22.01" 44 9

48˚55'06.52" 124˚27'27.95" 45 10

48˚55'17.64" 124˚27'21.59" 45 11

48˚54'40.26" 124˚20'07.06" 50 12

48˚54'28.45" 124˚ 18'48.18" 51 13

48˚54'07.77" 124˚17'46.34" 52 14

48˚51'53.93" 124˚10'31.99" 18 15

48˚51'10.03" 124˚07'11.38" 18 16

48˚51'04.96" 124˚06'58.80" 18 17

The streams are distributed throughout the lake as follows:

South Arm (Area A) - 2 streams

North Arm (Area B) - 3 streams

Main Arm (Area C) - 12 streams

In September 2011, a field assessment of these GPS waypoints revealed that only 14 stream channels

could be confirmed on the ground, despite extensive effort to investigate the shoreline vicinity (50 meters

in either direction). A possible reason for this discrepancy has to do with the small size of these

watercourses. Most of the subject streams are 1st order, with very small drainage areas. In September

2011, these drainages had not experienced any rainfall for over 2 months, so some channels were

probably hidden in vegetation. A summary table of all the streams assessed is presented in Appendix D1.

A site inspection form was completed for each stream and can be found in Appendix D2.

A total of 4 streams had measurable flows at the time of survey, with 10 streams found in a dry condition.

Two of the streams were located in the "North Arm," and appeared to be sustained by artesian flows. The

remaining wetted streams were located in the "Main Arm," near Heather campground.

For the purpose of summarizing whether these streams "contribute" to fish habitat, it must first be

understand how fish in Cowichan Lake use the stream(s) to carry out their life processes. Over geologic

time, inlet streams have likely provided salmonids with essential habitats to sustain their life history

needs, in whole or in part. Fish simply adapted to the natural hydrology of these small streams, so the

fact that 72% are dry (or nearly so) by early fall is a natural phenomenon which native species likely

“anticipate.” The observed seasonal migration of most fry to the lake for rearing is testimony to this

adaptation behavioural response.


55

For the purpose of summarizing whether these streams contribute to fish habitat, they have been grouped

into the following categories:

Modified Stream- the channel has been directly modified by humans; and

Natural Stream - the channel appears to function in a natural condition.

During field inspections a total of five watercourses were found to be highly "modified" by human

disturbance (Table 7). These were heavily impacted by ditching and drainage management from adjacent

roadways or land developments. Only one modified stream had a measurable flow. Many streams

appeared to be managed drainage ditches, with little or no hydraulic or structural cover such as pools or

wood debris to shelter rearing fish, and substrates were rated as poor for possible fish spawning. Ditching

in the Wardroper/McKay Creek area, where recreational vehicles are parked for extended periods, is an

example of a modified stream (Figure. 43). It is presently unknown whether these new ditches are small

streams being re-directed to allow for campsite development.

A key indicator for possible fish use in "modified streams" is the gradient (or slope) of the channel.

Modified stream channels, with low gradient (<5%), are accessible to salmonids depending on the time of

year they are wetted. A low gradient ditch (stream 2) in the Honeymoon Bay area was identified in the

survey as "fish habitat," as it provides over-winter refuge for juvenile salmonids (T. Burns, pers. comm.).

One modified channel in the Youbou area is fed by an artesian spring that provides reliable flows which

attract fish into its lower 40m for spawning and rearing. This stream was ditched many years ago by area

landowners, however, some re-vegetative cover is restoring year-round fish habitat.

Table 7. Summary of fish habitat conditions in modified small streams of Cowichan Lake.

Stream

Number

Wetted

Width

(m)

Bankful

Width

(m)

Slope

(%)

Substrate

Condition

G=Good

P=Poor

Cover

Condition

G=Good

P=Poor

Fish

Habitat

G=Good

P=Poor 2 dry 2.4 0.5 P G G

13 dry 1.5 10.5 P P P

14 dry 2.2 14.0 P P P

15 0.82 2.0 2.0 G G G

16 dry unconfined 15.0 P P P


56

Figure 43. Example of modified (ditched) stream channel in the Wardroper/McKay Creek area.

The remaining nine streams had channel conditions that were identified as "natural" with no measurable

human impacts in the reaches assessed (Table 8). The majority of channels were dry at the time of

survey. These watercourses drain small forested basins (Figure. 44). Three had wetted channels at the

time of survey and two had confirmed fish presence. One stream, east of Youbou, was artesian fed but its

steep slope limits fish use.

In general, physical and biological conditions of all nine natural streams were good to very good. In

assessing the viability of streams as fish habitat, stream gradient was found to be a key indicator. Low

gradients (<5%) for 7 of the 9 streams, with no fish barriers at their mouths, is a clear indication that

juvenile and adult fish can use the streams during typical wet periods (i.e., November to May).

Table 8. Summary of fish habitat conditions in ‘natural’ small streams of Cowichan Lake.

Stream

Number

Wetted

Width (m)

Bankful

Width

(m)

Slope

(%)

Substrate

Condition

G=Good

P=Poor

Cover

Condition

G=Good

P=Poor

Fish

Habitat

G=Good

P=Poor 4 dry 3.4 5.0 G G G

5 dry 1.5 4.0 P G G

6 dry 2.3 16.0 G G P

7 dry 1.5 3.0 G G G

8 dry 5.15 3.0 G G G

9 3.1 4.3 5.0 G G G

10 5.0 5.4 0.5 G G G

11 dry 4.5 3.5 G P G

17 0.5 2.0 18.0 G P P


57

Figure 44. Example of dry "natural" small stream channel, Cowichan Lake.

In a review of published stream inventory and assessment reports, completed on tributaries for Cowichan

Lake, the most comprehensive reports are by Griffith (1989) and Burns (2002). In the Cowplan report,

Burns attempted to identify all salmonid-bearing waters in the Cowichan Watershed, and provided a

prescription for fish habitat restoration (Burns 2002). Burns identified 53 lake tributary streams

contributing to salmonid recruitment. When comparing locations provided for streams in these reports

with the 2011 stream assessments, there were five in common with those previously identified by Burns

(2002). The possible reason for this overlap of stream assessments is that there has not been a

comprehensive stream inventory using a “Sensitive Habitat Inventory Mapping” (or comparable

methodology) approach, that can provide a comprehensive “geo-referenced” location of all streams

around the lake.

These include the following streams with an appropriate commentary:

Stream #8, Mossy Creek - Coho and Cutthroat spawning to 400m from the lake.

Stream #9, Log Dump Creek - Coho spawning to 145m from the lake. Cutthroat spawning and

rearing to 1500m from the lake.

Stream #10, Lakehead (Junction) Creek - Coho and Cutthroat trout spawning and rearing to

2.5km from the lake. DFO Research (PBS) has sampled this stream for many years (1980's to

2008) as a Coho abundance index site (S. Baillie, DFO, pers. comm.).

Stream #11, Lakehead (Hall) Creek - Coho and Cutthroat trout spawning to 1km from the lake.

Stream #15, Price (Noni) Creek. - Coho and Cutthroat spawning and rearing to 65m from the

lake.


58

5.0 Discussion and Recommendations Land Planning

Cowichan Lake is a biologically significant ecosystem containing wild fish populations and habitats that

are highly valued throughout BC’s south coast region. The importance of the lake as a water supply for

the Catalyst pulp mill and source for drinking water for the Town of Lake Cowichan, Crofton and

surrounding area residents, must be also be acknowledged and respected. In recent years, many people

travel to the lake for its recreational attractions and pursuits, with popular outdoor activities in all four

seasons. Consequently, demand for recreational properties is strong and growing, and development

approvals over the past 10 years have the potential of doubling the area's population in the next 20 years.

The combination of irreplaceable fish, wildlife and water resources, along with an increasing demand for

real estate, make it crucial that governments and communities properly manage and protect the lake’s

natural capital. Data collected during this FIM can begin the process of building local biophysical

knowledge essential for sound land use planning, and identify future monitoring protocols for protecting

valuable shoreline ecosystems. The report is also a useful tool for helping to educate property owners and

land managers about natural shoreline processes.

The FIM (2010) concluded that over 70% of the lake shoreline currently remains in a natural "base"

condition. The main arm of the lake, surrounded by large tracts of private forest land, represents the

greatest area of presently undisturbed shoreline. The remaining 30% of the lake's shoreline is rated as

disturbed. The Youbou and Honeymoon Bay communities have the most modified shorelines, however,

new residential developments have expanded along the North and South Arms in the past 10 years. The

Town of Lake Cowichan has also expanded (Point Ideal).

The FIM found lands zoned for commercial or industrial use have the highest levels of disturbance to the

shoreline, however, they account for just over 3% of total shoreline length. To date, commercial RV

parks on the lake have developed campsites with marinas and swimming beaches with little regard for

natural shoreline habitats.

In future, the importance of the FIM's results will be in how local governments respond to increased

"demand" for recreational property while minimizing "impacts" on natural shorelines from existing single

family developments and similar re-zoning applications.

Cowichan Lake’s shoreline has widespread and valuable ecological assets worth preserving. The 2011

fish population inventory provided important insights into species abundance and distribution across a

range of lake shore types. In field sampling completed in the summer and fall of 2011, the two species

that dominate shoreline habitats include Coho salmon and Three-Spined Stickleback. The most important

factors determining distribution of fish in different lakeshore habitats include:

availability of food,

cover from predators,

water temperature regime.


59

The summer distribution of fish was highlighted by seasonal movement of Coho fry into deeper water in

search of cooler conditions and cover from predators. With surface water averaging 21°C, schools of

Coho were observed along steep rocky shores near sunken large woody debris. Wetland and creek mouth

shore types were also very important for Coho rearing due to abundant cover from riparian vegetation.

Taken collectively, these valuable habitats do not account for much of the lineal shore length so they

warrant special shoreline development prescriptions and treatments (i.e., zoning protection).

Fish presence/abundance along the gravel beach shore type (which represents 72% of the lake's total

shore length) was closely tied to presence of vegetation (emergent or submergent). In winter and spring,

lake levels rise and flooded shorelines are dominated by emergent shrubs. Importance of gravel

shorelines as fish habitat is believed to be much higher during these periods. That said, more fish

population assessment is needed to confirm how gravel shorelines are used in winter conditions.

Recommendations:

1. Results of these field surveys should be available to all stakeholders, government agencies,

CVRD planning committees, and the general public. Environmental data, including GIS maps

and air photos, are integral to informed land-use planning.

2. Shore types with high biological values should be included in OCP's, with a recognition that

these areas need significant protection in future developments. Stream-mouth, rocky shore

and wetland types must be identified on community plans and given priority in habitat protection

prescriptions.

3. Create shoreline environmental reserves. Single family or residential zoning on Cowichan Lake

generally represents the greatest level of (disturbance) risk to shoreline habitats. Therefore, a

form of ‘setback’ from the shore that retains land in public ownership for conservation should be

considered by the CVRD and Town of Lake Cowichan. This may require a review of re-zoning

potential in some areas where shoreline alienation is imminent.

As an example, Alberta has adopted "Environmental Reserves" on lakeshores to protect habitats

and reduce seasonal flooding hazards to proposed new housing. This may be an approach which

warrants consideration for Cowichan Lake, especially for critical habitats identified in #2, above.

Another approach might be to provide tax credits to owners who retain intact riparian vegetation

on their lakeshore properties.

Biophysical Inventory Data Requirements

To date, the FIM has focused on relative productivity of the lake's shorelines to fish species and their

habitats. The fisheries scientific literature also affirms that native fish species in Cowichan Lake are

dependent on a healthy shoreline for at least part of their life histories. Field assessments completed in

summer and fall, 2011 provide a ‘snapshot’ of what is needed to better understand seasonal fish use of

lake shore types. To extend this knowledge, fish sampling of lake shore index sites should be conducted

in winter and spring seasons to derive an annual measure of fish abundance and habitat dependencies

around the lake.


60

To ensure the Lake Cowichan FIM is inclusive of all major ecosystem components, a more

comprehensive assessment of wildlife use of sensitive riparian areas, including herpetofauna (reptiles &

amphibians), is needed. This will presumably add more scientific rigor to arguments for enhanced

protection of specific shore habitat types, that can be incorporated into land use planning and zoning

processes.

Attempts were made in the fall of 2011 to confirm lake/stream spawning and rearing habitats by SARA-

listed Vancouver Lamprey. Unfortunately, field work was abandoned due to poor weather conditions, so

this inventory remains a critical data gap to complete under the Cowichan Lake FIM. A short-list of

potential sites where lamprey may spawn and rear was provided, however, these sites need confirmation

from actual field sampling.

Kokanee represent the lake’s largest fish biomass, however, historical information on their spawning

locations is fragmented and dated. This needs to be a priority in future FIM field investigations.

A long term strategy for fish abundance monitoring is also needed. Consideration should be given to how

stewardship organizations can assist, especially given senior governments’ current staffing limitations.

The 2011 Cowichan Lake fish index sampling sites could provide a useful baseline. Other innovative and

relatively low cost sampling techniques, like night snorkel surveys, should also be considered.

Recommendations:

1. Wetlands and stream mouth shore types are extremely productive and important elements

of a large lake ecosystem. These should be assessed for use by herpetofauna and wildlife species. Numerous low to mid-level flood benches and shoreline marshes were mapped during this survey. Detailed Wetland Inventory and Mapping (WIM) of these features is recommended.

Detailed mapping of terrestrial wetlands is also important to ensure that natural linkages between

the lake’s foreshore and upland habitats are recognized.

2. Terrestrial Ecosystem Mapping (TEM) should be completed on wetlands and stream mouth shore types to identify important/rare emergent and terrestrial riparian plants. These

inventories help land managers identify blue/red-listed species that require special protection

under current federal/provincial laws.

3. Field assessments of the SARA-listed Vancouver Lamprey must be completed. DFO should

support further study of the lamprey’s preferred spawning and rearing habitats in Cowichan Lake

to ensure their future conservation. This should include expanded efforts to inform the public and

land managers of the importance of this rare species.

4. Kokanee spawning locations must be identified and protected. There is a critical need to

identify where this species routinely spawns before damage is inadvertently caused by lake shore

developments that compromise sensitive aquatic habitats.

5. Eurasian water milfoil should be inventoried. Existence of Eurasian Water Milfoil in

Cowichan Lake is troubling. The species is highly invasive and will out-compete native

macrophytes in both the lake and upper Cowichan River. Mapping locations of local infestations


61

should be initiated, along with a public awareness campaign about the risks of transporting these

plants elsewhere in Cowichan or other lakes.

6. FIM data gaps should be addressed with a commitment to long term monitoring. The

Cowichan Lake FIM provides a ‘snapshot’ of the lake's biophysical conditions, however, there

remain significant data gaps, such as fish distribution in the winter and spring periods. Long term

monitoring is essential to ensure progress is achieved in sustaining this large lake ecosystem. The

FIM provides a strong baseline from which to measure annual progress.

Foreshore Modifications

Gravel shorelines are the dominant (72%) shore type observed on Cowichan Lake. These beaches

typically feature moderately sloped (5-20°) shores with cobble, gravel and sand substrates, and are widely

distributed throughout the lake. In the report by KWL Assoc. Ltd. (2011), it is understood that shorelines

are subject to natural and manmade erosion processes. The stability or ‘equilibrium’ of these gravel

shorelines is dictated by their sediment budget and seasonal wave energy in the lake. What is of special

concern is that gravel shorelines are subject to the majority of all shoreline disturbances (92%) measured

in the FIM (2010).

Most significant disturbances included riparian vegetation removal (25%), substrate modification (17%)

and built retaining walls (9%). KWL indicated that any modification to a gravel beach, especially below

the lake's mean annual high water mark (164m elevation), is going to cause a change in the

sediment/erosion equilibrium, potentially aggravating local erosion effects.

To date, assessment of erosion has been at an overview level, describing the physical processes at work

around the lake. This included reference to the major effects of high winter lake levels on these same

processes. A detailed level assessment of shoreline erosion’s effects on specific areas of the lake has not

been done, and should be the focus of further study. An important element of such a study should be

educating property owners in how they can protect/restore natural shoreline processes, using low cost

bioengineering techniques, such as protecting/planting emergent hydrophilic plants to prevent the onset of

erosion.

Recommendations:

1. Lake shore Erosion Hazard Mapping (EHM) should be conducted. This should be directed at

single family, industrial and commercially zoned lands to identify areas at erosion risk, and

reverse the damaging trend of unnecessary shoreline hardening and construction of retaining

walls. This methodology would be helpful in identifying areas that are sensitive to boat wake

erosion. The Province uses standard methodology for lakeshore hazard mapping and this

template, or some adaptation of it for Cowichan Lake, would be preferred (Guthrie and Law,

2005). EHM mapping should be integrated with the FIM results, and be completed for each high

priority shoreline segment. Dock and boom-stick protection, flood risk, terrain stability and

alluvial fan hazard mapping should be part of this review, along with proposed future

development areas on the lakeshore.


62

2. Creation of a lakeshore BMP website with technical support for low cost solutions to

common shoreline development issues. Often landowners need advice for a project, but they do

not want to engage in a "perceived" costly government-run process in getting their project

completed. Perhaps a local (stewardship) group could provide a series of brochures on Best

Management Practices that can provide simple approaches to avoiding/reducing impacts of

proposed shoreline developments. A new link could be created on the CVRD and Town of Lake

Cowichan web sites that could fulfill the same education purpose.

3. Create a Best Management Practices DVD focused on "simple low-cost solutions" to

shoreline erosion. Using a coastal erosion specialist (P.Eng. or P.Geo.) familiar with erosion and

deposition processes at Cowichan Lake, develop a simulation model of how erosion occurs and a

Best Management Practices DVD to guide property owners in how to minimize development

impacts on natural shoreline processes and habitats. Topics should include dock construction

(“where and how”), boom-stick protection structures, groynes and retaining walls, and why they

must meet certain design specifications and requirements.

4. Implement habitat restoration opportunities, wherever possible. Identify potential habitat conflicts as early as possible in the new development review process. For existing urbanized lake

shore areas, assess options for dismantling groynes, adding large woody debris, live staking and

re-planting shorelines, naturalizing beaches, etc. There is a significant opportunity for partnerships in these endeavours (i.e., agencies working with stewardship groups) to facilitate

habitat restoration around the lake.

Shoreline Development Trends

Comparison of videos between 2006 and 2010, assessing shoreline development in three different

residential areas of the lake, indicated the shoreline continues to undergo change, with most "new"

disturbance occurring in newer developments versus older, more established sub-divisions. This finding

was surprising given new subdivisions face more rigorous review and reporting requirements under the

CVRD and Town of Lake Cowichan bylaws that require a Riparian Assessment Report (RAR). The

objective of the Provincial RAR is to protect riparian habitat adjacent to fish bearing waters, with the

designation of a "no-touch" set-back or SPEA.

Video comparison of the Creekside subdivision noted that as new houses are built and occupied, there is a

slow creep into the SPEA, resulting in cumulative removal of vegetation, even though property owners

(should) know the local government restrictions on clearing in these (SPEA-designated) areas. Riparian

vegetation has typically been cleared along the gravel beach, and trimming (or removal) of trees to allow

better views of the lake were the most common modifications.

In more developed communities, where the same bylaw restrictions apply, shoreline developments are

generally not associated with vegetation but rather unauthorized construction (or re-construction) of

retaining walls. Future re-development in the Walton Road and Youbou area of Cowichan Lake will need

to address the subject of flood construction level. How landowners, the CVRD and senior governments

work to resolve potential impacts to shorelines in meeting re-construction standards, will benefit from

results of this FIM.


63

Efforts to improve enforcement of non-permitted activities on shorelines by all agencies (local

government, Provincial and Federal), is a difficult task. Lack of resources to investigate all reports of

violations, and ineffective legal tools to successfully prosecute alleged violators, are frequent reasons for

non-engagement of enforcement staff. Without effective environmental regulations, coupled with prompt

and willing enforcement, the average property owner on Cowichan Lake will continue to ignore

permitting requirements for lakeshore "improvements/developments.”

This "cloud" over regulatory jurisdiction and enforcement is a common problem throughout BC.

Consequently, a new "collaborative" approach is now being tested at Shuswap Lake in BC’s southern

interior. The Shuswap Lake Integrated Planning Process (SLIPP) is a collaborative attempt to find local

solutions to enforcement and ultimately promote more sustainable development around the lake

(http://slippbc.com/). While the initiative is just in its second year, it has brought agencies and

communities together in a working-level partnership that holds much promise for effecting positive

change. More information on the progress and experiences of SLIPP should be actively pursued by

Cowichan lakeshore stewardship interests.

Recommendations:

1. Hold a workshop on the "Future Environmental Health of Cowichan Lake." This session

should be held to evaluate the experiences of other jurisdictions (throughout BC and Alberta) in

managing lakeshore development and preserving environmental assets. A focus should be on the

Shuswap Lake Integrated Planning Process to profile its goals, successes and continued

challenges. The workshop should be professionally facilitated and target/involve local

stewardship representatives, federal and provincial agency staff, along with local government

planning and bylaw enforcement personnel. Representatives from TimberWest Forest

Corp./Couverdon Real Estate, as the owner of the lake bottom, should be key workshop

participants.

2. A communication and outreach strategy should be developed to inform stakeholders and

the public of the Cowichan Lake FIM results. Initially, it is recommended this report be

distributed to the Cowichan Watershed Board, Cowichan Tribes, Ministry of Forests, Lands and

Natural Resource Operations, Ministry of Environment, CVRD Area I and F Directors, CVRD

Planning and Development Services Departments, Town of Lake Cowichan and local lake and

river stewardship organizations.

3. A landowner contact and lakeshore education program should be developed. A local

stewardship group should be encouraged to launch a landowner education program starting

immediately, with a goal of educating lakeshore owners about the lake's natural capital, and how

poorly planned developments can impact important shoreline biophysical processes. Funding for

this initiative should be sought from the CVRD, Pacific Salmon Foundation, Habitat

Conservation Trust Foundation, Real Estate Foundation of BC, Royal Bank’s Blue Water Fund

and similar granting organizations.

4. Development of a "flood avoidance" strategy for future developments on the lake.

Cowichan Lake is subject to annual fluctuations in water levels that are known to flood certain


64

low-lying properties in typical wet winters. The CVRD implemented a LiDAR mapping project

(2009) for all lakeshore properties to confirm elevations of existing and future developments with

respect to risk from the “mean annual” to “extreme flood events”. Some lands identified in this

process have yet to be developed, and should be designated with some form of development

restriction, if below 167.33m elev. (the CVRD’s 200 year flood construction level).

A land designation such as the "Environmental Reserve" used in Alberta should be considered for

Cowichan Lake foreshore areas subject to seasonal flooding. Some owners of properties already

developed may request re-development variances, in future. A proactive and collaborative

approach by all agencies dealing with existing and potential impacts from such requests should be

established. This could even include some form of "Habitat Banking" as a means of

compensating for lost/impacted shoreline habitats, if unavoidable.

Mapping and Protection of Cowichan Lake Inlet Streams

Small streams subject to field assessment in summer 2011 were primarily 1st and 2

nd order watercourses,

which because of their small drainage areas, have not been properly mapped/recorded at a 1:5,000 scale.

Most possess habitats that can sustain salmonids for a short period of their life histories. Several were

previously impacted from urban development, primarily through ditching and culvert installations. It is

essential to dedicate mapping and field resources to complete an inventory of all 53 streams, especially

those that may be subject to intensive land developments in the near future.

Recommendation:

1. Sensitive Habitat Inventory and Mapping (SHIM) is a GIS based mapping tool that

provides substantial information on small streams and should be applied to all such

watercourses around Cowichan Lake. Initially, mapping should focus on the most

significant salmonid-producing systems (i.e., those supporting anadromous species), and then

smaller tributaries containing resident fish, followed by non-fish bearing streams. Well

prepared maps will provide highly useful information to fish and wildlife managers,

municipal engineering departments (e.g., engineering staff responsible for drainage

maintenance), and home owners. This information is also very useful for Source Water

Protection initiatives because it identifies potential contaminant sources through a field

inventory process.


65

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GLOSSARY OF TERMS AND ACRONYMS Alluvial Fan / Stream Mouth– Alluvial fans are considered to be areas where a stream has the potential

to have a direct active influence (e.g., sediment deposition or channel alignment changes) on the lake.

Allocthonous Inputs - Organic material (e.g., leaf litter) reaching an aquatic community from a terrestrial community

Anadromous – Anadromous fish as sea run fish, such as Coho, Chinook, and Sockeye salmon.

Aquatic Habitat Index (AHI)-The index is a ranking system based upon the biophysical attributes of

different shoreline types. The index consists of parameters such as shore type, substrate type, presence of retaining walls, marinas, etc. to determine the relative habitat value based upon a mathematical

relationship between the parameters.

Aquatic Vegetation – Aquatic vegetation consists of any type of plant life that occurs below the high

water level. In some instances, aquatic vegetation can refer to grasses and sedges that are only submerged for short periods of time.

Biophysical – Refers to the living and non-living components and processes of the ecosphere. Biophysical attributes are the biological and physical components of an ecosystem such as substrate type,

water depth, presence of aquatic vegetation, etc.

Best Management Practice (BMP) - Is a method or means by which natural resources are protected

during development or construction. For example, the Ministry of Environment have been recently creating documents containing guidelines for work in and around water.

Emergent Vegetation - Emergent vegetation includes species such as cattails, bulrushes, varies sedges, willow and cottonwood on floodplains, grasses, etc. Emergent vegetation is most commonly associated

with wetlands, but is also occurs on rocky or gravel shorelines.

Fisheries and Oceans Canada (DFO) – Federal agency responsible for management of fish habitats

Fisheries Productivity - The maximum natural capability of habitats to produce healthy fish, safe for

human consumption, or to support or produce aquatic organisms upon which fish depend.

Floating Vegetation - Floating vegetation includes species such as pond lilies and native pondweeds with

a floating component.

Foreshore – The foreshore is the area that occurs between the high and low water marks on a lake.

Foreshore Inventory Mapping (FIM)-FIM is methodology used to collect and document fish and

riparian habitats lake corridors and was performed by the Regional District of Central Okanagan and

partners. A full discussion of this mapping can be found in Regional District of Central Okanagan (2005)

Georeferencing - Georeferencing establishes the relationship between page coordinates on a planar map (i.e., paper space) and known real-world coordinates (i.e., real world location)


70

Groyne – A protective structure constructed of wood, rock, concrete or other materials that is used to stop sediments from shifting along a beach. Groynes are generally constructed perpendicular to the shoreline

Instream Features – Instream features are considered to be construction of something below the high

water

mark. Instream features may include docks, groynes, marinas, etc.

Lacustrine – Produced by, pertaining to, or inhabiting a lake

Lentic - In hydrologic terms, a non-flowing or standing body of fresh water, such as a lake or pond.

Life History – Life history generally means how an organism carries out its life. Activities such as

mating and resource acquisition (i.e., foraging) are an inherited set of rules that determine where, when

and how an organism will obtain the energy (resource allocations) necessary for survival and reproduction. The allocation of resources within the organism affects many factors such as timing of

reproduction, number of young, age at maturity, etc. The combined characteristics, or way an organism

carries out its life, is a particular species’ life history traits.

Lotic – In hydrologic terms, a flowing or moving body of freshwater, such as a creek or river.

Non Anadromous – Non anadromous fish are fish that do not return to the sea to mature. Examples include rainbow trout (excluding steelhead), bull trout, and whitefish.

Retaining Wall – A retaining wall is any structure that is used to retain fill material. Retaining walls are commonly used along shorelines for erosion protection and are constructed using a variety of materials.

Bioengineered retaining walls consist of plantings and armouring materials and are strongly preferred over vertical, concrete walls. Retaining walls that occur below the Mean Annual High Water Level pose a

significant challenge, as fill has been placed into the aquatic environment to construct these walls.

Sensitive Habitat Inventory Mapping (SHIM)- The SHIM methodology is used to map fish habitat in

streams.

Shore zone - The shore zone is considered to be all the upland properties that front a lake, the foreshore,

and all the area below high water mark.

Streamside Protection and Enhancement Area (SPEA) - The SPEA means an area adjacent to a stream

that links aquatic to terrestrial ecosystems and includes both the existing and potential riparian vegetation and existing and potential adjunct upland vegetation that exerts influence on the stream. The size of the

SPEA is determined by the methods adopted for the Provincial Riparian Areas Regulation.

Stream Mouth / Alluvial Fan – Stream mouths are considered to be areas where a stream has the

potential to have a direct active influence (e.g., sediment deposition or channel alignment changes) on the lake.

Submergent Vegetation – Submergent vegetation consists of all native vegetation that only occurs within the water column. This vegetation is typically found in the littoral zone, where light penetration

occurs to the bottom of the lake. Eurasian milfoil is not typically considered submergent vegetation as it is non-native and invasive.


Appendix

Refer to Volume II - Appendices.