BOBS LAKE CATCHMENT TAY RIVER SUBWATERSHED REPORT 2011

Transcription

1 Catchment Facts During the 1950 s, electrification became available around the lake and the pace of waterfront lot development notably increased. Over the last 30 years there has been a trend to larger urban type dwellings and reconstruction/conversion of seasonal to permanent residences In 2004, one subdivision created 35 lots (including back lots). As of 2007, there were over 1500 dwellings and 24 commercial resorts on Bobs and Crow lakes. In non-waterfront rural areas, there is limited severance activity Lake community created Imagine: A Stewardship Plan for Bobs and Crow Lakes (March 2007) with various partners that guide the communities priorities for protecting water quality and the natural environment of the lake Mississippi-Rideau Source Protection Assessment Report indicates that the shallowest upper bedrock aquifer is considered to be highly vulnerable to land-use activity due to thin soil cover Situated in part of the Algonquin Highlands, an ancient geologic region of hilly bedrock made up of such Precambrian rocks as marble, conglomerates, and dark or colour banded granite-like rocks. A veneer of glacial drift (glacial till, sand etc.) overlies the bedrock Comprised of eight smaller areas, those being Buck, Green, Mill, Mud and Norris Bays, Long Bay in the East Basin, the Central Narrows and West Basin 69% of the catchment falls within South Frontenac Township, 17% within Tay Valley Township, 13% within Central Frontenac Township and 1% within Rideau Lakes Township Drains 132 sq. km of land or 16.5% of the Tay River Subwatershed and 3.1% of the Rideau Valley Watershed Dominant land cover is woodland (53%) and water (25%), followed by wetland The RVCA produces individual reports for 14 catchments in the Tay River Subwatershed. Using data collected and analysed by the RVCA through its watershed monitoring and land cover classification programs, surface water quality conditions are reported for eight bays and basins in Bobs Lake along with a summary of environmental conditions for the surrounding countryside every six years. This information is used to help better understand the effects of human activity on our water resources, allows us to better track environmental change over time and helps focus watershed management actions where they are needed the most. The following pages of this report are a compilation of that work. For other Tay River Catchments and the Tay Subwatershed Report, please visit the RVCA website at Inside 1. Surface Water Quality Conditions 2 Buck Bay/Central Narrows 2-6 East Basin/Long Bay/Green Bay 7-11 Mill Bay/Mud Bay Norris Bay/West Basin Rock Lake Riparian Conditions 24 Overbank Zone 24 Shoreline Zone 25 Instream Aquatic Habitat Land Cover Stewardship & Protection Issues Opportunities for Action 33 (12%), grassland (3%), crop and pastureland (3%), settlement (3%) and roads (1%) 30 metre wide riparian buffer around Bobs Lake and along both sides of Davern Creek is comprised of woodland (57%), wetland (31%), settlement (7%) crop and pastureland (2%), grassland (2%) and roads (1%) Contains a cold/cool/warm water baitfish and recreational fishery with 26 fish species Water quality rating in Bobs Lake ranges from good in Green Bay, to fair in Buck/ Long/Norris Bays, Central Narrows and East/West Basins, to poor in Mud Bay and very poor in Mill Bay MOE well records indicate there are 597 private water wells or 13% of all wells in the Tay River Subwatershed 10 stewardship (landowner tree planting/ clean water/shoreline naturalization) projects have been completed

2 BOBS LAKE: BUCK BAY SURFACE WATER QUALITY CONDITIONS Page 2 Introduction Surface water quality in the Bobs Lake Catchment is assessed using water and aquatic insect samples collected in Bobs Lake, Rock Lake and Davern Creek through RVCA s surface water quality monitoring programs. Analyzed results are presented below. RVCA has adopted the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) to provide an overall measure of surface water quality in Tay River catchments using a rating for water quality ranging from Very Poor, Poor, Fair, Good to Very Good. WQI scores for lakes and streams are based on how often, how many and by how much sample results for each parameter exceed established water quality guidelines. In applying the CCME WQI, the RVCA has selected five parameters that are available for all lakes in the Tay Subwatershed: total Kjeldahl nitrogen (TKN), total phosphorus (TP), ph (acidity), water clarity (Secchi depth) and dissolved oxygen (for fish habitat). Assessment of streams is based on 21 parameters including nutrients (total phosphorus, total Kjeldahl nitrogen, nitrates), E. coli, metals (like cadmium and copper) and additional chemical/physical parameters (such as alkalinity, chlorides, ph and total suspended solids). 1) a. Bobs Lake: Buck Bay Water Quality Surface water quality conditions in Bobs Lake (Buck Bay) have been monitored by RVCA s Watershed Watch Program since 2003 (Fig.1).This report covers the five year period from 2006 through 2010 and 2011 data is also shown where it is available. The Water Quality Index for Buck Bay is rated as Fair, mainly due to instances of nutrient exceedances and slightly elevated ph (alkaline conditions). Elevated nutrient concentrations can help stimulate the growth of algae blooms and other aquatic vegetation in a lake. Figure 1. Watershed Watch sampling on Bobs Lake Deep Point: Nutrients Figures 2 and 3 show that there has been variability in nutrient concentrations at the deep point (RVL-16DP). The majority of samples are below established guidelines. Ninety percent of samples analysed for TP are less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/l (Fig.2), indicating that nutrients are not often elevated. Ninety percent of samples analysed for TKN fell below RVCA s guideline of mg/l (Fig.3). Observed exceedances may be partially attributed to the natural aging of a lake, but can be slowed down by lake residents reducing nutrient inputs through the proper maintenance of their septic systems, by keeping shorelines natural and using phosphate free soaps and detergents. The WQI also considers ph as it is an important factor for aquatic life. Waters do tend to be a bit more alkaline (higher ph) in this part of the watershed. This can generally be attributed to geology rather than anthropogenic activities. The variation of ph concentrations is minimal which suggests that high ph is a natural feature of Buck Bay. Figure 2. Buck Bay total phosphorus concentrations at the deep point (from RVCA Watershed Watch Program)

3 BOBS LAKE: BUCK BAY SURFACE WATER QUALITY CONDITIONS Page 3 Table 1 shows the average concentrations of each nutrient summarized for each year. There are variations in overall nutrient concentrations; however, differences are minimal in the concentrations of both TP and TKN throughout the monitoring period. Figure 4. Buck Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 3. Buck Bay total Kjeldahl nitrogen concentrations at the deep point (from RVCA Watershed Watch Program) Table 1. Average nutrient concentrations in Buck Bay at the deep point (from Watershed Watch). Year Average TP Average TKN Figure 5. Buck Bay Average Total Kjeldahl Nitrogen (TKN) concentrations (from RVCA Watershed Watch Program) Around the Lake: Nutrients The average nutrient concentrations at shoreline sites (Figures 4 and 5) show year to year changes, deep point concentrations have also been included to show variability between the near shore and open water locations. Total phosphorus concentrations (Fig.4) at site A are typically greater than at the deep point and exceed the PWQO on more than one occasion. Please note that site A and the deep point (DP) are monitored each year, while other sites are monitored every fifth year. TKN concentrations were consistent across shoreline and deep point sites (Fig.5), as well as year to year. Results for site A also exceed RVCA s TKN guideline. These results provide further evidence that nutrient enrichment may be a problem in some near shore areas and could results in abundant plant or algal growth. Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 6 shows that all readings exceed the minimum PWQO of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Habitat: Dissolved Oxygen and Temperature Two other factors, dissolved oxygen/temperature and ph were also assessed to provide an overall idea of the health of Buck Bay from a fish habitat perspective. Figure 7 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4mg/l). The vertical axis represents the total lake depth at the site of 16 metres where the profile is taken.

4 BOBS LAKE: BUCK BAY SURFACE WATER QUALITY CONDITIONS Page 4 Suitable oxygen temperatures exist to an average depth of nine metres and has remained fairly consistent through sampling years. Spring and early summer typically have good conditions for fish habitat but as temperatures warm and the deeper waters are depleted of oxygen, there is limited habitat available in late summer and early fall. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth), which depletes oxygen levels as this organic matter dies off and begins to decay. irritation for anyone using the waters for recreational purposes. In some areas of the Tay River Subwatershed, surface waters tend to be a bit more alkaline (higher ph) which can generally be attributed to geology rather than anthropogenic activities. The variation in sampled ph concentrations is minimal, which suggests that high ph is a naturally occurring conditions in Buck Bay. This being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Figure 8. ph concentrations at the deep point in Buck Bay Figure 6. Secchi depths at the deep point in Buck Bay Around the Lake: E.coli E. coli is also sampled at monitored shoreline sites at least twice each sampling season. Figure 9 shows that all samples were well below the guideline of 100 colony forming units (CFU) per 100ml, suggesting that bacterial contamination is not presently an issue in Buck Bay (please note that the E. coli data is not used in the calculations of the WQI rating for the bay). Figure 7. Depths suitable for warm water fish in Buck Bay Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; ph concentrations in Buck Bay are shown in Figure 8. Seventy five percent of samples are within guidelines established by the PWQO which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent Figure 9. Average E. coli concentrations for Buck Bay shoreline sites (from RVCA Watershed Watch Program)

5 BOBS LAKE: CENTRAL NARROWS SURFACE WATER QUALITY CONDITIONS Page 5 Summary Buck Bay may be characterized as a lake with clear waters and moderate nutrient levels with an increasing chance of limited oxygen in the deep waters that may limit some fish populations. Abundant aquatic vegetation (macrophytes) may occur but the lake should generally have good aesthetics for recreational use. While the bay is generally considered to be healthy, there is a potential for the aquatic ecosystem to be impacted by increasing nutrients and poor oxygen levels. Residents should consider the cumulative effect of their activities on the lake and what can be done to about it. 1) b. Bobs Lake: Central Narrows Water Quality Surface water quality conditions in Bobs Lake (Central Narrows) have been monitored under the RVCA s Watershed Watch Program since 2003 (Fig.1). This report covers the five years from 2006 through 2010 and 2011 data is shown where it is available. Figure 10. Total phosphorus concentrations at the deep point in Central Narrows The Water Quality Index rating for Central Narrows is Fair (for an explanation of the WQI, please refer to the Introduction section on Pg.2 of this report), The rating of fair is due to nutrient concentrations that exceed their respective guidelines. Deep Point: Nutrients Figures 10 and 11 show that though there has been variability in nutrient concentrations at the deep point (RVL-22DP). The majority of samples are below established guidelines. Eighty six percent of samples analysed for TP were less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/l (Fig. 10), indicating that at times nutrients may be elevated. Table 2 shows the average concentrations of each nutrient summarized for each year. There are differences in the concentrations of both nutrients from year to year but no clear trend showing an increasing/decreasing concentration of nutrients in the lake. TP and TKN exceedances at the deep point provide evidence of nutrient loading within this portion of the waterbody. It is important for property owners and lake users to continue to employ best management practices to ensure the continued health of the lake. Ninety percent of samples analysed for TKN fall below RVCA s guideline of 0.5 mg/l (Fig. 11). Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 12 shows that all readings have exceeded the minimum PWQO of 2 metres, indicating that Figure 11. Total Kjeldahl nitrogen concentrations at the deep point in Central Narrows Table 2. Average nutrient concentrations in Central Narrows at the deep point Year Average TP (mg/l) Average TKN (mg/l) waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Habitat: Dissolved Oxygen and Temperature Two other factors, dissolved oxygen/temperature and ph are also assessed to provide an overall idea of the health of Central Narrows from a fish habitat perspective.

6 BOBS LAKE: CENTRAL NARROWS SURFACE WATER QUALITY CONDITIONS Page 6 concentrations in Central Narrows are shown in Figure 14. Ninety-three percent of samples are within PWQO guidelines, which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. One ph sample is below the minimum guideline of 6.5 and is most likely an anomaly as surface waters tends to be more alkaline (higher ph) in this part of the watershed and the observed ph concentration of all other results vary minimally. This being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Figure 12. Secchi depth measurements at the deep point in Central Narrows Figure 13 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4 mg/l). The vertical axis represents the total lake depth at the site of 21 metres where the profile is taken. Suitable oxygen temperatures exist to an average depth of 14 metres and has remained fairly consistent through sampling years. Spring and early summer typically have good conditions for fish habitat but as temperatures warm and the deeper waters are depleted of oxygen there is more limited habitat available. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth) which depletes oxygen levels as this organic matter dies off and begins to decay. Figure 14. ph concentrations sampled at the deep point in Central Narrows Figure 15. Average E. coli concentrations for Central Narrows shoreline sites (from RVCA Watershed Watch Program) Around the Lake: E.coli Figure 13. Suitable depths for fish habitat of warm water species in Central Narrows Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; E. coli was sampled at site A twice during the 2008 monitoring season. Average results are well below the guideline of 100 colony forming units per 100ml (Fig. 15), suggesting that bacterial contamination is not presently an issue in Central Narrows (please note that the E. coli data is not used in the calculation of the WQI).

7 BOBS LAKE: EAST BASIN/LONG BAY SURFACE WATER QUALITY CONDITIONS Page 7 Summary Central Narrows may be characterized as a waterbody with clear waters and moderate nutrient levels. The lake should generally have good aesthetics for recreational use. While the lake is generally considered to be healthy, there is a potential for it to be impacted by increased nutrient loading and poor oxygen levels. 1) c. Bobs Lake: East Basin/Long Bay Water Quality Surface water quality conditions in Bobs Lake (East Basin/ Long Bay) have been monitored by RVCA s Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is also shown where it is available. The Water Quality Index rating for East Basin/Long Bay is Fair (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). This is largely due to total phosphorus concentrations that exceed the Provincial Water Quality Objective (PWQO) and instances of reduced oxygen concentration throughout much of the water column in the late summer, which may stress the resident fish population. Deep Point: Nutrients Nutrient concentrations have been relatively consistent at the deep points for East Basin (RVL-21DPA) and Long Bay (RVL-21DPB) with the majority of samples below established guidelines. Ninety-five percent of samples analysed for TP were less than the Provincial Water Quality Objective of mg/l (Fig. 16), indicating that nutrients are rarely elevated. All samples analysed for TKN fell below RVCA s guideline of mg/l (Fig. 17). Figure 17. Total Kjeldahl nitrogen concentrations at the deep point in East Basin/Long Bay Table 3 shows the average concentrations of each nutrient summarized for each year. With the exception of 2010, when very low concentrations of both TP and TKN were observed, differences are minimal from year to year. There is no clear trend showing an increasing/decreasing concentration of nutrients in the bay. Table 3. Average nutrient concentrations in East Basin/ Long Bay at the deep point Year Average TP (mg/l) Average TKN (mg/l) Around the Lake: Nutrients The average nutrient concentrations at shoreline sites (Figures 18 and 19) show year to year changes; deep point concentrations have also been included to show variability between the near shore and open water locations. Please note that sites A, C and D are not monitored each year. TP concentrations (Fig.18) at site B are typically greater than at the deep point and exceed the PWQO in Figure 16. East Basin/Long Bay total phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) TKN concentrations are consistent across shoreline and deep point sites (Fig.19), as well as from year to year. Results for site B also exceed RVCA s TKN guideline. This provides evidence that nutrient enrichment may be a problem in some near shore areas and could result in abundant plant or algal growth.

8 BOBS LAKE: EAST BASIN/LONG BAY SURFACE WATER QUALITY CONDITIONS Page 8 Figure 18. East Basin/Long Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 20. Secchi depth measurements at the deep point in East Basin/Long Bay Figure 19. East Basin/Long Bay Average Total Kjeldahl Nitrogen concentrations (from RVCA Watershed Watch Program) Water Clarity Figure 20a. Suitable depths for fish habitat of warm water species in East Basin Water clarity is measured using a Secchi disk during each deep point sample. Figure 20 shows that all readings at both sites exceed the minimum PWQO of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Habitat: Dissolved Oxygen and Temperature Dissolved oxygen and temperature are used to show the health of East Basin and Long Bay from a fish habitat perspective. Results of the temperature-dissolved oxygen profile are shown in Figures 20a and 20b. The grey bars on the graph show the depths to which suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4mg/l). The vertical axis represents the total depth at the deep point where the profile is taken. Figure 20b. Suitable depths for fish habitat of warm water species in Long Bay

9 BOBS LAKE: EAST BASIN/LONG BAY/GREEN BAY SURFACE WATER QUALITY CONDITIONS Page 9 Spring and early summer typically have good conditions for fish habitat at both deep points, but as temperatures warm, the deeper waters are often depleted of oxygen limiting available fish habitat. Care should be taken to avoid nutrient enrichment as it fuels primary productivity (aquatic plant and algal growth), which depletes oxygen levels as this organic matter dies off and begins to decay. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life. ph concentrations in East Basin/Long Bay are shown in Figure 21. Ninety percent of samples are within guidelines established by the PWQO, which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Surface waters tend to be a bit more alkaline (higher ph) in this part of the watershed. This can generally be attributed to geology rather than anthropogenic activities. Two results are less than the minimum concentration of 6.5 and are most likely an anomaly as the majority of samples are fairly alkaline. However care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Figure 22. Average E. coli concentrations for East Basin/Long Bay shoreline sites (from RVCA Watershed Watch Program) Summary East Basin/Long Bay may be characterized as a waterbody with clear waters and moderate nutrient levels with an increasing chance of limited oxygen in the deep waters that may limit some fish populations. Given the presence of TP exceedances at the deep point and low oxygen levels it is important for property owners and lake users to continue to employ best management practices to reduce nutrient loading and ensure the continued health of the aquatic ecosystem. 1) d. Bobs Lake: Green Bay Water Quality Surface water quality has been monitored in Bobs Lake (Green Bay) under the RVCA Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is also shown where it is available. Figure 21. ph concentrations sampled at the deep point in East Basin/Long Bay Around the Lake: E. coli E. coli is also sampled at shoreline sites at least twice each sampling season. All samples are well below the PWQO guideline of 100 colony forming units per 100ml (Fig. 22), suggesting that bacterial contamination is not presently an issue in East Basin/Long Bay (please note that E. coli data is not used in the calculation of the WQI rating for the bay). The Water Quality Index rating for Green Bay is Good (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). All parameters, with the exception of ph, are within their respective guidelines. ph frequently exceeded its Provincial Water Quality Objective. This is likely due to geological characteristics of the bay rather than human influences; nonetheless it has the potential to stress resident aquatic species within the bay. Deep Point: Nutrients Nutrient concentrations vary in Green Bay but are consistently below established guidelines. All samples analyzed for TP are below the Provincial Water Quality Objective (PWQO) of mg/l (Fig. 23). Likewise, all TKN results are below RVCA s guideline of 0.5 mg/l (Fig. 24).

10 BOBS LAKE: GREEN BAY SURFACE WATER QUALITY CONDITIONS Page 10 Table 4 shows the average concentrations of each nutrient summarized for each year. There are minimal differences in the concentrations of both nutrients throughout the reporting period. point concentrations have also been included to show variability between the near shore and open water locations. Please note not all sites are monitored each year. TP concentrations (Fig. 25) at shoreline sites are often slightly greater than the deep point but still do not exceed the Provincial Water Quality Objective. TKN concentrations are similar across shoreline and deep point sites (Fig. 26). The one exception is site D, which is above RVCA s guideline. The majority of the data collected is below established guidelines/objectives and this suggests that nutrient loading is not presently a significant problem in the near shore area. Figure 23. Green Bay total phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) Figure 25. Green Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 24. Total Kjeldahl nitrogen concentrations at the deep point in Bobs Lake Green Bay Table 4. Average nutrient concentrations in Green Bay at the deep point Year Average TP (mg/l) Around the Lake: Nutrients Average TKN (mg/l) The average nutrient concentrations at shoreline sites (Figures 25 and 26) show year to year changes. Deep Figure 26. Green Bay Average Total Kjeldahl Nitrogen concentrations (from RVCA Watershed Watch Program) Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 27 shows that all readings have exceeded the minimum Provincial Water Quality Objective

11 BOBS LAKE: GREEN BAY SURFACE WATER QUALITY CONDITIONS Page 11 (PWQO) of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. shown by the red points. Spring and early summer typically have good conditions for lake trout habitat but as temperatures warm and the deep waters are depleted of oxygen there is minimal habitat available. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life. ph concentrations in Green Bay are shown in Figure 29. Figure 27. Secchi depth measurements at the deep point in Green Bay Habitat: Dissolved Oxygen and Temperature Dissolved oxygen and temperature are used to show the health of Green Bay from a fish habitat perspective (Fig. 28). The grey bars show the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4 mg/l). The vertical axis represents the total depth of 26 metres at the deep point where the profile is taken. Suitable oxygen temperature exists on average to a depth of 20 metres and has remained fairly consistent through sampling years. Optimal conditions for lake trout habitat (temperature less than 10 C and dissolved oxygen greater than 7mg/l) are Figure 29. ph concentrations sampled at the deep point in Green Bay Fifty three percent of samples are within PWQO guidelines which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Six samples exceed the maximum PWQO. The variation in ph concentrations is minimal which suggests that high ph is a natural feature of Green Bay. Surface waters tend to be a bit more alkaline (higher ph) in some parts of the Tay River Subwatershed, which can generally be attributed to geology rather than human activities. That being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Around the Lake: E. coli E. coli is also sampled at shoreline sites at least twice each sampling season. All results, except site F, in 2008 are well below the PWQO of 100 colony forming units (CFU) per 100ml (Fig. 30). Figure 28. Suitable depths for fish habitat of warm water species in Green Bay Subsequent sampling at site F has shown a drop in E. coli counts below the PWQO, allowing us to suggest that bacterial contamination is presently not an issue in Green Bay (please note the E. coli data is not used in the calculation of the WQI).

12 BOBS LAKE: MILL BAY SURFACE WATER QUALITY CONDITIONS Page 12 Summary Green Bay may be characterized as a waterbody with clear waters, low nutrient levels and good oxygen availability throughout the water column. Green Bay is unique as it supports a natural lake trout population. Special care should be taken to preserve the habitat for this much valued fish species, including minimizing nutrient loadings that can deplete oxygen in the deep waters and negatively affect the resident trout population. though exceedances seem to be more prevalent in the past with the majority of recent samples below respective guidelines. Eighty-six percent of samples analysed for TP are less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/l (Fig. 31), indicating that nutrients have been elevated at times, although its seems to have been a greater issue in Figure 30. Average E. coli concentrations for Green Bay shoreline sites (from RVCA Watershed Watch Program) 1) e. Bobs Lake: Mill Bay Water Quality Surface water quality conditions in Bobs Lake (Mill Bay) have been monitored under the RVCA Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is also shown where it is available. Figure 31. Mill Bay Total Phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) Eighty six percent of samples analyzed for TKN are below RVCA s TKN guideline of 0.5 mg/l (Fig. 32). Table 5 shows average TP and TKN concentrations for each year. With the exception of 2006, there are minimal differences in concentrations from year to year. The Water Quality Index (WQI) rating for Mill Bay is Very Poor (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). This is due to the fact that multiple parameters (nutrients, dissolved oxygen and ph) do not fall within their respective guidelines. Nutrient exceedances are a concern as they fuel the growth of algal blooms and other aquatic vegetation. Elevated TP results did occur in 2006 but have not reoccurred since. The WQI also considers the proportion of the lake that is suitable for fish habitation based on its oxygen concentrations and water temperatures. Since the bay is quite shallow, its waters warms fairly quickly, which often reduces the depths of water suitable for some species. Deep Point: Nutrients Figures 31 and 32 show that there have been elevated nutrient concentrations at the deep point (RVL-23DP), Figure 32. Total Kjeldahl Nitrogen concentrations at the deep point in Mill Bay Around the Lake: Nutrients The average nutrient concentrations at shoreline sites (Figures 33 and 34) show year to year changes; deep

13 BOBS LAKE: MILL BAY SURFACE WATER QUALITY CONDITIONS Page 13 point concentrations are also included to show variability between the near shore and open water locations. TP concentrations (Fig. 33) at shoreline sites are often slightly higher than at the deep point, but no site exceeds the PWQO. Table 5. Average nutrient concentrations in Mill Bay at the deep point Year Average TP (mg/l) Average TKN (mg/l) Figure 34. Mill Bay Average Total Kjeldahl Nitrogen (TKN) concentrations (from RVCA Watershed Watch Program) Figure 33. Mill Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) TKN concentrations are similar across the shoreline and deep point sites (Fig. 34). The exception is site D that is above RVCA s TKN guideline. However, the majority of data is well below RVCA s guideline and PWQO, suggesting that nutrient loading is not presently a problem in these near shore areas. Water Clarity Figure 35. Secchi depth measurements at the deep point in East Mill Bay Water clarity is measured using a Secchi disk during each deep point sample. Figure 35 shows that all readings exceed the minimum PWQO of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Habitat: Dissolved Oxygen and Temperature Dissolved oxygen and temperature are used to show the health of Mill Bay from a fish habitat perspective. Results of the dissolved oxygen/temperature profile are shown in Figure 36. Figure 36. Suitable depths for fish habitat of warm water species in Mill Bay

14 BOBS LAKE: MILL BAY/MUD BAY SURFACE WATER QUALITY CONDITIONS Page 14 This grey bars on the graph show the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4 mg/l). The vertical axis represents the total depth of 4 metres at the deep point where the profile is taken. Suitable oxygen temperatures exist on average to a depth of 3 metres and has remained fairly constant through sampling years. It should be noted that in August 2007 and July 2010, no portion of the water column met habitat conditions for warm water fish because temperatures exceeded 25 C throughout the water column. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life. ph concentrations in Mill Bay are shown in Figure 37. Seventy eight percent of samples are within PWQO guidelines stating that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. The variation in sampled ph concentrations is minimal, which suggests that high ph is a natural feature of Mill Bay and can generally be attributed to geology. That being said, care should be taken to not add any additional pollutants to the water that may alter ph levels. Figure 38. Average E. coli concentrations for Mill Bay shoreline sites (from RVCA Watershed Watch Program) nutrient concentrations (2006 TP/TKN results). There has been a reduction in nutrient concentrations since 2006, which will hopefully improve the Mill Bay score in the future. Due to the fact that the bay is quite shallow it is likely that habitat conditions will continue to be limited during the warm summer months. Property owners should continue to focus their efforts to minimize nutrient loadings as excessive nutrient concentrations are likely to result in algal blooms and abundant macrophyte growth. 1) f. Bobs Lake: Mud Bay Water Quality Surface water quality conditions in Bobs Lake (Mud Bay) have been monitored by RVCA s Watershed Watch Program since 2003 (Fig. 1). This report covers the five year period from 2006 through 2010 and 2011 data is also shown where it is available. Figure 37. ph concentrations at the deep point in Mill Bay Around the Lake: E. coli E. coli is also sampled at shoreline sites at least twice each season. All results are below the PWQO of 100 colony forming units per 100ml (Fig. 38), suggesting that bacterial contamination is not presently an issue in Mill Bay (please note that E. coli data is not used in the calculation of the WQI). Summary The Very Poor water quality rating for Mill Bay using the WQI is largely driven by previous instances of high The Water Quality Index rating for Mud Bay is Poor, due to instances of nutrient exceedances and low oxygen levels at the deep point. Elevated nutrient levels promote algae blooms and the growth of aquatic plants, which may deteriorate the aesthetic quality, limit oxygen availability and lead to the decay of aquatic vegetation. Reduced oxygen in the water column may also negatively impact resident fish populations. Deep Point: Nutrients Figures 39 and 40 show that although there has been variability in nutrient concentrations at the deep point (RVL -16DP), the majority of samples are below established guidelines. Ninety-five percent of samples analysed for TP are less than the Provincial Water Quality Objective of 0.02 mg/l (Fig.39), indicating that nutrients are not often elevated. Ninety-five percent of samples analysed for TKN also fall below RVCA s guideline of 0.5 mg/l (Fig. 40).

15 BOBS LAKE: MUD BAY SURFACE WATER QUALITY CONDITIONS Page 15 Table 6. Average nutrient concentrations in Mud Bay at the deep point Year Average TP (mg/l) Average TKN (mg/l) Figure 39. Mud Bay total phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) Figure 41. Mud Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 40. Total Kjeldahl nitrogen concentrations at the deep point in Mud Bay Table 6 shows the average concentrations of each nutrient summarized for each year. There are fluctuations in overall nutrient concentrations. However, there are minimal differences in the concentrations of both nutrients throughout the monitoring period. Around the Lake: Nutrients The average nutrient concentrations at shoreline sites (Figures 41 and 42) show year to year changes; deep point concentrations have also been included to show variability between near shore and open water locations. Please note that site B and the deep point (DP) are monitored each year while other sites are monitored every fifth year. Total phosphorus concentrations (Fig.41) at site B are relatively similar to the deep point and average concentrations at each site are below the PWQO. Figure 42. Mud Bay Average Total Kjeldahl Nitrogen (TKN) concentrations (from RVCA Watershed Watch Program) TKN concentrations are consistent across shoreline and deep point sites (Fig. 42), as well as year to year. No averaged result exceeds the guideline. Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 43 shows that all readings have exceeded the minimum Provincial Water Quality Objective

16 BOBS LAKE: MUD BAY SURFACE WATER QUALITY CONDITIONS Page 16 (PWQO) of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth), which depletes oxygen levels as this organic matter dies off and begins to decay and would act to eliminate even more habitat. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; ph concentrations in Mud Bay are shown in Figure 45. Seventy seven percent of samples are within guidelines established by the PWQO, which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Figure 43. Secchi depth measurements at the deep point in Mud Bay Habitat: Dissolved Oxygen and Temperature Two other factors, dissolved oxygen/temperature and ph are also assessed to provide an overall idea of the health of Mud Bay from a fish habitat perspective. Figure 44 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4 mg/l). The vertical axis represents the total lake depth at the site of eight metres where the profile is taken. Suitable oxygen temperatures exist to an average depth of five metres and has remained fairly consistent through sampling years. Figure 45. ph concentrations sampled at the deep point in Mud Bay In some areas of the Tay River Subwatershed, surface waters tend to be a bit more alkaline (higher ph), which can generally be attributed to geology rather than human activities. The variation in sampled ph concentrations is minimal, which suggests that high ph is a naturally occurring conditions in Mud Bay. That being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Around the Lake: E. coli Figure 44. Suitable depths for fish habitat of warm water species in Mud Bay Spring and early summer typically have good conditions for fish habitat but as temperatures warm conditions in the water surface water are too warm to meet the temperature criteria for warm water fish species resulting in limited habitat available in late summer and early fall. E. coli is also sampled at monitored shoreline sites at least twice each sampling season. Figure 46 shows that all samples were well below the guideline of 100 colony forming units (CFU) per 100ml, suggesting that bacterial contamination is not presently an issue in Mud Bay (please note that the E. coli data is not used in the calculations of the WQI rating for the bay). Summary Mud Bay may be characterized as a waterbody with clear waters and moderate nutrient levels due to the warm shallow water of the bay, which may limit some fish

17 BOBS LAKE: NORRIS BAY SURFACE WATER QUALITY CONDITIONS Page 17 populations. Abundant aquatic vegetation (macrophytes) may occur but the lake should generally have good aesthetics for recreational use. While the bay is generally considered to be healthy, there is a potential for the aquatic ecosystem to be impacted by increasing nutrients and poor oxygen levels. Residents should consider the cumulative effect of their activities on the lake and what can be done about it. Figure 47. Norris Bay Total Phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) Figure 46. Average E. coli concentrations for Mud Bay shoreline sites (from RVCA Watershed Watch Program) 1) g. Bobs Lake: Norris Bay Water Quality Surface water quality conditions in Bobs Lake (Norris Bay) have been monitored under the RVCA s Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is shown where it is available. The Water Quality Index rating for Norris Bay is Fair (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). This is largely driven by limited fish habitat (high water temperatures and low oxygen concentrations) at the deep point in the late summer. Deep Point: Nutrients Figures 47 and 48 show that there has been variability in nutrient concentrations at the deep point (RVL-22DP); however, all samples analyzed for both TKN and TP fall below established guidelines. One hundred percent of samples analysed for TP are less than the Provincial Water Quality Objective of 0.02 mg/l (Fig.47), indicating that nutrients are not elevated. One hundred percent of samples analysed for TKN also fall below RVCA s guideline of 0.5 mg/l (Fig. 48). Table 7 shows the average concentrations of each nutrient summarized for each year. There are differences Figure 48. Total Kjeldahl nitrogen concentrations at the deep point in Norris Bay Table 7. Average nutrient concentrations in Norris Bay at the deep point Year Average TP (mg/l) Around the Lake: Nutrients Average TKN (mg/l) in the concentrations of both nutrients from year to year but no clear trend showing an increasing/decreasing concentration of nutrients in the bay. Shoreline sites are only monitored in Norris Bay every fifth year, therefore results are available only for Deep

18 BOBS LAKE: NORRIS BAY SURFACE WATER QUALITY CONDITIONS Page 18 point (DP) data has been included to show variability between this near shore and open water locations. The average TP concentrations (Fig. 48) at site A in 2008 exceed the PWQO, while all shoreline sites have higher TP concentrations than the deep point. TKN concentrations are similar across the shoreline and deep point sites (Fig. 49) and do not exceed the TKN guideline. These results show that there have been some guideline exceedances; however, nutrient loading is not presently a problem in the near shore area. Figure 50. Secchi depth measurements at the deep point in Norris Bay Habitat: Dissolved Oxygen and Temperature Two other factors, dissolved oxygen/temperature and ph are also assessed to provide an overall idea of the health of Norris Bay from a fish habitat perspective. Figure 48. Norris Bay Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 51 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4 mg/l). The vertical axis represents the total lake depth at the site of ten metres where the profile is taken. Suitable oxygen temperatures exist to an average depth of 6 metres and has remained fairly consistent through sampling years. Spring and early summer typically have good conditions for fish habitat but as temperatures warm and the deeper waters are depleted of oxygen there is more limited habitat available. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth) which Figure 49. Norris Bay Average Total Kjeldahl Nitrogen (TKN) concentrations (from RVCA Watershed Watch Program) Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 50 shows that all readings have exceeded the minimum Provincial Water Quality Objective (PWQO) of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. Figure 51. Suitable depths for fish habitat of warm water species in Norris Bay

19 BOBS LAKE: NORRIS BAY/WEST BASIN SURFACE WATER QUALITY CONDITIONS Page 19 depletes oxygen levels as this organic matter dies off and begins to decay. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; concentrations in Norris Bay are shown in Figure 52. Ninety-three percent of samples are within guidelines established by the PWQO which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Surface waters tend to be more alkaline (higher ph) in this part of the watershed which can generally be attributed to geology rather than human activities. This being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Figure 53. Average E. coli concentrations for Norris Bay shoreline sites (from RVCA Watershed Watch Program) Care should be taken to limit nutrient loading to the bay as this fuels the growth of many aquatic plants and can deplete the overall availability of oxygen for many aquatic species as vegetation dies off and begins to decay. 1) h. Bobs Lake: West Basin Water Quality Surface water quality conditions in Bobs Lake (West Basin) have been monitored under the RVCA s Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is shown where it is available. The Water Quality Index rating for West Basin is Fair (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). This is largely due to TKN concentrations exceeding the guideline and slightly elevated ph levels. Figure 52. ph concentrations sampled at the deep point in Norris Bay Around the Lake: E. coli E. coli was sampled at site A twice during the 2008 monitoring rounds. Average results are well below the guideline of 100 colony forming units per 100ml (Fig. 53) at all sites except site A (please note that the E. coli data is not used in the calculation of the WQI). Summary Norris Bay may be characterized as a lake with clear waters and moderate nutrient levels. The lake should generally have good aesthetics for recreational use. Due to the shallow water throughout the bay a good portion of the water column is often too warm to meet the requirements of warm water fish habitat. When this is combined with low oxygen levels in the deep waters, it may result in a limit on some fish populations. Deep Point: Nutrients Nutrient concentrations in West Basin have been relatively variable at the deep point for both TP and TKN with the majority of samples below respective guidelines. Ninety-five percent of samples analysed for TP were less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/l (Fig. 54). Similarly ninety-five percent of samples analysed for TKN fall below RVCA s guideline of 0.5 mg/l (Fig. 55), indicating that although nutrients have exceeded the guidelines, they are rarely present in excessive concentrations. There are differences in the concentrations of both nutrients from year to year but no clear trend showing an increasing/decreasing concentration of nutrients in the basin. TP and TKN exceedances at the deep point provide evidence of nutrient loading is possible within this portion of the waterbody. It is important for property

20 BOBS LAKE: WEST BASIN SURFACE WATER QUALITY CONDITIONS Page 20 Around the Lake: Nutrients Shoreline sites A, B and K are monitored in West Basin twice each year, all other sites are sampled every five years; only results from 2008 are available. Deep point data has been included to show variability between the near shore and open water locations. The average TP concentrations at site K (Fig. 56) consistently exceed the Provincial Water Quality Objective (PWQO), while site B has shown increasing concentrations above the PWQO in recent years (2010 and 2011). All shoreline sites generally have TP concentrations greater than the deep point. Figure 54. West Basin Total Phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) Figure 56. West Basin Average Total Phosphorus concentrations (from RVCA Watershed Watch Program) Figure 55. Total Kjeldahl Nitrogen concentrations at the deep point in West Basin owners and lake users to continue to employ best management practices to ensure the continued health of the lake. TKN concentrations often exceed the TKN guidelines at site K (Fig. 57). All other sites are similar in average concentrations, though generally greater than that of the DP. These results suggest that nutrient loading may be an issue in some near shore areas. Table 8 shows the average concentrations of each nutrient summarized for each year. Table 8. Average nutrient concentrations in West Basin at the deep point Year Average TP (mg/l) Average TKN (mg/l) Figure 57. West Basin Average Total Kjeldahl Nitrogen concentrations (from RVCA Watershed Watch Program)

21 BOBS LAKE: WEST BASIN SURFACE WATER QUALITY CONDITIONS Page 21 Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 58 shows that all readings have exceeded the minimum Provincial Water Quality Objective (PWQO) of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. temperatures exist to an average depth of 16 metres and have remained fairly consistent through sampling years. Spring and early summer typically have good conditions for fish habitat but as temperatures warm and the deeper waters are depleted of oxygen there is more limited habitat available. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth) which depletes oxygen levels as this organic matter dies off and begins to decay. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; concentrations in West Basin are shown in Figure 60. Eighty-eight percent of samples are within guidelines established by the PWQO which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Figure 58. Secchi depth measurements at the deep point in West Basin Habitat: Dissolved Oxygen and Temperature Two other factors, dissolved oxygen/temperature and ph are also assessed to provide an overall idea of the health of West Basin from a fish habitat perspective. Figure 59 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4mg/l). The vertical axis represents the total lake depth at the site of 22 metres where the profile is taken. Suitable oxygen Figure 60. ph concentrations sampled at the deep point in West Basin In some areas of the Tay River Subwatershed, surface waters do tend to be a bit more alkaline (higher ph), which can generally be attributed to geology rather than human activities. This being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Around the Lake: E. coli Figure 59. Suitable depths for fish habitat of warm water species in West Basin E. coli is also sampled at shoreline sites at least twice each sampling season. Figure 61 shows that all samples are well below the guideline of 100 colony forming units per 100 ml, suggesting that bacterial contamination is not an issue in West Basin (please note that E. coli data is not used in the WQI rating for the bay).

22 BOBS LAKE: ROCK LAKE SURFACE WATER QUALITY CONDITIONS Page 22 Table 9 shows the average concentrations of each nutrient summarized for each year. There are differences in the concentrations of both nutrients from year to year but no clear trend showing an increasing/decreasing concentration of nutrients in the lake. Figure 61. Average E. coli concentrations for West Basin shoreline sites (from RVCA Watershed Watch Program) Summary West Basin may be characterized as a lake with clear waters and moderate nutrient levels. The lake should generally have good aesthetics for recreational use. While the lake is generally considered to be healthy, there is a potential for it to be impacted by increased nutrient loading which may result in increased aquatic vegetation and algal blooms. Figure 62. Rock Lake total phosphorus concentrations at the deep point (from RVCA Watershed Watch Program) 1) i. Rock Lake Water Quality Surface water quality conditions in Rock Lake have been monitored under the RVCA s Watershed Watch Program since 2003 (Fig. 1). This report covers the five years from 2006 through 2010 and 2011 data is shown where it is available. The Water Quality Index rating for Rock Lake is Good (for an explanation of the WQI, please refer to the Introduction section on Pg. 2 of this report). This is due to the fact that the majority of monitored parameters are well within respective guidelines. Deep Point: Nutrients Figures 62 and 63 show that there has been variability in nutrient concentrations at the deep point (RVL-45DP). The majority of samples are below established objectives and guidelines. All samples analysed for TP are less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/l (Fig. 62). Likewise, all samples analysed for TKN fall below RVCA s guideline of 0.5 mg/l (Fig. 63). These results indicate that nutrient loading is not a problem in Rock Lake. Figure 63. Total Kjeldahl nitrogen concentrations at the deep point in Rock Lake Table 9. Average nutrient concentrations in Rock Lake at the deep point Year Average TP (mg/l) Average TKN (mg/l)

23 BOBS LAKE: ROCK LAKE SURFACE WATER QUALITY CONDITIONS Page 23 Water Clarity Water clarity is measured using a Secchi disk during each deep point sample. Figure 64 shows that all readings have exceeded the minimum Provincial Water Quality Objective (PWQO) of 2 metres, indicating that waters are usually clear and sufficient sunlight is able to penetrate the water column to support aquatic life. vertical axis represents the total lake depth at the site of 29 metres where the profile is taken. Suitable oxygen temperatures exist to an average depth of 19 metres and has remained fairly consistent through sampling years. Spring and early summer typically have good conditions for fish habitat but as temperatures warm and the deeper waters are depleted of oxygen there is slightly less habitat available. Care should be taken to avoid nutrient enrichment, as it fuels primary productivity (plant and algal growth) which depletes oxygen levels as this organic matter dies off and begins to decay. Habitat: ph ph is a basic water quality parameter used to assess the acidity of water, an important factor for aquatic life; concentrations in Rock Lake are shown in Figure 66. Eighty-eight percent of samples were within guidelines established by the PWQO which state that ph should be between 6.5 and 8.5 to protect aquatic life and prevent irritation for anyone using the waters for recreational purposes. Figure 64. Secchi depth measurements at the deep point in Rock Lake Habitat: Dissolved Oxygen and Temperature Surface waters tends to be more alkaline (higher ph) in this part of the watershed and the concentration of all other results had minimum variation. This being said, care should be taken to ensure that no additional pollutants enter the water that may alter ph conditions. Two other factors, dissolved oxygen/temperature and ph are also assessed to provide an overall idea of the health of Rock Lake from a fish habitat perspective. Figure 65 shows the depths where suitable conditions exist for warm water fish species (temperature less than 25 C and dissolved oxygen greater than 4mg/l). The Figure 66. ph concentrations sampled at the deep point in Rock Lake Summary Figure 65. Suitable depths for fish habitat of warm water species in Rock Lake Rock Lake may be characterized as a lake with clear waters and low nutrient levels. The lake should have good aesthetics for recreational use and is considered to be healthy. Property owners should continue to employ best management practices to ensure that continued health of the lake ecosystem.

24 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 24 2) a. Overbank Zone Riparian Buffer along Davern Creek, Bobs Lake and Other Catchment Lakes and Tributaries Figure 67 shows the extent of the naturally vegetated riparian zone in the catchment, 30 metres either side of all waterbodies and watercourses. Results from the RVCA s Land Cover Classification Program show that 90 percent of streams, creeks and lakes are buffered with woodland, wetland and grassland; the remaining 10 percent of the riparian buffer is occupied by settlements and crop and pastureland. Habitat is Enough?) is to maintain a minimum 30 metre wide vegetated buffer along at least 75 percent of the length of both sides of rivers, creeks and streams. Figure 68 demonstrates the buffer conditions of the left and right banks separately. The majority of Davern Creek has a buffer of greater than 30 metres: 85 percent of the right bank and 96 percent of the left bank. Percentage (%) Davern Creek Buffer Evaluation Left Bank Right Bank 0 0 5m 5 15m 15 30m >30m Buffer Width (m) Figure 68. Vegetated buffer width along Davern Creek Land Use beside Davern Creek Figure 67. Catchment land cover in the riparian zone Data from the RVCA s Macrostream Survey Program (Stream Characterization) is used in this section of the report and is generated from an assessment of nine (100 metre long) sections along Davern Creek. Riparian Buffer along Davern Creek The riparian or shoreline zone is that special area where the land meets the water. Well-vegetated shorelines are critically important in protecting water quality and creating healthy aquatic habitats, lakes and rivers. Natural shorelines intercept sediments and contaminants that could impact water quality conditions and harm fish habitat in streams. Well established buffers protect the banks against erosion, improve habitat for fish by shading and cooling the water and provide protection for birds and other wildlife that feed and rear young near water. A recommended target (from Environment Canada s Guideline: How Much The RVCA s Macrostream Survey Program identifies nine different land uses beside Davern Creek (Fig. 69). Surrounding land use is considered from the beginning to end of the survey section (100m) and up to 100m on each side of the creek. Land use outside of this area is not considered for the surveys but is nonetheless part of the subwatershed and will influence the creek. Natural areas make up 85 percent of the stream, characterized by wetland, forest, scrubland and meadow. The remaining land use consists of active agriculture, pasture, abandoned agriculture, residential, and infrastructure. 17% 15% Davern Creek Adjacent Landuse 3% 1% Active Agriculture 2% 9% 1% Pasture 2% Abandoned Agriculture 50% Figure 69. Land use alongside Davern Creek Residential Forest Scrubland Meadow Wetland Infrastructure

25 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 25 2) b. Shoreline Zone Erosion Erosion is a normal, important stream process and may not affect actual bank stability; however, excessive erosion and deposition of sediment within a stream can have a detrimental effect on important fish and wildlife habitat. Bank stability indicates how much soil has eroded from the bank into the stream. Poor bank stability can greatly contribute to the amount of sediment carried in a waterbody as well as loss of bank vegetation due to bank failure, resulting in trees falling into the stream and the potential to impact instream migration. Figure 70 shows the bank stability of the left and right banks along Davern Creek. Figure 71. Undercut streambank along Davern Creek Figure 70. Erosion along Davern Creek Streambank Undercutting Undercut banks are a normal and natural part of stream function and can provide excellent refuge areas for fish. Figure 71 shows that Davern Creek has few identified areas with undercut banks. Stream Shading Grasses, shrubs and trees all contribute towards shading a stream. Shade is important in moderating stream temperature, contributing to food supply and helping with nutrient reduction within a stream. Figure 72 shows stream shading along Davern Creek. Figure 72. Stream shading along Davern Creek Human Alterations Figure 73 illustrates the classes of anthropogenic alterations observed along Davern Creek. Of the nine sections sampled, 67 percent of the creek remained without any human alteration. Sections considered natural, but with some anthropogenic changes made up the remaining 33 percent of the sections sampled. There were no sections identified as altered or highly altered along Davern Creek.

26 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 26 Davern Creek Anthropogenic Changes 33% Not Altered Altered (Natural) 67% Figure 73. Alterations to Davern Creek Overhanging Trees and Branches Figure 74 shows that the majority of Davern Creek has varying levels of overhanging trees and branches. Overhanging trees and branches provide a food source, nutrients and shade which helps to moderate instream water temperatures. Figure 75. Instream Woody Debris 2) c. Instream Aquatic Habitat Habitat Complexity Streams are naturally meandering systems and move over time, there are varying degrees of habitat complexity, depending on the creek. A high percentage of habitat complexity (heterogeneity) typically increases biodiversity of aquatic organisms within a system. One hundred percent of Davern Creek was considered heterogeneous. There was high variability in substrate type and habitat features observed within the creek, as shown in Figure 76. Davern Creek Instream Habitat Complexity Figure 74. Overhanging trees/branches along Davern Creek Heterogenity Instream Woody Debris Figure 75 shows that the majority of Davern Creek has low levels of instream woody debris in the form of branches and trees. Instream woody debris is important for fish and benthic habitat, by providing refuge and feeding areas. 100% Figure 76. Instream Habitat complexity in Davern Creek.

27 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 27 Instream Substrate Diverse substrate is important for fish and benthic invertebrates habitat because some species have specific substrate requirements and for example will only reproduce on certain types of substrate. Figure 77 indicates that a wide variety of substrate is found in Davern Creek. Davern Creek Instream Substrate 8% 2% 32% 7% 9% 11% 16% 15% Figure 77. Instream substrate in Davern Creek Bedrock Boulder Cobble Gravel Sand Silt Clay Detritus Figure 78. Instream cobble and boulder habitat along Davern Creek Davern Creek Instream Morphology Boulders create instream cover and back eddies for large fish to hide and/or rest out of the current. Cobble provides important over wintering and/or spawning habitat for small or juvenile fish. Cobble can also provide habitat conditions for benthic invertebrates that are a key food source for many fish and wildlife species. Figure 78 shows where cobble and boulder substrate is found in Davern Creek 7% 9% Pools Riffles Runs Instream Morphology Pools and riffles are important features for fish habitat. Riffles are areas of agitated water and they contribute higher dissolved oxygen to the stream and act as spawning substrate for some species of fish, such as walleye. Pools provide shelter for fish and can be refuge pools in the summer if water levels drop and water temperature in the creek increases. Pools also provide important over wintering areas for fish. Runs are usually moderately shallow, with unagitated surfaces of water and areas where the thalweg (deepest part of the channel) is in the center of the channel. Figure 79 shows that Davern Creek has variable morphology; seven percent pools, nine percent riffles and 84 percent runs. Types of Instream Vegetation The majority of Davern Creek had a high diversity of instream vegetation as seen in Figure 80. The dominant 84% Figure 79. Instream Morphology in Davern Creek Davern Creek Types of Instream Vegetation Narrow Emergent 23% Broad Emergent 39% Robust Free Floating Floating 23% Submerged 7% 2% Algae 2% 4% Figure 80. Instream Vegetation Type in Davern Creek

28 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 28 vegetation type recorded at 39 percent consisted of narrow emergent vegetation. The next two types of vegetation each recorded at 23 percent were algae and submerged vegetation. A total of seven percent recorded broad leafed emergents while robust emergent vegetation was recorded at 4 percent. Free floating and floating each were recorded at 2 percent. Amount of Instream Vegetation Instream vegetation is an important factor for a healthy stream ecosystem. Vegetation helps to remove contaminants from the water, contributes oxygen to the stream, and provides habitat for fish and wildlife. Too much vegetation can also be detrimental. Figure 81 demonstrates the frequency of instream vegetation in Davern Creek. Davern Creek had a healthy level of instream vegetation for most of its length. Seventy-one percent of the stream was considered to have common and normal levels of instream vegetation. Twenty six percent of the stream had low levels of instream vegetation and only three percent of the surveyed area had extensive levels (choked with vegetation) 26% 18% Davern Creek Instream Abundance 3% 53% Extensive (choked) Common (>50% Vegetation) Normal (25 50% Vegetation) Low (<25% Vegetation) Figure 82. Invasive Species along Davern Creek biological health. Two temperature dataloggers were deployed in Davern Creek from April to late September (Fig. 83) to give a representative sample of how water temperature fluctuates. Many factors can influence fluctuations in stream temperature, including springs, tributaries, precipitation runoff, discharge pipes and stream shading from riparian vegetation. Water temperature is used along with the maximum air temperature (using the Stoneman and Jones method) to classify a watercourse as either warmwater, coolwater or cold water. Figure 81. Vegetation Abundance in Davern Creek Invasive Species Invasive species can have major implications on streams and species diversity. Invasive species are one of the largest threats to ecosystems throughout Ontario and can outcompete native species, having negative effects on local wildlife, fish and plant populations. Davern Creek had 56 percent sections recorded with invasive species ( Fig.82). The species observed was flowering rush (Butomus umbellatus). Thermal Classification Temperature is an important parameter in streams as it influences many aspects of physical, chemical and Figure 83. Temperature Dataloggers along Davern Creek

29 DAVERN CREEK RIPARIAN ZONE CONDITIONS Page 29 Analysis of the data collected indicates that Davern Creek is considered a warmwater system. Fish Sampling shown on the preceding map are listed in Table 10 beside the common name of those fish species identified in Davern Creek and Bobs Lake. Fish sampling sites located along Davern Creek are shown in Figures 84 and 85, fish sampling occurred between May and July The provincial fish codes The above image is RVCA staff fish sampling using the seine net method. Table 10. Fish species observed in Davern Creek and Bobs Lake BrS BnMin BrBul CrChu brook s ckleback bluntnose minnow brown bullhead creek chub CoShi FallF FhMin FsDac Figure 84. Fish species observed along Davern Creek common shiner LmBas fallfish Logpe Fathead minnow IoDar finescale dace Pumpk largemouth bass log perch iowa Darter pumpkinseed RoBas WhSuc YeBul YePer rock bass white sucker Yellow bullhead yellow perch Figure 85. Identified spawning and nursery sites on Bobs Lake as reported in the Tay River Fish Habitat and Opportunities for enhancement report The above image is of a white sucker that was caught and released

30 LAND COVER TAY RIVER SUBWATERSHED REPORT 3) Land Cover Woodland is the dominant land cover type in the catchment as shown in Table 11 and displayed in the land cover map on the front cover of the report. Page 30 figure referred to in the Environment Canada Guideline that is considered to be the minimum threshold for supporting edge intolerant bird species and other forest dwelling species in the landscape. Table 11. Catchment land cover type Cover Type Area (ha) Area (% of Cover) Woodland Water Wetland Grassland Crop & Pasture Settlement Roads Woodland Cover The Bobs Lake catchment contains 6976 hectares of woodland (Fig.86) that occupies 53 percent of the drainage area. When combined with treed wetlands (treed swamps), wooded areas cover 7101 hectares or 54 percent of the catchment. This figure is greater than the 30 percent of woodland area required to sustain forest birds, according to Environment Canada s Guideline: How much habitat is enough? When forest cover declines below 30 percent, forest birds tend to disappear as breeders across the landscape. One hundred and eighty-seven (50%) of the 377 woodland patches in the catchment are very small, being less than one hectare in size. Another 145 (38%) of the wooded patches ranging from one to less than 20 hectares in size tend to be dominated by edge-tolerant bird species. The remaining 45 (12%) of woodland patches range between 20 and 1072 hectares. Thirty of these patches contain woodland between 20 and 100 hectares and may support a few area-sensitive species and some edge intolerant species, but will be dominated by edge tolerant species. Figure 86. Catchment woodland cover and forest interior Most patches (295) have less than 10 hectares of interior forest, 195 of which have small areas of interior forest habitat less than one hectare in size. Conversely, one patch has greater than 100 hectares of interior forest habitat (at 107 hectares). Conversely, fifteen (4%) of the 377 woodland patches in the drainage area exceed the 100 plus hectare size needed to support most forest dependent, area sensitive birds. Six of these woodlands (from 100 to 200 ha.) are large enough to support approximately 60 percent of edge-intolerant species. Another nine patches top 200 hectares, which according to the Environment Canada Guideline will support 80 percent of edge-intolerant forest bird species (including most area sensitive species) that prefer interior forest habitat conditions. Forest Interior The same 377 woodlands contain 316 forest interior patches (Fig.86) that occupy eight percent (1120 ha.) of the catchment land area. This is below the ten percent Figure 87. Present day wetland cover in the catchment

31 STEWARDSHIP AND PROTECTION 4) Stewardship and Protection The RVCA and its partners are working to protect and enhance environmental conditions in the Tay River Subwatershed. Rural Clean Water Projects Figure 88 shows the location of all Rural Clean Water Projects in the Bobs Lake drainage area. From 2005 to 2010, landowners completed 5 projects including 3 septic system repairs/replacements, 1 streambank stabilization and 1 buffer/windbreak planting. The total project cost is $52,329 with $9,000 of that amount funded by grant dollars received from the RVCA. With the assistance of the RVCA s Shoreline Naturalization Program, 90 trees and shrubs were planted to create a three metre wide buffer along 21 metres of shoreline on 1 property, at a total project value of $690. Page 31 Valley, Stream, Wetland and Hazard Lands within the Regulation Limit Nine square kilometres or 7 percent of the catchment drainage area is within the regulation limit of Ontario Regulation 174/06 (Fig.89), giving protection to wetland areas and river or stream valleys that are affected by flooding and erosion hazards. Prior to 2005, the RVCA completed 1 streambank stabilization project in the area. Total project cost is $3,130 with RVCA grant dollars contributing $2,347 towards that amount. Figure 89. RVCA regulation limits Figure 88. RVCA stewardship program project locations Tree Planting and Shoreline Naturalization Projects The location of tree planting and shoreline projects is also shown in Figure 88. From 2005 to 2010, 23,250 trees were planted at 2 project sites through the RVCA Tree Planting Program. Total project value is $36,711 with fundraised dollars contributing $18,981 of that amount. No trees were planted in the drainage area from 1984 to 2004 using the program. Natural features within the regulation limit include 3.2 sq. km. of wetlands (representing 21 percent of all wetlands in the catchment) and 21.2 kilometers of streams (representing 7 percent of all streams in the catchment). The majority of these regulated watercourses (15.6 km or 6 percent of all streams) flow through regulated wetlands. Regulation limits mapping has been plotted along 5.6 km (or 2 percent) of the streams that are outside of wetlands. Plotting of the regulation limit on the remaining km (or 93 percent) of streams requires identification of flood and erosion hazards and valley systems. Within the regulation limit, development and site alteration require RVCA permission, as do any proposed works to alter a watercourse, which are subject to the alteration to waterways provision of Ontario Regulation 174/06.