Barrhaven Creek 2015 Summary Report

Barrhaven Creek 2015 Summary Report Watershed Features 7.20 square kilometres Area 0.17% of the Rideau Valley watershed 12% agriculture 68% urban Land Use 5% forest 14% rural 1% waterbody 67% clay Surficial 1% Paleozoic bedrock Geology 31% diamicton 1% gravel Watercourse Type: 88% natural Watercourse 12% channelized Type Flow Type: 100% permanent There were seven invasive species observed in 2015: Invasive Common buckthorn, Species European frogbit, flowering rush, glossy buckthorn, Manitoba Figure 1 Land cover in the Barrhaven Creek catchment maple, Norway maple, purple loosestrife Woodlot Cover % of Size Number of 26 fish species have Woodlot Category Woodlots been captured in Cover Fish Barrhaven Creek Community 10-30 ha 1 3 historically including eight game fish species >30 ha 0 0 Wetland Cover 0% of the catchment is wetland Upper reach of Barrhaven Creek The Rideau Valley Conservation Authority, in partnership with seven other agencies in Ottawa (City of Ottawa, Heron Park Community Association, Ottawa Flyfishers Society, Ottawa Stewardship Council, Rideau Roundtable, National Defence HQ - Fish and Game Club, and the National Capital Commission) form the 2015 City Stream Watch collaborative. Barrhaven Creek 2015 Summary Report Page 1 Introduction The headwaters of Barrhaven Creek begin at Woodroffe Avenue and flow east through a large two– celled stormwater management pond, before crossing Prince of Wales Drive and entering the Rideau River. Historically, the headwaters of Barrhaven Creek used to begin near Greenbank Road but they have since been lost to development. Most of the vegetation in the catchment was cleared years ago for agricultural purposes, aside from the banks of the creek itself. The shoreline of the creek is mainly wooded, consisting of a mix of deciduous tree species. In 2015, 15 sections (1.5 km) of Barrhaven Creek were surveyed as part of the City Stream Watch monitoring activities. The following is a summary of observations made by staff and volunteers along those 15 sections. Barrhaven Creek Overbank Zone Riparian Buffer Width Evaluation Adjacent Land Use The riparian or shoreline zone is that special area where The RVCA’s City Stream Watch Program identifies the land meets the water. Well-vegetated shorelines are seven different land uses beside Barrhaven Creek critically important in protecting water quality and (Figure 3). Surrounding land use is considered from the creating healthy aquatic habitats, lakes and rivers. beginning to end of each 100m survey section and up to Natural shorelines intercept sediments and contaminants 100m on each side of the creek. Land use outside of that could impact water quality conditions and harm fish this area is not considered for the surveys but is habitat in streams. Well established buffers protect the nonetheless part of the subwatershed and will influence banks against erosion, improve habitat for fish by the creek. Natural areas made up 64 percent of the shading and cooling the water and provide protection for surveyed stream, characterized predominantly by forest birds and other wildlife that feed and rear young near with a small amount of scrubland. Twenty six percent of water. A recommended target (from Environment the land use along the surveyed sections of the stream Canada’s Guideline: How Much Habitat is Enough?) is to was made up of residential and infrastructure which maintain a minimum 30 meter wide vegetated buffer includes road crossings. Seven percent of the land use along at least 75 percent of the length of both sides of was abandoned agriculture and the remaining three rivers, creeks and streams. Overall, Barrhaven Creek percent of the land use surveyed was recreational and does not meet the recommended target above. The industrial/commercial. creek has a buffer of greater than 30 meters along 38 percent of the right bank and seven percent of the left bank. The buffer on the right bank of Barrhaven Creek was wider than the buffer on the left bank due to residential development which has been focused along the south side of the creek. Figure 2 demonstrates the buffer conditions of the left and right banks separately. Left Bank Abandoned Agriculture Right Bank 2% 100% 1% 90% 10% 7% Residential 80% 4% 16% Forest 70% 60% Scrubland 50% 40% Industrial/Commercial 30% 20% 60% Recreational 10% 0% Infrastructure 0-5m 5-15m 15-30m 30+m Figure 2 Vegetated buffer width along Barrhaven Creek Figure 3 Land use along Barrhaven Creek Barrhaven Creek 2015 Summary Report Page 2 Barrhaven Creek Shoreline Zone Erosion Undercut Stream Banks Erosion is a normal, important stream process and may Undercut banks are a normal and natural part of stream not affect actual bank stability; however, excessive function and can provide excellent refuge areas for fish. erosion and deposition of sediment within a stream can Figure 5 shows that the bank undercutting on Barrhaven have a detrimental effect on important fish and wildlife Creek varied considerably. Much of the creek had low habitat. Poor bank stability can greatly contribute to the levels of bank undercutting, but this was interspersed amount of sediment carried in a waterbody as well as with sections of moderate to high levels of undercutting loss of bank vegetation due to bank failure, resulting in especially downstream of the stormwater management trees falling into the stream and the potential to impact pond. instream migration. Figure 4 shows low to moderate levels of bank erosion were observed along most sections of Barrhaven Creek. Figure 4 Erosion along Barrhaven Creek Figure 5 Undercut stream banks along Barrhaven Creek Stream bank erosion along the right bank of Barrhaven Creek Bank undercutting along Barrhaven Creek Barrhaven Creek 2015 Summary Report Page 3 Stream Shading Instream Woody Debris Grasses, shrubs and trees all contribute towards shading The forested buffer along Barrhaven Creek also a stream. Shade is important in moderating stream contributes to the amount of woody debris, in the form of temperature, contributing to food supply and helping with branches and trees, found in the stream. Figure 7 shows nutrient reduction within a stream. Figure 6 shows that overall Barrhaven Creek had moderate levels of stream shading along Barrhaven Creek. Barrhaven instream woody debris downstream of the stormwater Creek benefits from the forested buffer that was management pond and high levels of instream woody maintained when the area was historically cleared for debris upstream of the pond. Instream woody debris is development and agriculture. As a result, very high important for fish and benthic habitat, by providing levels of shading were seen along most of the creek. refuge and feeding areas. Figure 6 Stream shading along Barrhaven Creek Figure 7 Instream woody debris along Barrhaven Creek Stream shade along Barrhaven Creek Instream woody debris along Barrhaven Creek Barrhaven Creek 2015 Summary Report Page 4 Overhanging Trees and Branches Anthropogenic Alterations Trees and branches that are less than one metre from Figure 9 shows that 60 percent of the sections on the surface of the water are defined as overhanging. At Barrhaven Creek remain "natural". Sections considered this proximity to the water branches and trees provide a "altered" account for 33 percent of the stream, while only food source, nutrients and shade which helps to seven percent of the sections sampled were considered moderate instream water temperatures. Figure 8 shows “highly altered”. None of the sections of Barrhaven that the forested buffer along Barrhaven Creek has a Creek were considered “unaltered”, meaning that all of high canopy since most of the creek sections had low to the sections had some form of human influence or the moderate levels of overhanging branches and trees riparian buffer was less than 30 metres. The highly within one metre of the surface of the water. altered sections of Barrhaven creek refer to areas where the creek approaches and runs through a culvert or there is a road crossing with associated instream/shoreline modifications especially at the Prince of Wales Drive crossing. 7% Natural 33% Altered 60% Highly Altered Figure 9 Anthropogenic alterations along Barrhaven Creek Figure 8 Overhanging trees and branches A highly altered section of Barrhaven Creek at Prince of Wales Drive Overhanging trees and branches on Barrhaven Creek Barrhven Creek 2015 Summary Report Page 5 Barrhaven Creek Instream Aquatic Habitat Instream Substrate Habitat Complexity Diverse substrate is important for fish and benthic invertebrate habitat because some species have Streams are naturally meandering systems that move specific substrate requirements and, for example, will over time with varying degrees of habitat complexity. only reproduce on certain types of substrate. Figure 11 Examples of habitat complexity include habitat types such shows that 53 percent of the instream substrate as pools and riffles as well as substrate variability and observed on Barrahven Creek was clay. Ten percent woody debris structure. A high percentage of habitat of the substrate was recorded as cobble, seven complexity (heterogeneity) typically increases the percent was boulders, and 10 percent was recorded as biodiversity of aquatic organisms within a system. gravel. The remaining 20 percent was made up of 16 Habitat complexity is strongly influenced by the percent silt and four percent sand. Figure 12 shows variability of substrate types found in a creek. Forty the distribution of the dominant substrate types along seven percent of Barrhaven

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