3.0 Jock River-Ashton Dwyer Hill Catchment: Riparian Conditions
3.1 Jock River Overbank Zone
3.1.1 Riparian Buffer Land Cover Evaluation
Figure 11 demonstrates the buffer conditions of the left and right banks separately. The Jock River in the Ashton - Dwyer Hill catchment had a buffer of greater than 30 meters along 71 percent of the right bank and 70 percent of the left bank.
3.1.2 Riparian Buffer Alterations
Alterations within the riparian buffer were assessed within three distinct shoreline zones (0-5m, 5-15m, 15-30m), and evaluated based on the dominant vegetative community and/or land cover type (Figure 12). The riparian buffer zone along the Jock River within the Ashton - Dwyer Hill catchment was found to have highly variable conditions along the riparian corridor. These alterations were generally associated with infrastructure in the form of road crossings, recreational and agricultural land uses.
3.1.3 Adjacent Landuse
The RVCA’s Stream Characterization Program identifies ten different land uses beside the Jock River in the Ashton - Dwyer Hill catchment (Figure 13). Surrounding land use is considered from the beginning to end of the survey section (100m) and up to 100m on each side of the river. 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 made up 65 percent of the stream, characterized by forest, scrubland, meadow and wetland. Forest habitat was dominant in the adjacent lands along the Jock River in the Ashton - Dwyer Hill catchment at 35 percent. The remaining land use consisted of active agriculture, pasture, abandoned agriculture, residential, recreational and infrastructure in the form of road crossings.
3.2 Jock River Shoreline Zone
3.2.1 Instream Erosion
Stream erosion is the process by which water erodes and transports sediments, resulting in dynamic flows and diverse habitat conditions. Excessive erosion can result in drastic environmental changes, as habitat conditions, water quality and aquatic life are all negatively affected. Bank stability was assessed as the overall extent of each section with “unstable” shoreline conditions. These conditions are defined by the presence of significant exposed soils/roots, minimal bank vegetation, severe undercutting, slumping or scour and potential failed erosion measures. The majority of the Jock River in the Ashton-Dwyer Hill catchment had low levels of erosion with the exception of three areas along the system which had moderate to high levels of erosion. Figure 14 shows erosion levels along the Jock River in the Ashton-Dwyer Hill catchment.
3.2.2 Undercut Stream Banks
Stream bank undercuts can provide excellent cover habitat for aquatic life, however excessive levels can be an indication of unstable shoreline conditions. Bank undercut was assessed as the overall extent of each surveyed section with overhanging bank cover present. Figure 15 shows that Jock River in the Ashton - Dwyer Hill catchment had low levels of undercut banks along the majority of the system with a few specific locations having high levels of undercut banks observed.
3.2.3 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. Stream cover is assessed as the total coverage area in each section that is shaded by overhanging trees/grasses and tree canopy, at greater than 1m above the water surface. Figure 16 shows variable conditions of low to high levels of stream shading along the Jock River in the Ashton - Dwyer Hill catchment.
3.2.4 Instream Woody Debris
Figure 17 shows that the majority of Jock River in the Ashton - Dwyer Hill catchment had predominantly low levels of instream woody debris in the form of branches and trees along the system. Instream woody debris is important for fish and benthic invertebrate habitat, by providing refuge and feeding areas.
3.2.5 Overhanging Trees and Branches
Trees and branches that are less than one meter from the surface of the water are defined as overhanging. Overhanging branches and trees provide a food source, nutrients and shade which helps to moderate instream water temperatures. Figure 18 shows the system is highly variable with low to high levels of overhanging branches and trees along Jock River in the Ashton - Dwyer Hill catchment.
3.2.6 Anthropogenic Alterations
Stream alterations are classified based on specific functional criteria associated with the flow conditions, the riparian buffer and potential human influences. Figure 19 shows 46 percent of the Jock River in the Ashton - Dwyer Hill catchment remains “unaltered” with no anthropogenic alterations. Forty nine percent of Jock River in the Ashton - Dwyer Hill catchment was classified as natural with minor anthropogenic changes while four percent was considered altered and two percent was classified as highly altered. The alterations along the Jock River in this reach were in the form of shoreline modifications, reduced buffers and road crossings.
3.3 Jock River Instream Aquatic Habitat
3.3.1 Benthic Invertebrates
Freshwater benthic invertebrates are animals without backbones that live on the stream bottom and include crustaceans such as crayfish, molluscs and immature forms of aquatic insects. Benthos represent an extremely diverse group of aquatic animals and exhibit wide ranges of responses to stressors such as organic pollutants, sediments and toxicants, which allows scientists to use them as bioindicators. As part of the Ontario Benthic Biomonitoring Network (OBBN), the RVCA has been collecting benthic invertebrates at the Franktown Road site on the Jock River since 2011 (Site Code JO-3). Monitoring data is analyzed for each sample site and the results are presented using the Family Biotic Index, Family Richness and percent Ephemeroptera, Plecoptera and Trichoptera.
Hilsenhoff Family Biotic Index
The Hilsenhoff Family Biotic Index (FBI) is an indicator of organic and nutrient pollution and provides an estimate of water quality conditions for each site using established pollution tolerance values for benthic invertebrates. FBI results for the Jock River Ashton - Dwyer Hill catchment sample location at Franktown Road are summarized by year from 2011 to 2015. “Good” to “Poor” water quality conditions was observed at the Jock River Ashton - Dwyer Hill sample location for the period from 2011 to 2015 (Figure 20) using a grading scheme developed by Conservation Authorities in Ontario for benthic invertebrates.
Family Richness measures the health of the community through its diversity and increases with increasing habitat diversity suitability and healthy water quality conditions. Family Richness is equivalent to the total number of benthic invertebrate families found within a sample. The Jock River Ashton - Dwyer Hill site is reported to have “Fair” family richness (Fig.xx).
Ephemeroptera (Mayflies), Plecoptera (Stoneflies), and Trichoptera (Caddisflies) are species considered to be very sensitive to poor water quality conditions. High abundance of these organisms is generally an indication of good water quality conditions at a sample location. The community structure typically has species that are more tolerant to poorer water quality conditions. As a result, the EPT indicates that the Jock River Ashton - Dwyer Hill sample location is reported to have “Fair” to “Poor” water quality (Figure 22) from 2011 to 2015.
Overall the Jock River Ashton - Dwyer Hill sample location aquatic habitat conditions from a benthic invertebrate perspective is considered “Poor” from 2011 to 2015 as the samples are dominated by species that are moderately sensitive and tolerant to high organic pollution levels.
3.3.2 Habitat Complexity
Habitat complexity is a measure of the overall diversity of habitat types and features within a stream. Streams with high habitat complexity support a greater variety of species niches, and therefore contribute to greater diversity. Factors such as substrate, flow conditions (pools, riffles) and cover material (vegetation, wood structure, etc.) all provide crucial habitat to aquatic life. Habitat complexity is assessed based on the presence of boulder, cobble and gravel substrates, as well as the presence of instream woody material.
Low to high habitat complexity was identified for the Jock River Ashton - Dwyer Hill catchment (Figure 23). Regions with increased habitat complexity were observed in the lower to middle reaches of the system within the catchment.
3.3.3 Instream Substrate
Diverse substrate is important for fish and benthic invertebrate habitat because some species have specific substrate requirements and for example will only reproduce on certain types of substrate. The absence of diverse substrate types may limit the overall diversity of species within a stream. Figure 24 shows that 77 percent of the sections observed in the Jock River in the Ashton - Dwyer Hill catchment had the presence of cobble substrate. Overall substrate conditions were highly diverse along the Jock River Ashton - Dwyer Hill reach with all substrate types being recorded along the reach. Figure 25 shows the dominant substrate type observed for each section surveyed along the Jock River in the Ashton - Dwyer Hill catchment.
3.3.4 Instream Morphology
Pools and riffles are important habitat features for aquatic life. Riffles are fast flowing areas characterized by agitation and overturn of the water surface. Riffles thereby play a crucial role in contributing to dissolved oxygen conditions and directly support spawning for some fish species. They are also areas that support high benthic invertebrate populations which are an important food source for many aquatic species. Pools are characterized by minimal flows, with relatively deep water and winter/summer refuge habitat for aquatic species. Runs are 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 26 shows that the Jock River in the Ashton - Dwyer Hill catchment is highly variable; 66 percent consists of runs, 12 percent riffles and 21 percent pools. Figure 27 shows where the riffle habitat areas were observed along the Jock River in the Ashton - Dwyer Hill catchment.
3.3.5 Vegetation Type
Instream vegetation provides a variety of functions and is a critical component of the aquatic ecosystem. Aquatic plants promote stream health by:
- Providing direct riparian/instream habitat
- Stabilizing flows reducing shoreline erosion
- Contributing to dissolved oxygen through photosynthesis
- Maintaining temperature conditions through shading
For example emergent plants along the shoreline can provide shoreline protection from wave action and important rearing habitat for species of waterfowl. Submerged plants provide habitat for fish to find shelter from predator fish while they feed. Floating plants such as water lilies shade the water and can keep temperatures cool while reducing algae growth. Narrow leaved emergents were present at 89% of the sections surveyed, algae was observed in 74% of sections, while free floating plants were observed in 27% of surveyed sections. Broad leaved emergents were observed in 44% of sections, submerged plants in 81%, floating plants in 27% and robust emergents in 50% of sections surveyed. Figure 28 depicts the plant community structure for the Jock River Ashton - Dwyer Hill catchment. Figure xx shows the dominant vegetation type observed for each section surveyed along the Jock River in the Ashton - Dwyer Hill catchment.
3.3.6 Instream Vegetation Abundance
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 30 demonstrates that the Jock River Ashton - Dwyer Hill reach had no vegetation to low levels of instream vegetation for 53 percent of its length. Normal to common levels of vegetation were recorded at 26 percent of stream surveys. Extensive levels of vegetation were observed along 21 percent of the systems length.
3.3.7 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 out compete native species, having negative effects on local wildlife, fish and plant populations. Ninety three percent of the sections surveyed along the Jock River Ashton - Dwyer Hill reach had invasive species. The invasive species observed in the Jock River Ashton - Dwyer Hill reach were European frogbit, poison/wild parsnip, dog strangling vine, yellow iris, purple loosestrife, rusty crayfish, glossy buckthorn, garlic mustard and Manitoba maple. Invasive species abundance (i.e. the number of observed invasive species per section) was assessed to determine the potential range/vector of many of these species (Figure 31).
3.3.8 Water Chemistry
During the stream characterization survey, a YSI probe is used to collect water chemistry information. Dissolved oxygen (DO), specific conductivity (SPC) and pH are measured at the start and end of each section.
184.108.40.206 Dissolved Oxygen
Dissolved oxygen is a measure of the amount of oxygen dissolved in water. The Canadian Environmental Quality Guidelines of the Canadian Council of Ministers of the Environment (CCME) suggest that for the protection of aquatic life the lowest acceptable dissolved oxygen concentration should be 6 mg/L for warmwater biota and 9.5 mg/L for coldwater biota (CCME, 1999). Figure 32 shows that the dissolved oxygen in the Jock River Ashton - Dwyer Hill catchment was within the threshold for warmwater biota in this reach of the system. The average dissolved oxygen levels observed within the main stem of the Jock River Ashton - Dwyer Hill was 6.72mg/L which is within the recommended levels for warmwater biota. The upper sections of the reach fell below the recommended 6.0mg/L for warmwater biota.
Conductivity in streams is primarily influenced by the geology of the surrounding environment, but can vary drastically as a function of surface water runoff. Currently there are no CCME guideline standards for stream conductivity; however readings which are outside the normal range observed within the system are often an indication of unmitigated discharge and/or stormwater input. The average conductivity observed within the main stem of Jock River in the Ashton - Dwyer Hill catchment was 404.36 µs/cm. Figure 33 shows the conductivity readings for the Jock River in the Ashton - Dwyer Hill catchment.
Based on the PWQO for pH, a range of 6.5 to 8.5 should be maintained for the protection of aquatic life. Average pH values for the Jock River Ashton - Dwyer Hill catchment averaged 7.95 thereby meeting the provincial standard (Figure 34).
220.127.116.11 Oxygen Saturation (%)
Oxygen saturation is measured as the ratio of dissolved oxygen relative to the maximum amount of oxygen that will dissolve based on the temperature and atmospheric pressure. Well oxygenated water will stabilize at or above 100% saturation, however the presence of decaying matter/pollutants can drastically reduce these levels. Oxygen input through photosynthesis has the potential to increase saturation above 100% to a maximum of 500%, depending on the productivity level of the environment. In order to represent the relationship between concentration and saturation, the measured values have been summarized into 6 classes:
- <100% Saturation / <6.0 mg/L Concentration. Oxygen concentration and saturation are not sufficient to support aquatic life and may represent impairment
- >100% Saturation / <6.0 mg/L Concentration. Oxygen concentration is not sufficient to support aquatic life, however saturation levels indicate that the water has stabilized at its estimated maximum. This is indicative of higher water temperatures and stagnant flows.
- <100% Saturation / 6.0—9.5 mg/L Concentration. Oxygen concentration is sufficient to support warmwater biota, however depletion factors are likely present and are limiting maximum saturation.
- >100% Saturation / 6.0—9.5 mg/L Concentration. Oxygen concentration and saturation levels are optimal for warmwater biota.
- <100% Saturation / >9.5 mg/L Concentration. Oxygen concentration is sufficient to support coldwater biota, however depletion factors are likely present and are limiting maximum saturation.
- >100% Saturation / >9.5 mg/L Concentration. Oxygen concentration and saturation levels are optimal for coldwater biota.
Dissolved oxygen conditions on the Jock River in the Ashton - Dwyer Hill catchment are generally sufficient for both warm and coolwater species (Figure 35). Dissolved oxygen conditions are higher in the lower reach which is a function of the riffle habitat in those sections of the Jock River. Oxygen levels in wetland habitats are typically lower than they are in areas where the substrate is dominated by cobble and riffle habitat.
18.104.22.168 Specific Conductivity Assessment
Specific conductivity (SPC) is a standardized measure of electrical conductance, collected at or corrected to a water temperature of 25⁰C. SPC is directly related to the concentration of ions in water, and is commonly influenced by the presence of dissolved salts, alkalis, chlorides, sulfides and carbonate compounds. The higher the concentration of these compounds, the higher the conductivity. Common sources of elevated conductivity include storm water, agricultural inputs and commercial/industrial effluents.
In order to summarize the conditions observed, SPC levels were evaluated as either normal, moderately elevated or highly elevated. These categories correspond directly to the degree of variation (i.e. standard deviation) at each site relative to the average across the system.
Normal levels were maintained along the majority of the Jock River in the Ashton - Dwyer Hill catchment, however there were elevated areas immediately downstream of the Riverbend golf course and in two specified locations in the middle and upper reaches within the Ashton - Dwyer Hill catchment area (Figure 36).
3.3.9 Thermal Regime
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 warm water, cool water or cold water. Figure 37 shows where the thermal sampling sites were located along Jock River Ashton – Dwyer Hill catchment. Analysis of the data collected indicates that Jock River Ashton - Dwyer Hill catchment is classified as a warm water system with cool to warm water reaches (Figure 38).
Each point on the graph represents a temperature that meets the following criteria:
- Sampling dates between July 1st and September 7th
- Sampling date is preceded by two consecutive days above 24.5 °C, with no rain
- Water temperatures are collected at 4pm
- Air temperature is recorded as the max temperature for that day
Groundwater discharge areas can influence stream temperature, contribute nutrients, and provide important stream habitat for fish and other biota. During stream surveys, indicators of groundwater discharge are noted when observed. Indicators include: springs/seeps, watercress, iron staining, significant temperature change and rainbow mineral film. Figure 39 shows areas where one or more of the above groundwater indicators were observed during stream surveys and headwater assessments.
3.3.11 Fish Community
The Jock River Ashton - Dwyer Hill catchment is classified as a mixed community of warm and cool water recreational and baitfish fishery with 35 species observed. Figure 40 shows the sampling locations along the Jock River in the Barrhaven catchment.
The following table contains a list of species observed in the watershed.
|Fish Species||Fish code||Fish Species||Fish code|
|banded killifish||BaKil||golden shiner||GoShi|
|blackchin shiner||BcShi||hornyhead chub||HhChu|
|blacknose dace||BnDac||Johnny darter||JoDar|
|bluntnose minnow||BnMin||longnose dace||LnDac|
|brassy minnow||BrMin||mottled sculpin||MoScu|
|brook stickleback||BrSti||northern pearl dace||PeDac|
|brown bullhead||BrBul||northern redbelly dace||NRDac|
|central stoneroller||CeSto||Rainbow darter||RaDar|
|chrosomus sp.||PhoSp||Redhorse sp.||MoxSp|
|common shiner||CoShi||rock bass||RoBas|
|creek chub||CrChu||smallmouth bass||SmBas|
|emerald shiner||EmShi||spotfin shiner||SpShi|
|fathead minnow||FhMin||yellow bullhead||YeBul|
3.3.12 Migratory Obstructions
It is important to know locations of migratory obstructions because these can prevent fish from accessing important spawning and rearing habitat. Migratory obstructions can be natural or manmade, and they can be permanent or seasonal. Figure 41 shows that Jock River in the Ashton - Dwyer Hill catchment had two weir barriers at the time of the survey in 2015. The Ashton Station Dam along with several natural grade barriers were observed, one debris dam and three beaver dams were identified along the Jock River in the Ashton - Dwyer Hill catchment.
3.3.13 Riparian Restoration
Figure 42 depicts the locations of riparian restoration opportunities as a result of observations made during the stream survey.
3.3.14 Instream Restoration
Figure 43 depicts the locations of instream restoration opportunities as a result of observations made during the stream survey. Only one small stream garbage cleanup restoration opportunity was observed in the Ashton - Dwyer Hill catchment.
3.4 Headwater Drainage Features Assessment
3.4.1 Headwater Sampling Locations
The RVCA Stream Characterization program assessed Headwater Drainage Features for the Jock River subwatershed in 2015. This protocol measures zero, first and second order headwater drainage features (HDF). It is a rapid assessment method characterizing the amount of water, sediment transport, and storage capacity within headwater drainage features (HDF). RVCA is working with other Conservation Authorities and the Ministry of Natural Resources and Forestry to implement the protocol with the goal of providing standard datasets to support science development and monitoring of headwater drainage features. An HDF is a depression in the land that conveys surface flow. Additionally, this module provides a means of characterizing the connectivity, form and unique features associated with each HDF (OSAP Protocol, 2013). In 2015 the program sampled 20 sites at road crossings in the Jock River Ashton - Dwyer Hill catchment area (Figure 44).
3.4.2 Headwater Feature Type
The headwater sampling protocol assesses the feature type in order to understand the function of each feature. The evaluation includes the following classifications: defined natural channel, channelized or constrained, multi-thread, no defined feature, tiled, wetland, swale, roadside ditch and pond outlet. By assessing the values associated with the headwater drainage features in the catchment area we can understand the ecosystem services that they provide to the watershed in the form of hydrology, sediment transport, and aquatic and terrestrial functions. The headwater drainage features in the Ashton - Dwyer Hill catchment are primarily classified as wetland with seven, five features classified as natural, four features classified as a road side ditch, two multi thread and two features as channelized. Figure 45 shows the feature type of the primary feature at the sampling locations.
3.4.3 Headwater Feature Flow
The observed flow condition within headwater drainage features can be highly variable depending on timing relative to the spring freshet, recent rainfall, soil moisture, etc. Flow conditions are assessed in the spring and in the summer to determine if features are perennial and flow year round, if they are intermittent and dry up during the summer months or if they are ephemeral systems that do not flow regularly and generally respond to specific rainstorm events or snowmelt. Flow conditions in headwater systems can change from year to year depending on local precipitation patterns. Figure 46 shows the observed flow condition at the sampling locations in the Jock River Ashton - Dwyer Hill catchment in 2015.
3.4.4 Headwater Feature Channel Modifications
Channel modifications were assessed at each headwater drainage feature sampling location. Modifications include channelization, dredging, hardening and realignments. The Jock River Ashton - Dwyer Hill catchment area had five site as having been recently dredged, four locations had mixed modifications, one had channel had been hardened and ten had no channel modifications observed. Figure 47 shows the channel modifications observed at the sampling locations for Jock River Ashton - Dwyer Hill.
3.4.5 Headwater Feature Vegetation
Headwater feature vegetation evaluates the type of vegetation that is found within the drainage feature. The type of vegetated within the channel influences the aquatic and terrestrial ecosystem values that the feature provides. For some types of headwater features the vegetation within the feature plays a very important role in flow and sediment movement and provides wildlife habitat. The following classifications are evaluated no vegetation, lawn, wetland, meadow, scrubland and forest. Figure 48 depicts the dominant vegetation observed at the sampled headwater sites in the Jock River Ashton - Dwyer Hill catchment.
3.4.6 Headwater Feature Riparian Vegetation
Headwater riparian vegetation evaluates the type of vegetation that is found along the adjacent lands of a headwater drainage feature. The type of vegetation within the riparian corridor influences the aquatic and terrestrial ecosystem values that the feature provides to the watershed. Figure 49 depicts the type of riparian vegetation observed at the sampled headwater sites in the Jock River Ashton - Dwyer Hill catchment.
3.4.7 Headwater Feature Sediment Deposition
Assessing the amount of recent sediment deposited in a channel provides an index of the degree to which the feature could be transporting sediment to downstream reaches (OSAP, 2013). Evidence of excessive sediment deposition might indicate the requirement to follow up with more detailed targeted assessments upstream of the site location to identify potential best management practices to be implemented. Sediment deposition ranged from none to extensive for the headwater sites sampled in the Jock River Ashton - Dwyer Hill catchment area. Figure 50 depicts the degree of sediment deposition observed at the sampled headwater sites in the Jock River Ashton - Dwyer Hill catchment.
3.4.8 Headwater Feature Upstream Roughness
Feature roughness will provide a measure of the amount of materials within the bankfull channel that could slow down the velocity of water flowing within the headwater feature (OSAP, 2013). Materials on the channel bottom that provide roughness include vegetation, woody debris and boulders/cobble substrates. Roughness can provide benefits in mitigating downstream erosion on the headwater drainage feature and the receiving watercourse by reducing velocities. Roughness also provides important habitat conditions for aquatic organisms. Figure 51shows the feature roughness conditions at the sampling location in the Jock River Ashton - Dwyer Hill catchment.