3.0 Long Lake Catchment: Riparian Conditions
The Stream Characterization Program evaluated two tributaries in the Long Lake catchment in 2016. A total of 2.2 kilometres along Stub Creek was surveyed in the middle of June, while 2.5 kilometres along Uens Creek was assessed in July and August.
During the summer and fall of 2016, the Rideau Valley watershed experienced periods of severe drought. Precipitation levels were measured at less than 40% of the long-term average, as the water supply was unable to meet local demand. The lack of rainfall affected the success and function of farm crops, municipal and private wells, lawns and gardens, navigation and ultimately the health of our lakes, rivers and streams.
Low water conditions were readily observed throughout the watershed, as many of the streams were highly fragmented or completely dry. Aquatic species such as amphibians, fish and macroinvertebrates were affected, as suitable habitat may have been limited. Fragmentation of habitat was observed in sections along Stag, Stub and Uens Creek during drought conditions in 2016.
3.1 Uens Creek and Stub Creek Overbank Zone
3.1.1 Riparian Buffer Land Cover Evaluation
The quality of the riparian area increases with the width, complexity and linear extent of its vegetation along a stream or creek. A complex riparian community consists of diverse plant species native to the site, with multiple age-classes providing vertical structural diversity along a watercourse.
Here is a list of watershed benefits from a healthy riparian buffer zone:
- Reduces the amount of pollutants that reach the stream from surface runoff
- Helps reduce and mitigates erosion
- Provides a microclimate that is cooler during the summer months providing cooler water for aquatic organisms
- Provides large wood structure from fallen trees and limbs that form instream cover, create pools, stabilize the streambed, and provide habitat for aquatic organisms
- Provides organic material for stream biota that, among other functions, is the base of the food chain in lower order streams
- Provides habitat for terrestrial insects that drop in the stream and become food for fish and travel corridors for other terrestrial animals
- Dissipates energy during flood events
- Often provides the only refuge areas for fish during out-of-bank flows (behind trees, stumps, and logs)
Figure 39 demonstrates the buffer conditions of the left and right banks separately. Uens Creek had a buffer of greater than 30 meters along 100 percent of the left bank and 88 percent of the right bank.
Figure 40 shows that Stub Creek had a buffer of greater than 30 meters along 100 percent of the left bank and 98 percent of the right 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 41). The riparian buffer zone along Uens and Stub Creek were found to be dominated by wetland, forest and scrubland conditions.
3.1.3 Adjacent Land Use
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.
The RVCA’s Stream Characterization Program identifies seven different land uses along Uens Creek (Figure 42). Wetland habitat was dominant at 60 percent of sections surveyed; scrubland habitat was found at 56 percent of sections, 52 percent forested habitat, while 40 percent was classified as meadow habitat in the adjacent lands along Uens Creek. The remaining land use consisted of active agriculture, residential and infrastructure in the form of road crossings.
The RVCA’s Stream Characterization Program identifies four different land uses along Stub Creek (Figure 43). Wetland habitat was dominant at 64 percent of sections surveyed; forested habitat was found at 55 percent of sections and 14 percent of sections had scrubland habitat in the adjacent lands along Stub Creek. The remaining land use consisted of infrastructure in the form of road crossings.
3.2 Uens Creek and Stub Creek 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 Stub Creek had no evidence of erosion observed along the surveyed sections, however there was one location with moderate levels of erosion observed (Figure 44). Uens Creek was more variable in relation to erosion levels along the system with low levels of erosion to one location with high erosion levels observed.
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 45 shows that Uens and Stub Creek had highly variable conditions ranging from no undercut stream banks to high levels 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 46 shows highly variable levels of stream shading along Uens and Stub Creek.
3.2.4 Instream Wood Structure
Forested shorelines provide essential complex habitat through the perpetual process of shoreline trees falling into the water. This continuous recruitment of trees creates a wood-based physical structure in the littoral zone that is common on natural systems. Insects, fish, amphibians, birds, and other animals have also evolved with this abundance of near shore wood and it is essential to their life cycles. With increased development along many waterways, forested lakeshores have been altered and wood-based physical structure in many waterways has been reduced. It is important to restore this essential habitat to aquatic ecosystems.
- Protects shorelines by providing a barrier from wind and wave erosion
- Reduces sedimentation of the water caused by shoreline slumping due to bank erosion
- Allows detritus to collect and settle on the lake or creek bed providing the substrate structure required for native aquatic vegetation to establish and outcompete invasive species
- Wood complexes are an important food source for invertebrates
- Small fish feed on the abundance of invertebrates that are found around these structures
- Larger fish, waterfowl and shorebirds all benefit from the abundance of invertebrates and small fish feeding around woody structures in the littoral zone
- Cover from predators is essential for many fish and animals to successfully complete their life cycle
- The nooks and crannies of wood complexes offer critters safety from predators while at the same time concentrating prey to make predators more efficient
- Wood provides the structure on which many species must lay or attach their eggs, therefore these complexes provide quality spawning and nesting habitat
- Wood complexes in the littoral zone provide unique edge habitat along the shoreline
- Edge habitats contain more species diversity and higher concentrations of species than the adjoining habitats themselves will have
Figure 47 shows that the majority of Stub Creek had high to moderate levels of instream structure along the system. Uens Creek was highly variable with low to high levels of in water trees and branches observed along the majority of the system.
3.2.5 Overhanging Wood Structure
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 48 shows the systems are highly variable with no overhanging branches and trees where the system is wide and is dominated by wetland habitat to areas in the middle reach of Uens Creek with high levels of overhanging wood structure. Stub creek had low levels of overhanging wood structure along the majority of the system as it is dominated by wide wetland habitat conditions.
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 49 shows seventy six percent of Uens Creek remains “unaltered” with no anthropogenic alterations. Twenty four percent of Uens Creek was classified as natural with minor anthropogenic changes. The minor alterations along Uens Creek were in the form of road crossings. There were no sections that were classified as being altered or highly altered.
Figure 50 shows ninety five percent of Stub Creek remains “unaltered” with no anthropogenic alterations. Five percent of Stub Creek was classified as natural with minor anthropogenic changes. The minor alterations along Stub Creek were in the form of road crossings. There were no sections that were classified as being altered or highly altered.
3.3 Uens Creek and Stub Creek Instream Aquatic Habitat
3.3.1 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 Uens and Stub Creek (Figure 51).
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 52 shows the dominant substrate type observed for each section surveyed along Uens and Stub Creek.
Figure 53 shows the overall presence of various substrate types observed along Uens Creek. Substrate conditions were highly diverse along Uens Creek with all substrate types being recorded at various locations along the creek. Silt was the dominant substrate recorded in 96% of survey sections.
Figure 54 shows the overall presence of various substrate types observed along Stub Creek. Substrate conditions were somewhat diverse along Stub Creek with all substrate types being recorded at various locations along the creek. Silt and clay substrates were dominant along Stub Creek.
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 55 shows where riffle habitat occurs along Uens and Stub Creek.
Figure 56 shows that Uens Creek has highly variable instream morphology: 64 percent of sections recorded runs, 52 percent pools and 16 percent riffles. Figure 57 shows that Uens Creek has a somewhat variable instream morphology: 95 percent of sections recorded pools, 27 percent runs and 23 percent riffles.
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. Figure 58 shows the dominant vegetation type observed for each section surveyed along Uens and Stub Creek.
The plant community structure was extremely diverse along Uens Creek. Narrow leafed emergents were observed in 96 percent of sections, algae was observed in 76 percent of survey sections, submerged plants were present in 68 percent of the survey sections, 44 percent for floating plants, 12 percent free floating plants, 60 percent broad leaved emergents and robust emergents were observed in 44 percent of sections surveyed. Figure 59 depicts the plant community structure for Uens Creek.
The plant community structure was fairly diverse along Stub Creek. Narrow leafed emergents were observed in 100 percent of sections, 73 percent for floating plants, submerged plants were present in 64 percent of the survey sections, algae was observed in 55 percent of survey sections, 50 percent free floating plants and 45 percent broad leaved emergents. Figure 60 depicts the plant community structure for Stub Creek.
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 61 demonstrates that Uens Creek reach had normal to common levels of vegetation recorded at 36 and 44 percent of stream surveys. Extensive levels of vegetation were observed in 64 percent of the surveyed sections, while 20 percent of sections had areas with no vegetation.
Figure 62 demonstrates that Stub Creek reach had normal to common levels of vegetation recorded at only 14 and 9 percent of stream surveys. Low levels of vegetation were observed in 23 percent of survey sections. Extensive levels of vegetation were observed in 64 percent of the surveyed sections, while 9 percent of sections had areas with no vegetation.
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. Sixty percent of the sections surveyed along Uens Creek had invasive species. The invasive species observed in Uens Creek were European frogbit, purple loosestrife, banded mystery snail, common/glossy buckthorn and Manitoba maple. Sixty four percent of the sections surveyed along Stub Creek had invasive species. The invasive species observed in Stubs Creek was European frogbit. This invasive aquatic plant dominated areas where extensive vegetation conditions were observed along Stub Creek. 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 63).
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.
18.104.22.168 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).
The average dissolved oxygen level observed within Uens Creek was 5.2mg/L which is below the recommended level for warmwater biota (Figure 64). The lower and middle reaches of Uens Creek were within the threshold to support warmwater biota. The upper reaches fell below the recommended threshold to support warmwater aquatic biota.
The average dissolved oxygen level observed within Stub Creek was 5.5mg/L which is below the recommended level for warmwater biota (Figure 65). The lower and upper reaches of Stub Creek were within the threshold to support warmwater biota. The middle reaches fell below the recommended threshold to support warmwater aquatic 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 Uens Creek was 297.1 µs/cm. Figure 66 shows the conductivity readings for Uens Creek.
The average conductivity observed within the main stem of Stub Creek was 153.6µs/cm. Figure 67 shows the conductivity readings for Stub Creek.
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 along Uens Creek averaged 7.22 thereby meeting the provincial standard (Figure 68).
Average pH values along Stub Creek averaged 7.01 thereby meeting the provincial standard (Figure 69).
22.214.171.124 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:
126.96.36.199 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 both creeks; however there were several areas with moderate levels of conductivity and one area on Stub Creek with high levels of conductivity observed (Figure 71).
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 72 shows where the thermal sampling sites were located on Uens and Stub Creek.
Each point on the two following graphs represents a temperature that meets the following criteria:1) Sampling dates are between July 1st and September 7th 2) Sampling date is preceded by two consecutive days above 24.5 °C, with no rain 3) Water temperatures are collected at 4pm and 4) Air temperature is recorded as the max temperature for that day.
Analysis of the data collected indicates that Uens Creek is classified as a warm water system with cool water reaches (Figure 73).
Analysis of the data collected indicates that Stub Creek is classified as a cool water system with cool to warm water reaches (Figure 74).
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 75 shows areas where one or more of the above groundwater indicators were observed during stream surveys and headwater assessments.
The Long Creek catchment is classified as a mixed community of warm and cool water recreational and baitfish fishery with 19 species observed (Table 19). Figure 76 shows where the listed species were observed in the watershed in 2016 and historically.
|Fish Species||Scientific Name||Fish code||Historical||2016|
|blacknose shiner||Notropis heterolepis||BnShi||X||X|
|bluntnose minnow||Pimephales notatus||BnMin||X|
|brassy minnow||Hybognathus hankinsoni||BrMin||X||X|
|brook stickleback||Culaea inconstans||BrSti||X||X|
|brown bullhead||Ameiurus nebulosus||BrBul||X||X|
|bullhead catfishes||Ameiurus sp.||CATFI||X|
|carps and minnows||Cyprinidae||CA_MI||X|
|central mudminnow||Umbra limi||CeMud||X||X|
|creek chub||Semotilus atromaculatus||CrChu||X||X|
|etheostoma sp.||etheostoma sp.||EthSp||X|
|fathead minnow||Pimephales promelas||FhMin||X||X|
|finescale dace||Phoxinus neogaeus||FsDac||X||X|
|golden shiner||Notemigonus crysoleucas||GoShi||X||X|
|iowa darter||Etheostoma exile||IoDar||X||X|
|largemouth bass||Micropterus salmoides||LmBas||X|
|northern pike||Esox lucius||NoPik||X|
|northern redbelly dace||Chrosomus eos||NRDac||X||X|
|sunfish family||Lepomis sp.||LepSp||X|
|yellow perch||Perca flavescens||YePer||X||X|
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 77 shows the migration barriers in the Long Lake catchment at the time of the survey in 2016. There were seven perched/blocked culverts, five wood debris dams and two natural grade barriers within the catchment.
3.3.13 Beaver Dam Locations
Overall beaver dams create natural changes in the environment. Some of the benefits include providing habitat for wildlife, flood control and silt retention. Additional benefits come from bacterial decomposition of wood material used in the dams which removes excess nutrient and toxins. Beaver dams can also result in flooding of agricultural lands and may be potential barriers to fish migration. Several beaver dams were identified in the Long Lake catchment area in 2016 (Figure 78).
3.4.1 Headwaters Sampling Locations
The RVCA Stream Characterization program assessed Headwater Drainage Features for the Long Lake catchment in 2016. 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 2016 the program sampled 33 sites at road crossings in the Long Lake catchment area (Figure 79).
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 Long Lake catchment are predominantly dominated by natural and wetland features. Figure 80 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 81 shows the observed flow condition at the sampling locations in the Long Lake catchment in 2016.
3.4.4 Feature Channel Modifications
Channel modifications were assessed at each headwater drainage feature sampling location. Modifications include channelization, dredging, hardening and realignments. The Long Lake catchment area had a majority of features with no channel modifications with the exception of three sites having mixed modifications and two having been historically dredged or straightened. Figure 82 shows the channel modifications observed at the sampling locations for the Long Lake catchment.
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 83 depicts the dominant vegetation observed at the sampled headwater sites in the Long Lake 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 84 depicts the type of riparian vegetation observed at the sampled headwater sites in the Long Lake catchment. The majority of the headwater drainage features are classified as having natural riparian vegetation with only six features having altered vegetation.
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 substantial for the headwater sites sampled in the Long Lake catchment area. Figure 85 depicts the degree of sediment deposition observed at the sampled headwater sites in the Long Lake catchment. Sediment deposition conditions ranged from no sediment deposition to extensive.
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, wood structure 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 86 shows that the feature roughness conditions at the sampling locations in the Long Lake catchment were highly variable ranging from minimal to extreme.