3.0 Monahan Drain Catchment: Riparian Conditions
3.1 Monahan Drain Instream Aquatic Habitat
3.1.1 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 9 shows where the thermal sampling site was located on Monahan Drain. Analysis of the data collected indicates that Monahan Drain is classified as a warm water system (Figure 10).
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 11 shows areas where one or more of the above groundwater indicators were observed during the headwater assessments.
3.1.3 Fish Community
The Monahan Drain catchment is classified as a mixed community of warm and cool water recreational and baitfish fishery with 23 species observed. Figure 12 shows the sampling locations in the Monahan Drain catchment.
The following table contains a list of species observed in the watershed.
|Fish Species||Fish code||Fish Species||Fish code|
|banded killifish||BaKil||fathead minnow||FhMin|
|blackchin shiner||BcShi||golden shiner||GoShi|
|blacknose shiner||BnShi||lepomis sp. (sunfish)||LepSp|
|brook stickleback||BrSti||mimic shiner||MiShi|
|Brown bullhead||BrBul||northern pike||NoPik|
|central mudminnow||CeMud||northern redbelly dace||NRDac|
|common shiner||CoShi||rock bass||RoBas|
|cottus sp. (sculpin)||CotSp||spotfin shiner||SpShi|
|creek chub||CrChu||white sucker||WhSuc|
|Etheostoma sp. (darter)||EthSp|
3.2 Headwater Drainage Features Assessment
3.2.1 Headwaters 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 13 sites at road crossings in the Monahan Drain catchment area (Figure 13).
3.2.2 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. Six features were classified as having been channelized, 3 features were roadside ditches, one wetland which was an online stormwater pond/constructed wetland and two features were identified as natural. Figure 14 shows the feature type of the primary feature at the sampling locations.
3.2.3 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 15 shows the observed flow conditions at the sampling locations in the Monahan Drain catchment in 2015.
3.2.4 Feature Channel Modifications
The majority of the headwater drainage features in the Monahan catchment are classified as municipal drains and have been historically created and or modified natural systems. Channel modifications were assessed at each headwater drainage feature sampling location. Modifications include dredging, channel hardening and mixed modifications. The Monahan Drain catchment area had one feature which was classified as being hardened, seven classified as dredged and four were identified as having mixed modifications. Figure 16 shows the channel modifications observed at the sampling locations for Monahan Drain.
3.2.5 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 fish and wildlife habitat. The following classifications are evaluated no vegetation, lawn, wetland, meadow, scrubland and forest. The features assessed in the Monahan Drain catchment were classified as being dominated by wetland and meadow vegetation. Three features were classified as having no vegetation within the channel. Figure 17 depicts the dominant vegetation observed at the sampled headwater sites in the Monahan Drain catchment.
3.2.6 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. Four sample locations in Monahan Drain were dominated by natural vegetation in the form of scrubland and meadow vegetation. Nine sample locations were dominated by other forms of vegetation of either crops or ornamental grasses. Figure 18 depicts the type of riparian vegetation observed at the sampled headwater sites in the Monahan Drain catchment.
3.2.7 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. Conditions ranged from no deposition observed to extensive deposition recorded. Figure 19 depicts the degree of sediment deposition observed at the sampled headwater sites in the Monahan Drain catchment.
3.2.8 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. The sample locations in the Monahan Drain catchment area ranged from minimal to extreme roughness conditions. Figure 20 shows the feature roughness conditions at the sampling locations in the Monahan Drain catchment.