Jock River Barrhaven

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4.0 Jock River-Barrhaven Catchment: Land Cover

Land cover and any change in coverage that has occurred over a six-year period is summarized for the Jock River-Barrhaven catchment using spatially continuous vector data representing the catchment during the spring of 2008 and 2014. This dataset was developed by the RVCA through heads-up digitization of 20cm DRAPE ortho-imagery at a 1:4000 scale and details the surrounding landscape using 10 land cover classes.

4.1 Barrhaven Catchment Change

As shown in Table 10 and Figure 1, the dominant land cover type across the Barrhaven catchment in 2014 was settlement, followed by crop and pastureland, transportation, aggregates and woodland.

From 2008 to 2014, there was an overall change of 446 hectares (from one land cover class to another). Most of the change in the Barrhaven catchment is a result of the conversion of crop and pastureland to settlement and transportation (Figure 57).

Table 11 provides a detailed breakdown of all land cover change that has taken place in the Barrhaven catchment between 2008 and 2014.

4.1.1 Barrhaven Catchment Change - Urban Area

As shown in Table 12, the dominant land cover type in the Urban Area of the Barrhaven catchment in 2014 was settlement, followed by crop and pastureland, transportation and woodland.

From 2008 to 2014, there was an overall change of 398 hectares from one land cover class to another, the majority of which can be attributed to the conversion of crop and pasture to settlement along with areas previously subjected to pre-development, site preparation activity being converted to commercial and residential development. Table 13 provides a detailed breakdown of all land cover change that has taken place in the Urban Area of the Barrhaven catchment between 2008 and 2014.

4.1.2 Barrhaven Catchment Change - Rural Area

As shown in Table 14, the dominant land cover type in the Rural Area of the Barrhaven catchment in 2014 was aggregate, followed by settlement, woodland, crop and pastureland and transportation.

From 2008 to 2014, there was an overall change of 48 hectares from one land cover class to another, the majority of which can be attributed to the conversion of crop and pasture to settlement. Table 15 provides a detailed breakdown of all land cover change that has taken place in the Rural Area of the Barrhaven catchment between 2008 and 2014.

4.2 Woodland Cover

In the Environment Canada Guideline (Third Edition) entitled “How Much Habitat Is Enough?” the opening narrative under the Forest Habitat Guidelines section states that prior to European settlement, forest was the predominant habitat in the Mixedwood Plains ecozone. The remnants of this once vast forest now exist in a fragmented state in many areas (including the Rideau Valley watershed) with woodland patches of various sizes distributed across the settled landscape along with higher levels of forest cover associated with features such as the Frontenac Axis (within the on-Shield areas of the Rideau Lakes and Tay River subwatersheds). The forest legacy, in terms of the many types of wildlife species found, overall species richness, ecological functions provided and ecosystem complexity is still evident in the patches and regional forest matrices (found in the Jock Rideau subwatershed and elsewhere in the Rideau Valley watershed). These ecological features are in addition to other influences which forests have on water quality and stream hydrology including reducing soil erosion, producing oxygen, storing carbon along with many other ecological services that are essential not only for wildlife but for human well-being.

The Guideline also notes that forests provide a great many habitat niches that are in turn occupied by a great diversity of plant and animal species. They provide food, water and shelter for these species - whether they are breeding and resident locally or using forest cover to help them move across the landscape. This diversity of species includes many that are considered to be species at risk. Furthermore, from a wildlife perspective, there is increasing evidence that the total forest cover in a given area is a major predictor of the persistence and size of bird populations, and it is possible or perhaps likely that this pattern extends to other flora and fauna groups. The overall effect of a decrease in forest cover on birds in fragmented landscapes is that certain species disappear and many of the remaining ones become rare, or fail to reproduce, while species adapted to more open and successional habitats, as well as those that are more tolerant to human-induced disturbances in general, are able to persist and in some cases thrive. Species with specialized-habitat requirements are most likely to be adversely affected. The overall pattern of distribution of forest cover, the shape, area and juxtaposition of remaining forest patches and the quality of forest cover also play major roles in determining how valuable forests will be to wildlife and people alike.

The current science generally supports minimum forest habitat requirements between 30 and 50 percent, with some limited evidence that the upper limit may be even higher, depending on the organism/species phenomenon under investigation or land-use/resource management planning regime being considered/used.

As shown in Figure 58, eleven percent of the Barrhaven catchment contains 344 hectares of upland forest versus the 26 percent of woodland cover in the Jock River subwatershed. This is less than the 30 percent of forest cover that is identified as the minimum threshold required to sustain forest birds according to the Guideline and which may only support less than one half of potential species richness and marginally healthy aquatic systems. When forest cover drops below 30 percent, forest birds tend to disappear as breeders across the landscape.

4.2.1 Woodland (Patch) Size

According to the Ministry of Natural Resources’ Natural Heritage Reference Manual (Second Edition), larger woodlands are more likely to contain a greater diversity of plant and animal species and communities than smaller woodlands and have a greater relative importance for mobile animal species such as forest birds.

Bigger forests often provide a different type of habitat. Many forest birds breed far more successfully in larger forests than they do in smaller woodlots and some rely heavily on forest interior conditions. Populations are often healthier in regions with more forest cover and where forest fragments are grouped closely together or connected by corridors of natural habitat. Small forests support small numbers of wildlife. Some species are “area-sensitive” and tend not to inhabit small woodlands, regardless of forest interior conditions. Fragmented habitat also isolates local populations, especially small mammals, amphibians and reptiles with limited mobility. This reduces the healthy mixing of genetic traits that helps populations survive over the long run (Conserving the Forest Interior. Ontario Extension Notes, 2000).

The Environment Canada Guideline also notes that for forest plants that do not disperse broadly or quickly, preservation of some relatively undisturbed large forest patches is needed to sustain them because of their restricted dispersal abilities and specialized habitat requirements and to ensure continued seed or propagation sources for restored or regenerating areas nearby.

The Natural Heritage Reference Manual continues by stating that a larger size also allows woodlands to support more resilient nutrient cycles and food webs and to be big enough to permit different and important successional stages to co-exist. Small, isolated woodlands are more susceptible to the effects of blowdown, drought, disease, insect infestations, and invasions by predators and non-indigenous plants. It is also known that the viability of woodland wildlife depends not only on the characteristics of the woodland in which they reside, but also on the characteristics of the surrounding landscape where the woodland is situated. Additionally, the percentage of forest cover in the surrounding landscape, the presence of ecological barriers such as roads, the ability of various species to cross the matrix surrounding the woodland and the proximity of adjacent habitats interact with woodland size in influencing the species assemblage within a woodland.

In the Barrhaven catchment (in 2014), forty-five (46 percent) of the 97 woodland patches are very small, being less than one hectare in size. Another 47 (49 percent) of the woodland patches ranging from one to less than 20 hectares in size tend to be dominated by edge-tolerant bird species. The remaining five (five percent of) woodland patches range between 20 and 100 hectares in size and may support a few area-sensitive species along with some edge intolerant species, but will be dominated by edge tolerant species.

No patch exceeds the 100 plus hectare size needed to support most forest dependent, area sensitive birds and which are large enough to support approximately 60 percent of edge-intolerant species. No patch tops 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.

Table 16 presents a comparison of woodland patch size in 2008 and 2014 along with any changes that have occurred over that time. A decrease (of 27 ha) has been observed in the overall woodland patch area between the two reporting periods with most change occurring in the 1 to 20 and 20 to 50 hectare woodland patch size class ranges.

4.2.2 Woodland (Forest) Interior Habitat

The forest interior is habitat deep within woodlands. It is a sheltered, secluded environment away from the influence of forest edges and open habitats. Some people call it the “core” or the “heart” of a woodland. The presence of forest interior is a good sign of woodland health, and is directly related to the woodland’s size and shape. Large woodlands with round or square outlines have the greatest amount of forest interior. Small, narrow woodlands may have no forest interior conditions at all. Forest interior habitat is a remnant natural environment, reminiscent of the extensive, continuous forests of the past. This increasingly rare forest habitat is now a refuge for certain forest-dependent wildlife; they simply must have it to survive and thrive in a fragmented forest landscape (Conserving the Forest Interior. Ontario Extension Notes, 2000).

The Natural Heritage Reference Manual states that woodland interior habitat is usually defined as habitat more than 100 metres from the edge of the woodland and provides for relative seclusion from outside influences along with a moister, more sheltered and productive forest habitat for certain area sensitive species. Woodlands with interior habitat have centres that are more clearly buffered against the edge effects of agricultural activities or more harmful urban activities than those without.

In the Barrhaven catchment (in 2014), the 97 woodland patches contain 11 forest interior patches (Figure 58) that occupy less than one percent (22 ha.) of the catchment land area (which is less than the three percent of interior forest in the Jock River Subwatershed). This is below the ten percent 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.

All 11 patches have less than 10 hectares of interior forest, four of which have small areas of interior forest habitat less than one hectare in size. Between 2008 and 2014, there was an overall loss of one hectare of interior forest habitat in the catchment (Table 17).

4.3 Wetland Cover

Wetlands are habitats forming the interface between aquatic and terrestrial systems. They are among the most productive and biologically diverse habitats on the planet. By the 1980s, according to the Natural Heritage Reference Manual, 68 percent of the original wetlands south of the Precambrian Shield in Ontario had been lost through encroachment, land clearance, drainage and filling.

Wetlands perform a number of important ecological and hydrological functions and provide an array of social and economic benefits that society values. Maintaining wetland cover in a watershed provides many ecological, economic, hydrological and social benefits that are listed in the Reference Manual and which may include:

• contributing to the stabilization of shorelines and to the reduction of erosion damage through the mitigation of water flow and soil binding by plant roots
• mitigating surface water flow by storing water during periods of peak flow (such as spring snowmelt and heavy rainfall events) and releasing water during periods of low flow (this mitigation of water flow also contributes to a reduction of flood damage)
• contributing to an improved water quality through the trapping of sediments, the removal and/or retention of excess nutrients, the immobilization and/or degradation of contaminants and the removal of bacteria
• providing renewable harvesting of timber, fuel wood, fish, wildlife and wild rice
• contributing to a stable, long-term water supply in areas of groundwater recharge and discharge
• providing a high diversity of habitats that support a wide variety of plants and animals
• acting as “carbon sinks” making a significant contribution to carbon storage
• providing opportunities for recreation, education, research and tourism

Historically, the overall wetland coverage within the Great Lakes basin exceeded 10 percent, but there was significant variability among watersheds and jurisdictions, as stated in the Environment Canada Guideline. In the Rideau Valley Watershed, it has been estimated that pre-settlement wetland cover averaged 35 percent using information provided by Ducks Unlimited Canada (2010) versus the 21 percent of wetland cover existing in 2014 derived from DRAPE imagery analysis.

Using the same dataset, it is estimated that pre-settlement (historic) wetland cover averaged 51 percent in the Jock River subwatershed versus the 24 percent of cover existing in 2014 (as summarized in Table 18).

This decline in wetland cover is also evident in the Barrhaven catchment (as seen in Figure 59) where wetland was reported to cover 45 percent of the area prior to settlement, as compared to less than one percent in 2014. This represents a 99 percent loss of historic wetland cover and what remains (in 2014) falls far below the 40 percent historic wetland threshold cited in the Environment Canada Guideline for maintaining key ecological and hydrological functions. To maintain critical hydrological, ecological functions along with related recreational and economic benefits provided by these wetland habitats in the catchment, the Guideline recommends a “no net loss” approach for currently existing wetlands combined with efforts to work towards restoring upwards of 40 percent of the historic wetland coverage, where feasible.

4.4 Shoreline Cover

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 the Environment Canada Guideline) 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 60 shows the extent of the ‘Natural’ vegetated riparian zone (predominantly wetland/woodland features) and ‘Other’ anthropogenic cover (crop/pastureland, roads/railways, settlements) along a 30-metre-wide area of land, both sides of the shoreline of the Jock River and its tributaries in the Barrhaven catchment.

This analysis shows that the riparian zone in the Barrhaven catchment in 2014 was comprised of crop and pastureland (36 percent), settlement (29 percent), woodland (20 percent), transportation (11 percent), aggregate (three percent) and wetland (one percent). Additional statistics for the Barrhaven catchment are presented in Table 19. Of particular interest is the observed increase in the area of "Settlement" and decrease in “Crop and Pastureland" along the shoreline of the Jock River and tributaries over a six year period.

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5.0 Jock River-Barrhaven Catchment: Stewardship and Water Resources Protection

The RVCA and its partners are working to protect and enhance environmental conditions in the Jock River Subwatershed. Figure 61 shows the location of all stewardship projects completed in the Jock River-Barrhaven catchment along with sites identified for potential shoreline restoration.

5.1 Rural Clean Water Projects

From 2010 to 2015, two septic system replacements were constructed. Between 2004 and 2009, two septic system replacements, two livestock fencing projects, one well upgrade and one well decommissioning were finished and prior to 2004, five septic system replacements and three livestock fencing projects were completed, Four of these projects were completed within the 30 metre riparian zone of the Jock River. Total value of all 16 projects is $156,866 with $28,227 of that amount funded through grant dollars from the RVCA.

5.2 Private Land Forestry Projects

The location of RVCA tree planting projects is shown in Figure 61. From 2010 to 2015, 300 trees were planted at one site and prior to 2004, 9,800 trees were planted at three sites. In total, 10,100 trees were planted resulting in the reforestation of six hectares. One of these projects was completed within the 30 metre riparian zone of the Jock River. No trees were planted in the catchment between 2004 and 2009. Total project value of all four projects is $50,135 with $23,421 of that amount coming from fundraising sources.

5.3 Shoreline Naturalization Projects

With the assistance of the RVCA’s Shoreline Naturalization Program, 475 trees and shrubs were planted to create an overall six metre long shoreline buffer at a total project value of $14,234.

5.4 Fish Habitat Restoration

Fish habitat compensation was required for the Barrhaven South development as a number of tributary watercourses were eliminated or modified to allow for development.  A bypass pond was constructed off the main stem of the Jock River in 2008 to provide spawning and nursery habitat for northern pike and muskellunge in the spring and nursery and refugia habitat in the summer and fall.   Under normal high water mark conditions, it provides approximately 9,000 meters square of habitat along with several small finger channels that extend from the larger pond to provide spawning habitat for northern pike. Post effectiveness monitoring work in 2010 revealed that thirteen species of fish were utilizing the habitat for spawning, nursery, rearing and feeding purposes, including northern pike. Subsequent fish sampling in 2015 confirmed that several species of fish continue to utilize the restored habitat within the pond feature.

5.5 Valley, Stream, Wetland and Hazard Lands

The Barrhaven catchment covers 31 square kilometres with 4.8 square kilometres (or 16 percent) of the drainage area being within the regulation limit of Ontario Regulation 174/06 (Figure 62), giving protection to wetland areas and river or stream valleys that are affected by flooding and erosion hazards.

Wetlands occupy 14.5 hectares (or less than one percent) of the catchment. Of these wetlands, 12.5 hectares (or 86 percent) are designated as provincially significant and included within the RVCA regulation limit. This leaves the remaining two hectares (or 14 percent) of wetlands in the catchment outside the regulated area limit.

Of the 50.3 kilometres of stream in the catchment, regulation limit mapping has been plotted along 22.1 kilometers of streams (representing 44 percent of all streams in the catchment). Some of these regulated watercourses (0.5 km or 1.0 percent of all streams) flow through regulated wetlands; the remaining 21.6 km (or 98 percent) of regulated streams are located outside of those wetlands. Plotting of the regulation limit on the remaining 28.2 km (or 56 percent) of streams requires identification of flood and erosion hazards and valley systems.

Within those areas of the Barrhaven catchment subject to the RVCA regulation (limit), efforts (have been made and) continue through RVCA planning and regulations input and review to manage the impact of development (and other land management practices) in areas where “natural hazards” are associated with rivers, streams, valley lands and wetlands. Additionally, in the rapidly urbanizing areas of the Barrhaven catchment, significant effort is made through land use planning and development control processes and carefully planned stormwater management systems, initially guided by master drainage planning and integrated subwatershed planning, to meet the natural heritage and natural hazards policies presented in the City of Ottawa Official Plan. Also, within areas beyond the regulation limit, protection of the catchment’s watercourses is provided through the “alteration to waterways” provision of the regulation.

5.6 Vulnerable Drinking Water Areas

The Jock River-Barrhaven drainage catchment is considered to have a Highly Vulnerable Aquifer. This means that the nature of the overburden (thin soils, fractured bedrock) does not provide a high level of protection for the underlying groundwater making the aquifer more vulnerable to contaminants released on the surface. The Mississippi-Rideau Source Protection Plan includes policies that focus on the protection of groundwater region-wide due to the fact that most of the region, which encompasses the Mississippi and Rideau watersheds, is considered Highly Vulnerable Aquifer.

For detailed maps and policies that have been developed to protect drinking water sources, please go to the Mississippi-Rideau Source Protection Region website at www.mrsourcewater.ca to view the Mississippi-Rideau Source Protection Plan.

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6.0 Jock River-Barrhaven Catchment: Challenges/Issues

Water Quality/Quantity

Surface chemistry water quality rating in the Jock River is “Fair” over two reporting periods (2004-2009 and 2010-2015). Frequent high nutrient concentrations and occasional exceedances of copper and aluminium contributed to the rating

Instream biological water quality conditions at the Jock River Barrhaven sample location range from “ Poor” to “Good” from 2004 to 2015 (using a grading scheme developed by Ontario Conservation Authorities in Ontario for benthic invertebrates) with an overall benthic invertebrate water quality rating of  “Good” determined for this period

Effect of climate change on the hydrologic function (water budget) of the Jock River subwatershed and associated natural hazards (flood risk) posed to the built/urban areas of the catchment are not understood

Existing hydrological and geochemical datasets and assessments (academic, RVCA, others) are only recently available and/or are not being considered in the characterization of the numerous hydrologic functions of the Jock River subwatershed. Further, there is a dearth of hydrologic information (hydroperiod, groundwater/surface water interactions, geochemistry) about the wetlands that remain in the Jock River subwatershed

Headwaters/Instream/Shorelines

‘Natural’ vegetation covers 21percent of the riparian zone of the Jock River and its tributaries (Figure 60) and is below the recommended 30 metre wide, naturally vegetated target along 75 percent of the length of the catchment’s watercourses

Hearts Desire weir is a seasonal impediment to fish movement along the Jock River and can fragment/isolate fish populations

Land Cover

Woodlands cover 11 percent of the catchment and is below the 30 percent of forest cover that is identified as the minimum threshold for sustaining forest birds and other woodland dependent species (Figure 58)

Pre-settlement wetlands have declined by 99 percent and now cover less than one percent (14 ha.) of the catchment (Figure 59)

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7.0 Jock River-Barrhaven Catchment: Opportunities/Actions

Water Quality/Quantity

Investigate the source of possible pollutants along the Jock River in the catchment and consider implementing measures to reduce nutrient and metal loadings, such as improved storm water management in developed areas along with the incorporation of low impact development features to assist with storm water management

In rural areas, private landowners should consider taking advantage of The Rural Clean Water Programs which offer grants to landowners interested in implementing projects on their property that will help to protect and improve water quality:

• Homeowners may be interested in projects to repair, replace or upgrade their well or septic system, or addressing erosion through buffer plantings and erosion control
• Farmers can take advantage of a wide range of projects, including livestock fencing, manure storage, tile drainage control structures, cover crops, and many more. 

Continue to coordinate environmental monitoring and reporting activities with the City of Ottawa

Use wetland restoration as a tool to improve surface water quality and help restore the hydrologic integrity of the Jock River and its tributaries

List, share and when possible, synthesize and use existing hydrological and geochemical datasets and assessment outcomes to facilitate the characterization of subwatershed and catchment hydrological functions. In addition, prepare guidance on best practices for the preparation of water budget assessments to better understand the hydrologic cycle requirements that occur at site specific scales; and share existing catchment and subwatershed scale water budget assessment outcomes

Headwaters/Instream/Shorelines

Promote the Rideau Valley Shoreline Naturalization Program to landowners to increase existing 21 percent of natural shoreline cover

Educate landowners about the value of and best management practices used to maintain and enhance natural shorelines and headwater drainage features

Work with the City of Ottawa to consistently implement current land use planning and development policies for water quality and shoreline protection (i.e., adherence to a minimum 30 metre development setback from water) adjacent to the Jock River and other catchment streams

Target shoreline restoration at sites identified in this report (shown as “Other riparian land cover” in Figure 60 and “Potential Riparian/Instream Restoration” in Figures 47/48) and explore other restoration and enhancement opportunities along the Jock River and its tributaries

Remove the fish migration barrier along the Jock River at Hearts Desire and improve riparian and instream conditions upstream of the structure

Land Cover

Promote the City of Ottawa’s Green Acres Reforestation Program to landowners to increase existing 11 percent of woodland cover

Encourage the City of Ottawa to strengthen natural heritage and water resources policies in official plans and zoning by-laws where shoreline, wetland, woodland cover and watercourse setbacks are determined to be at or below critical ecological thresholds. Information for this purpose is provided in the RVCA’s subwatershed and catchment reports

Explore ways and means to more effectively implement conditions of land-use planning and development approvals to achieve net environmental gains

Re-consider the RVCA’s approach to wetland regulation where there is an identified hydrologic imperative to do so (i.e., significant loss of historic wetland cover (see Figure 59) and/or seasonal, critically low baseflows in the Jock River and/or areas of seasonal flooding)

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