4.1.1 Project-Specific Impacts

The construction of the Inspection Plaza will likely require the realignment of 545 m of Broadway drain with a total of 1,090m2 of fish habitat affected and the enclosure of approximately 243 m of Healy Drain, which is not considered fish habitat.

Heavy impacts associated with agricultural and urban development affect all of these watercourses. These impacts include both physical (e.g. channelization, piping, barriers), and chemical (e.g. metals, organic compounds, nutrients) effects. Surface water runoff from existing transportation infrastructure in the study area currently flows directly into receiving watercourses.

This project is anticipated to result in increased areas of impermeable surfaces that could result in changes to drainage quantities. In addition, changes in the quality of stormwater runoff could result in cumulative effects to surface water quality at the subwatershed scale and indirectly affect fish community characteristics and capacity.

An increase in the area of impermeable surfaces also has the potential to increase the temperature of stormwater discharged into local watercourses, which could also impact fish community characteristics and capacity.

4.2 Mitigation Measures

Potential effects of highways and other roadways on fish and fish habitat are well documented. In general these potential effects fall into two broad categories of site preparation and construction phase (generally short to moderate duration) and the longer-term effects of the structures and channel alterations that remain, post construction. Each of these categories has elements that place fish and fish habitat at risk.

Permanent loss or impacts to fish habitat will require a Fisheries Act Authorization from Fisheries and Oceans Canada. Specific effects include: the realignment, enclosure or physical harm to watercourses in the study area. Direct fish mortality could result from dewatering activities (including alterations to base flow), or from the release of sediment or deleterious substances from spills. Potential effects on water quality and quantity, may also affect fish and fish habitat.

To address the potential impact to fish and fish habitat, the following construction mitigation measures with respect to the works and channel realignment of Broadway