WEASELHEAD SOUTH-WEST CALGARY RING ROAD IMPACT STUDY 2019 TO 2020Category: 2018, Community Grant, Completed, Grant, Land Use
By supporting continuous monitoring of key environmental indicators, this study will provide early warnings of ecosystem change in the Weaselhead, and the opportunity to link any observed change to inadequate or ineffective mitigation practices. It will provide evidence upon which to base requests for remedial action to protect Weaselhead Park.
The new South West Calgary Ring Road (SWCRR) runs along the western (upstream) edge of the Weaselhead Park located at the head of Glenmore Reservoir in Calgary. The highway will cross the Elbow River floodplain on a one kilometer long earthen embankment. Three parallel bridges will carry traffic lanes across the river. To allow for this, 1.2 km of the river has been realigned to a new channel. Two stormwater ponds will be built upstream of the bridges to collect runoff from the highway and adjacent interchange before discharge to the river. The highway is expected to carry ~100,000 vehicles/day upon completion in 2021.
The environmental mitigation measures proposed for the project satisfied Alberta Transport that negative impacts could be reduced to an acceptable level and alternative designs need not be pursued. In this context, the Weaselhead-Glenmore Park Preservation Society (the Society) initiated the SWCRR Impact Study to evaluate these impacts and to quantify the actual success of the mitigation. Data on key environmental components have been collected annually since 2015, two years before construction started. The long-term aim of the study is to have comparable data from the pre-disturbance, construction, and operational phases of the road.
With this community grant, the Society will be able to collect data collection from July 2019 to June 2020. During this period the road embankment will be completed (directly impacting one of the wetlands in the Weaselhead), stormwater ponds will be built, and revegetation begun.
Success of the study in the short-term will be early evidence of changes that allow timely action to correct or improve mitigation: in 2018 two sediment spills into wetlands in the park and concerns regarding the effectiveness of the wildlife corridor across the construction zone have been reported to Alberta Environment and Parks and KGL (the construction company); the Society is also investigating the cause of a significant increase in conductivity of surface water next to the construction site.
Success in the long-term will be a detailed understanding of the environmental impacts of such projects and the effectiveness of common mitigation measures, for example comparison of baseline data from 2015 to 2016 with data from 2017 shows a significant drop in aquatic invertebrate species richness next to the construction site. Future monitoring will help determine whether such changes are temporary fluctuations or permanent changes that can be linked to the adjacent construction. This knowledge will be made available to inform discussion around similar projects.