Ecologically Significant Groundwater Recharge Area Delineation in the
Central Lake Ontario Conservation Authority Area
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(As part of the Drinking Water Source Water Protection Program (SWP) established by the Clean Water Act, 2006, Source Protection Regions completed water budget assessments and delineated “significant groundwater recharge areas” (SGRA). SGRAs (also referred to as “high volume recharge areas”) are defined under SWP simply as areas where groundwater recharge is greater than 1.15 times the average rate of recharge.
While identifying high volume recharge areas is important, recharge volume alone does not imply ecological significance. To identify ecologically significant groundwater recharge areas (ESGRAs), a linkage must be established between the recharge area and the ecological features such as a cold water stream, provincially-significant wetland (PSW), or an area of natural or scientific interest (ANSI). Establishing this linkage requires an understanding of the local hydrogeology and the factors affecting groundwater/surface water interaction. More importantly, it requires a methodology, typically based on the use of a numerical model, to trace the movement of water from the ecological features back to the point of recharge.
This linkage was not established under the Source Water Protection initiative but is important to the Conservation Authorities mandate and to the development plan review process. CLOCA recently completed the scientific analyses to delineate the recharge areas important to ecological features utilizing CLOCA’s existing modelling tools and particle tracking analyses in this report.
This work along with supportive mapping represents CLOCA’s commitment to science based decision making and is expected to assist with the municipal development plan process and the administration of Ontario Regulation 42/06 with respect to the protection of groundwater fed features. Policies for the maintenance of infiltration will be especially important in these mapped areas.