A wetland evaluation is simply an assessment of a piece of land by a qualified professional using a range of wetland-related criteria developed by the province of Ontario. The approval of a full wetland evaluation falls within the jurisdiction of the Province of Ontario, but municipalities and others may use the term more loosely to indicate such activities as wetland mapping, environmental study related to wetlands, wetland boundary mapping, wetland boundary staking, or wetland staking.
Provincially Significant Wetlands, or PSWs, have been evaluated across a number of criteria, including how much recreational activity occurs there, how many sensitive and rare or endangered and threatened species might live there, and how large and/or pristine the wetland is. Through this evaluation process, wetlands that achieve a certain score are designated as provincially significant and are thus protected by the province.
The first thing to understand is that provincially significant wetlands (PSWs) fall under the jurisdiction of the province, not the region or municipality. Provincial policy tells us that development or site alteration is not permitted on or adjacent to a PSW unless you can demonstrate that there will be no negative impact on the ecological function of the wetland.
Only Ministry of Natural Resources and Forestry–certified evaluators can evaluate and map a PSW. It is a very comprehensive process that involves four-season studies, which can be costly. RiverStone employs staff who are certified to conduct these types of studies; however, it is not often that this type of comprehensive study is required by the requesting agencies.
Most often, RiverStone conducts a site visit to review the boundary of a wetland that has already been mapped by the province. Our wetland evaluators use what we call a 50% Rule. That rule requires that the evaluator look at the vegetation and determine the line where the vegetation is 50% upland and 50% wetland.
Our certified ecologists use high-accuracy GPS units to determine where the wetland boundary occurs, based on the 50% Rule.
For example: a client may be interested in constructing a dock or boathouse on their property but have been informed that a permit is required due to the shoreline frontage being classified as a PSW. RiverStone will provide a wetland evaluator to determine the proper boundary of the wetland. If the line that RiverStone ecologists have mapped is different from the provincial mapped line, the information can be submitted to the Ministry of Natural Resources and Forestry for consideration. In our experience, the MNRF would then confirm the evaluation and request that the province officially change the boundary, which would in turn allow the proposed project to proceed.