Mission Sports Park Detention Pond Review

Client: District of Mission

A portion of the bank of Silverdale Creek failed during an extreme rainfall event in October of 2003. The failure of the ravine bank was a result of soil saturation and instability, which led to a large earth movement toward the stream. The failure of the ravine bank damaged a detention pond that had been a part of the stormwater management system protecting the creek from adverse impacts resulting from urban development.

McElhanney was retained by the District of Mission to undertake the review of requirements, opportunities and constraints surrounding the Detention Pond Facility. The detention pond review at Mission Sports Park involved a detailed hydrologic and hydraulic study that addressed the need to provide a replacement detention pond and mitigation works due to loss of pond embankment and failure of the ravine slopes.

Innovative analysis techniques were utilized to assess the impacts on the stream as related to the potential for downstream erosion and the health of Silverdale Creek. The analysis resulted in a design concept that eliminated the pond while using BMP's to maintain stream health and the potential for stream erosion.