Mason Park Watershed Improvement

The Mason Regional Park and UC Irvine Watershed Improvement Project consists of a stormwater and dry-weather runoff capture and treatment project that will benefit regional water quality and Newport Bay. The project has been planned in two phases. Phase 1 of the project is specific to improvements in Mason Regional Park, and Phase 2 of the project incorporates projects elements for increased drainage area capture, and conveyance to provide water supply to the UC Irvine Marsh and potentially the San Joaquin Marsh. Phase 1 of the project consists of diversion of stormwater and dry-weather runoff passing through Mason Park from the OCPW Cascades (F15P11) double storm drain lines to vegetated natural treatment systems including a biofiltration system and a constructed wetland then to the existing lake. Phase 2 of the project includes expanding the storage capacity of the lake to allow for diversion of stormwater runoff and dry-weather runoff from Sand Canyon Channel. The diversion of Sand Canyon Channel may also include integration of vegetated natural treatment systems on the north side of the lake that could also assist with the historic flooding that occurs from significant storm events. Phase 2 of the project also includes creation of a gravity main storm drain line along University Drive to convey detained stormwater runoff and dry-weather runoff to the UCI Mesa Court Field. An underground storage tank or tanks to be integrated into the UCI Mesa Court Field for stormwater runoff and dry-weather runoff from both the UCI campus and from Mason Park. Phase 2 will also integrate a pump station adjacent the San Diego Creek channel that will allow the stormwater and dry-weather runoff from UCI and Mason Park detained in the UCI Mesa Court Field underground storage tank to be transferred across San Diego Creek in a pipeline attached to the Campus Drive bridge to the UCI Marsh, which currently suffers a lack of water, and potentially to the San Joaquin Marsh for additional treatment.