Dayton Juvenile Pond Renovation & Outlet Structure Replacement

Last Updated on Monday, 29 June 2009 07:52

Organization
Dayton Citizens for Community Projects

Timeframe
Jul 01, 2006 - Jun 30, 2007

Description
The project is to renovate a juvenile fishing pond within the City of Dayton, WA. The pond lies next to the Touchet River and utilizes an existing water right from ECOLOGY to fill and maintain the pond. The pond consists of two separate basins (North and South) separated by a small concrete box culvert. It was constructed in the 1950s, and has become shallow and weedy, causing in-pond summer water temperatures to rise, and the temperature of water returning to the Touchet River to be outside of State standards. Neither the inlet nor outlet structures were properly designed to meet current requirements for a river containing ESA listed salmonid populations; i.e. - exclude native fish from entering the pond and retain planted catchable fish in the pond. ESA listed populations of bull trout and summer steelhead use the Touchet River in the vicinity of the pond as a migratory corridor, and steelhead and rainbow trout also spawn and rear in the area. Spring Chinook salmon have been documented spawning upstream and downstream of the pond outlet in 2001, and salmon have been observed in the river three of the five years since then.

Renovation of the pond has begun with completion of a fully screened state-of-the-art water supply system in May 2006. To complete the renovation, construction and installation a new outlet structure to allow bottom water withdrawal (rather than the current surface overflow pipe) from the pond (to be completed primarily with DOE grant funds) and improve general maintenance, along with excavation of approximately 4,000–5,000 cubic yards of accumulated sediments from the pond (to be completed primarily with local contributions and Dayton City Council Park funds) will be completed. Design, construction, and installation of a new outlet structure represents the largest materials outlay. Excavation and recontouring of the pond will be scheduled during fall if possible, to coordinate with outlet structure completion and installation. This is a cooperative effort between the City of Dayton, Citizens for Community Projects, and the Dayton community .

High water temperature exacerbated by low summer stream flows limits the extent and quality of salmonid habitat in the Touchet River. Return flow from the Dayton Juvenile pond likely contributes to this problem. Renovation of the pond by excavating to increase maximum pond depth and decreasing the proportion of shallow pond area, along with installation of a modern screened pond-bottom-withdrawal outlet structure will allow greater flow through the pond and the return of cooler water to the Touchet River. Decreased water temperatures will improve rearing conditions in the river below the pond for juvenile steelhead that use the Touchet River for 11 miles below the City of Dayton for spawning and rearing.