DESCRIPTION
Diversion improvement, screen replacement, enhancement of off-channel refugia on lower Wenatchee River.
The Jones-Shotwell Ditch Board proposes to modernize their diversion facilities to comply with NOAA Fisheries criteria, improve fish passage, and enhance the habitat for threatened and endangered salmonid species at their diversion site in Monitor, WA. The existing diversion features consist of a rock wingdam, a 600 foot long man-made diversion channel, a traveling belt screen, and a forebay water surface control check structure.
Replacing the rock wingdam with a permanent rock structure will allow the district to divert water without having to rebuild its instream diversion annually. Reworking the diversion channel, including removal of some concrete structures and adding habitat elements, will eliminate the need to periodically excavate the channel to remove the continuously deposited sand and silts. These actions will improve valuable salmonid habitat.
The existing fish screens are at the end of their useful life and do not comply with the current NOAA Fisheries juvenile passage and protection criteria. Their replacement will prevent entrainment and impingement of juvenile salmonids, which is critical considering the habitat value that WDFW places on the diversion channel.
The forebay structure is a passage barrier to adult salmon attempting to enter the diversion channel from the downstream end. Building passage over the structure will allow downstream access to the diversion channel. WDFW has requested upstream passage for salmonids at this forebay check structure