Mill Creek will see many construction projects pop up over the summer, limiting or closing access to different areas at the trail and Bennington Lake.
The division works fish ladder, a structure that allows migrating fish passage will be replaced, along with the railing at the yellow pedestrian bridge. Bridge supports on the yellow bridge will also be repaired.
The $1.1 million fish ladder and hand railings project will increase fish passage in Mill Creek for steelhead, bull trout and chinook salmon and improve safety on the bridge, according to an announcement from the U.S. Army Corps of Engineers’ Walla Walla District.
The pedestrian bridge and parts of the trail in that vicinity will be closed, and a temporary detour path provided. A detour around the paved section of the levee next to the fish ladder also reroutes pedestrian traffic. That part of the project is expected to last until mid-October, the Corps said.
The current fish ladder was constructed before the Endangered Species Act. Since then much has been learned about the different flows that fish could easily travel when they are going up a fish ladder. The new ladder will make it easier for fish to pass the structure, Natural Resources Specialist Jeremy Nguyen said.
Visitors will be able to look down into the fish ladder and see where the fish jumps and the pool where it can rest to understand how the ladder works. The newer fish ladder will work in a larger range of flows from 5 to 400 cubic feet per second, he said.
Other projects include new outhouse-style restrooms at Bennington Lake, repaving Reservoir Road, Mill Creek Dam rehabilitation and more. Closures will begin after July 6 and continue through to the fall, he said.
Timing for these projects follows closures from the COVID-19 pandemic and closures due to the flooding in early February, according to a release.
“Our biggest mission this summer will be to keep visitors informed of the various closures to reduce frustrations people may be feeling about not being able to visit one of the busiest and appreciated recreation areas in the vicinity,” Nguyen said.
“It is really great that we are getting so much work accomplished this summer. The added benefit of getting people back to work in these unprecedented times will have positive impact well beyond the boundaries of Mill Creek Dam and Bennington Lake.”
The bridge and trail will most likely remain open until July 6 for the Division Works (yellow bridge) fish ladder construction, according to the Corps.
There will be a gravel detour in place from the Walla Walla Community College pathway upstream until the yellow bridge, he said. Staging areas for contractor equipment have been blocked off, and visitors with horse trailers are encouraged to park at the lake parking lot.
Restroom replacements at Bennington Lake will not have running water because the site experiences floods. Part of not reopening the restrooms at the lake is due to drinking water regulations. The concrete building will be without flushing toilets or running water to pump the toilets out and put new water in if there is flooding, Nguyen said.
The project will close the Bennington Lake parking lot.
Reservoir Road will be repaved, which will reduce access to the project office and a road access closure, but not foot traffic to Bennington Lake tentatively in late July. If people can find parking, they could walk to the lake, according to the Corps.
The Mill Creek Project parking lot will be closed for maintenance building construction. Portions of Rooks Park will also close down for Mill Creek Dam rehabilitation.
The diffuser blocks or “teeth” at the bottom of Diversion Dam, are almost 80 years old, so they are worn and will be updated to brand new structures in mid- to late July or early August, Nguyen said.
Construction equipment will move in and out of Rooks Park and into the area below the dam, which may impact access to the levee associated with the dam, he said.
Anchorage-based TDX received the contract for the work.