Springbrook Creek Weir System Oct 2025
We’re migrating from the east side of the Island to the west to visit the Springbrook Creek watershed this November! Springbrook Creek is one of the largest perennial streams on Bainbridge Island, and its an important one for salmonids and lots of other species.
The Springbrook Creek watershed spans about 1,000 acres, draining west-central Bainbridge Island and emptying into Fletcher Bay. Springbrook Creek has about 7 miles of stream channel, and nearly 5 of those miles are considered fish habitat, according to stream typing research conducted by Wild Fish Conservancy.
Lower Springbrook Creek, which is where this picture was taken just last week, contains a weir system that was built approximately 30 years ago to help salmon reach and pass through a culvert under Fletcher Bay Rd. Over time, this system has degraded, to the point now where some of the weirs are experiencing serious leakage around the sides of the structure. This means that at low flows, water is not being maintained through the notch that is supposed to provide salmon passage (see picture). This weir and culvert system is considered a partial barrier to fish passage, and it’s been identified as a priority for restoration in the watershed going back to the Springbrook Creek watershed assessment that was cooperatively completed in 2018 by the Land Trust, the City, the Watershed Council, and Department of Ecology.
But big projects like this – which will involve the removal and replacement of the culvert with a much wider bridge structure, and the removal of this concrete infrastructure to restore and regrade the channel- are not simple or inexpensive. For several years the City has been moving this project up their capital projects list and working to line up grants for the millions of dollars it will take to do this work. And unfortunately, some of the grants received are uncertain given the current state of the federal government. (Insert shameless plug to call your electeds and tell them you care about salmon conservation and they should be working to keep projects like this funded!!)
In the meantime, the City has to ask for permission yearly to conduct temporary sandbagging to raise water levels around the weirs so salmon can more easily pass through this system. That’s the reason for the sandbags you see in the picture above. This past week, staff and volunteers from the City, the Suquamish Tribe, the Bainbridge Island Land Trust, the Watershed Council, and Washington Department of Fish and Wildlife worked together to fill and place sandbags, raising the level of the water enough that adult salmon returning this fall can more easily pass through the weir and culvert system into breeding grounds upstream. Additional pictures of this work are below.
We are all collectively looking forward to a day when this work is no longer necessary and we can restore this part of the stream to a more functional state. But in the meantime, we’ll keep supporting our local salmon as best we can!
Staff and volunteers fill sandbags for raising water levels around the weirs in Springbrook Creek.
After sandbagging is complete, water levels are now higher through and below the weir. Photo courtesy C. Berg.