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SE 384th Street Culvert Replacement Project
Construction anticipated in summer 2025
The culvert replacement project is located on SE 384th Street west of 176th Ave SE near Auburn, WA. Crews will remove a four-foot-wide concrete pipe that is too small to handle water during storms. A new much larger concrete box culvert will be installed in its place and will prevent flooding on private property and on nearby roads.
Status update
Spring 2025
Construction requires a full road closure, and the closure is scheduled to last eight weeks. It is anticipated to begin in August 2025. Please check this website and sign up to receive email/text notifications about the project at Road Alerts.
Project overview
During heavy rains, the culvert under SE 384th Street west of 176th Avenue SE is too small to handle the water. This can lead to flooding upstream on roads as far as 176th Avenue SE along with flooding on nearby private property. The current four-foot-diameter concrete pipe will be replaced with a much larger concrete box culvert. This work will require an eight-week road closure.
Crews will dig a large pit in the road to remove the old 48-inch-wide concrete pipe. Then, they’ll prepare the ground to install a new culvert. They’ll use a large crane to put the bottom and sides of the new culvert in the ground. The inside of the new culvert will look like a streambed with natural materials. After that, crews will put the lid of the culvert in place with the crane and rebuild and pave the road.
While there are currently additional downstream barriers to fish, once those are removed this culvert is designed to be fish passable and will allow salmon, trout, and other fish to swim farther up Charlie Jones Creek to their spawning grounds.
What to expect during construction
SE 384th Street will be closed for eight weeks during construction. The road is too narrow—there isn’t enough space for the big construction crane and other equipment to keep even one lane open for traffic. All vehicles, including emergency vehicles such as fire trucks, bicycles, and pedestrians must use the detour route during the closure.
People living nearby may notice noise and smells from saw cutting, jackhammers, excavators, generators, and pumps. There will also be trucks hauling materials and large cranes in the roadway.
After the new culvert is open to traffic, crews will do some low-impact restoration work, like adding native plants and site cleanup.
Frequently asked questions
SE 384th Street is too narrow to have enough room for a large construction crane and other necessary equipment while safely maintaining even a single lane of alternating traffic through the work area. There are no shoulders to store equipment.
It will take approximately eight weeks to remove the old pipe and install the new box culvert under the road.
A fish passage barrier is anything that makes it very difficult for fish to swim upstream or downstream.
Most fish barriers in unincorporated King County are round pipes (culverts) that channel streams and water underneath the road. Many of these culverts were installed between 30 and 100 years ago. These older culverts allow water to flow but are so narrow and steep that they prevent fish from swimming through them.
The current concrete pipe is a fish passage barrier in Charlie Jones Creek, however, there are additional barriers downstream that will need to be removed before fish will be able to return to and from this location. Once the pipe is replaced under SE 384th Street it will no longer be a fish passage barrier and will allow passage if they return at a future date.
Once all fish passage barriers are removed the following species have the potential to return to Charlie Jones Creek:
- Winter steelhead
- Pink
- Coho
- Fall chum
- Fall chinook
- Odd year pink
- Coastal cutthroat trout
- Bull trout
Photos
The current four-foot diameter pipe will be removed and replaced with a much larger concrete box culvert. The new pipe will be large enough to handle water in the rainy season and during winter storms.
This concrete box culvert on SE 380th Place was built in 2022 and is a simular design to the new culvert on SE 384th Street. Both large structures are filled with gravel and large rocks along with natural materials to mimic a streambed.