Stream-channel Restoration

Addressing Barriers

Restoring Fish Passage

Culverts and dams can block fish and other wildlife from passing up-and-downstream, so that they cannot access food, habitat, and shelter from predators.

The most common barriers in our watershed are culverts: large pipes that convey water under roads and driveways. Culverts can block fish passage in many ways, such as drops at the outlets that are too high above the stream for fish to jump and high water velocity inside the culvert caused by improper installation or when a culvert is too small for the amount of streamflow.

In 2013-14, JCWC partnered with Portland State University to survey hundreds of culverts and dams in our watershed. Of the 273 surveyed culverts and dams, 74% were found to be full or partial barriers! We used a statistical model to prioritize these barriers for future restoration projects and produced a list of the 18 top-priority barriers.

Improving fish passage is one of the six restoration priorities in our 2015-2025 Action Plan. Since our first fish project in 2016, we have improved passage at 10 locations:

2016: Replaced the culvert under the Springwater Trail at Badger Creek
2017: Replaced the culvert under the Springwater Trail at North Fork Johnson Creek
2018: Retrofitted the culvert under SE 262nd St at North Fork Johnson Creek
2019: Removed two culverts near SE 272nd St on Mitchell Creek
2019: Retrofitted the culvert under Highway 26 on North Fork Johnson Creek and created a roughened channel to remove the jump at the culvert outlet
2020: Removed a dam on Kelley Creek near SE Foster Road
2021: Retrofitted the culvert under SE 267th St on North Fork Johnson Creek
2021: Removed concrete rubble from a failed footbridge near SE Baxter Road on Mitchell Creek
2022: Removed a culvert at a private residence on Telford Road on Badger Creek

And the following projects are in the planning stages:

2024: Remove a culvert on a farm near SE 282nd St on North Fork Johnson Creek
2025: Remove two undersized culverts and replace them with a larger culvert under SE Rugg Road on Badger Creek.

The three culvert retrofit projects on the North Fork of Johnson Creek were the first applications of an experimental passage technology in the Western United States known as the “Flexi-baffle” (developed in New Zealand). This technology offers cost-effective, short-term passage through culverts where replacement or removal is a longer-term, more expensive proposition.

Installation of the Flexi-baffle.

Flexi-baffles at high flow. Notice how a pool with low-velocity flow is created behind each baffle.

Working Together!

Replacing a culvert is a HUGE project involving landowner cooperation, working with local, state, and federal agencies, obtaining numerous permits, building relationships with contractors, and coordinating volunteers! Plus, the in-stream work window is a short time frame in late summer, so everything has to be ready to go.

In September 2016, we removed the top-priority barrier identified in our Action Plan by replacing the culvert where Badger Creek passes under the Springwater Trail. It was a colossal effort, and we couldn’t have done it without our partners and volunteers in the community.

BEFORE: 3 clogged, rusty culverts.

Springwater Trail detour around the project site.

The stream was temporarily diverted through pipes.

Excavation of the old culverts.

When removed, the old culverts broke in half!

Arrival of the new culvert.

10 feet in diameter!

Attaching two pieces together.

New culvert placement.

Pacific lamprey salvaged during construction.

AFTER: A single, large culvert.

And spreading mulch for planting…

Thanks, volunteers!