I-80 Fish Passage

Steelhead, an ocean-going trout, may be able to return to historic spawning grounds in the upper Pinole Creek Watershed and increase their numbers in coming years.  Steps are being taken to modify a fish barrier on Pinole Creek identified several years ago by fisheries biologists.  This 320 foot long double-box culvert under Highway I-80 (photo to right) limits the water depth and impacts the flow rate of Pinole Creek to a point where steelhead can’t swim through it most years.     

In 2009, the Contra Costa Resource Conservation District (RCD), in partnership with the East Bay Municipal Utility District (EBMUD), completed Steelhead Habitat Assessments and spawning surveys on Pinole Creek through funding from the Contra Costa County Fish and Wildlife Committee. These assessments were the first step in our goal to construct fish passage improvements at the I-80 culverts, the only major barrier for steelhead in reaching good spawning habitat upstream. The biologists reported that all survey parameters in Lower Pinole Creek were within a range suitable for steelhead and that this stream contains extensive pool habitat, as well. This suggests that the lower part of Pinole Creek has the potential to support steelhead if the passage issues at the I-80 culvert are remedied.   These habitat assessments are posted on the RCD website at www.ccrcd.org

Results of the assessment in the 4 mile stretch of Upper Pinole Creek on protected EBMUD property indicate that significant amounts of quality steelhead/rainbow trout habitat exist there also. The 2010 spawning surveys on Pinole Creek documented rainbow trout spawning on EBMUD lands and within the Pinole city limits.

The RCD obtained funding from the US Fish and Wildlife Service and has hired Roger Leventhal with FarWest Restoration Engineering to design the fish passage improvements which will include angled baffles to keep low flows concentrated into the south box culvert to increase flow depths for passage at the lower fish passage flows. The California Coastal Conservancy is also sponsoring this effort. To aid in the design of the project, a water level gauge was installed December 2009 which recorded the height of the creek every 15 minutes during storm events.  This water level data will also assist in designing restoration projects in the Flood Control Channel on lower Pinole Creek and the adjacent Chelsea Wetlands.

The RCD is planning construction of the fish passage improvements for the summer of 2012.  Partners on this project include EBMUD, the Contra Costa County Flood Control and Water Conservation District, CalTrans, the City of Pinole and the Friends of Pinole Creek Watershed.

Double box culvert under I-80 prior to construction

Fish Migration Barrier

Photo of box culvert prior to construction of fish passage. At low flows, there was insufficient depth to allow passage. High flows prevented fish from passing through.

Downstream view of fish passage at low water
Downstream view of fish passage at low water

After construction

A trench was constructed to provide sufficient water depoth during low flows.


Inside view

Baffles were added in the trench to provide hydrolic resting spaces for migrating fish at high flows.


High Water

January, 2017. High flows