Flood Control Channel

Impassable barriers in lower Alameda Creek have been the main obstacle to restoring migratory fish populations in the Alameda Creek watershed. The Alameda Creek Fisheries Restoration Workgroup is pursuing fish passage projects in the Alameda Creek flood control channel at the Alameda County Flood Control drop structure (known locally as the BART weir) and three inflatable rubber dams owned by the Alameda County Water District.

Fish passage project update and schedule as of fall 2008, provided by the Alameda County Water District

Fish Passage at the BART Weir

Aerial view of barriers in the flood control channel - left to right, moving usptream, are the BART tracks, BART weir, UP railroad tracks and ACWD rubber dam

The first total migration barrier in lower Alameda Creek is the “BART weir,” which is a bank-to-bank sloping concrete apron constructed by the U.S. Army Corps of Engineers to prevent channel erosion, and owned by the Alameda County Flood Control District (ACFCD). This drop structure allows flows to pass through a high gradient reach of the flood control channel without producing instability to the channel walls or the piers supporting the adjacent railroad and BART tracks.

2007 the Year for Fixing the BART Weir?

The Alameda County Flood Control District and Alameda County Water District signed an agreement in 2007 to design a fish ladder that will allow steelhead to bypass the BART weir and the adjacent inflatable water supply dam in the lower Alameda Creek flood control channel, the main barriers to fish migration into Alameda Creek. The agencies signed an agreement to fund preliminary design for the fish ladder and announced their goal to have the fish ladder constructed by 2010.

The ACFCD is currently evaluating potential fish passage projects at the site - in August 2006 the agency published the Lower Alameda Creek/Bart Weir Fish Passage Assessment - Draft Alternatives Evaluation Report, which evaluated the feasibility of four potential fish passage projects at the barrier and ranked these alternatives. In January 2007 the final report was published: Alternatives Evaluation Report, Lower Alameda Creek/Bart Weir Fish Passage Assessment.

Proposed fishway design for BART weir and rubber dam

Alameda County Water District Rubber Dams & Diversions

Lower ACWD rubber dam deflated - this dam is scheduled for removal in 2008

Alameda County Water District awarded $1.6 million to improve steelhead migration in lower Alameda Creek

The Alameda County Water District (ACWD) diverts water impounded behind three rubber dams in the Alameda Creek flood control channel to groundwater recharge ponds in the Quarry Lakes Regional Recreation Area in Fremont. This water percolates into the aquifers beneath the Tri-City area and supplies up to 50% of the water used in Fremont, Newark, and Union City.

The ACWD is moving forward with three fish passage projects in the flood control channel. In 2005 the ACWD was awarded two $500,000 grants from the National Fish and Wildlife Foundation to fund two projects that will help improve passage for steelhead trout in the flood control channel. Read the ACWD press release about the grant for the fish passage projects. One project will remove the lower inflatable rubber diversion dam from the channel, which acts as a barrier to migrating steelhead when inflated. The removal of the lower rubber dam (and possibly its foundation) will be done in summer of 2008.

In 2007 a state of the art fish screen facility was installed on the ACWD water supply diversion below Mission Boulevard. Four rotating fish screens will eliminate the potential for out-migrating juvenile steelhead from being trapped in the diversion pipelines and adjacent groundwater recharge ponds. The ACWD recently announced that it anticipates receiving a $600,000 grant from state Proposition 50 funds for installing an additional fish screen on their diversion just downstream at the Bunting Pond. This fish screen is planned to be installed in 2009.

Visit the ACWD web pages on the rubber dam decommissioning and the fish screen installation.

Four fish screens on ACWD water diversion below Mission Blvd. nearly completed October 2007

Close up of a rotating fish screen - the narrow openings prevent small fish from being sucked into water diversion intakes

The screens can slide out of the channel during storms and for maintenance

Humans helping fish!

The Alameda Creek Fisheries Restoration Workgroup is seeking funding for phase two of the fish passage projects in lower Alameda Creek. Phase two projects will include constructing a fish ladder around the drop structure and middle rubber dam (a 22 foot drop), building a fish ladder at the upper rubber dam (a 13 foot drop), and installing fish screens at remaining ACWD diversion facilites.

Union Sanitary District Sewer Line

The Union Sanitary District in 2007 stabilized a sewer pipe that crosses underneath Alameda Creek in Fremont in the flood control channel. USD discovered a large void where the creek bed had eroded beneath a 33-inch trunk sewer pipe on August 25, 2006. This left the sewer line at risk of breaking and discharging wastewater to the creek during expected high flows in the channel during the winter. The District declared an emergency and installed a temporary above-ground sewer bypass over the adjacent Ardenwood Bridge during Labor Day weekend. This bypass redirected all wastewater flow away from the undermined pipe and out of the creek, protecting it from a potential spill.

When the pipeline was installed in 1978, it was buried four feet below the creek bed. Changes in Alameda Creek have lowered the channel bottom level, causing USD’s pipe to be exposed and undermined. Since this is a temporary repair, the District is currently evaluating options for permanently stabilizing the pipe in the creek bed.

Alameda Creek "Estuary"

The planned restoration of salt ponds near the mouth of Alameda Creek to tidal marsh gives the opportunity to restore brackish water estuary habitat that could be critical to growth and survival of salmonids in Alameda Creek. The Alameda Creek Fisheries Restoration Workgroup will coordinate with other agencies on estuary restoration to improve steelhead rearing habitat and smolt growth.

South Bay Salt Pond Restoration