West Antioch Creek Channel Improvements

West Antioch Creek, in Antioch, California, is located approximately 36 miles from the City of San Francisco. Due to severe flooding of this creek two to three times a year, infrastructure and local commercial and residential buildings were damaged, and even in mild storms, flooding events in the area prevented access to businesses there. A high priority for the region, the City of Antioch partnered with us to develop capacity improvements for this creek.

To address the chronic flooding of West Antioch Creek, three box culverts, spanning 620 feet, were installed to increase the storm water capacity of the creek, in addition to the replacement of an undersized concrete trapezoidal ditch and arch culverts. This installation provides a 25-year level of flood protection to the buildings surrounding the channel. In addition, sediment was removed from an approximately 3,000 linear feet downstream section of the creek, which contributes to improved water quality.


In addition to reducing flooding in the area, this project also contributes to a number of other important benefits. One of these is the elimination of a significant public health threat to a disadvantaged community: chronic exposure to floodwaters that are both potentially dangerous and possibly contain contaminants from overflowing sewers, agricultural runoff, and chemicals from industrial areas. The reduction in flood-related debris and pollutant loading to the channel also improves overall water quality and protects habitats. Lastly, the frequent flooding in the area would often result in closure of the nearby Costa County Fairgrounds, Antioch Little League Complex, and Prosserville Park. Fewer closures boosts the potential recreational usefulness of the area substantially.

City of Antioch




Dave Richardson

Areas of Focus

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