Are you interested in the status of the Lopes Road Landslide Project or the Federal reimbursement process for this project? Visit the City of Fairfield's Lopes Road Project page here




The City of Benicia has a water main transmission line along Lopes Road in the City of Fairfield adjacent to I-680 between Gold Hill Road and Marshview Road that supplies Benicia with water from the California Delta and Lake Berryessa. The pipeline is 36” in diameter and is part of a 14- mile-long water transmission pipeline that carries water from between the City of Fairfield and the City of Benicia’s Water Treatment Plant. Benicia also has a secondary, short-term source of water, which is the Lake Herman Reservoir.  


Q: What happened? Why did the water transmission pipeline break? 

A: Due to a wet winter the earthen slope in the vicinity of the water transmission pipeline became oversaturated causing a landslide. The damage occurred when a hillside collapsed near I-680 and Lopes Road between Marshview Road and Gold Hill Road, in the City of Fairfield just outside Benicia city limits. The slope failure caused a brief closure of I-680. The large landslide caused severe damage to Lopes Road resulting in full road closure and broke a portion of the City of Benicia’s three-foot diameter water transmission pipeline which carries water from the Sacramento Delta and Lake Berryessa to the City’s Water Treatment Plant. 


Q: Where does the water from the water transmission line come from? 

A: The City’s water supply consists of three surface water sources: State Water Project water via the North Bay Aqueduct (NBA); Lake Berryessa transported through the Putah South Canal (PSC); and our local source, Sulphur Springs Creek diverted at Lake Herman. Each source provides clean and safe water for drinking, fire protection, irrigation, and industry. Learn more by reading our 2022 Annual Water Quality Report here. 

Q: Has the water transmission line been repaired? 

A: A temporary, above-ground bypass pipeline was successfully engineered and constructed that restored the transmission of water around the damage portion of the main pipeline.  Construction began on April 5, 2023.  Phase I included the installation of  two twelve-inch diameter plastic pipes connecting to the intact sections of the water transmission line on either side of the slide, and was completed on April 7, 2023.  Phase II included the installation of an additional two twelve-inch diameter plastic pipes for a total of four bypass pipelines, and the City may periodically use Lake Herman as a backup water source. 


Q: When will Lopes Road in Fairfield be repaired? 

A:  Per the City of Fairfield, the portion of Lopes Road will continue to remain closed until further notice.  It is not expected to be repaired until the end of 2024 as previously stated as part of the restoration project in accordance with FEMA requirements. 


Q: How much has this emergency cost the City? 

A:  The current estimated cost of the temporary bypass is $1.2 million.  The City is seeking reimbursement from FEMA/CalOES.  It is unknown how much the permanent restoration will cost at this time. 


Q: If the damaged pipe was built in 1960s, was it regularly maintained? 

A: Yes, the pipe is regularly monitored and maintained as issues arise. The pipe is buried without access points and in continuous use making inspection of the pipeline infeasible. Repairs are made as needed. Major valves are exercised throughout the year.  


Q: Are there any backup lines that can carry water to the City?  

A: The City’s alternate source of drinking water is own Lake Herman. 







Contact Sarah Shawky, Deputy City Manager, at or call (707) 746-4334