Aqueduct Supplying Rohnert Park's Drinking Water Could Fail in Earthquake

A seismic upgrade on the Santa Rosa aqueduct where it crosses the Rodgers Creek Fault is underway. The Sonoma County Water Agency over the last year has been identifying underground utility lines and exploring the fault in preparation.

Officials announced this winter that the water agency is currently taking bids for the project, and major construction is expected to start this summer.

The aqueduct — which supplies drinking water from the Russian River to nine cities in Sonoma and Marin counties and 600,000 residents, including Rohnert Park citizens — was built in 1959. Water agency officials say it could fail if an earthquake with the magnitude of 7.0 strikes — a natural disaster that .

“In our probability studies, the Rodgers Creek Fault has the highest probability of producing the next large Bay Area earthquake of any of the faults we’ve looked at,” said David P. Schwartz, an earthquake scientist and with the U.S. Geological Survey and co-chair of the Bay Area Earthquake Alliance. “Towns like Petaluma and Rohnert Park, which are really very, very close to the fault, are going to suffer a lot of damage.”

. We talk to seismologists and Sonoma State University experts about how a large earthquake could impact local communities.

“The seismic upgrade project will secure the Santa Rosa Aqueduct near the Rodgers Creek Fault in Sonoma Avenue against fault rupture during an earthquake and provide safe, reliable water supply,” said Water Agency Director Shirlee Zane in a news statement.

The $1.8 million project is funded by a $1.3 million Federal Emergency Management Agency Hazard Mitigation Grant and the remainder by the Water Agency’s water transmission budget, according to officials.

FEMA awarded the grant following a 2008 "natural hazard assessment" study, which found the aqueduct faulty.

"The goal of the plan is to better secure water supply facilities when natural disasters occur and seek funding opportunities from federal and state agencies to help pay for those facility upgrades," according to water officials.

“This project is an example of how the Water Agency continues to attract outside funding to leverage local dollars and make our water transmission system stronger and more secure," said water agency chair Efren Carrillo.

Project details: Crews will install "approximately 2,000 linear feet of a 36-inch diameter steel water supply pipeline on a portion of the Water Agency’s existing Santa Rosa Aqueduct pipeline where it crosses the Rodgers Creek Fault in Sonoma Avenue between Doyle Park Drive and Doctors Park Drive in Santa Rosa," according to the agency. The new 36-inch diameter pipeline will be designed to flex in the event of a fault rupture and offset due to a major seismic event."

Construction will impact vehicle and pedestrian traffic on Sonoma Avenue between Doyle Park Drive and Doctors Park Drive, according to a news release, and will last roughly three months. Traffic delays due to construction activities will be limited to Monday through Friday between 8:30 a.m. and 4:30 p.m.

Read more about Rohnert Park's drinking water here.
Read more about the project here.