Gov. Gavin Newsom declared a state of emergency Monday, Sept. 21, ordering agencies to stage flood equipment ahead of a potentially historic El Niño winter.
The declaration carries pointed urgency for Walnut Creek. Contra Costa County's flood control system spans 75 miles of channels, 35 detention basins and 25 trash racks, most built more than 55 years ago, according to a 2017 Contra Costa County Grand Jury report, figures this outlet first reported Sept. 17. The concrete-lined channels have a design life of about 70 years, meaning the oldest sections are now at or past that threshold.
The county Board of Supervisors agreed in its 2017 response to the Grand Jury that the system was approaching its design life and that existing funding was not enough to maintain and eventually replace it. A full rebuild would cost about $2.4 billion in 2016 dollars and take 40 or more years, the Grand Jury estimated.
Walnut Creek has seen what flooding can do. On Dec. 31, 2022, Walnut Creek Police Department closed Walnut Boulevard at Sierra Drive and Homestead Avenue after storm-caused flooding swamped roadways.
Under Newsom's emergency proclamation, the California Department of Water Resources (DWR) has positioned 4.4 million sandbags, 400,000 tons of rock and 211 flood material containers at 68 stockpile sites statewide, KQED reported. The California National Guard will stand ready for flood response and search-and-rescue operations, and Caltrans will stage road-closure and snow-removal equipment on the most vulnerable highways.
The National Oceanic and Atmospheric Administration (NOAA) puts the chance of a very strong El Niño at greater than 90% and the chance of a historic event at 75%. Sea surface temperatures in the key monitoring region have exceeded 3 degrees Celsius above normal for the first time on modern record, GovTech reported.
"We are not waiting for this season's storms to be on our doorstep," California Office of Emergency Services (OES) Director Caroline Thomas Jacobs said in a statement accompanying the declaration.
Thomas Jacobs added that storms rank among the deadliest disasters in California and that the greatest danger remains people underestimating the power of water. State leaders have not yet put a price tag on the overall flood work.
Laura Hollender, deputy director of the Department of Water Resources, said Bay Area counties with flooding vulnerabilities need to alert residents early. Even without storms, she said, coastal areas may see flooding this winter.
Newsom's order also directs OES to expand multilingual messaging about preparedness, power outages, evacuation and emergency alerts.
What residents can do
Walnut Creek residents can sign up for emergency alerts through the Contra Costa County Community Warning System (CWS) at CWSAlerts.com or by calling (925) 655-0111. The county's "Know Your Zone" tool on the same site shows evacuation zones in advance. CWS alerts arrive from caller ID (925) 655-0195.
