With its aging dams, collapsing levees and outdated flood control systems, a state report Wednesday said California is ground zero for devastating floods — as San Jose experienced last month — and that billions of dollars in additional funding is needed to fix decaying infrastructure.
The report from the nonpartisan Legislative Analyst’s Office found that one in five Californians live in a flood plain and an estimated $575 billion worth of structures are at risk of flood damage. But studies have estimated that reducing flood risk across the state will cost tens of billions of dollars above current expenditure levels over the next few decades, the report said.
The report follows a winter of historic rainfall that wrecked spillways and forced evacuations of 200,000 people near Oroville Dam. In San Jose, flooding along Coyote Creek prompted the evacuation of 14,000 residents and caused at least $100 million in damage.
“Much of the state’s extensive flood management infrastructure is aged and in need of improvements,” the report said. “As infrastructure ages, it faces a greater risk of malfunction and requires increasing maintenance and repair to remain effectual.”
In a different report obtained Wednesday by The Associated Press, a federal team of experts warned of “very significant risk” if Oroville Dam’s main spillway is not operational again by the next rainy season. Repair crews at Lake Oroville dam have only a few months to make sure the damaged spillway is in good enough shape for the next rainy season, which starts in November.
In San Jose, flood protection work since the 1990s kept the Guadalupe River within its banks during the recent storms. But similar flood protection for Coyote Creek is still in the planning stages. Anderson Dam near Morgan Hill, which controls water flow along Coyote Creek, is in need of an earthquake safety overhaul.
One of the biggest challenges, according to the state LAO report, is that funding for flood control is limited and inconsistent. Several studies show that upgrading the state’s current flood management system will cost billion of dollars above the current $2 billion to $3 billion annual expenditures.
While most of the money for flood management comes from a local level, the state spent an annual average of $2.8 billion on flood control from 2000 to 2010, according to a 2013 report by the Department of Water Resources and U.S. Army Corps of Engineers. The Public Policy Institute of California in 2014 estimated the state spent $2.2 billion a year from 2008 and 2011.
But that falls significantly short of what’s needed to upgrade flood systems and reduce risk in California.
It would cost $52 billion for 836 flood management projects across the state, the 2013 report found, and an additional $100 billion to address future flood risk. The Public Policy Institute of California estimated it would take $34 billion — or about $1.4 billion annually for 25 years — to implement flood risk reduction projects in California.
Most of the dams and weirs in the state are at least 60 years old, the report added, and many levees were built over 100 years ago and not to modern design standards.
Locally, officials from the Santa Clara Valley Water District — which oversees flood control in the region — have pleaded for federal funding to repair infrastructure and fund flood prevention projects. Annual federal flood management spending in California is estimated at between $254 million and $470 million, the LAO report said.
Water district spokesman Marty Grimes said some outside funding paid for the “planning and design” of flood protection projects along the lower part of Coyote Creek — but money ran out before any work could be done.
“We’ve been plugging away with what we had in the hopes that there would be more funding to address all of the flood risks along the creek,” Grimes said, adding that some of those measures would’ve included upgrading levees, widening the creek and installing flood walls. “More federal and state funding would be key to advancing this project.”
David Vossbrink, a spokesman for San Jose, said the city “is certainly strongly interested and supportive for comprehensive and effective flood management, and we do want to be involved in the solutions.”
“Going forward,” Vossbrink said, “we want to work closely with the district to identify priorities, resources, roles, and responsibilities for flood reduction, mitigation, and prevention efforts.”
Other challenges to managing floods in California, according to the report, are that multiple agencies are involved with flood management efforts — creating complicated layers of bureaucracy — and that certain land use decisions can increase flood risk.
As the state population grows, the report said, so does the push to develop into new areas.
San Jose has come under fire for approving the construction of apartments on Nordale Avenue in the flood-prone Rock Springs neighborhood — one of the areas inundated by the Coyote Creek flood.
The report said one approach is to “control the amount and type of development that occurs in flood‑prone areas” by developing land use policies that “discourage construction within floodplains.”
The Associated Press contributed to this report.
