This commentary was published by the Sacramento Bee on December 30, 2023.

Climate change is throwing California’s already variable climate for a loop, supercharging the extremes of drought and flood and leaving us with fewer “in-between” moments. But while we’ve done a great job preparing for increasingly frequent and severe droughts in California, our infrastructure and institutions remain woefully underprepared for the extreme floods that are coming our way.

It’s time to take this threat seriously, and accelerate planning for the wet years we know are bound to happen.

The need is urgent. Flood risk is widely distributed across the state: Each of California’s 58 counties has experienced flooding the last 25 years, and some one in five Californians is at risk of flooding. More than $580 billion worth structures are vulnerable, and the risks are growing. As the climate continues to change, megafloods — like those that swamped the state in 1862 — are increasingly likely, with the potential for damages well exceeding those for the largest earthquakes.

But alongside risk lies opportunity. In our increasingly arid state, we can harness the wet years to replenish our aquifers and store water for the dry times. Agencies have taken some good first steps, but it’s time to get rules and infrastructure in place now for the events that we know are on their way.

Last summer, the Public Policy Institute of California’s Water Policy Center convened groups of people working on the front lines of this challenge, from water managers and growers to agency staff. We wanted to better understand what went well this past winter and what could be improved upon in future years. Those experts told us the state needs better planning for wet years; to invest in infrastructure; improve regulation and permitting; and make low-income communities and the environment priorities during wet years.

The California Department of Water Resources (DWR), cooperating with other state agencies, federal agencies, counties, local reservoir operators and groundwater sustainability agencies, should seek to achieve water supply, flood control and environmental objectives simultaneously wherever possible. This will require unprecedented institutional coordination and cooperation.

California’s water supply and flood infrastructure is not up to the task of adapting to increasing climate volatility. DWR, in partnership with other state and local agencies, and with support from the Legislature, should develop a wet-year infrastructure plan, including how to implement and fund it. Integrating wet- and dry-year management will require a multi-decade infrastructure investment program that focuses on conveying water to recharge sites, improving flood defenses and integrating nature-based solutions where appropriate.

Despite improvements in recent years, efforts to simplify and streamline the permitting of recharge, infrastructure and restoration efforts remain a work in progress, with high costs, frequent delays and changing regulations and policies. The State Water Board, in cooperation with DWR and California Department of Fish and Wildlife, should also develop a wet-year permit management plan that guides actions during high-flow events.

Flood risk often falls disproportionately on low-income — and often rural — communities. Federal, state and local agencies involved in flood and supply management should integrate these communities’ needs into all facets of wet-year planning and implementation.

In addition, little attention is paid to the environment when conditions are wet, yet high flows without high-quality habitat have much less chance of building resilience in native species. Federal, state and local agencies managing floods and water supply should incorporate nature-based solutions to address flood control, water supply and ecosystem issues simultaneously.

The only certainty with climate change is uncertainty. Higher temperatures and more volatile precipitation are here to stay — and conditions will only get worse.

California has historically managed water through executive orders and emergency regulations, but that no longer cuts the mustard. We need to be ready for any eventuality, from unprecedented drought to epic floods, and we need to be ready to pivot on a dime, with plans and infrastructure in place to cope with whatever is happening.

Forecasting will only take us so far. Upgrading our systems and permitting will be a challenge, but we can and must do it.