Gathering storm: What California must learn from the Midwest floods

By Jacob Katz

Jacob Katz is a senior scientist at CalTrout where he directs the organization’s Central California region. jkatz@caltrout.org He wrote this commentary for CALmatters.

A bomb cyclone formed in the sky above Nebraska not long ago, and warm rain melted an above-normal snowpack, causing catastrophic flooding across six states.

The Missouri River is long way away. But this emergency offers California critical lessons about how we must prepare for severe storms in a changing climate.

In California, we call our greatest flood threat “atmospheric rivers.” One of these rivers in the sky directed a firehose of tropical moisture at Northern California, leading to March flooding along the Russian River. Truth is we got off easy, as we did in 2017 when Oroville Dam’s spillway nearly failed and 188,000 people were evacuated. It could have been so much worse.

Sacramento is, after all, among the cities in the country with the greatest risk of catastrophic flooding.

In the wake of the Midwest destruction, a group of scientists published the lessons learned to help protect families and livelihoods.

Among the conclusions:   

• A changing climate must be considered in flood planning.
• Engineering cannot provide protection from the most extreme floods.
• We must act proactively to prevent damage, rather than simply waiting to respond to emergencies.
• Building on floodplains greatly increases risk.
• Flooding in rural communities can be easily discounted.

Each of these lessons has remarkable applicability to the flood risk Central Valley residents face.

Fortunately, California has developed a forward-looking Central Valley Flood Protection Plan to meet this challenge. In his first state of the state address, Gov. Gavin Newsom highlighted the central tenet of the flood plan—investing in floodplain improvements that give rivers more room to safely bypass flood waters around cities and infrastructure.

The Yolo Bypass–that expanse west of Sacramento that is alternately rice fields and floodplain–is the best-known part of the Central Valley’s flood system. It will be expanded under the flood plan.

Other improvements include the new multi-benefit floodplain project on the Sacramento River 100 miles north of the city of Sacramento at Hamilton City, which kept residents safe during recent storms.

Improving floodplain management will help recharge depleted groundwater, preserve ranches and farms and enhance habitat by allowing rivers to function more naturally. These multiple benefits explain why farmers, fishermen and flood agencies all support the new flood plan.

Here are a few ideas to help Gov. Newsom turn a proactive vision of flood and water management into reality.

• Integration: California’s defining 21st Century challenge is to reconcile water supply, flood protection and ecosystem health in the face of a changing climate. We can address these challenges simultaneously by modernizing antiquated water infrastructure. Agencies must integrate expanded floodplains with efforts to implement California’s landmark Sustainable Groundwater Management Act of 2014. Floodplains can do triple duty by protecting communities from flood, replenishing over-tapped aquifers and enhancing river ecosystems.
• Justice: Disadvantaged communities are among the most at risk from floods. The upcoming update to the flood plan should focus on protecting vulnerable cities such as Stockton and Sacramento as well as small towns such as Firebaugh, which face the greatest climate-driven increase in flood risk.
• Investment: Writing a good plan is one thing; building it is another. To find the billions necessary to adapt to extreme weather will require tapping into many sources—reflecting the many benefits these investments will provide—including a mix of bonds, local contributions, habitat restoration, groundwater management, water supply reliability and climate change funds.

A Nobel laureate sang, “You don’t need a weatherman to know which way the wind blows.”

The destructive power of Hurricanes Katrina and Harvey, Super-storm Sandy and the bomb cyclone that hit Nebraska in March are yet more evidence climate change is upon us.

Severe storms and flooding will be more frequent and more dangerous. We must adapt. We must prepare. We have the plan. We must act on it.