In summary

California needs to make Stockton and San Joaquin Valley flood investments a priority — especially during a drought. Building flood management projects takes years. If we don’t start now, we may not be ready when the next big flood arrives.

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By Mike Machado, Special to CalMatters

Mike Machado is a farmer in the Sacramento-San Joaquin River Delta, a former state senator and the author of flood policy reform legislation.

As a result of our warming climate, Stockton and San Joaquin Valley communities face a growing risk of disastrous flooding in coming years. California’s budget surplus gives us an important opportunity for a major investment in climate-smart flood solutions.

Why make flood investments a priority during a drought? Preparing for future floods is like saving for retirement: Building flood management projects takes years. If we don’t start now, we may not be ready when the next big flood arrives.

The best flood solutions, such as restoring riverside flood plains, will make our communities stronger in many ways — starting with preparing us for the effects of a warming climate.

Climate change will make droughts more frequent and more severe, reducing our winter water storage system — snowpack. Warming temperatures will mean more rain and less snow. In the past, Sierra snowpacks melted gradually in the spring. Increasingly, heavy rain will run rapidly off our mountains. In dry years, this means less water stored as snow to supply our cities and farms. In wet years, this change means a growing risk of floods.  

Today, levees straitjacket the San Joaquin River, concentrating flood flows and aiming them at Stockton. Flood-plain restoration can allow floodwaters to spread out, slow down and sink into groundwater aquifers. Projects such as the Dos Rios Ranch Preserve on the San Joaquin River near Modesto demonstrate that this approach works. 

Flood-plain restoration can prepare us for both floods and droughts. In wet years, these projects can reduce flood damage. And by allowing floodwaters to sink into our groundwater aquifers, they increase our water supply in times of drought, complementing our overtapped rivers and reservoirs. 

Flood-plain restoration also increases habitat for endangered fish, water birds and even monarch butterflies. It locks up carbon dioxide, which helps fight climate change.

Riverside restoration creates open space for recreation that increases quality of life for park-starved Central Valley communities. More parks and reduced flood risk increase property values and attract business investment.

Reduced flood risk lowers flood insurance costs. These pocketbook benefits will help all Central Valley communities. That’s particularly important for low-income communities, for whom floods can cause lasting damage.

The state’s draft Central Valley Flood Protection Plan projects with certainty that peak San Joaquin River flood flows will double in coming decades. In the worst case, the biggest floods could increase fivefold, putting Stockton and San Joaquin Valley communities more at risk for a disaster than was New Orleans when floodwaters devastated the city in 2005.

San Joaquin River floods will not be ankle-deep inundations that merely ruin carpets. Unless we act now, in some areas, floods could rise to rooftops, posing tremendous danger to lives and homes. There are many opportunities for the state to build flood-plain projects upstream from Stockton. 

We also need local projects, such as the Van Buskirk flood plain and the Smith Canal Gate flood-wall projects, to incorporate flood protection, recreation and ecosystem restoration. Using a portion of the now-closed Van Buskirk Golf Course as a flood plain will protect communities in south Stockton. Building a new gate at the mouth of the Smith Canal and a flood wall at one end of the Stockton Golf and Country Club will reduce flooding in the Stockton area.

While the Yolo Bypass in the north delta helps protect Sacramento from floods, there is no flood bypass in the south delta. But there can be — the Paradise Cut Expansion Project would protect Stockton and nearby communities. 

Yet for the past few decades, the state has spent $10 on Sacramento Valley flood protection for every $1 it has spent on San Joaquin Valley flood protection projects.

Nearly all water interests see the broad benefits of flood-plain restoration and strongly support this solution. But these projects cannot be built without funds. And we need them now, not years from now. Call your legislators and urge them to fight to end that flood funding imbalance.

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