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When flooding hits, agriculture tries to be ready

A huge rain storm doesn’t always mean immediate relief for agriculture that has been dealing with drought for years. It can also mean flooding, which only if captured can provide long-term relief.

River flooding over road

Some of the water flooding across California replenished aquifers needed for agriculture across the state. Image via Shutterstock/JuShoot.

This article originally appeared as part of our Food Weekly newsletter. Subscribe to get sustainability food news in your inbox every Thursday.

California farmers have come to expect never-ending drought conditions. In 2021, the chair of the California Board of Agriculture, Don Cameron, told GreenBiz, "We’re going into next year with the reservoirs extremely low. We pray that we get a big snowpack and we get it early in the season."

As 2022 turned into 2023, that deluge came. December and January made atmospheric rivers a household name. The state saw an average of 11.47 inches of rain, with some cities breaking records into the high 30s and 40s. San Francisco saw its wettest 23-day stretch on record with 15.29 inches of rain. 

In the mountains, ski towns of Mammoth and Tahoe saw over 200 inches of snow — 250 percent more snow than average for this time of year. The weeks of heavy rain and a few more spouts throughout January have pulled the state completely out of extreme or exceptional drought conditions, according to the US Drought Monitor. 

But water experts are quick to remind Californians that one big storm isn’t enough. 

"One wet year isn’t enough for species recovery," said Ellen Hanak, executive director of the Water Policy Center at Public Policy Institute of California, during a webinar on the flooding. Animals need access to plentiful resources for multiple seasons to increase the food supply and decrease stress conditions.

However, the heavy rain and snowfall could provide relief to farmers, if the excess water capture projects perform as intended. In 2014, California passed Proposition 1, The Water Quality, Supply, and Infrastructure Improvement Act that gave $7.545 billion for water supply infrastructure projects, including surface and groundwater storage and other water restoration projects. The state is pursuing increasing groundwater replenishment by 500,000 acre-feet of recharge capacity.

California’s weather has always been characterized by periods of intense weather systems followed by long periods of milder conditions, even without climate change. This public proposal was supposed to help capture that water as these conditions got more intense because of climate change.

"We can do a better job of skimming off the water but because of the spiky weather, we should never imagine that we would be capturing all the flows," Hanak said.

Cameron’s project started in 2012 and was just finished last year. It involves 5 miles of canals that act as flood protection — storing the water for spreading across agricultural land when needed and that can be used for groundwater recharge to rebuild the aquifer. It’s about 30 miles southwest of Fresno and collects flood water from the Kings River. 

Lift pump

Lift pumps at the Fresno canal project that siphon rain water from the canal to spread onto agricultural land. Image courtesy of Don Cameron.

"We’ve got our infrastructure in place, we want to expand it beyond our area, and we want to be able to really include a large number of other farms and allow them to do groundwater recharge," he said. "When we do have this extra water it can cause damage, and we were working in critically overdrafted regions. Rather than pumping groundwater we'll use the surface water and the floodwater to grow the crops, when it's available. And it’ll prevent the aquifer from being depleted further." 

Driscoll’s has been working on a project in the Pajaro Valley since 2010 to recharge the aquifer in the basin. A coalition of organizations came together — the Natural Resources Conservation Service, the local Rural Community Development and researchers from UC Santa Cruz and CSU Monterey Bay — with funding from Driscoll’s to do geological surveys that concluded the basin could recharge significant volumes of water. Driscoll’s worked to get the permitting, make minor infrastructure improvements and create a small detention basin that helps prevent sediment from entering the recharge basin, affecting its ability to quickly infiltrate water. By 2015, it was the first managed recharge basin of its kind in the area. The basin is about 4.2 acres in size and receives water from 172 acres of natural and working lands.

According to Kyle Monper, regional environmental manager at Driscoll’s, it won’t know until the rainy season ends exactly how much water was recharged due to this year’s storms but in an email he wrote: "Anecdotally seeing how much water was in there and how quickly it infiltrated, I’d say it was a huge success."

The water that enters the basin doesn’t get used directly onto Driscoll’s crops. Instead the water that is recharged enters the aquifer, benefitting the entire Pajaro Valley.

According to Monper, over the past six years the basin has averaged 100 acre-feet per year of recharge, about as much water needed for 40-50 acres of strawberries.

Beyond company investment from food companies such as Driscoll’s, Prop 1 funded a good number of projects including the Kenneson-Sanchez Recharge Basin, a project that will capture and recharge floodwater that would otherwise be lost from the Kings Basin near Fresno. The recharged water will be available for pumping by nearby wells. The project will increase the district's surface storage, therefore increasing operational flexibility and flood protection. There is also the Floodwater Storage Reservoir Project, which will build a 30-acre storage reservoir that will store flood flows diverted from Mariposa and Owens creeks to meet crop demands for 2,100 acres of productive farmland.

But while Cameron’s and Driscoll’s storm capture project was up and running, many others that were part of the 2014 bill were not ready for the recent storms. 

As we move forward, we're going to see a lot more rain. So how do we capture the flow? And I don't know that we've totally wrapped our heads around that.

"I think one of the challenges that we have across the board is just the cycle of a project," said Anne Lynch, integrated water mangament lead at GHD, an engineering firm that works on water storage projects for public and private sectors. "A lot of times, we're not ready when the flood happens."

Many projects have 10- to 30-year timelines. Jerry Brown, executive director of Sites Reservoir, is working on the permitting process for his off-stream storage system project near the Sacramento River, funded in part by Prop 1, and won’t start construction until 2025 to hopefully be in operation by 2032. If the project comes to fruition, it would create 250,000 acre-feet of new water supply for farmers near the delta. 

"Unless there's a disaster, we don't think about it," Lynch said. "So we're always off cycles.

"We need to be better as a citizenry of thinking about that long term. There's a lot of infrastructure that needs to be built and repaired and we're asking it to do multiple things, help the environment, provide water supply, provide flood control; it adds complexity and timeline."

Cameron is heartened to see the state acting quickly on this most recent bout of flooding, giving out temporary permits for farmers to pull water from the flooded areas. 

But the flooding earlier this year actually isn’t the true test, according to Cameron. That will be in the spring.  

"We know there’s a huge snowpack this year. And sooner or later it's going to come down." 

Some big reservoirs have actually left space, anticipating a big snowmelt later on in the year. But the fact remains the rain will become more of an important reservoir and we need infrastructure to capture it when it is here.

"As we look at climate change, we’re going to be seeing more of our water as rain versus snow," Lynch said. "We've gotten really lucky in this event, because we've gotten a great snowpack — a second reservoir sitting there waiting for us. But as we move forward, we're going to see a lot more rain. So how do we capture the flow? And I don't know that we've totally wrapped our heads around that." 

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