Farmers Can Adapt to Alternating Droughts and Floods—Here’s How
Farmers like predictable weather, and this past year in California has been anything but. After the state suffered through the worst drought in modern history, a series of atmospheric rivers starting last December brought recurring deluges of heavy rain and snow that caused widespread and extensive damage, forcing people to evacuate in many areas across the state and resulting in multiple deaths. Snow levels are at historic highs in the Sierra Nevada mountains, with final snowpack numbers reported at a staggering 207% to 308% of normal—threatening more flooding to come as it all melts. And the agriculture industry, which uses an outsize amount of California’s water and has literally changed the state’s landscape, needs to change and adapt, fast.
California’s climate future is here
The year 2021 was the driest in the last 100 years and the western “megadrought” is the most severe in the last 1,200 years. Most places in the West received only a fraction of the normal rainfall in 2022. California’s recent rain and snow came as much-needed relief to a parched state. But with the heavy rain came floods that damaged lives, property, and crops. With fields waterlogged, many farmworkers were unable to work and pick produce, signaling that crops like strawberries might see lower yields and higher prices in the near future. The farmworkers themselves lost wages, and their communities are often hit the hardest by both floods and droughts because they tend to be politically underrepresented and have fewer resources to prevent the impacts from, and recover after, extreme weather events.
It is true that California’s surface water sources have greatly benefitted from this wet winter. Major water supply reservoirs including Lake Oroville and Shasta Lake are now well above their historical averages. In a surprise turn of events, a long-drained water body in California’s Central Valley, Tulare Lake, has reappeared. However, rain falling at this volume had little chance to soak into the ground and replenish aquifers—a missed opportunity for more sustainable water management. Successive years of higher-than-normal precipitation will be required to offset the severe water scarcity, replenish groundwater sources, and return surface water bodies and rivers to normal levels.
What California needs is effective water and soil management that facilitates surface water seepage into aquifers. But for now, to offset flood risk from rising water levels, the State Water Resources Control Board has agreed to send more than 600,000 acre-feet of water (pretty much what Los Angeles consumes in a year) to areas where it can soak into the ground and replenish the aquifer beneath the San Joaquin Valley.
It should also be noted that while California’s wet winter refilled the state’s surface water sources, the same is not true for other states in the region. Lake Mead and Lake Powell, the two largest reservoirs on the Colorado River, are still at or near historic low levels following several years of drought and continued overextraction.
What can farmers do to avoid weather “whiplash”?
Agriculture is the largest user of water in the western states. California uses about 27 percent of Colorado River water, making it the largest user of this water source. While a small number of winter crops such as small grains (wheat, oats, barley) and forage and pasture crops such as alfalfa can use some winter rain and snow, western agriculture largely depends on a steady supply of irrigated water that has led to extreme groundwater mining. During drought years, California is dependent on groundwater to a much larger extent than rainwater, and precipitation (in the form of rain and snow) is crucial in recharging the aquifers that hold groundwater.
In instances of weather whiplash (alternating cycles of severe drought and rain), what farmers need are effective soil management practices to capture rainwater and replenish aquifers. Industrial agricultural practices such as tillage (plowing) and leaving fields bare between growing seasons degrade soil structure, reduce water infiltration, lower water storage capacity, and increase runoff (the flow of water across the soil’s surface). Federal conservation programs and state-based programs like the California Department of Food and Agriculture’s Healthy Soils Program provide financial assistance to farmers and ranchers for adoption of various soil management practices that can restore soils damaged by industrial agriculture.
Agricultural water use is currently far from sustainable in California, and for that to change, the agricultural sector will need to significantly reduce its acreage of irrigated land. Research from the Union of Concerned Scientists (UCS) has shown that repurposing agricultural land in California can be a feasible solution for many communities and farmers, but it is not a simple linear process and stirs a lot of emotions and controversy. Merely retiring land can have several negative effects for landowners and even communities if locals aren’t involved, but repurposing land can create some socio-environmental opportunities.
Despite the amount of agricultural land that needs to be strategically repurposed, soil health will still need to be improved to build resilience across the US farming system. California faces specific challenges when it comes to water management, but as farmers across the country encounter more extreme weather, they will need soil management practices for building soil that handles water better.
Healthy soil is good at capturing and storing water
Our current agricultural system by and large fails to integrate science-based soil management practices that would replenish groundwater. Industrial agriculture has created soils that are less like sponges and more like concrete, making it difficult to soak up runoff and excess water. When implemented correctly, soil management practices can deliver multiple benefits to farmers and communities during periods of floods and droughts. More absorbent, sponge-like soils can help manage rainfall and store water, creating resilience in both wet and dry periods.
Practices that have measurable benefits for water sequestration include keeping soil covered all year with cover crops and relying more on perennial crops. Cover crops change the structure of the soil, increasing porosity (or “sponginess”). Maintaining a “continuous living cover” by planting cover crops and crops with deep roots can be a winner at managing large water flows during heavy rains.
Danger Season is around the corner, which means long stretches of record-breaking temperatures, intense heat, the onset of dry conditions, and possible water scarcity. Intentionally designed, diversified farming systems incorporating practices like perennial crops, grassland, cover crops, trees, grazing animals, and building a mulch layer that protects soil from direct sunlight and water loss through evaporation will increase water retention, build soil organic matter, and improve the ability of rainwater to reach the aquifer underneath.
The new food and farm bill can help farmers adopt practices that build healthy soil
Federal farm policies implemented by the US Department of Agriculture have played a major role in creating and maintaining the status quo of modern industrial agriculture, dominated by growing a single commodity crop (mostly for animal feed) with heavy inputs of fertilizers and pesticides. This system provides little to no flexibility for producers to diversify their land using ecological principles that have positive environmental effects, which leaves today’s farms particularly vulnerable to the consequences of climate whiplash.
However, the upcoming food and farm bill is an opportunity to push for more climate-resilient policies that can benefit farmers and create healthier soils. Some policy solutions that UCS is advocating for inclusion in the bill include funding for a suite of conservation programs and for agricultural research on the benefits of incorporating perennial crops and other soil management practices. Marker bills including the Agriculture Resilience Act focus on all these priorities. I encourage you to reach out to your member of Congress and ask them to pass a food and farm bill that’s a win for farmers, farmworkers, the environment, and our overall food and farming system.
Originally published in Union of Concerned Scientists.
