For the first time in the 54-year history of the State Water Project, the Department of Water Resources forecast in late January 2014 that there would be zero water deliveries to the 25 million people and 1 million acres of farmland that typically rely on its services. It was a move that clearly demonstrated the dire nature of our current California drought, which has left many wondering how farmers in the Central Valley will respond. Many farmers in the region are used to dealing with drought in California; yet, the extreme nature of this year’s drought certainly presents new challenges for California’s $45 billion agricultural industry.
Using Data to Understand How Will Farmers Respond
How will farmers cope? This is the theme of numerous media reports in early 2014 both locally and nationally. Rather than speculate, The Center for Environmental Policy and Behavior is using data to examine the issue. In 2011, UC Davis researchers conducted a survey to understand farmers’ perspectives on climate change and their potential responses to water scarcity and extreme events. More than 160 farmers in Yolo County responded to the survey. While not representative of the whole Central Valley, its gives some insight into how farmers may adopt different water coping mechanisms in a dry year.
“If there’s no surface water available, then that dictates that well water is the only thing available so that’s a major factor.” – Yolo County Farmer
Farmers Shift to Groundwater in Dry Years
Overall, we found that water resources shifted based on normal versus dry years (Table 1). In a normal year 51% of farmers use only or mostly surface water. Simultaneously, about 41% use only or mostly groundwater. The remainder use equal amounts of surface and groundwater or are entirely dryland operations. But, clear shifts happen in dry years – farmers using mostly surface water in a dry year drops to 35% from 51%, while farmers using mostly groundwater increases to nearly 54% from 41%.
Table 1.Yolo County Farmers Water Sources in Varying Conditions (Total number of respondents in parentheses)
SurfaceMost surface some ground
Surface & ground equal
Most ground some surface
Adopting New Strategies
The survey asked a very relevant question for the current drought- “If the future climate in Yolo County resulted in more severe droughts or decrease in water availability, what is the likelihood that you would use the following management strategies, above and beyond what you currently use in a normal rainfall year?” The Figure below shows the responses for this question among farmers who considered the practice applicable to their farm. We found that nearly three-fourths said they were likely to pump more groundwater, while 63% were likely to use drip or micro-sprinkler irrigation. Fifty-eight percent said they would be likely to concentrate surface water on a smaller percentage of acreage and 53% would likely use drought tolerant varieties of crops they already grow.
But what about farmers who rely on different water sources? Will farmers relying on mostly surface water, who will likely receive a lower allocation this year, respond differently than farmers who rely mostly on groundwater resources? Our data suggests yes. Table 2 shows the average likely adoption (on a scale of 1-5, with 5 being very likely and 1 being very unlikely) of drought adaptation practices based on water source in a wet and dry year. Many farmers use the same type of water in both normal and dry years; however, farmers who shift towards more groundwater are more likely on average to adopt different practices. Not surprisingly, they are more likely than other farmers to allocate less surface water on their acreage (and likely even fallow some land) and to pump more groundwater. However, they are also more likely to drill more wells or seek alternative water sources as well as implement conservation measures including drip or micro-sprinkler irrigation or using less water intensive crops. The results also suggest that farmers using only surface water are less likely to adopt drip or micro-sprinkler irrigation, while farmers using only groundwater are less likely to use drought tolerant varieties.
“In years when we know water’s gonna be scarce we definitely like to talk about which crops can be sold for more per acre because that is how we can judge water efficiency” – Yolo County Farmer
In short, farmers will use groundwater as a first line of defense in a dry year and then consider conservation practices. Farmers who shift to groundwater in dry years are also the farmers most likely to adopt other kinds of water scarcity and drought adaptation practices. This suggests that in these tough times farmers are looking to adopt new practices to help them cope with the extreme drought. With little or no surface allocations expected this year from the State Water Project, we can expect that farmers who rely on some type of surface water will shift to groundwater if possible, seek out new water sources, and also shift to conservation measures like drip irrigation. Simultaneously, a shift towards more groundwater pumping could potentially deplete groundwater resources if the drought is extensive and prolonged. The data also suggests a continued role for university and industry research as well as Cooperative Extension to develop varieties that are able to withstand droughts and are less water intensive overall.
Table 2. Farmer’Average Likely Adoption of Drought Adaptation Strategies Based on Water Sources
(1=Very Unlikely, 5=Very Likely).
|Only Mostly Surface, Some Ground
|Mostly Ground, Some Surface
|Shift to Ground
|Allocate surface water to fewer acres
Pump more ground water
More wells or alternative sources
Adopt drip or micro-sprinkler
Drought tolerant verity of same crop
Change to less water intensive crop
Do fewer cuts of hay/alfalfa
Move livestock to irrigated pasture
Reduce livestock stocking rates
* Using a one way anova test to compare each group of farmers on average with all other farmers using alternative water sources. Farmers in the “Shift to Groundwater” category move towards increased groundwater from any other category. Significant level *p.