Maximizing crop per drop for California farmers
Why is the agriculture industry watching Central California so closely? The region is one of the nation’s toughest spots to thrive for farmers and irrigation districts. Water is growing scarce, increasing regulations pose new challenges, and farmers constantly find themselves with different needs from their local water districts. One local agency, the Manteca, Calif.-based South San Joaquin Irrigation District (SSJID), is working with a group of growers to beat the industry odds and conserve resources while growing profits.
Surviving in the Wild West
SSJID endures the same challenges faced by many similar California agencies, including:
Water Scarcity: 80 percent of California’s water demand comes from agriculture.
Water Rights: Irrigation districts and their customers are in constant defense of their water diversion rights to supply water for other beneficial uses, including increased stream flows for aquatic life.
Groundwater Quantity: Laying claim and keeping ownership of access to groundwater is a battle for California farmers. Three recent state bills place higher scrutiny and additional monitoring on heavily used groundwater basins. If state agencies deem there is excessive use, they can deny permission for farmers to use independent pumps.
Groundwater Quality: Saltwater creeping in from the nearby San Joaquin Delta can reduce farm yield and cause yellowing of trees. Further complicating matters, traditional flood irrigation techniques often result in nitrates from fertilizer being washed into the groundwater.
Volumetric Pricing: California’s 2009 Water Conservation Act introduced a mandate to reduce per capita urban consumption by 20 percent by 2020, with an additional clause requiring agricultural water suppliers to implement efficient water management practices. The mandate includes the requirement that irrigation districts take actions to measure, report and bill customers for the delivery of actual volumes of water. Pricing structures must be based (at least in part) on the quantity of water delivered, posing a challenge for districts to invest in, and implement, metering technology.
New regulations and new farming needs have required the district to look at irrigation infrastructure in a different way, and balancing water delivery flows for growers who use traditional flood irrigation and those who have converted to drip or sprinkler systems has proved a challenge.
”For over 100 years, our growers relied on our gravity-based irrigation system,” says Jeff Shields, SSJID’s general manager. “However, as farming practices changed and the demand for surface water grew, our board recognized the need to make strategic decisions about how we could better service our customers with less water, but producing more crop. Our research led us to the concept of a closed, pressurized system which we implemented in one of our most challenging divisions.”
Seeds of success
In 2010, The SSJID board tapped Sacramento-based engineers from Stantec to work with district staff on a water enhancement project to address these concerns. The result was a new system: irrigation water originating from the Stanislaus River is distributed to customers across 3,800 acres of SSJID’s Ripon, Calif., territory using 19 miles of pressurized pipelines.
Using an online system similar to an airline ticketing platform, system growers now log in to schedule water deliveries using current and past weather forecasts, previous water usage information and historical evapotranspiration rates. Each farmer selects from available delivery dates and later receives alerts via email and text message before and after delivery to confirm volume and flow rate data. Also supporting the system, moisture sensors placed in the ground on each grower’s property help indicate optimal ordering times when almond and walnut trees are at their greatest need. After providing each parcel with water through 76 solar-powered customer connections including valves and meters, delivery information is recorded on a dedicated, secure website for both the district and the growers.
The project successfully reduces water applied by 30 percent and increases crop yield by 30 percent. By allowing the farmers to schedule precise, automated deliveries only when they’re most needed, the district has seen other benefits:
Spill Savvy: The system reduces spills by 10,000 acre-feet and overall conserves 12,000 acre-feet of water per year (the equivalent of 76,800 people’s water use).
Environmental Quality: The project has cleared 500 acres from groundwater pumping and reduced nitrate contamination. The pressurized system also helps farmers save on fuel and improve air quality by no longer running diesel-fueled pumps. In 2014, the International Commission on Irrigation and Drainage presented its WatSave Technology Award to the SSJID engineering team for efficient, water-conscious farming.
“We know there’s an uncertain future with water resources, so a certain level of innovation and unconventional thinking was needed from both our agency and our customers,” says Shields. “We’ve been through the learning curve and hope we can offer our experience to help others.”