Sustainable Groundwater Management Act
By David Eddy, Editor, American Fruit Grower
The atmospheric rivers that flowed over California in January dumped about a foot of rain — equal to an entire year’s average — in many parts of the state’s parched Central Valley, which encompasses only 1% of U.S. farmland but produces 40% of the nation’s table fruits, vegetables, and nuts.
With February, ordinarily the second wettest month, still to be counted, talks of all the land that will have to fallowed as a result of the drought have quieted for now. But most Golden State growers have come to realize that droughts will simply be a part of farming going forward, and the safety net is gone.
That safety net was groundwater pumping. For more than a half-century, farmers in the Central Valley, the multi-faceted state’s chief production area, have been pumping more water from aquifers than can be replenished, causing wells to be drilled deeper and deeper. Don Cameron, Vice President/General Manager of Terranova Ranch in Helm, CA, notes that when he started farming in 1981, the attitude at that time was growers just pumped what their crops needed.
“Back then, we used 75- and 100-horsepower wells to get the volume of water we needed,” he says. “Today, we run 200- to 250-horsepower motors to get the same amount of water out of the ground. And we’ve had wells go dry over the last 10 to 15 years.”
Over drafting the aquifers is a problem, and not just because it means the loss of a source of water that can be applied during a drought, but it can lead to subsidence. With no water below, there’s nothing there to hold the land in place. There are parts of Fresno County that have dropped 30 feet or more through years of unfettered pumping.
The situation got so bad during a drought last decade — the one before the current drought, which hopefully will end with winter rains — that in 2014 the state passed the Sustainable Groundwater Management Act (SGMA), which Californians refer to as “sigma.” SGMA requires local agencies to form groundwater sustainability agencies (GSAs) for the high- and medium-priority basins. GSAs develop and implement groundwater sustainability plans (GSPs) to avoid undesirable results and mitigate overdraft within 20 years. The GSAs have until 2040 to reach sustainable levels, though a few submitted GSA plans have already been rejected by the state.
SGMA will mean fewer irrigated farmed acres in the Central Valley. Larger growers can afford to buy land elsewhere that has water rights which means there will be fewer smaller growers. There will be less crop diversity in the Central Valley as growers will farm only the most profitable crops; they can’t afford to grow anything else.
For example, Almond Board of California President Richard Waycott says the future of the almond industry is inextricably tied to SGMA. California required the state’s Groundwater Management Areas (GMAs) to submit sustainability plans this year. However, several GMAs have found their respective regions have sustainable yields that are too low to provide adequate amounts for farming — largely because they simply don’t have enough access to water.
“California ag is all about the SGMA story — how much land will be fallowed when,” he says. “What will be grown on that [remaining] acreage? It remains to be seen what crops will be favored.”
Waycott is confident because the almond industry has flourished in recent decades, although there will certainly be a slower growth rate from now until the end of this decade.
“But as long as almonds continue to be a crop of choice,” he says, “you’ll continue to see them planted wherever water is available.”
Demonstrating the gravity of the situation, more than 400 Californians attended an event last May titled “Save Our Communities” in the San Joaquin Valley town of Visalia to discuss the impending impacts of SGMA to the communities in the valley. A total of 53 organizations co-hosted the event, including the California Fresh Fruit Association, American Pistachio Growers, and the Western Agricultural Processors Association, whose President/CEO, Roger Isom, gave the opening remarks at the event, stating, “The time to act is now.”
How did the problem get so bad? Isom noted that in the same year SGMA was passed, 2014, the state passed a multi-billion-dollar water bond act. Many agricultural groups helped successfully campaign for the bond act, thinking it would fund new water storage, such as reservoir construction, as well as such actions as groundwater recharge projects, injecting flood waters into underground aquifers that have been depleted.
Only one significant water storage project has emerged as a result of the bond act, Isom says. The Sites Reservoir is a proposed $5.2 billion off-stream reservoir project west of Colusa in the Sacramento Valley that will capture excess water in wet years, but California hasn’t seen many of those in recent times. However, the project won’t break ground until 2024 and won’t have any significant storage until about 2039, or a full 60 years since the last new significant water storage facility was built in California, the New Melones Reservoir near Modesto.
Pouring salt in their wounds, bankers attending the Visalia meeting told the growers in attendance if they can’t show access to enough water to produce a crop, they won’t get the necessary loans.
Growers clearly need solutions, which means many will be looking to technology. However, Cameron, who farms grapes and nuts in addition to a wide range of vegetables, is showing the technology need not be new. He is employing water banking to help capture winter run-off by diverting excess river water into fallow fields or pastures to enhance groundwater recharge.
By adding strategic improvements on farms such as catchment basins, optimizing drainage ditches by widening them, and installing weirs and vegetation, a greater portion of rainfall can be infiltrated on site to recharge underlying aquifers. Farmers also can help conserve groundwater by irrigating with water recycled from urban areas instead of pumping from wells.
“We’re also putting up a berm or small levy around our fields to help hold the water in,” Cameron says. “And we’re creating little dams around the field, so we can hold more water when it comes. That allows us to then put it on the fields and recharge the groundwater.”
The state’s growers will face increasing pressure to justify their water usage, and depending on their location, could face tough restrictions. Irrigation suppliers are, of course, very familiar with the law, and they say there are high-tech answers to growers’ problems. Many of them started by noting that growers should not wait until the next serious drought hits; the time to act is now.
“There is an old adage: ‘You can’t manage what you don’t measure,’” says Neil Schultz, General Manager of Altrac, an agriculture automation software company. He notes that prior to 2014, when SGMA was passed, most of California’s agricultural water use was off record. Irrigators were not required to measure, much less report, how much water they pumped from the ground. That has now obviously changed, and GSAs have issued their recommendations on the “safe yield” per acre-feet of well water available for each grower.
Using technology to collect accurate usage data will be critical, he says. “There are estimates that 20% of farmland will go fallow while growers optimize their groundwater usage. Eventually water banking systems will develop to provide credits to growers who consume less than their safe yield allotments.”
Monitoring soil moisture levels is absolutely critical, agrees Davis Instruments Senior Marketing Manager Doug Analla, as it allows growers to build health when water is available, then cut back to, but not beyond, lower levels of irrigation needed for fruit growth. Davis weather stations allow them to monitor evapotranspiration (ET), and thus replenishment, and rain received on site. However, he notes growers don’t have to install an entire, costly new system, they can put it together piece by piece.
“Start with a … weather station for ET, frost, and effective weather monitoring, for a low startup cost,” he says. “Then expand to soil moisture monitoring, then irrigation monitoring, and beyond as budget permits.”
Growers will certainly need to keep close tabs on their water supply, and not just for the obvious reasons, says Curtis Lutje, General Manager of Laurel Ag & Water.
“Play ball with your district if you can help distribute water during wet years and be as efficient as you can during dry years,” he says. “The best metric of success may start to be crop per drop, not total yield.”
By taking these steps, growers can help set a precedent for regulatory agencies, says Semios Technical Support Specialist Ben Smith. By using better irrigation monitoring and control measures — and properly documenting these practices — growers are better able to defend their actions and maintain their rights to irrigate according to the needs of their crop.
“Don’t wait until the next drought to figure out how to irrigate better; it takes experimentation and improvement to get your practices right,” he says. “You will want to know how to accomplish your goals before the difficulty of a drought or regulations direct your actions.”
Knowing their goals and acting on them is indeed critical for growers, says John Rowley, Nelson Irrigation Rotator Product Manager. But make no mistake, it will take some research to figure out what infrastructure will be necessary. He suggests that each of the following be considered:
Hydraulic valves with solenoids for automation and with pressure controls
Wireless automation of the control valves with pressure and flow monitors
Replacing and upgrading micro-sprinklers that don’t flow-regulate, that no longer flow-regulate accurately, or that don’t flow-regulate at low pressure.
Testing and then replacing drip hose that no longer flow-regulates accurately.
Improving filtration systems in which high amounts of labor are used to unplug emission devices.
But no matter what steps growers take, they’ve got to get moving. “Start preparing for water shortages now,” he concludes.
Jonathan Walters, a wine grape grower in Northern California, farms 500 acres at elevations from 1,800 to above 3,000 feet above scenic Clear Lake, the state’s largest natural lake. With those vast elevation changes, Walters, the General Manager of Brassfield Estate Winery, farms on steep slopes. Complicating matters, he grows a total of 18 varieties with wide variability in the soils.
The steep slopes mean the variation in the vines’ irrigation needs varies widely. It’s not unusual at all for the vines at the top of a given block to need three times as much water as the vines at the bottom of a block, such as in the pictured example from the “Ridgeline Center” guide.
Winters tackles the needed variation with a sophisticated Netafim system with a controller and solenoid valves in the field. The system allows Winters to not only precisely control the amount of water applied, at the same time he’s mixing in various inputs, or “micro-dosing the vines,” as he puts it.
It requires a lot of water to be available at all times, so Winters has two huge tanks that are constantly being filled from a 100-acre-foot reservoir Brassfield installed which is nearly a mile away. The extensive system means they have a total of 20 miles of pipe in the ground.
The system is sophisticated, with valves turning on and off automatically as required. The system is so efficient that if an emitter falls off, it can compensate for the lost pressure. Some would say it’s an excellent example of precision agriculture, though Winters has a slightly different spin.
“It’s precision, and it’s efficiency,” he says. “To me, to be precise, you have to be efficient.”
