The buzzword “deficit” is far from limited to federal debt when it comes to the world of water, whether the wet stuff goes into crops or out of the faucets in homes.
And parallels to banking abound as municipalities and individual farming operations save up for a dry day, not a rainy one.
The subjects of banking water and overdrawing water savings came up frequently in a water technology conference in Clovis, Calif., presented by the International Center for Water Technology at California State University, Fresno.
Coming out of a relatively dry winter and perennially challenged to find water, representatives of the neighboring cities of Clovis and Fresno opened the program with talk of steps they are taking — including water banking and recycling water.
Near the end of the program, an Oregon farmer discussed how he banks winter water and uses recycled water to supplement rainfall every bit as sparse as what falls in California’s central San Joaquin Valley.
“We’ve overdrafted the water bank,” said Martin Querin, assistant director of public utilities for the City of Fresno.
Querin said Fresno has “a large and resilient aquifer that has been both a blessing and a curse.” Sitting between two rivers, the San Joaquin and Kings, and below the snowpack of the Sierra Nevada mountain range, the city’s residents for decades have been permitted to draw water without metering until recently. That is changing, and 110,000 meters will be installed starting Jan. 1.
Querin said the city’s water sources include 1,300 acres of recharge basins.
Lacking a good Fresno-like aquifer, neighboring Clovis uses recycled water and has two ground water banks that add to its liquid arsenal, said Michael Leonardo, public utilities director for the City of Clovis.
Clovis has partnered with the Fresno Irrigation District on banking facilities, and Leonardo said they are important for “drought backup.”
“Do they work?” he asked. “From the physical aspect, they work. Are they cost efficient? Surface water is about $30 per acre feet. Banked water is about $150 per acre feet, but to acquire that water in a dry year on the open market would be much more. Without groundwater banks, we would not have a drought supply.”
Gary Serrato, general manager of the Fresno Irrigation District, explained how the district evolved from pushing water through canals “to wheat fields” and moved into banking and ponding basins.
He said a 30-year-old study showed where best to locate groundwater banking, but said it was not an easy sale for farmers connected to the district.
“I’m a farmer myself, and when you get into a roomful of farmers and set out to do something different, they may have a rope,” he quipped. “We had to approach it gingerly and carefully.”
One strategy he used was to put those who were most outspoken in opposition on a groundwater banking committee.
Serrato said the banking has not only boosted water quantity, but quality as well. A system of monitoring wells helps assure that.
Aquifer storage and recovery
In a separate presentation, third-generation Oregon farmer Kent Madison described his system for aquifer storage and recovery, storing water from winter flood flows. Madison said he farms in northeast Oregon where annual rainfall on average is below 9 inches.
He uses an existing infrastructure including drain tiles and a 700-foot well to store water, and also gets water from the Lamb-Weston potato processing plant in Hermiston, water that also contains nitrogen that is used to fertilize crops. Madison Farms takes the facility’s treated water year round.
“We deliberately built an irrigation system based off of deficit irrigation to deliberately under-irrigate ag crops for optimum economic benefit, not for yield benefit,” Madison said.
Madison Farms produces a wide variety of vegetables, grass seeds, and canola for biodiesel.
Finding groundwater in the first place poses its own challenges, said Dennis Williams, president of Geoscience Support Service Inc. in La Verne, Calif. He opened his talk on “Prospecting for Groundwater” with the admonition “water witching doesn’t work,” saying that water dousers have poor track records.
Instead he recommended a much more scientific approach, “a need to understand the geology and hydrology and fundamental principles of groundwater flow.” Tools include global positioning systems and geographical information systems, geologic mapping, aerial photos and test wells.
And there’s another more commonsense step, he said: “Talk with farmers and with agencies that may have knowledge. Get records; find out if there are existing wells, abandoned wells, any wells drilled. Understand the rocks.”
The threat of contaminated drinking water posed by nitrates was a topic for one panel that included University of California hydrologist Thomas Harter, who headed a study on the subject released in March.
Later this year, the state will issue rules for controlling salts, nitrates and other contaminants in underground water. Panelist Parry Klassen, a grower and executive director of the East San Joaquin Water Quality Coalition, said he believes farmers are being efficient with fertilizer but “just don’t have the data to show it.” He recommends paperwork that would show nitrogen demand from a crop and how much is supplied.
Other preventative steps, Klassen said, could include testing well water for nitrogen levels, leaf tissue testing, ensuring the integrity of wellhead casings, preventing collection of runoff around the wellhead through grading and diversion and installing backflow preventers for use when fertigating.
At one of the breakout sessions later in the day, Fatemah Shirazi, founder and president of Microvi Biotech Inc. in Union City, Calif., talked briefly about a biotechnology approach, using natural organisms and biocatalysts, to degrade nitrates and other pollutants in water without leaving a waste stream.
Microvi targets industrial and municipal waste water as well as surface water, ground water and water in the oil and gas industry.
In other presentations:
• David Zoldoske, director of the Center for Irrigation Technology, took issue with a Pacific Institute report that between 4.5 and 6 million acre feet of water could be saved in irrigated agriculture.
He and other researchers released a report stating water conservation alone would not free up large amounts of water for other uses. He said the study did not take into account that water is reused if there is deep irrigation or runoff: “The water goes someplace.”
Groundwater overdraft of about 2 million acre feet per year continues to be a problem, Zoldoske said. “Instead of the groundwater rising, the opposite is happening,” he said.
Switching from flood irrigation to drip reroutes water within a region but does not create new water outside the basin, Zoldoske said.
• Tim Quinn, executive director of the Association of California Water Agencies, said the concept of “coequal goals” for water use is costly as efforts are made to improve water supplies while restoring ecosystems.
Despite shunning of surface water storage, he said, there have been success stories in the past 15 years as new water supplies totaling 2 million acre feet — more than the current yield of the State Water Project — have been created. He said some $6 billion has been spent, mostly by local agencies.
• Eduardo Currea, sales manager for the U.S. and Mexico with Rain Bird, talked of the use of water for overhead frost protection in vineyards.
Currea said ice encasement serves as a heat source. He said it is important to determine the capacity of water needed. Running out of water and ceasing application early can compound problems, he said. And starting the systems too late can also be a problem.
Currea said it is vital that sprinkling systems be aligned so that water is falling on the vines. He said it may be necessary to have workers in raincoats check on that alignment.
• Andy Smith, an accounts manager with Reinke Mechanized Irrigation Systems in Boyne, City, Mich., talked of mechanized irrigation with pivots and diversity they offer.
He said systems can deliver water above the canopy, in the canopy and at ground level. He said they can be used for chemigation and fertigation and for “regenerative water use,” for example applying “dirty water” from dairies to forage crops.
For municipalities, they can be used to apply treated effluent.
“But it’s not ‘set it and forget it,’” he said, citing an example of the need to clean pig hair out of a filter.