A local water district is developing a novel, market-based groundwater trading program that, if successful, could be expanded or copied to help Central Valley farmers cope with new state restrictions against over-pumping the region's aquifers.
The Rosedale-Rio Bravo Water Storage District's pilot program, set for testing later this summer or early fall, would allow certain landowners to buy or sell groundwater to or from another property owner within the district.
Water trading is not entirely new to California, and similar projects exist in other states. But the district's model appears to be the first such program being designed specifically to meet Central Valley agriculture's need to make groundwater use sustainable over the long term, as required under 2014's Sustainable Groundwater Management Act.
A report produced in part by The Environmental Defense Fund, which plans to work with Rosedale-Rio Bravo and Idaho consulting firm WestWater Research to administer the program, lauds water trading as a promising strategy for helping farmers smoothly and effectively reallocate water toward high-value uses.
"Appropriately constructed," the report states, "groundwater trading offers enormous potential to encourage and reward groundwater conservation."
Rosedale-Rio Bravo General Manager Eric Averett likened the system to a checking account. Farmer members of the district would receive a periodic groundwater allocation, as called for under SGMA. Their account would then be credited or debited, depending whether they bought or sold groundwater within the district.
The idea is that SGMA provides a base and water trading allows adjustments.
"SGMA is a requirement that we balance our checkbooks, and the (water-trading) market basically, you know, gives people who have perhaps been writing too many checks the ability to purchase water from those who have not been writing as many," Averett said.
Some growers might choose to fallow their land for a year in order to sell their allotted groundwater to another farmer, though both parties would still have to pay their district assessment fee regardless, he said.
Restrictions would apply. Only farmers would be eligible to trade water under the program, not commercial or residential property owners. Also, traders would have to have more than 10 acres within the district.
Other limitations may also be introduced, Averett said, such as rules on how much water total may be moved from one part of the district to another. The 44,000-acre district is mostly located north of Rosedale Highway west of Allen Road; all but 9,000 acres are used for agriculture.
Averett doesn't anticipate very large amounts of water changing hands under the pilot program. He said individual trades will likely measure in the thousands of acre-feet but not the tens of thousands. Trades would not require approval under the system, he added.
(One acre-foot is enough water to cover an acre of land one foot deep.)
State water officials were unavailable to comment on the project.
Rosedale-Rio Bravo has hired a third party software developer to create the project's trading platform and base it on assessor parcel numbers, which are unique identifiers tied to real estate records. The program may be created in such a way that trades are carried out anonymously on both sides of the transaction.
Written materials provided by Averett state each eligible district member might receive an annual allocation of 3.13 acre-feet that can then be traded.
Averett said other water districts around the Central Valley are looking at the idea, with an eye toward possibly replicating it elsewhere. That's partly why the underlying software is being written in open-source computer coding, so it can be shared and adjusted.
The water district's request for proposals to develop the program's software states expansion of the program is a desired goal, and the platform "should be constructed such that additional geographies with differing water trading rules and accounting can be added as needed."