Implementing the state’s Sustainable Groundwater Management Act—which requires overdrafted groundwater basins to achieve balance between supply and demand by the 2040s—could require taking at least 500,000 acres of irrigated cropland out of production in the San Joaquin Valley. While some lands will be converted to uses such as solar energy, groundwater recharge, and restored habitat, there are no current plans for most of this acreage. We talked to Soapy Mulholland, president and CEO of Sequoia Riverlands Trust, about this impending challenge.
PPIC: What key challenges does this land use transition pose?
Soapy Mulholland: The challenges of managing this amount of land if it’s fallowed piecemeal―5 acres here, 30 there—are huge. A hodgepodge of retired lands would be very difficult to manage and restore.
When farmland is left bare it can cause dust and weed problems, so it will need cover crops. Finding the right cover crops that don’t use a lot of water is likely to be expensive. Grazing can help keep weeds down, but that requires fencing and most of the valley’s farms aren’t fenced.
PPIC: What are some top priorities for ensuring these lands are well managed?
SM: What we need is a vision for how to retire large blocks of land. That will require a “banking” system that pays farmers for retiring land and allows other farmers to purchase credits for a portion of the retired lands’ water, which they can then use on their own lands.
Let’s say you are a highly productive walnut farmer. You don’t want to fallow any of your 100 acres, so you would prefer to purchase a block of unproductive land to get water credits and keep your farm going. It’s a form of water trading. We need to figure out systems for how best to do that.
The idea is to buy farmland with low productivity, retire it, and link it to existing natural habitats. This could extend wildlife corridors from other parts of the region and allow for landscape-scale conservation on the valley floor. For example, there is a lot of potential to do this with less-productive lands at the edge of Tulare Lake Basin—we could conceivably get blocks of land 30,000 to 40,000 acres in size there.
We’ll need an organization or agency that can buy up retired lands—and systems in place to help manage them. We’ll also need a broad coalition of expertise, for example, appraisers and bankers to keep track of credits, and land managers with expertise in open space. We’ll need sophisticated systems that address all the different rules and regulations in California, and that connect all the various stakeholders and agencies that will be involved. And we’ll need funding—both for planning and for the systems themselves.
PPIC: Are there good examples of ways to use the idled lands?
SM: The establishment of solar plants in the Carrizo Plain area in eastern San Luis Obispo County is a good example. The solar companies had to figure out how to mitigate for impacts to habitat and agricultural land. They ultimately purchased more than 30,000 acres of rangeland and dry farmland, and entrusted future management to state agencies or land trusts (including our organization). Using grazing and other management techniques, these lands are now being restored, and even the areas under solar arrays are being managed to benefit at-risk species like the San Joaquin kit fox. Connecting these lands with the nearby Carrizo Plain National Monument offers even greater opportunities to multiply the benefits that each protected area provides on its own. It’s a good example of how to manage large parcels for multiple uses: habitat, agriculture, and renewable energy.
We need more pilot projects to set examples and figure out how best to do this. In the San Joaquin Valley, projects could focus on converting large parcels of retired farmland to semi-irrigated pasture or native grassland, with management in the hands of experienced land trusts. This approach could have benefits ranging from carbon sequestration and natural groundwater recharge to improved air quality and habitat for threatened and endangered species. As in Carrizo, landscape-scale conservation could produce much better outcomes than disconnected projects.
Bringing our region’s groundwater use in line with sustainable supplies will require significant changes in land use, agriculture, and water markets. Figuring out the right answers is likely to push all of us―farmers and ranchers, urban dwellers and conservationists alike―out of our comfort zones. But a coordinated approach to farmland retirement offers opportunities for landscape-scale conservation that can benefit people and nature.