The State of the Valley Report identifies water as “one of the central management challenges of the San Joaquin Valley,” and emphasizes that “[b]oth surface water and water pumped from underground aquifers are critical to the region’s farming, ranching, urban users, industry, and natural ecosystems.” Implementation of the Sustainable Groundwater Management Act (SGMA) is just beginning, but the overall dialogue about water sustainability has focused more on technological solutions than on ways to improve the natural ability of watersheds to absorb, store and gradually release water in forms useful to people and the land. Sequoia Riverlands Trust’s (SRT’s) San Joaquin Valley Greenprint Demonstration Project explores the potential contribution of land-based strategies to watershed effectiveness, usable water supply and groundwater sustainability, focusing on three themes:
- Soil Enhancement and Water Resources;
- Floodwater Threats and Opportunities; and
- Mineral and Water Resources.
These approaches are not new. Many have been extensively researched, incorporated into funding programs and regulatory requirements, and applied to varying degrees.However, relatively little attention has been paid to the relationship of these land-based strategies to effective watershed function and groundwater sustainability. Sequoia Riverlands Trust applied existing Greenprint data and other information to map areas where these approaches might yield the greatest water-related benefits, and to roughly quantify their potential contribution to groundwater sustainability in the Kaweah and Tule River Watersheds.
Our results suggest that practical applications of these strategies could offset at least 25% of the annual groundwater deficit in the Kaweah and Tule River Watersheds by addressing both the supply and demand sides of the water balance equation. This assertion is based on estimates that:
- Soil organic matter-enhancing land management practices have the potential to increase the effective capture of precipitation by at least 14,500 AF, both reducing the need for supplemental irrigation and increasing the amount of water available for recharge;
- On-farm flooding and recharge could reduce annual groundwater overdrafts by up to 20% based on studies of similar groundwater basins in other parts of the Southern San Joaquin Valley; and
- Projects that restore at least some natural function to modified floodplains (e.g., at reclaimed alluvial mines, streamside areas of farms and ranches, or sites like SRT’s Kaweah Oaks Preserve) could make a measurable contribution to groundwater recharge by slowing floodwaters down and providing larger areas for infiltration.
Furthermore, all of these land-based strategies provide additional ecological, economic and community benefits, such as increased agricultural production, flood management, habitat enhancement, drought resilience and aesthetic values, that make them politically palatable alternatives to new dams or regulations about water use. Water-focusedland conservation, restoration and management strategies therefore deserve serious consideration as we work together to solve our region’s pressing groundwater sustainability concerns.
Thorne et al., 2014.
 Cal. Water Code § 10720 et seq.
Please view the project PowerPoint presentation HERE.