Navigating Groundwater-Surface Water Interactions under the Sustainable Groundwater Management Act

Addressing SGMA’s requirements for groundwater-surface water interactions will be difficult. Defining the issues at stake in any given basin, let alone successfully balancing the range of uncertainties and potentially conflicting interests, will pose challenges for many GSAs. No clear, pre-defined line exists to guide GSAs in determining what significant and unreasonable depletions of interconnected surface water will be, or whether their planned actions will sufficiently avoid them. Yet they are required to do so. Many GSAs will face pressure to aggressively address impacts on surface water in their basin. Many will face equal or greater pressure to draw the line more loosely. Nevertheless, it will fall to the GSAs to make a determination, and to defend it in their groundwater sustainability plans. Therefore, GSAs will likely take on some level of risk—either of successful legal challenges to their Groundwater Sustainability Plan (GSP), or of successful political opposition to the GSP, or of the GSP performing ineffectively, or of all these outcomes. Given the aggressive timeline inherent to SGMA, addressing this risk early will be crucial for preserving management options.

Challenges and risk are not the whole story, however. The process of addressing groundwater-surface water interactions also offers GSAs an opportunity to help communities and other stakeholders resolve, or avoid, difficult conflicts, and to do so in lasting ways. While California law has only recently begun to seriously address conflicts between surface and groundwater uses, those conflicts have been occurring for decades, and in some places for over a century. SGMA, in other words, did not create conflict between groundwater pumping and beneficial uses of surface water; it just created an opportunity—as well as an obligation—to respond to those challenges. Embracing that opportunity will not be easy, but GSAs that take SGMA as an opportunity to resolve longstanding issues can do lasting good.

The research presented here examines some of the legal and institutional questions that will inevitably arise as GSAs seek to address groundwater-surface water interactions under SGMA. The core goal of this report is to help parties identify and address these questions, and ultimately to let GSAs and stakeholders manage groundwater-surface water interactions proactively and effectively.