When an irrigation canal was breached in the early 1900s, the resulting flood created Southern California’s Salton Sea. It was a rare event that quickly created a beneficial presence in the Imperial Valley, as the lake provided recreation opportunities, tamped down dust, and became a stopover for birds on the Pacific Flyway. But now, with inflows declining, this hundred-year-old sea is drying up, and that’s having a host of negative consequences for wildlife and air quality in the region. We spoke with Kurt Schwabe—professor of public policy at the University of California, Riverside and adjunct fellow at the PPIC Water Policy Center—about some of the biggest issues facing the sea, as well as potential solutions.

What are the big issues in the Salton Sea, and why has it taken so long to take action?

The first problem is that it’s a terminal lake whose inflows are primarily composed of agricultural drainage flows from the Imperial Irrigation District (IID) (around 80%) and wastewater from Mexico (around 10%). This set-up leads to an increasingly polluted sea; as this chemical-laden water evaporates, it leaves behind salts and other pollutants such as metals, fertilizers, and pesticides.

The second problem is that the agricultural drainage flows that have contributed to maintaining the sea’s volume for most of the 20th century are considered to be the result of wasteful and unreasonable water use. This legal opinion opened up the doors for water transfers to southern California municipal water agencies from IID, including the large transfers under the Quantitative Settlement Agreement (QSA) of 2003, which helped California meet the federal government’s mandate to reduce its Colorado River allocations to its legally allocated annual amount of 4.4 million acre-feet.

The transfers of water from IID to cities is made possible by land fallowing and improvements in irrigation efficiency; both practices lessen runoff and, consequently, inflows to the sea. As the sea shrinks, winds pick up sediments from the increasingly exposed dry lake bed and spread them into surrounding communities, which are mostly low-income, making asthma and other respiratory diseases worse. The smaller lake is also more polluted and saline, which reduces habitat for fish and birds.

It’s been almost two decades since the state said it would take on liability to address these issues as part of the QSA deal. It’s been underperforming in its short-term responses and wrestling with what would constitute a long-term sustainable solution.

What, in your view, are the most feasible ways to address this problem?

Early plans focused on protecting the Salton Sea’s vibrant, productive ecosystem: they looked at engineering solutions to keep the sea water fresh enough with a smaller footprint. Perceptions then were that the plans were pretty expensive—$5 billion over 75 years. And initially human health wasn’t a focus; good engagement with the local population would have made that priority number one.

Recently an expert panel formed to look at a long-term solution involving importing water from the Sea of Cortez and to make a recommendation to the California Natural Resource Agency (CNRA) on the merits and flaws of such an approach. The expert panel found it wasn’t viable: the import option was extremely expensive and posed risks of environmental harm, and it wasn’t clear what benefits Mexico might receive to incentivize such cooperation. Finally, the process of drafting treaties and building infrastructure would likely take more than a decade or two, a long time given the current and likely worsening impacts on health and habitat.

The expert panel also evaluated another option: combining voluntary water transfers from IID—something like what our research explored in 2018—with the development of a large desalination plant on the Salton Sea’s shore. This option would help address both quantity and quality—at least with respect to salinity—although the sea would still be much smaller than in the past, and require additional mitigation to manage dust.

Are there signs of hope?

The state has been rightly criticized for not making much progress and not engaging much with local communities during the first decade or so this process. More recently, the state—with new leadership and positions at the CNRA—has upped its game. It’s engaging with frontline communities and making investments in the sea and its communities. Of course, with the recent attention on the lithium resources in the south side of the lake, additional challenges, opportunities, and uncertainties have arisen that complicate the whole process. So, as to signs of hope? Perhaps cautious optimism.