The Salton Sea is a terminal saltwater lake. It’s a flooded basin with no natural outlet, similar to the Great Salt Lake or the Aral Sea. And the Salton Sea is shrinking. One of the reasons for that is the Imperial Water Transfer deal that has brought hundreds of thousands of acre feet of water to San Diego over the last two decades. The deal, signed 21 years ago, meant the Imperial Valley began transferring excess water from the valley’s farm fields to San Diego’s water taps. That meant a lot less farm runoff that had been sustaining the Salton Sea. San Diego State University economics professor Ryan Abman said the biggest effects of that conservation plan were seen about eight years into the agreement. “So really, after 2011, we see a noticeable increase in the rate of decline of the water level and that leads to an increase in the increased rate of playa exposure. So more of this dust-emitting surface is being exposed every single year,” Abman said.