Water diversions for agriculture reduce ecosystem services provided by saline lakes around the world. Exposed lakebed surfaces are major sources of dust emissions that may exacerbate existing environmental inequities. This paper studies the effects of water diversions and their impacts on particulate pollution arising from reduced inflows to the Salton Sea in California via a spatially explicit particle transport model and changing lakebed exposure. We demonstrate that lakebed dust emissions increased ambient and concentrations and worsened environmental inequalities, with historically disadvantaged communities receiving a disproportionate increase in pollution. Water diversion decisions are often determined by political processes; our findings demonstrate the need for distributional analysis of such decisions to ensure equitable compensation.