Monday March 17, 2025
Mono Lake Committee —
Water diversions by the Los Angeles Department of Water & Power (DWP) began more than 80 years ago, depriving Mono Lake of water and upending the hydrologic balance between inflow and evaporation. The lake shrank rapidly, losing half its volume and declining 45 vertical feet by 1982.
As the lake shrank, the salts and minerals that make it unique remained abundant. And as a result, for every foot that diversions lowered the lake, salinity increased.
Mono Lake’s endemic brine shrimp and alkali flies are specially adapted to thrive in the lake’s salty waters which were 50 grams per liter (g/l) when diversions began. These two species, which each number in the trillions at Mono Lake, are a critical food resource for vast numbers of nesting and migratory birds, making the lake a site of international importance for bird migration. But as water diversions caused salinity to increase, the productivity of these essential species declined.
That’s why the California State Water Resources Control Board carefully considered ecological studies of the relationship between salinity and the health of brine shrimp and alkali flies in establishing its Mono Lake mandate. And though the status of Mono Lake is most often represented by lake level (6,383 feet above sea level this February), every foot of lake level has a corresponding lake salinity (81 g/l in February) that is directly relevant to ecosystem health.