Mono Lake: Tufa Towers and the Fight for Water

A short drive north of Mammoth lies a lake that looks like nowhere else on Earth, its shores crowded with pale, knobby stone towers rising out of salty blue water. Mono Lake is ancient, roughly three-quarters of a million years old, and it has no outlet, so minerals concentrate until the water is about two to three times saltier than the ocean. The towers are called tufa.

They form underwater where calcium-rich springs bubble up through the lake bottom and meet the carbonate-rich water, and the two react to build limestone, tower by tower. You see them today only because the lake dropped and left them exposed, and that drop is a story of thirst. Starting in nineteen forty one, the Los Angeles Department of Water and Power began diverting the streams that fed Mono Lake, sending the water down an aqueduct to the city.

Over about forty years the lake fell forty five feet and lost half its volume, its salinity doubled, and the ecosystem edged toward collapse. In nineteen seventy eight local activists founded the Mono Lake Committee. Their fight reached the California Supreme Court, which ruled in nineteen eighty three that the state must protect the lake under the public trust doctrine.

In nineteen ninety four the state set a target level to let the lake slowly recover.