Mono Lake Crisis: Ecology, Law, and Water Rights

Overview of the Mono Lake Crisis

Mono Lake, located in eastern California near the city of Los Angeles, has been in the spotlight for the extensive environmental damage done to it over the past several decades. As the population of Los Angeles soared, the city faced a shortage of water for its residents. This semi-arid region had few options to meet the growing water needs of its population, so Mono Basin became a prospective source of supply. By 1941, water was being diverted from four of the five streams feeding Mono Lake into the LA Aqueduct (Kahrl, 1983).

This water diversion benefited the Los Angeles Department of Water and Power (LADWP) and city consumers alike, because water from Mono Basin was available at a lower cost than water from other sources such as the Colorado River. The favorable economics increased demand, and more water was drawn from the basin over time. Soon, water levels in the lake began to fall and salinity began to rise. This triggered a disruption of the local ecosystem. Algae in the lake provides food for brine shrimp, which in turn attract California Gulls that use Mono Lake as a resting stop during migration. The increased salinity impaired algae by preventing photosynthesis, which in turn disrupted the reproduction cycles of the brine shrimp. Additionally, falling water levels exposed the lake bed, making it easier for predators such as raccoons to attack nesting California Gulls. Together, these changes caused widespread ecological damage in the surrounding area.

As residents and environmental groups came to understand the scale of the problem, legal battles began. The Mono Lake Committee was formed in 1976 and pursued extended legal proceedings to restore the lake's water levels. Finally, on August 22, 1989, the California State Water Resources Control Board (SWRCB) ruled that the city of Los Angeles must allow Mono Lake's water level to rise to an elevation of 6,391 feet above sea level — an increase of approximately 17 feet (Strong-Aufhauser, 1995). This ruling effectively ended large-scale diversions from the lake, and water levels have been rising since.

Scientific Data on Water Loss and Ecosystem Decline

Scientific data show that before water diversions began, Mono Lake's water level fell by roughly one foot per year through natural evaporation. After a second aqueduct was opened, that rate climbed to 1.6 feet per year. It is estimated that approximately 83,000 acre-feet of water were removed from Mono Lake annually from the 1970s through the 1990s, and the overall volume of the lake shrank by about 22 cubic miles (Monolake.org, 2012). This dramatically increased the lake's salt concentration — roughly doubling it — and destroyed much of the local ecosystem.

In addition, the reduced water levels exposed the alkali lake bed of Mono Lake, generating dust storms that posed significant risks to human health in the surrounding region.

As water levels dropped, mineral formations known as tufa towers emerged from the lake's surface. Their appearance drew increased tourism — an irony, given that the conditions that made them visible had rendered the lake ecologically barren.

Social and Legislative Barriers to Conservation

Water is a basic necessity, and this semi-arid region needed it urgently. Water from Mono Basin was cheaper than water from the Colorado River, which generated considerable resistance from both LA residents and the LADWP to any reduction in diversions. The combination of limited alternative water sources and a rapidly growing population made it politically difficult for city officials to walk away from Mono Lake's supply. Any lawsuit that sought to restrict water use was viewed as a social burden that was difficult to enforce.

Beyond public resistance, conservationists also faced substantial legislative barriers. A state constitutional amendment passed in 1928 required that all water in California be put to beneficial use, with water rights administered by the SWRCB. A water right was initiated by a prospective applicant who was required to meet the SWRCB's terms and conditions, including the submission of regular progress reports. Over time, the SWRCB would grant formal water rights — which is precisely what had happened in the case of Mono Lake (Mono Basin EIR, 1993). Overturning those established rights required a lengthy legal battle, and this 1928 amendment posed serious obstacles for the Mono Lake conservationists throughout their campaign.