Ecologic Flows

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Over the past century, the diversion of water from Owens River has had detrimental impacts on the ecological integrity of Owens Lake and surrounding areas. When Los Angeles first diverted the water into the Aqueduct in 1911, the desiccation of Owens Lake was already well underway (as a result of years of agricultural diversion further upstream). Salt that had been accumulating through mineral deposition from the Sierras was now being exposed on the dying lake bed, and a new industry of salt harvesting was born. Salt works sprung up on the eastern and western shores, but soon after the falling water level left the eastern salt pans dry these works were abandoned. As of 1923, only a dusty playa and a greatly diminished brine pool occupied the lowest portions of the once-mighty lake. By 1926, dust storms were a regular occurrence.

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In the 1930s, LADWP began drilling hundred of wells to tap the Owens Valley groundwater as a way to bolster the flow down the Aqueduct. Until the 1970s, these wells had a relatively minor impact on life in the valley, at least compared to the draining of Owens River. The completion of the second Los Angeles Aqueduct provided the capacity for Los Angeles to greatly increase their pumping. Predictably, groundwater levels dropped and the verdant meadows – once fed by a myriad of sparkling springs – were replaced by a xeric landscape of sagebrush and sand dunes.

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In 1940, LADWP bored eleven miles through solid rock to create the Mono Craters Tunnel so they could divert more water directly from Mono Lake located further upstream. Or course, Mono Lake’s water level dropped and exposed the previously isolated nesting sites of the California Gull to danger from predators who could now traverse an uncovered land bridge to encroach on their breeding grounds. In 1979, the Mono Lake Committee, with the leadership of biologist David Gaines, sued the LADWP to protect the nesting site. The 1994 Mono Lake Accord established a minimum water level for Mono Lake to protect the rookery and establish a schedule of water diversions to gradually allow the lake to increase to a sustainable level.

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[Data Sources: LADWP, Inyo Water, Mono Lake Committee, California State Lands Commission, California Department of Fish and Game, USGS, National Atlas, Elmore/Mustard/Manning (2003), Koehler & Anderson (1994), Sauder (1989), Mike Prather, Dr. Sally Manning, students in LA302L/LA499, the AF 606 WsW team, and the Aqueduct Futures Project] 

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