L.A. Declares Emergency over Flood Risk along Aqueduct

Los Angeles Aqueduct (Brian Melley / Associated Press)
Brian Melley / Associated Press

Los Angeles Mayor Eric Garcetti declared an emergency on Monday, as a mass snowmelt in the Eastern Sierras threatens communities in the Owens Valley and along the 221-mile Los Angeles Aqueduct.

The emergency, as the Los Angeles Times notes, will last seven days.

Mammoth Mountain in January experienced an all-time-record of 244 inches of snow in just 23 days. The 524 inches of snowfall this season is a record for this time of year, and is trending to top the 626-inch total in 2011, when the ski runs stayed open until mid-July.

But temperatures spiking into the 50s last weekend, and another 50-degree spike coming next week, could unleash an early snowmelt of 1 million acre feet water into the usually dry Owens Lake. Although the L.A. Aqueduct is designed to handle the safe transport of half of that quantity of runoff, the remaining half is expected to cause flooding.

In the early 20th century, the L.A. Department of Water and Power’s William Mulholland, and Harrison Grey Otis of the Los Angeles Times, fought the California Water Wars for the right to expropriate the Eastern Sierras’ 2,600-square-mile Owens Valley watershed.

They then spent $23 million to have 5,000 workers build 215 miles of road, lay 280 miles of pipeline, drill 142 tunnels, pour one million barrels of cement, and blow up 6 million pounds of dynamite over five years to begin bringing water to a desolate Southern California plain that, 104 years later ,is America’s largest metroplex. The L.A. Aqueduct still provides over 50 percent of Los Angeles’s water demand.

But the luck of L.A.’s pioneers ran out 15 years later, when they built the 205-foot-high St. Francis Dam near Saugus. Constructed to hold 12 billion gallons of reserve water pumped from the L.A. Aqueduct, groundwater subsidence and earthquake activity caused the 3-year-old dam to leak. The dam later collapsed, resulting in the deaths of over 400 people.

An October 2015 report by the U.S. Geological Service regarding California aqueducts expressed concerns “that fluctuating land-surface elevations due to subsidence and uplift in the valley could cause serious operational-maintenance” problems for the state’s surface-water delivery systems.

At the time, the state was in its fourth year of drought. In addition, the Democrats that dominate Los Angeles and the State of California were claiming that the science was settled that global warming would drastically reduce rainfall and cause a dramatic rise in the oceans. No one was really concerned with impacts of a potential 1,000-year record rainfall and snowpack.

With Mayor Garcetti declaring a seven-day emergency late on March 20, residents of cities like Lee Vining, Bishop and Independence were immediately advised to head for high ground in the event that the melting snowpack sends a torrent of water toward the Owens Valley. The flood is expected to be halfway down Highway 395 by Thursday morning.

Southern California Public Radio was reassured by the L.A. Department of Water and Power that the utility took “emergency action to armor and repair certain Los Angeles Aqueduct facilities from floodwater impacts.” But the DWP estimates that the cost of the early snowmelt runoff could be about $500 million.


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