$27 million later, the LA Snowpack Emergency of 2017 is over

The emergency that Los Angeles declared last spring to prevent flooding and damage from a near-record Sierra snowpack is over, Mayor Eric Garcetti has declared.

The city spent $27 million to reduce the risk that homes and roads could be flooded and that the Los Angeles Aqueduct could be blocked with silt and damaged. The money also went to prevent flood damage to more than $1 billion worth of pipes, pumps, berms and plants installed on the Owens Dry Lake to reduce dust and air pollution.

In normal years, the city gets a good portion of its water from melted snow in the Eastern Sierra, channeled south on the 200-mile Los Angeles Aqueduct. Over five years of drought, the aqueduct carried very little water to L.A., but the last winter's snows changed that. The snowpack on the Eastern Sierra was 203 percent of a normal year, and was  the second largest recorded, after the 1969 snowfall.

This June 25, 2017, photo taken by an unmanned aerial vehicle and released by the Tulare County Sheriff's Office shows flooding from the Kings River at the Kings River Golf and Country Club in Kingsburg, Calif. The Kings River began to flood about 25 miles (40 kilometers) north of Fresno as temperatures soared, melting snow in the Sierra Nevada and sending it downstream.

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Tulare County Sheriff's Office via AP

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Suddenly, the city's Department of Water and Power was facing the prospect of being able to get twice a normal year's water supply from its century-old aqueduct.

But the surplus of water carried other risks, and by declaring the emergency in March, before the snow began melting, the city was able to get out ahead of the surplus with a lot of maintenance and repair work, said Jim Yannotta, assistant director of DWP's Northern District, which includes the aqueduct. The amount of water coming from the melting snow peaked in June, he said.

The money paid for work that might be done by other agencies, he told the DWP Board of Commissioners in July. For example, the DWP replaced a Caltrans culvert running under Highway 395 because there were indications the heavy snowmelt could undermine the road.

DWP crews also used excavating equipment to clear rocks and silt, keeping streams flowing in their channels where they might otherwise overtop their banks and flood homes and property. Measures were taken to keep Crowley Lake from spilling water into an area where it could have harmed an endangered species of fish.

The snow melt could have put as much as 200,000 acre feet of water into the Owens Dry Lake bed, damaging the dust reduction pipes, pumps, berms and vegetation installed to keep air pollution down. The work to re-direct the water away from those elements kept the amount of water flow into the lakebed to just 15,000 acre feet. The DWP lost about 5 percent of its dust control capacity due to the excess water.

The Owens River flooding in June 2017 at the peak of the Sierra snowmelt.

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Los Angeles Department of Water and Power

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The emergency declaration also enabled the work to be done faster, speeding permissions from such landowners as the Bureau of Land Management and the U.S. Forest Service, Yannotta said.

The DWP also increased the amount of water it spread in the Owens River Basin, raising the groundwater level there by nine feet. The money covered extra work to clear canals and lower water reservoir levels along the Aqueduct, making room for the runoff.

This June 25, 2017, photo taken by an unmanned aerial vehicle and released by the Tulare County Sheriff's Office shows flooding from the Kings River at the Kings River Golf and Country Club in Kingsburg, Calif. The Kings River began to flood about 25 miles (40 kilometers) north of Fresno as temperatures soared, melting snow in the Sierra Nevada and sending it downstream.

(

Tulare County Sheriff's Office via AP

)

Closer to home, the money paid for work to recover and change the use of the long-defunct Maclay Highline. It is a pipe that originally carried water from the end of the aqueduct in Sylmar to an open-air reservoir, but it fell out of use a decade ago. It was revamped to carry water from the aqueduct to a spreading ground in Pacoima. Previously, the DWP had no means of moving excess water from the aqueduct to recharge groundwater.

DPW used aqueduct water in Los Angeles in place of more costly water imported from the Colorado River. A spokesman for the DWP could not immediately say how much the excess water saved ratepayers on their water bills.