Tag Archive for: Sierra Nevada

State Asked to Stop Diverting Iconic Mono Lake’s Water to Los Angeles

As trickling snowmelt in the Sierra Nevada slowly raises Mono Lake —  famed for its bird life and outlandish shoreline mineral spires — advocates are pressuring state water officials to halt diversions from the lake’s tributaries to Los Angeles, which has used this clean mountain water source for decades.

California Pledges to Build Channel for Threatened Fish to Bypass Gold Rush-Era Dam

California officials on Tuesday said they will spend about $60 million to build a channel along the Yuba River so that salmon and other threatened fish species can get around a Gold Rush-era dam that for more than a century has cut off their migration along the chilly waters of Sierra Nevada streams.

Snow Surveys Help Plan Snowmelt Runoff Forecasts

The California Department of Water Resources May 1 conducted the fifth snow survey of the season at Phillips Station. The manual survey recorded 59 inches of snow depth and a snow water equivalent of 30 inches, which is 241% of average for this location on May 1.

The last time there was measurable snow at the Phillips snow course on May 1 was 2020, when only 1.5 inches of snow and .5 inches of snow water equivalent was measured.

DWR’s electronic readings from 130 snow sensors placed throughout the state indicate the statewide snowpack’s snow water equivalent is 49.2 inches, or 254% of average for May 1.

The snow water equivalent measures the amount of water still contained in the snowpack and is a key component of DWR’s water supply run-off forecast.

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Snow Surveys Help Plan Snowmelt Runoff Forecasts

The California Department of Water Resources May 1 conducted the fifth snow survey of the season at Phillips Station. The manual survey recorded 59 inches of snow depth and a snow water equivalent of 30 inches, which is 241% of average for this location on May 1. The last time there was measurable snow at the Phillips snow course on May 1 was 2020, when only 1.5 inches of snow and .5 inches of snow water equivalent was measured

DWR’s electronic readings from 130 snow sensors placed throughout the state indicate the statewide snowpack’s snow water equivalent is 49.2 inches, or 254% of average for May 1.

The snow water equivalent measures the amount of water still contained in the snowpack and is a key component of DWR’s water supply run-off forecast.

“While providing a significant boost to California’s water supplies, this year’s massive snowpack is posing continued flood risks in the San Joaquin Valley,” said DWR Director Karla Nemeth. “The snowpack will not disappear in one week or one month but will lead to sustained high flows across the San Joaquin and Tulare Basins over the next several months and this data will help us inform water managers and ultimately help protect communities in these regions.”

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Snowmelt runoff forecasts

Snow surveys like the one at Phillips Station are critical to planning for impacts of the coming snowmelt runoff on communities. DWR uses the most updated technology to gather data from snow surveys, a network of 130 remote snow sensors, and airborne snow observatory data to gather information on current real-world conditions to create the most accurate snowmelt runoff forecasts possible. These runoff forecasts, published through DWR’s Bulletin 120, allow reservoir operators to plan for anticipated inflows and water managers downstream of reservoirs to plan and prepare for flood risks.

Despite a brief increase in temperatures in late April, the statewide snowpack overall melted at a slower pace than average over the month of April due to below average temperatures early in the month and increased cloud cover. An average of 12 inches of the snowpack’s snow water equivalent has melted in the past month and it now contains an average of 49.2 inches.

Water supply, flood control planning

“No matter how you look at the data, only a handful of years in the historical record compared to this year’s results,” said Sean de Guzman, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit. “Survey results from our partners in the California Cooperative Snow Surveys Program and other data, including data from Airborne Snow Observatory flights, allow us to incorporate these data into our models to provide the most accurate snowmelt runoff forecasts possible right now to inform water supply, flood control, and planning.”

Climate Change and snowpack averages

According to historical records, only the April 1 measurements from the years 1952, 1969, 1983 and this year were above 200 percent, although it is difficult to directly compare individual years across the decades due to changes in the number of snow courses measured over time.

Due to the impact of climate change on California’s snowpack, since 2021, snowpack averages have been calculated using a timeframe of 1991 through 2020 so that results better reflect the current climate conditions.

DWR is maximizing the amount of water that can be stored and diverted from this record snowpack.

In April, DWR announced a 100% allocation of requested supplies from the State Water Project, which delivers water to 29 public water agencies that serve 27 million Californians and 750,000 acres of farmland. The last time the SWP allocated 100% was in 2006. DWR is also maximizing the amount of water that can be diverted towards recharging groundwater basins so more water is stored for future use in underground reservoirs.

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Flooding impacts in California

Last week, Governor Newsom visited the Tulare Basin to tour flood impacts first hand, met with community leaders and emphasized the state’s commitment to supporting and providing appropriate assistance to counties impacted by recent and anticipated flooding this spring and summer.

Snowmelt runoff forecasts are an instrumental part of the assistance provided by DWR’s State-Federal Flood Operations Center (FOC), which is supporting emergency response in the Tulare Lake Basin and Lower San Joaquin River by providing technical and materials assistance to support ongoing flood response activities.

Storms this year have caused impacts across the state including flooding in the community of Pajaro and communities in Sacramento, Tulare, and Merced counties. The FOC has helped Californians by providing more than 1.4 million sandbags, 1 million square feet of plastic sheeting, and 9,000 feet of reinforcing muscle wall, across the state since January.

(Editor’s  Note: Information in this story was provided by the California Department of Water Resources).

California Faces Rapid Snowmelt From Heat Wave; Flood Fears in Yosemite, Elsewhere

After weeks of uncertainty, forecasters say an incoming California heat wave will trigger rapid snowmelt on the slopes of the Sierra Nevada and cause more flooding in portions of the San Joaquin and Owens valleys this week.

Temperatures in Central California are forecast to climb into the high 80s and mid-90s beginning Wednesday and into the weekend, with the potential for some areas to approach daily records.

As Epic Snow Melts, A California Community Braces for Floods

Ron Caetano is packed and ready to go. His family photos and valuables are in the trailer and he’s put food in carry totes. He moved the rabbits and chickens and their automatic feeders to higher ground.

Fears Grow as Floodwaters Threaten to Drown This California City and Prison Complex

Just west of this normally dusty prison town, a civic nightmare is unfolding: Tulare Lake, a body of water that did not exist just two months ago, now stretches to the horizon — a vast, murky sea in which the tops of telephone poles can be seen stretching eerily into the distance.

California Snowpack Data Debunked: 2023 Was No Record Year. And Neither Was 1952

It was the snowpack reading that spawned a hundred headlines. “California ties 1952 record for all-time Sierra snowpack,” proclaimed KTVU. “California’s snowpack soars to record high after 17 atmospheric rivers,” trumpeted the Washington Post.

State officials largely seemed to agree.

California Sees Record Snowpack Levels, Boost in Water Supply

Molly White, Water Operations Manager for the State Water Project at the California Department of Water Resources, said atmospheric river storms have to led to near-record snowpack in many parts of the Sierra Nevada and reservoir storage is above average for this time of year.

Record Snowpack Conditions in California, Parts of Southwest

After a three-year drought in California and throughout the Southwest, many states throughout the West are measuring record snowpack conditions at NRCS SNOTEL stations and snow courses. Utah especially has seen a benchmark year for snowfall levels throughout the state.