Posts

As Arizona Looks to Desalination as a Drought Solution, Questions Mount

While Arizona received more rain and snow in recent months, a wet winter will not save the state from the decades-long mega-drought that is gripping the region. Water officials have worked on finding unique solutions, including desalination.

Opinion: No Choice But For Big Cuts Along The Colorado River Basin

Water levels have dwindled and remain at a historic low in Lake Mead and Lake Powell, the largest human-made reservoirs in the United States – so low in Lake Mead a year ago that it came close to hitting dead pool status, which occurs when water levels are too low to generate electricity.
Snow Surveys-DWR-Snowmelt-Flooding-May 1

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.”

Snowpack Surveys-Sierra Nevada-Reservoirs-Snow Water Equilvalent-Snowmelt

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.

Snowmelt-reservoirs-snow surveys-flooding

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).

Water Levels Are Going Up in the West’s Massive Reservoirs. Has the Water Crisis Been Averted?

Historic snowfall across the Rocky Mountains is helping recharge some of the country’s biggest reservoirs and provide – briefly – some much-needed breathing room for the oversubscribed Colorado River.

Forecasts say the melting snow flowing into Lake Powell via the Colorado River and its tributaries could hit 177% of average this year, a major boost at a time when lake levels had hit historic lows.

BOS Declares End to Local Drought Emergency in Mendocino County

A drought emergency declaration in place over the past two years was lifted in the Mendocino County Board of Supervisors meeting Tuesday. “Current conditions are not beyond the control of the services, personnel equipment and facilities of the county” after a stormy winter and spring helped replenish local water reserves, the resolution states.

‘We Can’t Be Living in an Economy of 40 Million People This Close to the Edge.’

Lake Mead, in Arizona and Nevada, is the largest reservoir in the United States and part of the Colorado River system, which supplies water to seven U.S. states and part of Mexico, including one third of the water used in Southern California. It also supplies 30 Tribal Nations.

At the end of last year, experts predicted that, due to drought and heavy demand for water, Lake Mead was just two years shy of dead pool, when water levels drop below the point at which it can flow downstream of the reservoir.

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.

Did the Months of Recent Rain End California’s Drought? Experts Say It’s Complicated

Over the last four months, storm after storm pounded the California coast – leading to dramatic changes in our water supply and drought conditions – including in San Diego. But many are asking whether it’s safe to say the drought is complete “over.”

The weekly published Drought Monitor shows that conditions significantly improved compared to last year.

State Water Project to Deliver 100% of Requested Supplies as Reservoirs Fill

The California Department of Water Resources announced Thursday that the State Water Project will be able to deliver 100% of requested water supplies this year thanks to full reservoirs following record winter rain and snow.

Opinion: Lake Mead Could Get a Lot More Colorado River Water. What Changed So Quickly?

What a difference a month makes.

The March 24-month forecast, which predicts reservoir levels along the Colorado River for the next two years, had Lake Mead on a steady trajectory downward.