Tag Archive for: Water Supply

The Fate of the Imperiled Colorado River and Attempts to Mitigate Disaster

A water shortage on the Colorado River has put tremendous strain on the states that rely on it as a main water source. The fate of California’s Salton Sea is tied to the future of the river, and a catastrophic drought has only worsened conditions.

El Niño is Coming: What it Means for California Weather

El Niño conditions — the warming of ocean waters off South America that can alter weather across the globe, including California’s summer temperatures and the amount of rain it might receive next winter — are emerging in the Pacific Ocean for the first time in 4 years.

While El Niños do not automatically guarantee wet weather for California, historically, the stronger they are, the more likely it is that the state will have a rainy winter season. And after the dramatic series of storms this past winter that ended the drought and filled nearly empty reservoirs, another one back-to-back could increase flood risks.

Wildfires May Have Stoked Rare ‘Triple-Dip’ La Niña

In 2019, Australian skies glowed crimson in one of the country’s worst recorded fire seasons. The infernos blackened some 190,000 square kilometers of land, killing dozens of people along with an estimated 1 billion animals and destroying thousands of structures. The bushfires also unleashed plumes of smoke so voluminous they could be seen from space.

Water Agencies Lift Some Restrictions Following Wet Winter: What’s Changed, What Hasn’t

Coachella Valley water agencies are lifting some drought restrictions following an exceptionally wet winter in California, although experts and officials warn that California residents should keep getting used to “conservation as a way of life.”

Report Urges Metropolitan Water District to Abandon Newsom’s $16-Billion Delta Tunnel Plan

Gov. Gavin Newsom and his administration have touted plans to build a tunnel to transport water beneath the Sacramento-San Joaquin River Delta, saying the project would modernize California’s water infrastructure and help the state adapt to climate change.

But an advocacy group is urging the Metropolitan Water District of Southern California to abandon the $16-billion project, saying it doesn’t make financial sense for the state’s largest urban water agency.

Lower Colorado River Water Users Anticipate Dry 2024

Following one of the wettest winters in recent history, Arizona officials anticipate a dry 2024 as federal water usage cuts loom.

In a joint Colorado River shortage briefing held by the Arizona Department of Water Resources and the Central Arizona Project, officials analyzed current conditions in Colorado River Basin reservoirs and how they’ll change in the near future.

Pasadena’s Watering Rules Could Be Relaxed, 15% Water Conservation Target Could Be Lifted

The City Council on Monday will consider shifting watering rules from the current two days per summertime week to three days per summertime week and to simultaneously lift the 15 percent voluntary water-use reduction target.

The current Level 2 of the City’s Water Shortage Plan went into effect on August 16, 2021, before the state was deluged with trillions of gallons of rain from a series of atmospheric river storms.

Water Authority Testifies on California’s Efforts to Support the Colorado River

During state Assembly testimony on Tuesday, May 2, San Diego County Water Authority General Manager Sandra L. Kerl highlighted the steps taken by the Water Authority and partner water agencies across California to support the Colorado River in the era of climate change.

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.

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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).