Breaking News
More () »

California's 'broken' water supply forecast to be audited

The audit comes after California's water operations substantially overestimated the forecast and released more water than was necessary, officials said.

CALIFORNIA, USA — There'll be an audit of California's water supply forecast after the state overestimated and prematurely released 700,000 acre-feet of water last year, officials announced Monday.

A news release from Assemblymember Adam Gray (D-Merced) announced that Gray's request for audit was approved. It aims to examine the impacts of the flawed forecasts and the Department of Water Resources (DWR) and State Water Board.

“Errors on this scale have real and measurable consequences,” Gray said in the news release. “The managers of the largest local, state, and federal reservoirs use this information to determine when to let water accumulate and when to let water out to make room for the coming snowmelt. Growers use the information to predict how much water they can expect for their farms and how many acres they can afford to plant. The estimates are used to inform everything from flood control to power generation and water quality standards.”

California's water operations overestimated the forecast by 68% for the Sacramento River  region, 45% for the San Joaquin River region and 46% for the Tulare Lake region, according to a state report. Those overestimations left the operators with less stored water than was necessary, according to Gray's news release.

Gray said the state's error was contrasted by other agencies and local irrigation districts who didn't make the same mistakes in their own forecasts.

“No one expects DWR or any of these organizations to get the number exactly right,” Gray said. “But when the state’s best forecasts are demonstrably inferior to local and federal forecasts we need to ask why, and we need to fix the problems as soon as possible. Until we understand what has gone wrong with the agencies charged with managing California’s water, we cannot understand how to fix the problem.”

The audit is expected to take six to seven months to complete.

DWR Director Karla Nemeth provided the following statement regarding the audit:

The requested audit by Assemblymember Adam Gray continues to promote two important inaccuracies:  DWR did not release 700,000 acre-feet of water for flood control purposes during the spring or summer of 2021.  Also, the State Water Resources Control Board is not responsible for forecasting.

Spreading this misinformation is a disservice to the public, especially those communities that rely on water from the State Water Project.

As has been widely communicated, California is in a third year of drought and in April 2021,  California witnessed unprecedented runoff loss, following a dry winter in 2020.  We saw our anticipated water supply disappear due to extremely dry soils and early season heat waves driven by our changing climate. This run off scenario is entirely attributable to nature.  DWR welcomes this audit and assistance to the Department in improving its forecasting accuracy.  Significant work is already underway thanks to increased funding from the Legislature in 2021.

ABC10 In Your Inbox: Sign up now for the Daily Blend Newsletter for local headlines, weather, tips and even something to make you smile.


California Drought: Aircraft tech hopes to help conserve even more water in California

Before You Leave, Check This Out