Tag: Department of Water Resources

Expert panel recommended that Water Board require documentation of model weaknesses

~ Deirdre Des Jardins ~ Leave a comment

On June 27, 2022, the legislature authorized the Acting State Auditor to perform an audit of the reasons for major errors Department of Water Resource's snow runoff forecasts in 2021. The Department of Water Resources' Director, Karla Nemeth, told the legislature that "the forecasting work is undertaken exclusively by the Department of Water Resources. The … Continue reading Expert panel recommended that Water Board require documentation of model weaknesses

Problems with Bay-Delta water resources modeling have been recognized for decades

~ Deirdre Des Jardins ~ Leave a comment

The drought years of 2021 and 2022 saw major errors in the Department of Water Resources' Bulletin 120 runoff forecasts and Delivery Capability Report water supply projections. The Joint Legislative Audit Committee authorized an audit of DWR's modeling and water management on June 27, 2022. But the model errors are part of larger institutional issues … Continue reading Problems with Bay-Delta water resources modeling have been recognized for decades

Legislature approves audit of water management by DWR and SWRCB during 2021

~ Deirdre Des Jardins ~ 1 Comment

On Monday, June 27, the California Joint Legislative Audit Committee approved Assemblymember Adam Gray's request for an audit of the management of surface water by the Department of Water Resources (DWR) and the State Water Resources Control Board in 2021. The Acting State Auditor is also proposing to audit DWR's plan to uphold its contractual … Continue reading Legislature approves audit of water management by DWR and SWRCB during 2021

The State Water Project Delivery Reliability Report may have created systemic drought vulnerability

~ Deirdre Des Jardins ~ 1 Comment

On June 7, 2022, Adel Hagekhalil, general manager of the Metropolitan Water District of Southern California, issued the following statement: We are in an unprecedented situation, where our water supplies from the State Water Project are so limited by drought and climate change that they do not meet demands. Southern Californians must decrease their water … Continue reading The State Water Project Delivery Reliability Report may have created systemic drought vulnerability

Models that forecast water that isn’t there hurt all beneficial uses

~ Deirdre Des Jardins ~ 1 Comment

Assemblymember Adam Gray has called for an audit of the Department of Water Resources and the State Water Resources Control Board, in part to answer the question, What happened in the Water Year 2021 (October 1, 2020 to September 30, 2021) to lead the state to miscalculate by some 700,000 acre-feet the amount of water … Continue reading Models that forecast water that isn’t there hurt all beneficial uses

Fatal errors in DWR’s runoff forecasting: comments to the State Water Resources Control Board

~ Deirdre Des Jardins ~ 4 Comments

The State Water Resources Control Board held a workshop today (March 16, 2022) on Sacramento River Temperature Management. Among the topics considered were "hydrologic conditions, including operations, forecasting, and accounting." These were my comments. This is Deirdre Des Jardins with California Water Research. I’m the physicist who sent comments to DWR in 2012 predicting the … Continue reading Fatal errors in DWR’s runoff forecasting: comments to the State Water Resources Control Board

We need to step up our game on evaluating drought risk

elevated drought risk impact Feb 20 2022
~ Deirdre Des Jardins ~ Leave a comment

The Department of Water Resources’ new California Water Watch website is a great new resource, however, the site appears to miss information on the rapidly developing drought. The website displays statewide precipitation for the water year to date. It also displays a map of “Drought Risk Impacts” based on precipitation being less than 70% of … Continue reading We need to step up our game on evaluating drought risk

Dear DWR, in runoff forecasting, stationarity is dead

~ Deirdre Des Jardins ~ 1 Comment

For decades, the California Department of Water Resources (DWR) has relied on runoff forecasts from the California Cooperative Snow Surveys (Bulletin 120) for planning State Water Project operations in the late winter and early spring. In 2021, the Bulletin 120 runoff forecasts, which were based on the last 50 years of historic runoff data, were … Continue reading Dear DWR, in runoff forecasting, stationarity is dead

Will State Water Contractors support disclosure of forecast SWP operations?

~ Deirdre Des Jardins ~ Leave a comment

On January 22, 2022, Dan Bacher published an article, Why is California’s DWR increasing State Water Project allocations in the middle of a drought?  Jennifer Pierre, the General Manager for the State Water Contractors: tweeted the following response to the article: All of the allocated water is already in storage downstream of the Delta. It … Continue reading Will State Water Contractors support disclosure of forecast SWP operations?

In increasing State Water Project allocations, DWR is taking huge risks

~ Deirdre Des Jardins ~ 3 Comments

The Department of Water Resources has just announced that they are increasing the State Water Project allocations to 15%. Given the huge problems last year with watershed runoff forecasts, DWR is taking a huge risk of not meeting environmental water needs later in the year. In November 2021, nine scientists from leading California water research … Continue reading In increasing State Water Project allocations, DWR is taking huge risks