Central Valley Project
Credit: USBR
July 22, 2022 - SACRAMENTO – With three consecutive years of drought reducing state and federal water project reservoirs to historic lows, the State Water Resources Control Board on Wednesday readopted measures for the Delta to protect drinking water supplies, prevent salinity intrusion and minimize impacts to fish and the environment.
The State Water Board decision updating an emergency curtailment and reporting regulation authorizes staff to determine the amount of water available to certain right holders during the drought, preserving drinking water for 27 million Californians and the irrigation supply for more than three million acres of farmland.
The regulation also helps limit the salty ocean water that enters the Delta and contaminates freshwater flows, threatening harm to fish and wildlife from habitat loss and contributing to the growth of toxic algal blooms.
The regulation enables staff to adjust the number and location of curtailments – or restrictions on the amount of water that can be taken - as conditions change. Right holders with more senior rights or claims also could be affected unless conditions improve. The previous regulation would have expired in August.
“Climate change and extreme heat continue to place a tremendous strain on the Delta’s reservoir storage levels,” said Erik Ekdahl, deputy director for the Division of Water Rights. “Forecasts indicate most of the Delta watershed will remain in extreme or severe drought for the rest of the year. Today’s action is critical to preserving what we can and preparing for a challenging future.”
The 1,153 square-mile watershed not only provides two-thirds of Californians with drinking water, it also supports 80% of the state’s commercial salmon fisheries and is an important habitat for more than 750 animal and plant species, including waterfowl, birds of prey and threatened or endangered fish such as the Delta smelt, Chinook salmon and steelhead.
So far this summer, about 4,300 right holders and nearly 10,000 of 16,700 water rights in the Delta have been curtailed. Altogether, these curtailments are reducing diversions by 789,000 acre-feet in July alone, or enough water to sustain over two million threeperson households for a year.
The board first issued Delta curtailment orders in August 2021 in response to the drought, but based on watershed conditions and forecasted supplies, most curtailments had been suspended until early last month.
As of July 19, the lack of precipitation and early season snowmelt reduced reservoir storage at Shasta and Oroville, which supply the watershed, to 38% and 46% of capacity, respectively.
The new regulation includes minor changes to clarify requirements, streamline administration and provide flexibility in the method used to determine water unavailability. The revisions also address the reduced allocation to Sacramento River Settlement and Feather River Contractors.
The regulation will take effect when approved by the Office of Administrative Law, which generally occurs within 10 working days. More information is available on the Delta drought website.
The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health and all beneficial uses, and to ensure proper allocation and efficient use for present and future generations.
Source: CA. State Water Boards
