Due to the worsening drought, the Bureau of Reclamation updated initial Central Valley Project 2021 water supply allocations for municipal and industrial water service and agricultural contractors. Allocation amounts are based on an estimate of water available for delivery to CVP water users and reflects current reservoir storages, precipitation, and snowpack in the Central Valley and Sierra Nevada.
The initial CVP water supply allocation was announced Feb 23. Since then, hydrologic conditions have degraded. The 2021 water year for the Sacramento-San Joaquin River Basin is currently the driest since 1977. Between the April 1 and May 1 forecasts, there was a 685,000 acre-feet reduction in the projected natural flow to the Sacramento, Feather, Yuba and American rivers.
Due to worsening hydrologic conditions, the bureau, which operates the CVP, announced the following updates to the initial 2021 CVP water supply allocation:
• M&I water service contractors—north-of-Delta and south-of-Delta—allocation is reduced from 55% to 25% of historic use, which may be adjusted in accordance with the CVP M&I Shortage Policy.
• The 5% allocation for CVP agricultural water service contractors—both north-of-Delta and south-of-Delta—which was previously suspended until further notice, is confirmed at 0%.
There are no updates to other CVP allocations at this time.
Previously announced allocations included:
North-of-Delta contractors (including American River and In-Delta contractors)
• Sacramento River Settlement Contractors are allocated 75% of their contract supply of 2.2 million acre-feet.
Eastside water service contractors
•Eastside water service contractors (Central San Joaquin Water Conservation District and Stockton East Water District) are allocated 100% of their contract total.
• The San Joaquin River Exchange Contractors and San Joaquin Settlement Contractors are allocated 75% of their contract supply.
• Wildlife refuges (Level 2) north and south of the Delta, which also have allocations subject to pre-established Shasta inflow criteria, are allocated 75% of their contract supply of 122,000 acre-feet
• Friant Division contractors’ water supply develops in the Upper San Joaquin River Basin Watershed and is delivered from Millerton Lake through Friant Dam to the Madera Canal and Friant-Kern Canal. The first 800,000 acre-feet of available water supply is considered Class 1; Class 2 is considered the next amount of available water supply up to 1.4 million acre-feet.
Given the current hydrologic conditions, Friant Class 1 initial allocation will be 20% and Class 2 will be 0%.
For the San Joaquin River Restoration Program, Reclamation is currently forecasting a “dry” water year type, providing for 170,732 acre-feet to be used for restoration program purposes.
As the water year progresses, changes in hydrology and opportunities to deliver additional water will influence future allocation decisions.
The Bureau of Reclamation contributed this information.