Restoration Flows to be reduced and halted

On April 1, Reclamation will start deliveries to the San Joaquin River Exchange Contractors from Friant Dam. Normally, Exchange Contractor water supply is met from north-of-Delta water delivered through the Delta-Mendota Canal. However, because this is a “Shasta Critical” water year, Exchange Contractors are scheduled to receive 75% of their normal allocation, a total of 650 thousand acre-feet. While some of this supply is being met through normal means, the remainder is being met with supplies from Millerton Lake and released through Friant Dam to the San Joaquin River.

The San Joaquin River Restoration Program (SJRRP) Seepage Management Plan establishes groundwater thresholds to address any material adverse impacts from groundwater seepage as a result of Restoration Flows. While Restoration Flows are constrained to these seepage limitations, other releases, such as the deliveries to the Exchange Contractors, are not. SJRRP anticipates that Friant Dam releases for the Exchange Contract will utilize most or all of the available capacity to operate. Therefore, SJRRP will cede available capacity in the river dynamically based on groundwater conditions.

San Joaquin River releases from Friant Dam will range between 700 cfs and 2000 cfs from April until August or September. Any releases above approximately 800 cfs will not include Restoration Flows (expected in mid-April). Exchange Contractor deliveries will be diverted at Mendota Dam and Sack Dam, with no Restoration Flows planned for release below Sack Dam for the remainder of the summer. This will result in the river being disconnected from below Sack Dam to the confluence with the Merced River. Once Exchange Contractor deliveries via the San Joaquin River diminish and there is capacity for Restoration Flows, the Restoration Administrator will schedule the resumption of Restoration Flows and reconnection of the San Joaquin River.

The public is strongly encouraged to monitor flow conditions if recreating on or near the San Joaquin River. Flows of this planned magnitude have not been seen since 2019 and currents will be strong.

The Restoration Flow schedule will be amended in the coming days and is presented in general terms below for public notification:

Date Friant Dam Releases Restoration Flows at Gravelly Ford Exchange Contractor Flows reaching Mendota Pool
March 1 –
March 31
Approximately 700 cfs 420 cfs 0 cfs
April 1 –
April 30
700 cfs increasing to
approximately 1000 cfs
425 cfs declining to
0 cfs
 

0 cfs increasing to approximately 700 cfs

May 1 –
August 15
1000 cfs varying to
approximately 2000 cfs
 

Likely 0 cfs

700 cfs varying to approximately 1200 cfs
 

August 16 – September 30

 

Decreasing to approximately 700 cfs Variable Variable, decreasing to 0 cfs
October 1 – February 28, 2023 Approximately 450 to 700 cfs Likely 200 cfs to 420 cfs      0 cfs

Any questions regarding the Exchange Contractor releases from Friant should be directed to the California Great-Basin Public Affairs Officer, Mary Lee Knecht, at 916-978-5101 or via email at mknecht@usbr.gov.

For Information about Restoration Flows, please visit http://www.restoresjr.net/restoration-goal/restoration-flows/.

For the Restoration Administrator recommendations, please visit http://www.restoresjr.net/documentsreports/ra-recommendations/

For additional information about the San Joaquin River Restoration Program, please visit http://www.restoresjr.net or contact Josh Newcom, Public Affairs Specialist, at 916-978-5508 or snewcom@usbr.gov.