July 5, 2013

The Department of Water Resources and the U.S. Bureau of Reclamation may conduct transfers beginning as early as July 4th.  The maximum rate of planned transfers is 1,600 cfs. 
 
The attached files contain forecasted water quality at Holland Tract, Old River near Middle River, San Joaquin River at Brandt Bridge, and Old River at Tracy Road as well as forecasted water levels at the following south Delta locations--Old River west of Union Island near Coney Island, Middle River at Howard Road, Old River at Tracy Road, Doughty Cut, and the head of Grant Line Canal for both the "with-" and "without-transfers" cases.  In the alternative case, an additional 1,600 cfs is being exported from the Delta.
 
The attached model results cover the period of July 2 – July 22, and are based on the following assumptions:  
 - Delta Cross Channel Gates were opened June 14 and remain open during the entire forecast period.
 - The Old River Tracy barrier is installed with all culverts tidally operating as of June 3. 
 - The Middle River barrier is installed with all of the culverts tidally operating as of June 3 with the weir height raised to 2’ on Jun 21.
 - The Grant Line Canal barrier is fully installed with all culverts tidally operating as of June 19.  
 - The Head of Old River barrier is not installed.
 - Suisun Marsh salinity control flashboards were removed and the boatlock was closed as of May 29.
 - San Joaquin River flows at Vernalis would decrease from 664 cfs at the beginning of the forecast period to 650 cfs by the end of the forecast period.  (Recent Vernalis flows have been approximately 664 cfs.)

The model results showed no significant difference in forecasted low water levels between the base case and the alternative case at any station.  We will continue to monitor water levels at the five south Delta stations listed above.  Before and during the time we are planning to conduct transfers, DWR and Reclamation will monitor water levels at the five south Delta stations listed above.  If we are not meeting the requirements of the WLRP, the Projects would not initiate or would cease transfers until water levels improved.

The model results showed no significant difference in water quality between the base case and the alternative case at Old River near Middle River, Holland Tract, Old River at Tracy Road, and SJR at Brandt Bridge.  The 30-day average electrical conductivity (EC) objective for the interior south Delta stations is 0.7 mmhos/cm April through September.  South Delta EC is highest at the Old River at Tracy station; the current mean daily and 30-day average EC values are 0.92 mmhos/cm and 0.97 mmhos/cm EC, respectively.