The following report on the Temporary Barriers Project is for your information and action, as appropriate. This report will be transmitted whenever changes occur to the operation of the barriers, and as a result of modeling and/or field monitoring of water levels in the south Delta.
http://baydeltaoffice.water.ca.gov/sdb/tbp/index_tbp.cfm.

STATUS AS OF: June 10, 2005

Head of Old River Barrier (HORB):

No HORB was installed this spring due to high San Joaquin River flows.

Agricultural Barriers (Old River near DMC, Middle River, Grant Line Canal):

The Old River near Tracy barrier was closed (channel completely blocked) on May 31, 2005. Work at the other two barriers on Grant Line Canal and Middle River is complete, although the center portion of the Grant Line Canal barrier remains open until the need to close it for water level improvement is demonstrated in accordance with our permits. Closure will occur at the Grant Line barrier when water levels are too low for adequate agricultural diversions and the closure does not adversely affect fisheries. The culverts at all the barriers have been tied open because water levels have been very high, but we will look to untie them and begin normal tidal operation of the culverts later next week.

Modeling:

Modeling results for this week are attached. Water levels will remain above the trigger level (0.0 feet MSL) for complete closure of the Grant Line Canal barrier. However, water levels will be dropping during the modeled period due to gradually lower flows on the San Joaquin River and the Sacramento River, along with stronger tides toward the end of the period.

Modeling Outputs:

Middle River at Howard Road Bridge
Doughty Cut above GLC Barrier
Old River near Tracy Road Bridge


Notes:

The Temporary Barriers Project will begin installing temporary pumps through mid-June to assist two shallow agricultural diversions operated by a Union Island farmer located downstream of the rock barriers. Because the farmer is downstream of the barriers, he has had diversion problems related to water levels whenever temporary barriers are installed. These diversions are being planned for dredging as early as this fall to provide a more permanent fix to these diversion problems.

These weekly updates are also available for your information on our website http://baydeltaoffice.water.ca.gov/sdb/tbp/index_tbp.cfm