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/web_pg/tempmesr.cfm.

STATUS AS OF: July 8, 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):

All barriers are installed, although the center portion of the Grant Line Canal barrier remains open until next week when its expected to close on or about July 14. The OR and MR barrier culvert flap gates were untied this week on Wednesday, which slightly improved low water level conditions upstream of those barriers. A dramatic improvement in water levels is expected (and shown by modeling results) next week when the GLC barrier is closed. Actual improvements will begin a few days earlier above the GLC barrier as the rock begins to be placed in the channel with maximum improvement occurring when the barrier is fully closed. However, modeling doesn’t depict the gradual improvement due to limitations of the model.

Modeling:

Modeling results for this week are attached. Water levels are currently above the trigger level (0.0 feet MSL) and will improve when the GLC barrier is closed. SJR flows will continue to drop about 100 cfs per day over the next couple weeks, along with higher ag water supply demands as the weather heats up and crops mature. Tide strength is decreasing as we approach the first quarter moon Thursday.

Modeling Outputs:

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


Notes:

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