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: June 24, 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 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. Water levels have not dropped enough to justify operating the culverts yet, but we will continue to monitor levels and have the culverts flap gates untied when the need arises. Full culvert operations and perhaps closing the GLC barrier may occur before mid-July as SJR flows drop and irrigation demand increases.

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, SJR flows will continue to drop a couple thousand CFS over the next two weeks, so we probably will look at fully operating the culverts and maybe even closing the GLC barrier during that time.

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