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: September 30, 2005

Head of Old River Barrier (HORB):

Late this week the contractor for the Temporary Barriers Project completed the barrier installation. Remaining is some minor cleanup and installation of the security fence. The culverts are in the default closed position; however water flows continuously over the notch created in the center of the barrier for salmon passage.

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

The Middle River (MR) barrier and Old River near Tracy (DMC) barrier are closed and have their culverts flap gates operating normally (tidally). Both the DMC and MR barriers had 20 foot wide notches created in the rock weirs to allow for passage of adult salmon that are migrating this time of year. The Grant Line Canal (GLC) barrier flashboard structure had boards removed to allow passage as well.

Modeling:

Modeling was completed this week and the results attached. Water levels are well above the trigger level (0.0 feet MSL at DMC and GLC barriers, 0.3 feet MSL at the MR barrier). The drop in water levels on September 29 reflects the closure of the HORB. However, the notch to provide continuous downstream flow for salmon passage had not been created yet. If water levels approach the trigger point, we will initiate actions to open two culverts to provide more downstream flow in Old River.

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