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 23, 2005

Head of Old River Barrier (HORB):

This week the contractor for the Temporary Barriers Project began work on installing the fall Head of Old River barrier. Work is in progress on preparing the gravel pad for the prefabricated culvert structure. The structure is expected to be in place the middle of next week. Work to install the bulk of the rock to close the channel will begin after the culvert installation. The fall HORB has a large notch in the center to allow continuous flow to benefit adult salmon crossing the barrier. The barrier is scheduled to be completed about October 4.

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 not completed this week but will begin next week. Modeling will be done weekly to monitor water levels and assist in decisions regarding HORB culvert operations. Initially the culverts will all be closed and will be opened as needed later.

Notes:

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