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.

STATUS AS OF:   June 17, 2010

Head of Old River (HOR) Barrier:

The spring Head of Old River rock barrier was not installed this season.  Instead, as in 2009, a Non-Physical Barrier (NPB) was installed.  Installation began April 5 and was completed on April 15.  The operation of the NPB supported the VAMP fish study and includes a determination of the NPB’s effectiveness.  The salmon smolt monitoring was concluded on May 26 at the end of the VAMP and the NPB stayed in operation to benefit non-VAMP smolts through June 15th in compliance with our NMFS biological opinion.  The removal of the NPB started on June 16, the complete removal will be finished by Friday June 18.

Agricultural Barriers (Old River near Tracy [ORT], Middle River [MR], Grant Line Canal [GLC]):

Construction of the MR barrier began on May 19.  Due to equipment problems, closure of the MR barrier was delayed to May 24. All flap-gates were untied on June 16 and the barrier is now fully operating.

Construction of the ORT barrier began on May 10 and the boat ramp was completed on May 13.  Closure of ORT barrier was achieved on June 3. All flap-gates were untied on June 16 and the barrier is now fully operating.

Installation of the GLC barrier began on June 16 with work on the boat ramp.  The GLC barrier site needs to remain open to allow passage of a large barge/crane that will has been dismantling the NPB.  By Friday, June 18, the barge should pass the GLC site which will allow work to begin on the weir section. It will take between two to three weeks to complete the construction.

Water Levels/Water Quality Problem Notifications:  None this week.


Modeling results this week compared water levels near the MR, ORT, and GLC barriers with the flap-gates tidally operated. Modeling results and CDEC data indicated that water levels at Middle River at Howard Road Bridge and Tracy Road Bridge would be above the +0.3 feet and 0.0 feet action trigger.  The water levels near the GLC barrier may drop slightly below the 0.0 foot trigger, but will improve as work on the GLC progresses. 

See attached.

These weekly updates are also available for your information on our website:

If you know of anyone else that should be receiving this update, please let me know by email, and I'll add them to the mailing list.  Thanks!

Mark A. Holderman, P.E.
Chief, Temporary Barriers Project and Lower San Joaquin
Bay-Delta Office
California Department of Water Resources
1416 9th St., P.O. Box 942836
Sacramento, CA 94236-0001
Phone: (916) 653-7429  FAX: (916) 653-6077
Cell: (916) 601-6036 E-Mail: