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:   October 18, 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 was finished June 18.

Dissolved oxygen concentrations in the Stockton Deep Water Ship Canal have been above the 6.0 mg/l objective, and the Department of Fish and Game notified DWR that they will not be requesting a fall HOR barrier this year.   


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. The elevation of the MR weir was raised by one foot on  9/1/2010. The removal of the Middle River barrier will begin on October 27, complete removal of the barrier is expected on November 2.

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.  ORT barrier culvert flap gates have been closed to tidal operation since 8/26/2010.  In order to help evaluate the effectiveness of improving water quality with the increased weir height at Middle River, the four center culvert at the ORT barrier were tied up from 10/1/2010 to 10/8/2010.  After 10/8/2010 all culverts were tidally operated.  The removal of the ORT barrier will begin on October 18, complete removal of the barrier is expected on November 10.

Installation of the GLC barrier began on June 16 and the boat ramp was completed on July 2nd.  Barrier closure was completed on July 7.  The barrier is now fully operating.  Removal of the GLC barrier started on 10/11/2010 in order to allow additional time to remove culverts that need to be replaced. New culverts will be installed next season.  It will take about 7 weeks to complete the removal.  The GLC barrier was breached on 10-14-10 at 8:30 AM.

On September 15, 2010 the weir at MR and ORT was notched and the flash boards removed at GLC to allow salmon passage.


Water Levels/Water Quality Problem Notifications:




Modeling results are attached. Water levels for all stations are above the target levels.   The forecasted stages have diverged with the actual stages approximately 0.5 to 0.75 feet lower than what the model is predicting.  Reasons include difficulty modeling the notches in the weirs that were done in September and inoperable flap gates on the GLC barrier that were recently discovered during the GLC removal.  Because the GLC culverts will be replaced in Spring 2011, this cause will no longer be a factor. 

Testing of the Middle River raise on EC concentrations in the south Delta has been completed.  The test included opening 4 culverts at the ORT barrier from 10-1-10 to 10-8-10.  Data is being compiled and results are forthcoming. 



This report is being send out late. Please note that modeling results are for the period of 10-11-10 to 10-29-10.  Actual stage data through noon on 10-14-10 is included.

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!

Jacob McQuirk, 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) 653-9883  FAX: (916) 653-6077
Cell: (916) 425-6857 E-Mail: