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:  May 11 , 2007

Head of Old River Barrier (HORB):

The HOR barrier is closed with three culverts closed and three open.  For now, we’re keeping three open to allow some downstream flow into Old River to help with circulation.  The HOR barrier will normally be removed beginning after the VAMP experiment, probably the latter part of the week of May 21.  Fishery agencies may request later or earlier removal depending on conditions for SJR salmon and delta smelt.

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

Barrier installations began April 2, 2007. The ORT and MR barriers are closed and culverts operating tidally.  The GLC barrier closed on Thursday, May 10.


Modeling was completed this week and the results attached.  The HOR barrier has three culverts open and three closed.  Flap gates are operating tidally at the ORT, MR, and GLC barriers.  Modeling assumed the GLC barrier would be closed May 9; however it was actually closed on May 10. 

Modeling Outputs:

Middle River at Howard Road Bridge
Doughty Cut above GLC Barrier
Old River near Tracy Road Bridge


Fishery agencies and DWR will be closely monitoring conditions for Delta smelt which might effect operations of the barriers during April-May.  Changes in flap-gate operations on the culverts, removal of the barriers, and changes to SWP/CVP export operations are all possible actions that could be taken to protect smelt if necessary.  


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

Please delete your old “favorite” for the Temporary Barriers Project and add this new site!

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/Pager: (916) 601-6036 E-Mail: