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 5, 2009

Head of Old River (HOR) Barrier:

The spring Head of Old River rock barrier was not installed this season.  Instead a Non-Physical Barrier (NPB) or “bubble barrier” was installed.  Installation began April 7 and was completed and tested in time for the first of seven VAMP experiment fish releases that began April 22.  This experimental barrier—placed near the channel bottom and extending across the entrance to Old River—uses a combination of bubbles, lights, and sound to guide out-migrating Chinook salmon smolts away from Old River to continue their migration down the San Joaquin River.  Underwater receivers were installed to detect tagged smolts to study the effectiveness of this NPB.  Preliminary results indicated the NPB significantly improved the number of smolts staying in the SJR over a no-NPB condition.  The NPB was removed beginning late May and was completely removed as of June 1.  Minor site cleanup continued this week. 

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

Installation of the ag barriers began May 18 with work at the MR and ORT barrier followed by the GLC barrier.  Installation of the MR barrier required installing replacement culverts for the old culverts that had deteriorated over many years.  The MR barriers is expected to be completed the week of June 8 with the culvert flap gates tied open.  The ORT barrier is expected to be completed the week of June 15 with flap gates also tied open.  The GLC barrier boat ramp began work on May 29 and the ramp is expected to be completed the week of June 15.  The center portion of the GLC barrier will remain open until the week of June 22, when approval is expected from the fish agencies to close the GLC barrier and untie the flap gates on the MR and ORT barriers.  Approval will be dependent upon delta smelt status in the south Delta.


Modeling will begin the week of June 15 as installation of the ag barriers advances enough to provide accurate modeling conditions.


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: