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:   July 20, 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 4.

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

DWR personnel untied the flap gates on the MR and GLC barriers on Tuesday, July 7, so they now operate tidally.  The ORT barrier culverts flap gates were ALL untied on Wednesday, July 15, to help alleviate poor water levels due to weak neap tides and high diversion rates. 

Modeling:

Modeling results are attached.  Actual water levels are above the trigger levels (1.0 feet MSL at Old River and Grant Line Canal barriers, 0.3 feet MSL at Middle River barrier), and have improved since we untied the flap gates on the Old River barrier and tides began gaining strength as a spring tide approaches, July 22.

Click here to see modeling outputs

Notes:

The GLC barrier culverts are in need of repair and are not operating to their fullest potential (some leakage and poorly sealing flap gates).  DWR staff will be diving the barrier to determine the extent of repairs with the intent of completing repairs by the 2010 season.

Due to “Furlough Friday’s” on three of four Fridays each month, the TBP weekly update will go out on Mondays until further notice.

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


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: markho@water.ca.gov