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:   September 21, 2009

Head of Old River (HOR) Barrier:

DWR is awaiting a decision by DFG whether the fall HOR barrier is needed to increase flows down the San Joaquin River to help improve dissolved oxygen in the Stockton Deep Water Ship Channel for the benefit of migrating adult Chinook salmon.  DFG generally makes a decision in September and the barrier is installed in late September or early October if requested. 

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

The MR and GLC agricultural barriers are operating tidally.  Since September 15, three culvert flap gates at the ORT barrier have been tied open.  Tomorrow, September 22, these three flap gates will be untied and all nine culverts will be operating tidally.   We plan to operate all barriers fully tidally for the remainder of the season until commencing removals in November.  Operations of the culverts may change depending upon conditions.

Modeling results are attached.  Actual water levels are well above the trigger levels (0.0 feet MSL at Old River and Grant Line Canal barriers, 0.3 feet MSL at Middle River barrier), and should remain that way through the modeled period.

Click here to see modeling outputs


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.

DWR has applied for permits this summer to allow raising the weir height at the MR barrier an additional one foot.  This would not change the barrier footprint, but would potentially provide improved circulation and water quality upstream in Middle River and downstream in Old River.  It appears unlikely that this change will be permitted in time for the current irrigation season due to the need to prepare additional documentation required by Federal regulatory agencies before review and permitted can be completed.

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:

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: