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 27, 2009

Head of Old River (HOR) Barrier:

No fall HOR barrier will be installed this year.

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

All agricultural barriers are operating tidally and will continue to do so through this week until they are removed beginning the first week of November (next week!).  All in-water work will be completed by the Thanksgiving holiday weekend.  Due to a large accumulation of water hyacinth at the boat portage facility at the GLC barrier, boat tenders are having difficulty using the boat ramp to move boats across the barrier.  Later this week, if we can’t keep the ramps clear of hyacinth, we may begin removing a portion of the GLC weir early to allow boaters to cross the barrier without using the portage ramps.

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: