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 28 2007

Head of Old River Barrier (HORB):

On Thursday this week, DFG requested DWR install the fall HOR barrier.  This barrier will block much of the water entering Old River to help increase SJR flows past Stockton and improve dissolved oxygen in the Deep Water Ship Channel for the benefit of salmon.  The barrier contractor is being notified and will mobilize crews to begin work at the site late next week.

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

All agricultural barriers are in place with the GLC and MR barriers have been operating normally.  No flap gate changes were made this week.  Currently, at the ORT barrier, a total of six culverts have flap gates tied open (allows tidal flows to move both ways) and three have flap gates untied (opening and closing with the tides).  We will continue to monitor water levels and quality, and adjust the status of the culvert flap gates depending on conditions.  Barriers were notched in mid-September in the center of their weirs to allow increased weir flow depths and improve passage for adult salmon migrating upstream.



Modeling was done to monitor water levels at various locations.  The modeling shows water levels remaining above the level of concern at the ORT, and GLC monitoring stations (0.0 feet MSL) and the level of concern at the MR station (0.3 feet MSL)

Click here to see modeling outputs


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