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:   May 26, 2011

Head of Old River (HOR) Barrier:

The planned spring Head of Old River non-physical barrier was not installed this season due to high flows in the San Joaquin River as a result of late season storm activity and associated heavy snow pack.  High velocity currents posed excessively dangerous conditions for divers which ruled out the possibility of installing the necessary equipment on the channel bottom.  As a result, fish studies at the HOR have been re-structured to evaluate predatory fish behavior in the absence of a non-physical barrier.  In support of this analysis, the Fisheries Foundation is capturing and tagging predators in the HOR vicinity. The movement of VAMP and  6-yr study releases of tagged salmon smolts and steelhead are being tracked in 2 dimensions to evaluate behavior in absence of the NPB. 


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

Installation of the Old River at Tracy (ORT) barrier is scheduled to commence tomorrow May 27, 2011 and Middle River (MR) barrier installation is anticipated to begin approximately June 1, 2011.  Installation of the ORT and MR barriers will accommodate on-going fish monitoring studies even though water levels are all well above the required stages.  The fish monitoring studies are required by the 2008 National Marine Fisheries Service (NMFS) biological opinion to: 1) examine the movements and survival of listed fish through the channels of the South Delta and ; 2) examine predation effects associated with the TBP.   DWR staff have been coordinating with VAMP to delay the fish releases intended to evaluate juvenile salmonid and predator behavior in the vicinity of the barriers.  DWR staff continue to capture and tag predators in support of this study.

Installation of the Grantline Canal (GLC) barrier will include re-construction of the south abutment and culvert structures which were removed at the end of the 2010 season.  The Grantline Canal culverts had reached the end of their service life and required replacement to provide on-going barrier effectiveness.  Construction of the GLC barrier will begin following the installation of the MR and ORT.  Presently high channel flows are creating unsafe conditions for construction, therefore installation will also be delayed until flows decrease.  Installation is anticipated to begin in mid June.


Modeling will begin once the agricultural barriers are installed, however, water level plots are attached for your reference.

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!

Jacob McQuirk, 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) 653-9883  FAX: (916) 653-6077
Cell: (916) 425-6857 E-Mail: