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:  June 27 , 2008


Head of Old River Barrier (HORB):

The spring HOR barrier work will not be installed this year due to a court decision by US District Court Judge Wanger that prohibited the installation of the spring barrier to increase protections for delta smelt.  This is an interim decision that effects the 2008 season only.  The fall HORB is not effected.

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

Work began May 12 at the DMC barrier with closure being completed on Wednesday, June 4.  The Middle River barrier construction began on May 20 and was completed May 21.  Crews began construction of the Grant Line Canal north abutment (boat ramp) on May 19.  Partial closure (completion of the boat ramp) was completed on Monday, June 2.  Full closure of the GLC barrier was complete this week on Thursday, June 26.  All the GLC culvert flap gates are untied and operating tidally.  Flap gates on the MR and ORT barriers remain tied open at the request of the fishery agencies for the benefit of delta smelt, however, we will revisit the need to keeping the flap gates tied open early next week.



Modeling was begun this week but was not received in time for today’s update.  Modeling results will be again sent out in a separate emailing early next week.  A look at CDEC data for this week shows water levels have been rising steadily since work began on the GLC barrier to close the center portion.  Even with the weak neap tide, water levels have improved considerably and are well above the trigger point for each station monitored.


Fishery agencies and DWR will be closely monitoring conditions for Delta smelt which might effect operations of the barriers during May/June.  At this late date, changes in flap-gate operations on the culverts are the only likely action that might be taken to protect smelt if necessary.    



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: