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 6 , 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 will be determined afterwards depending on water levels and delta smelt issues. All flap gates on the barriers remain tied open. The flap gates may be untied (operating normally) if necessary to protect south Delta water levels but only with fishery agencies approval. Currently fishery requirements dictate that the gates will remain tied open until at least June 10.
A look at CDEC data for this week shows water levels improving at the three sites monitored above the barriers. This is partly due to closure of the ORT barrier this week. We included actual water levels through yesterday morning (6/9/08). Actual water levels at Old River and Middle River are significantly better than modeled forecasts while on Grant Line Canal, actuals and modeled conditions are fairly close. The modeling shows water levels remaining above the level of concern at the ORT station (0.0 feet MSL) and the level of concern at the MR station (0.3 feet MSL), however levels are slightly below the level of concern at the GLC monitoring station (0.0 feet MSL). Conditions on Grant Line Canal won’t improve significantly until the GLC barrier is fully closed. We’ll be requesting permission from the fishery agencies to close the GLC barrier while leaving all the culvert flap gates tied open on all the barriers for Delta smelt protection.
Click here to see modeling outputs.
Fishery agencies and DWR will be closely monitoring conditions for Delta smelt which might effect operations of the barriers during May/June. Changes in flap-gate operations on the culverts, delaying filling of the GLC center section, removal of the barriers, and changes to SWP/CVP export operations are all possible actions that could be taken to protect smelt if necessary.
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Mark A. Holderman, P.E.
Chief, Temporary Barriers Project and
California Department of Water Resources
Phone: (916) 653-7429 FAX: (916) 653-6077
Cell/Pager: (916) 601-6036 E-Mail: email@example.com