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: July 9, 2010
Head of Old River (HOR) Barrier:
The spring Head of Old River rock barrier was not installed this season. Instead, as in 2009, a Non-Physical Barrier (NPB) was installed. Installation began April 5 and was completed on April 15. The operation of the NPB supported the VAMP fish study and includes a determination of the NPB’s effectiveness. The salmon smolt monitoring was concluded on May 26 at the end of the VAMP and the NPB stayed in operation to benefit non-VAMP smolts through June 15th in compliance with our NMFS biological opinion. The removal of the NPB started on June 16, the complete removal will be finished by Friday June 18.
Agricultural Barriers (Old River near Tracy [ORT], Middle River [MR], Grant Line Canal [GLC]):
Construction of the MR barrier began on May 19. Due to equipment problems, closure of the MR barrier was delayed to May 24. All flap-gates were untied on June 16 and the barrier is now fully operating.
Construction of the ORT barrier began on May 10 and the boat ramp was completed on May 13. Closure of ORT barrier was achieved on June 3. All flap-gates were untied on June 16 and the barrier is now fully operating.
Installation of the GLC barrier began on June 16 and the boat ramp was completed on July 2nd. The center portion of the GLC barrier remained open throughout the July Fourth weekend. Crews resumed works on Monday July 5, and the barrier closure was completed on July 7.
Water Levels/Water Quality Problem Notifications:
Low water levels inside Tom Paine Slough reported by South Delta Water Agency on July 4. Water levels outside the slough should improve after the GLC barrier is closed, which should help with conditions inside TPS.
Modeling results are attached. Since the GLC barrier was closed on Wednesday, actual water levels rose well above the trigger levels (1.0 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. Actual data for the MR station after 7/7 was not available from CDEC but increased water levels can be expected similarly to the other stations. DWR staff is investigating the reason for the missing data.
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Mark A. Holderman, P.E.
Chief, Temporary Barriers Project and Lower San Joaquin
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: email@example.com