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 4, 2012
As stipulated by court order, the Head of Old River, Middle River, and Old River Tracy Temporary Rock Barriers were installed approximately two weeks early. The early closure of the Head of Old River Rock barrier is intended to benefit out-migrating juvenile Chinook salmon and steelhead.
Head of Old River (HOR) Barrier:
Construction of the Head of Old River barrier began on March 15, 2012. Barrier closure and operation were achieved at noon on April 1, all eight slide-gate culverts are in open position. Crews completed construction the clay weir section of the barrier on April 11, 2012.
The Head of Old River Fish Study is underway, and telemetry data is being collected. The first release of acoustically tagged juvenile Chinook salmon occurred on 4/27/12. This study is being conducted in collaboration with the 6-yr Steelhead study.
Agricultural Barriers (Middle River [MR], Old River near Tracy [ORT], Grant Line Canal [GLC]):
Construction of the Middle River barrier began on March 12 and closure was obtained on March 16. All flap gates are tidally operated.
Construction of the Old River near Tracy barrier began on March 15 and closure and operation was achieved at 5:00 p.m. on March 31. All nine flap-gate culverts are tidally operated. The boat ramp and portage is in full operation as of Wednesday, April 4. Demobilizing and site cleanup was completed on Friday April 6.
The construction of the Grant Line Canal barrier is complete except the center weir portion. USFWS and DFG approved full closure as trawl data indicates the Delta smelt concern in the South Delta is low. Culvert flap gates will remain tied open. Construction to close the center portion of GLC started today, and full closure is anticipated on May 7, 2012.
Water Levels/Water Quality/Sound Monitoring Problem Notifications:
In compliance with the 401 Certification, staff performs twice daily turbidity and settable solids water sampling during construction. No violation of the conditions have been observed.
Modeling results are attached and forecasted minimum water levels are above target levels at Middle River at Howard Road (MHR) and Old River at Tracy Boulevard (OLD) stations, and Doughty Cut (DGL) station. Modeling assumes a full closure of GLC on May 7, 2012, and this significantly increases the DGL water level. As construction for full closure of GLC started today, water levels should remain above the DGL target elevation.
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Jacob McQuirk, 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) 653-9883 FAX: (916) 653-6077
Cell: (916) 425-6857 E-Mail: email@example.com