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 03, 2013
The is our first TBP update of the season. Neither the Head of Old River barrier rock barrier nor the non-physical barrier was installed this spring and agricultural barrier installation has not yet started.
Head of Old River (HOR) Barrier:
Spring Head of Old River barrier will not be constructed in 2013.
Agricultural Barriers (Middle River [MR], Old River near Tracy [ORT], Grant Line Canal [GLC]):
DWR anticipates to receive the Section 404 CWA/Section 10 RHA permit for 2013-2017 on Monday May 6, and construction of the south Delta temporary rock barriers is scheduled to start on Tuesday May 7. The scheduled construction start date for Middle River barrier has been moved up to May 7, 2013 with closure later in the week. Closure of the Old River Tracy barrier will occur next. Closure of the Grant Line Canal barrier is subject to the Delta smelt conditions within the Delta. DWR plans to maintain an accelerated construction schedule until all barriers are closed. Better estimates of closure dates are forthcoming in the next update.
Environmental Permits Compliance Reporting:
Preconstruction nesting raptor surveys have been conducted to determine the proximity and locations of nesting raptors in the vicinity of the TBP construction. Nesting Red-Tailed Hawks, Swainson’s Hawks, Great Horned Owls and other birds have been documented near the barrier construction sites. Surveys and monitoring have been and will continue to be conducted based on environmental permit requirements.
Water Quality Monitoring:
Water sampling is scheduled to begin as soon as the barrier construction begins.
Water Levels and Water Quality Notifications:
It is discovered that flap-gates at Tom Paine Slough siphons are in need of replacement. DWR is in the process of procuring and installing the new flap-gates as expeditiously as possible. Currently the repair is scheduled to begin the week of May 13, 2013. In order to protect water level in Tom Paine Slough, Pescadero Irrigation District siphons are being stopped and started with tides until the repair is complete.
This week modeling simulation assumed that Middle River barrier to be closed on May 17th, Old River near Tracy barrier to be closed on May 29th, and Grantline Canal barrier to be partially closed on June 10th, 2013. All flap-gates on the Middle River and Old River near Tracy barriers would be released to tidal operation on June 1st, 2013, Grant Line Canal flap-gates to stay tied open until Delta Smelt concerns have passed. Modeling is based on the best available information at the time the modeling is started.
Modeling results are attached and forecasted minimum water levels will drop below target levels at all three monitoring locations.
Water levels for the forecast period are as follows:
Middle River at Howard Road (sta MHR) – Actual low water levels are currently approximating the modeled forecast. Modeling shows water levels currently at -0.5 ft will rebound to -0.1 ft on May 7th then drop to -1.0ft (1.3 ft below the target of 0.3 ft) on May 17, 2013, the end of the forecast period.
Old River at Tracy Blvd. (sta OLD)– Actual low water levels are currently approximating the modeled forecast. Modeling shows water levels currently at -0.6 ft will rebound to -0.1 ft on May 7th then drop to -0.9 ft (0.9 ft below the target of 0.0 ft) on May 17, 2013, the end of the forecast period.Doughty Cut (sta DGL) – Actual low water levels are currently approximating the modeled forecast. Modeling shows water levels currently at -0.5 ft will rebound to 0.0 ft on May 7th then drop to -0.8 ft (0.8 ft below the target of 0.0 ft) on May 17, 2013, the end of the forecast period.
Real-time south Delta water level data is available on CDEC at the URL below:
These weekly updates are also available for your information on our website:
We recently moved this email list to a new list server, and this is the first message to the list. The new server has enhanced capabilities. Anyone can subscribe or unsubscribe to the list by clicking the link below:
Alternatively you can contact me, and I can make additions or removals to the mailing list.
Jacob McQuirk, P.E.
Temporary Barriers and Lower San Joaquin
1416 9th St., Room 215-23
Sacramento, CA 95814
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