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: October 28, 2016
Removal of the barriers started on October 19, 2016 at the Old River near Tracy barrier site, breach of the barrier was achieve on October 20, 2016; the culverts and their frames were removed this week, removal of the rocks continues until completion of the removal anticipated to be reached by November 9, 2016.
Work on the removal of the Grant Line Canal barrier started this week, breach was achieved Friday October 28, 2016 at 8:30 AM work was discontinued early in the afternoon due to muddy conditions.
work on the Middle River barrier>; will start on the October 08, 2016 and it will take approximately ten days to complete the removal.
At the head of Old River barrier site, three more culverts were opened on October 20, 2016 in an attempt to enhance the water quality in south Delta. All six culverts will stay in the open position until the removal of the barrier which is scheduled to begin on November 9, 2016.
DWR continues to work with the Central Valley Regional Water Quality Control Board to monitor the algae bloom situation. The latest report indicates that concentration of the algae fell below the health concern level mainly because of high flow on the SJR and the latest series of rain storms.
Finally, Siqing of the Delta Compliance Section performed a computer modeling run for the period from 10-26-16 through 11-14-16. For the modeling duration, the water level was above the concern level of 2.5 feet National American Vertical Datum at the Old River near Tracy barrier, the Grant Line Canal barrier, and the Middle River barrier for the first week of November then water level dipped below the concern level due to the breach of the barriers. Modeling results are attached.
Agricultural Barriers (Middle River [MR], Old River near Tracy [ORT], Grant Line Canal [GLC]):
The installation of the Middle River barrier started on March 2, 2016; closure was achieved by March 9, 2016. All flap gates are tidally operating as of April 1, 2016. DWR raised the weir crest by one additional foot on June 22, 2016 to aid south Delta farmers during the high demand irrigation season.
The installation of the Old River near Tracy barrier started on March 3, 2016; the construction crew closed the barrier on March 25, 2016. The flap gates were released to tidal operation on April 1, 2016. The barrier is functioning as designed, and the boat tender is on duty.
The construction crew started working on the Grant Line Canal barrier on Monday March 28, 2016; the in-water work started on March 30, 2016 with partial closure attained by April 14, 2016. Mobilization to close the barrier started on May 25, 2016, the work started on May 26, 2016, and the barrier was closed on June 8, 2016. All flap gates resumed tidal operation as of June 17, 2016. The barrier is functioning as designed, and the boat tender is also on duty.
Notching of the MR and ORT barriers for salmonid passage was conducted on September 12, 2016 and the top flashboard of the GLC flashboard structure was set at 2.5 feet.
Removal of the Temporary Barriers Project will start on October 19, 2016. The completion of barriers removal is scheduled for November 30, 2016. Removal of Old River at Tracy barrier will begin on October 19, 2016, and should complete by November 8, 2016. Removal of Middle River barrier will begin on November 8, 2016, and should complete by November 18, 2016. Removal of Grant Line Canal barrier will begin on November 4, 2016, and will be completed on or before November 30, 2016. Barrier removal schedule has been moved up to allow additional time to fully remove the Middle River barrier. Per agreement with South Delta Water Agency, all culvert slide gates at the Head of Old River will be opened just prior to breach of any agricultural barrier. This timing of the slide gates opening at the Head of Old River barrier will allow retaining as much of the pulse flow in the San Joaquin River as possible.
Head of Old River Barrier [HORB]:
The construction of the Spring Head of Old River barrier started on March 10, 2016 with closure achieved by April 1, 2016. All slide gates were placed in the open position in accordance environmental permits. Mobilization for the removal of the barrier started on May 27, 2016; the breach was achieved on June 01, 2016, and the removal was completed on June 14, 2016.
On September 1, 2016 CDFW requested DWR to install the Fall Head of Old River Barrier (FHORB). The FHORB construction started on Wednesday September 15, 2016 and channel closure was achieved on September 27th, 2016 at 1100 hours. Construction was completed on September 29th. On October 12 three of the six culvert slide gates were opened.
Removal of Fall Head of Old River barrier will begin on November 9, 2016, and should complete by November 24, 2016.
Environmental Permits Compliance Reporting:
Environmental staff conducted pre-construction surveys as required by the State and Federal permits and by Biological Opinions. Environmental monitors have and will be presented for construction activities. No environmental issues have been observed.
Water Levels and Water Quality Notifications:
No exceedance were observed of the water quality turbidity measurements during the installation of the MR, ORT, GLC, and HORB installations and no exceedance was observed during the construction of the Fall HORB. However, thick algal bloom was observed near the vicinities of the barrier sites and toxic algae (cyanobacteria) has been verified. DWR will continue to monitor the water quality parameters and the water levels. Three of the six culvert slide gates at Head of Old River barrier were opened on 10/12/16 to help with circulation and the cyanobacteria problem.
Thanks to Reza of the Delta Compliance and Modeling Section, computer modeling was performed and a copy of the modeling results is attached for the modeling duration from 10-5-16 through 10-31-16. For the modeling duration, the water levels at the Old River near Tracy barrier, Middle River barrier, and the Grant Line Canal barrier near Doughty Cut were above the concern level of 2.5 feet National American Vertical Datum. Field data collected by the monitoring stations revealed a close match to modeled results for both the Old River near Tracy and the Grant Line Canal barriers, but monitoring station data for the Middle River at Howard Road is lower than predicted by modeling.
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:
Water Resources Engineer
1416 Ninth Street
Sacramento, Ca 95816
(916) 653-6077 FAX
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