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:   August 23, 2013

Due to low water level issues in the south Delta, the opening of culverts at the Old River Near Tracy Barrier has been indefinitely postponed.  Water levels have significantly improved compared to last week. Water hyacinth continues to be an issue and is currently impacting boat portage operations at Old River Near Tracy. 

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 received the Section 404 CWA/Section 10 RHA permit for 2013-2017 on Tuesday May 7, and construction of the south Delta temporary rock barriers started on Wednesday May 8. Construction of the Middle River barrier and Old River near Tracy barrier both started on May 8, and closure of the Middle River barrier was obtained on May 14 at approximately 2 PM.  The Old River near Tracy barrier was closed on May 30, and the Grant Line barrier was fully closed with culverts tidally operated on June 19. The modification to raise the weir height of Middle River barrier was completed on June 21.  Culverts at ORT and MR have been tidally operated since June 1, 2013. 


Temporary Barriers Culvert Operations.jpg

Environmental Permits Compliance Reporting:

Environmental compliance monitoring has occurred as scheduled. No construction or monitoring is currently planned until the weirs are notched for salmon passage in the fall.

Middle River-- Construction is complete at this site.  A nesting pair of Swainson’s hawks were observed on an island west of the Middle River Barrier and appeared to be incubating eggs as of June 3rd.  Nesting Barn Swallows were observed in one of the flap gate control boxes and was monitored until the young fledged on May 18th.  Once the young had fledged the nest was removed and the control box was covered to exclude the swallows.  No western pond turtles were observed during construction.  A request to the USFWS and CDFW to raise the Middle River Barrier was approved and the barrier weir height was raised by one foot on June 21.

Old River Tracy-- Construction is complete at this site.   A pair of nesting great horned owls was observed with young before construction on the South side of Old River, East of the barrier site, however, when construction began the nest was empty and appeared to have failed.  A nesting pair of red-tailed hawks was located on the South side of Old River across from the storage and staging area.  As of June 3rd, the two young had fledged.  Acoustical monitoring occurred at the construction site on Monday, May 20th and Thursday, May 23rd.  No western pond turtles were observed in the construction area; however, one had been seen sunning itself to the East of the construction area.

Grant Line Canal-- At Grant Line Canal three pairs of nesting Swainson’s Hawks were observed near the barrier construction site.  All three pairs have been observed incubating eggs as of May 18th and as of June 14th all the nests hatched young.  Observations of these nests suggest that construction activities are not causing significant disturbances to the nesting pairs.  A western pond turtle was seen crossing the haul road and was monitored to ensure safe passage.  Acoustical monitoring occurred at the construction site on May 24th, May 29th and May 30th.  A request to the USFWS and CDFW to close the center section of the barrier was approved. The barrier was fully closed and tidally operated on Tuesday June 19.

Water Levels and Water Quality Notifications:

Closure of Grant Line Canal and increased weir height on the Middle River was completed, and DWR continues to monitor the water levels.


Modeling Assumptions:
Middle River barrier was closed on May 14th, Old River near Tracy barrier was closed on May 30th, and Grantline Canal was partially closed on June 6th, 2013, then fully closed on June 19th, 2013.  All flap-gates on the Middle River and Old River near Tracy barriers were released to tidal operation on June 1st, 2013. The Grantline Canal barrier flap-gates were released to tidal operation on June 19th, 2013.  The Middle River barrier weir was raised by one additional foot on June 21, 2013. 

Water levels and quality continue to be monitored.  Due to recurring low water levels in Middle River, plans to operate culvert flap-gates at the ORT barrier have been postponed indefinitely. Water levels have significantly improved compared to last week.

Modeling results with measured water levels are provided in the graphs below. 






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:

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Thank you!
Jacob McQuirk, P.E.
DWR|Bay-Delta Office
Temporary Barriers and Lower San Joaquin
1416 9th St., Room 215-23
Sacramento, CA 95814
office:   916-653-9883
Fax:        916-653-6077


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