U.S. Fish & Wildlife Service

U S Fish and Wildlife Service

Sacramento Fish & Wildlife Office

External Affairs

U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife Office

News Release

Delta Water Flows Cut Back in Compliance with Court Order

February 27, 2008

Contacts:

Al Donner, (916) 414-6566
al_donner@fws.gov

The U.S. Fish and Wildlife Service (Service) today identified new target flows in Old and Middle Rivers (OMR) for the purpose of protecting young delta smelt, as ordered by the U.S. District Court for the Eastern District of California.

Upstream (negative) flows in OMR will be reduced to 3,000 cubic feet per second (cfs) average for the next seven days, in compliance with the preliminary injunction issued by the Court on Dec. 14, 2007 to protect this year's delta smelt. Upstream flows had been limited to 5,000 cfs starting in early January under another provision of the court order.

The Service believes this is a prudent action to protect the young fish and satisfies its responsibilities under the law, in accordance with the express direction of the court.

The action complies with Paragraph 4.a of the Court's interim order that directs the Service to use the best available scientific and commercial data, in consultation with the federal Bureau of Reclamation (BOR) and the State Department of Water Resources (DWR), to set an upstream flow level in Old and Middle Rivers between 750 cfs and 5,000 cfs when any of three thresholds is reached.

The court order further directs the Service to review and set the flow target each week, based on the available information including flow data generated through a particle tracking model.

The first threshold in Paragraph 4.a, detecting spent female delta smelt (that is, smelt that have deposited their eggs) was reached last week and the Service began the process of complying with the Court's order.

The action will be implemented by BOR and DWR, which operate the two large pumping facilities that are partially responsible for upstream flows on OMR. In their natural state Old and Middle Rivers are arms of the San Joaquin River that move some of its flow out to sea through the Delta. The two pumps are located at the southern end of OMR, near the city of Tracy.

The court's interim order is in place until the Service completes a new long-term Biological Opinion (BO) for the BOR and DWR export pumps. Under the court's order, the new BO must be completed by Sept. 15.

The 4.a process will continue until June 20, but under the Court's order could end earlier if "in their reasonable discretion of the Bureau, FWS and DWR the entrainment risk is abated."

Background

The Service, in consultation with the four other member agencies in the Smelt Working Group (BOR, DWR, State Department of Fish and Game, and the U.S. Environmental Protection Agency) and the Water Operations Management Team (WOMT) made its decision based on the best available information about the distribution and status of the delta smelt. The information will be reviewed each week and may be revised, as the Service identifies relevant new information. WOMT Notes

The process involves an analysis, conducted by DWR, of the pumps' relevant hydrological influence on distribution of the species in the Delta at different OMR negative flows. In effect, the Service analyzes how stronger or weaker pump-caused negative flows offset the exposure to this year's delta smelt for being taken at the pumps. See chart of Pump Entrainment at Various Levels of Negative Flow.

Then five factors used in reaching a decision are:

  1. The previous year's fall survey numbers
    (Current Situation: the fall 2007 numbers were at a record low);
  2. The number of fish taken at the pumps
    (Current Situation: relatively few at this point); See BOR chart.
  3. Where the delta smelt are located in the Delta
    (Current Situation: closer to the pumps is a higher level of concern; recent surveys show some delta smelt in the South Delta nearer to the pumps);
  4. Where the so-called X2 salinity level occurs
    (Current Situation: young smelt tend of congregate near the X2 point, thus when X2 is further away from the pumps the concern tends to be lower);
  5. Water temperature
    (Current Situation: when water warms above 25°C the likelihood of young smelt surviving decreases; the current water temperature is approximately 11.5°C).

Pursuant to the court's order, the Service makes the determination, in consultation with BOR and DWR. The Service's direction to BOR and DWR is to achieve a seven-day running average upstream flow of no more than 3,000 cfs over the next week. The Service will review the situation every week, using the most recent information, and call for adjustments using the five factors.

Under the Court's order, this process will be suspended for 31 days when additional downstream flows from the San Joaquin watershed are made under the existing Vernalis Adaptive Management Plan (VAMP). The VAMP flows must begin no later than May 1. Under the Court's order, at the completion of the 31-day VAMP flow the Paragraph 4.a process resumes.

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit www.fws.gov.

Sacramento Fish & Wildlife Office
www.fws.gov/sacramento
2800 Cottage Way, Room W-2605
Sacramento, CA 95825
(916) 414-6600