Operational Changes in Support of Lake Cascade Fishery Restoration, Boise Project, Payette Division, ID

AGENCY:

Bureau of Reclamation, Interior.

ACTION:

Notice of cancellation.

SUMMARY:

The Bureau of Reclamation (Reclamation) is canceling work on the environmental impact statement (EIS) for proposed operational changes at Lake Cascade, on the North Fork Payette River near Cascade, Idaho. Because of a potential for irrigation shortages, and a high probability of a reduction in salmon flow augmentation water as a result of the proposal, both Reclamation and Idaho Department of Fish and Game (IDFG) decided that the draining of Lake Cascade is not a viable option for sport fish restoration. The notice of intent was published in the Federal Register (68 FR 41842, July 15, 2003).

FOR FURTHER INFORMATION CONTACT:

Mr. Steve Dunn, Snake River Area Office at telephone 208-334-9844, or e-mail sdunn@pn.usbr.gov. TTY users may call 208-334-9844 by dialing 711 to obtain a toll free TTY relay.

SUPPLEMENTARY INFORMATION:

In early 2003, IDFG requested that Reclamation consider draining Lake Cascade to assist in a fishery restoration project to help rebuild the Lake Cascade sport fishery. IDFG had determined that the presence of large numbers of northern pikeminnow and largescale suckers in the lake were a major cause of the decline of the important yellow perch and trout fishery and would prevent recovery of the fishery unless their number were significantly reduced. IDFG had analyzed different methods to remove and/or reduce the numbers of northern pikeminnow and largescale suckers. They concluded the most economical method, with the highest probability for success, would entail lowering the reservoir's water level as much as possible and utilizing a fish toxicant (rotenone) to kill any remaining fish. The reservoir would then be restocked with yellow perch, trout and other gamefish.

Preliminary analysis of the draining proposal identified the potential for significant environmental and socioeconomic effects, and Reclamation concluded that an EIS, because draining the lake would be considered a Federal action, would need to be prepared to comply with the National Environmental Policy Act of 1969. In July 2003, Reclamation published a Notice of Intent to prepare an EIS in the Federal Register and to conduct public scoping meetings. Scoping meetings were held in southwest Idaho in early August 2003, and written comments were accepted into September. Over 340 distinct comments were received and reviewed.

The first analysis needed for the proposal was a complete understanding of the physical and logistical aspects of draining Lake Cascade and the reservoir's subsequent refill. Information was needed on how the project would affect irrigation deliveries, salmon flow augmentation supplies, the reservoir conservation pool, river flows and other uses of the Payette River drainage. Reclamation water operations experts conducted reservoir drawdown and refill studies in the fall of 2003 and recently presented their findings. Major findings of the water studies concluded that the reservoir could be drained to accommodate the fishery renovation proposed by IDFG, but with varying impacts to irrigation deliveries and salmon flow augmentation, depending on hydrologic conditions in the months and years following the drawdown.

The water studies indicated that under one of the drawdown scenarios studied, irrigation deliveries would have little chance of being impaired. Another drawdown scenario identified possible irrigation impacts in the first irrigation season following the drawdown if it was a very dry year, and possibly for more than one year in successive dry years.

However, salmon flow augmentation supplies were likely to be affected by all of the drawdown scenarios analyzed. Impacts would occur in the first augmentation season following the drawdown and potentially for several years afterward. Reclamation has committed to provide up to 427,000 acre-feet of flows, as a result of consultation under the Endangered Species Act, to aid in juvenile salmon migration in the Snake and Columbia Rivers. The Payette River annually supplies approximately one-third of the salmon flow augmentation from Idaho and provides irrigation water to more than 100,000 acres of farmland.