Final EIS/EIR, Nimbus Hatchery Fish Passage Project
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Final Environmental Impact Statement/ Environmental Impact Report for the Nimbus Hatchery Fish Passage Project Rancho Cordova, California U.S. Department of the Interior Bureau of Reclamation California Department of Fish and Game August 2011 Final Environmental Impact Statement/ Environmental Impact Report for the Nimbus Hatchery Fish Passage Project Rancho Cordova, California Prepared by Tetra Tech U.S. Department of the Interior California Department Bureau of Reclamation of Fish and Game Mid-Pacific Regional Office Sacramento, California August 2011 Nimbus Hatchery Fish Passage Project Final Environmental Impact Statement/Environmental Impact Report (State Clearinghouse No. 2009042050) NEPA Lead Agency: United States Department of the Interior, Bureau of Reclamation CEQA Lead Agency: California Department of Fish and Game The United States Department of the Interior, Bureau of Reclamation (Reclamation) and the California Department of Fish and Game (CDFG) have jointly prepared this Environmental Impact Statement/Environmental Impact Report (EIS/EIR) for the Nimbus Hatchery Fish Passage Project (Project). The Nimbus Fish Hatchery (Hatchery) is on the lower American River, a quarter-mile downstream of Nimbus Dam in Rancho Cordova, California. Reclamation built the Hatchery in 1955 to mitigate for the loss of spawning habitat for Chinook salmon and Central Valley steelhead trout that were blocked by the construction of Nimbus Dam, and CDFG operates and maintains the Hatchery. The fish weir, which helps adult salmon enter the fish ladder, is aging, is susceptible to damage from high flows, and requires annual flow reductions for maintenance. Reclamation has identified two alternatives that would address this issue. Alternative 1 is to extend the fish ladder from the Hatchery to the Nimbus Dam stilling basin, using the basin itself to hold and divert fish to the ladder. Under the first alternative, the weir would be permanently removed. Two implementation options, Alternative 1A and Alternative 1C, are being evaluated because the CDFG is considering modifying fishing closure regulations. Alternative 1A is consistent with current fishing regulations and would not require any change in these regulations. Alternative 1C requires a modification of fishing regulations to be approved by the Fish and Game Commission. Alternative 2 is to replace the existing weir with a new weir structure; the CDFG is considering no modifications to fishing regulations under Alternative 2. The EIS/EIR evaluates the potential impacts of implementing these alternatives and a No Action Alternative on fisheries, biological resources, recreation, cultural resources, geology and soils, water resources, hazardous materials, public health and safety, infrastructure (including utilities and transportation), energy, air quality, noise and vibration, land use, visual resources, and socioeconomics and environmental justice. For further information contact: Mr. David Robinson, Reclamation, at (916) 989-7179 or [email protected], or Mr. Joe Johnson, CDFG, at (916) 358-2943 or e-mail [email protected], or visit the project website at www.usbr.gov/mp/ccao/hatchery. This page intentionally left blank. Executive Summary Introduction The United States Department of the Interior, Bureau of Reclamation (Reclamation), and the California Department of Fish and Game (CDFG) have prepared this environmental impact statement/environmental impact report (EIS/EIR) to address the environmental effects of the proposed removal or replacement of a fish diversion weir (weir) at the Nimbus Fish Hatchery (Hatchery) in Rancho Cordova, Sacramento County, California. These agencies have prepared this EIS/EIR in accordance with the National Environmental Policy Act (NEPA) of 1969, 42 United States Code (USC) Section 4321 et seq., the Council on Environmental Quality (CEQ) regulations for implementing NEPA, 40 Code of Federal Regulations (CFR), Parts 1500-1508, the California Environmental Quality Act (CEQA) of 1970, California Public Resources Code, Section 21000 et seq., as amended, the Guidelines for Implementation of CEQA, Title 14, California Code of Regulations (CCR), Section 15000 et seq., and Reclamation and CDFG guidelines. Reclamation is the NEPA lead agency and the CDFG is the CEQA lead agency. Background and Setting The Hatchery is on the lower American River, approximately a quarter-mile downstream of Nimbus Dam. The Hatchery was built as mitigation for Chinook salmon (Oncorhynchus tshawytscha) and Central Valley steelhead trout (O. mykiss; “steelhead”) spawning areas blocked by the construction of Nimbus Dam. The weir was constructed to create a barrier in the river that allows adult Chinook salmon to locate the entrance to the fish ladder for collection by the Hatchery. The weir is needed from mid-September through early January during the Chinook salmon spawning season. The weir superstructure is removed for the remainder of the year, although its foundation and concrete piers remain in place year-round. Without the weir superstructure in place to block upstream passage of Chinook salmon, sufficient numbers to meet Hatchery mitigation production goals could not enter the ladder. Steelhead locate the ladder entrance in sufficient numbers to meet mitigation production goals without the weir superstructure in place. The Hatchery, weir, and fish ladder were constructed and became operational in 1955. Since then, much of the hatchery infrastructure has been modernized, but the weir and ladder system are largely unchanged. The weir structure is aging and shows signs of over 50 years of use. The weir foundation and piers are periodically damaged by significant August 2011 Nimbus Hatchery Fish Passage Project Final EIS/EIR ES-1 winter river flows, requiring major repairs in 1963, 1982, 1986, and 1999. There are also annual operational and maintenance problems with the weir that could jeopardize adult fish collection and the Hatchery’s ability to meet its mitigation obligations. Installation and maintenance of the weir require lowering river flows to levels that negatively affect steelhead, a protected species under the Endangered Species Act (ESA) and California Endangered Species Act (CESA). The weir racks and pickets cannot handle flows over 5,000 cubic feet per second (cfs) and sometimes requires removal before sufficient numbers of adult fall-run Chinook salmon can be collected. Worker safety during installation and removal and for routine cleaning is also a primary concern. The most recent flood to significantly damage the weir foundation and river embankment next to the Hatchery occurred in January 1997. Reclamation consulted with the NMFS on potential impacts of the repair project, including continued weir repair and associated flow reductions on federally protected fish. The NMFS recommended that “. Reclamation and CDFG develop a long-term solution and a schedule for implementation to minimize flow fluctuations associated with the installation and removal of the Nimbus Fish Hatchery fish diversion weir racks and pickets by June 2000” (NMFS 1999). Purpose and Need The purpose of the proposed project is to create and maintain a reliable system for collecting adult fish to allow Reclamation to remain in compliance with mitigation obligations for spawning areas blocked by the construction of Nimbus Dam, while adequately protecting Chinook salmon and Central Valley steelhead trout. Reclamation is authorized to replace the weir or to implement its functional equivalent in order to fulfill its obligation to raise four million Chinook salmon smolts and 430,000 steelhead yearlings annually at the Hatchery. This obligation was established as a result of the Fish and Wildlife Coordination Act Report (August 14, 1946, 60 Stat. 1080; United States Fish and Wildlife Service [USFWS] and CDFG 1953), which recommended measures to mitigate the impacts of constructing Nimbus Dam, as authorized by the American River Basin Development Act (October 14, 1949, 63 Stat. 852). The proposed project would support Reclamation’s need to address problems with the weir that could jeopardize adult fish collection and its ability to meet mitigation obligations. Annual river flow reductions are required in order to install and maintain the weir. In years with significant winter water flows, extensive repairs have been necessary to repair weir damage, including scouring (eroding) the weir foundation. Scouring creates holes that allow adult Chinook salmon to pass through the weir and continue upstream past the fish ladder entrance. In years where extensive damage has occurred, flow reductions of approximately five to nine days have been necessary to repair the weir. Extended periods of flow reduction negatively impact the availability of steelhead habitat in the river, which reduces the amount of cover from predation and increases fish densities in the remaining habitat, thus increasing the potential for predation and for August 2011 Nimbus Hatchery Fish Passage Project Final EIS/EIR ES-2 disease to spread. Lowering flows can also degrade habitat by raising temperatures and decreasing dissolved oxygen levels (NMFS 2009a). Reclamation formed a partnership with the CDFG to operate and manage the Hatchery. The CDFG also has responsibility statewide for overseeing fish hatchery operations and managing fishery resources.The CDFG maintains native fish, wildlife, plant species, and natural communities for their intrinsic and ecological value and their benefits to people. This includes habitat protection and