Native Fish Restoration in Redrock Canyon
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U.S. Department of the Interior Bureau of Reclamation Final Environmental Assessment Phoenix Area Office NATIVE FISH RESTORATION IN REDROCK CANYON U.S. Department of Agriculture Forest Service Southwestern Region Coronado National Forest Santa Cruz County, Arizona June 2008 Bureau of Reclamation Finding of No Significant Impact U.S. Forest Service Finding of No Significant Impact Decision Notice INTRODUCTION In accordance with the National Environmental Policy Act of 1969 (Public Law 91-190, as amended), the Bureau of Reclamation (Reclamation), as the lead Federal agency, and the Forest Service, U.S. Fish and Wildlife Service (FWS), and Arizona Game and Fish Department (AGFD), as cooperating agencies, have issued the attached final environmental assessment (EA) to disclose the potential environmental impacts resulting from construction of a fish barrier, removal of nonnative fishes with the piscicide antimycin A and/or rotenone, and restoration of native fishes and amphibians in Redrock Canyon on the Coronado National Forest (CNF). The Proposed Action is intended to improve the recovery status of federally listed fish and amphibians (Gila chub, Gila topminnow, Chiricahua leopard frog, and Sonora tiger salamander) and maintain a healthy native fishery in Redrock Canyon consistent with the CNF Plan and ongoing Endangered Species Act (ESA), Section 7(a)(2), consultation between Reclamation and the FWS. BACKGROUND The Proposed Action is part of a larger program being implemented by Reclamation to construct a series of fish barriers within the Gila River Basin to prevent the invasion of nonnative fishes into high-priority streams occupied by imperiled native fishes. This program is mandated by a FWS biological opinion on impacts of Central Arizona Project (CAP) water transfers to the Gila River Basin (FWS 2008a). The fish barrier construction program is one of several conservation measures intended to assist with recovery of federally listed fishes. ALTERNATIVES CONSIDERED Reclamation and the cooperating agencies considered No Action and two action alternatives in the EA. The proposed action was developed by Reclamation in consultation with the FWS and to meet the objectives of the 2008 CAP biological opinion. The following alternatives were considered during planning. No Action. Under the No Action alternative, Reclamation and the cooperating agencies would not implement the proposed native fish restoration project. Proposed Action. Under the Proposed Action, Reclamation will construct a fish barrier in Redrock Canyon on CNF land, approximately 4.25 miles upstream from Sonoita Creek. Following construction, the AGFD, with assistance from Reclamation and the other cooperating agencies, will: (1) salvage native fish, amphibians, and aquatic reptiles from waters of Redrock Canyon; (2) apply the piscicides antimycin A and/or rotenone and use mechanical methods to eradicate all nonnative fish in the watershed above the constructed barrier and reduce or eliminate bullfrog; (3) restore populations of native fish, frogs, salamanders, and semi-aquatic reptiles to all appropriate waters in the watershed; and, 2 (4) monitor the aquatic fauna of the watershed following treatment and restoration actions. If conditions are favorable, Gila chub will also be restored to the stream. Alternative A. Under Alternative A, no artificial barrier would be constructed. Nonnative species removal and native species restoration actions would affect the watershed only upstream of the existing natural barrier at the Falls and upstream of a set of natural barriers in upper Oak Grove Spring Canyon. The project area under Alternative A would differ from the Proposed Action in that about 1.6 miles of lower Redrock Canyon proper below the Falls, 2.2 miles of lower Oak Grove Spring Canyon, 1.8 miles of Oak Grove Spring Canyon tributaries, 1.4 miles of an unnamed tributary to lower Redrock Canyon, and one stock tank (Dry Tank) would be omitted. Other than this difference in the project area, the parameters for nonnative species removal and native species restoration would be the same as those described under the Proposed Action in the EA. Alternatives Considered But Rejected. Several alternative actions were considered and eliminated from detailed analysis during planning. These alternatives consisted of the following: 1. Alternative fish barrier sites. 2. Constructed barrier without nonnative removal and native species restoration. 3. Stock tank breaching. CONSULTATION, COORDINATION, AND PUBLIC INVOLVEMENT The project was listed on the CNF web site (http://www.fs.fed.us/r3/coronado) in a Schedule of Proposed Actions on January 1, 2007. On January 18, 2007, Reclamation posted a scoping notice on its Phoenix Area Office web site (http://www.usbr.gov/lc/phoenix) and mailed scoping information on the proposal to 53 potentially interested individuals, organizations, and agencies. In addition, a scoping meeting was held in Sonoita on February 8, 2007, to discuss the project with potentially affected grazing permittees. Reclamation and CNF received 11 letters of comment (including e-mail) during the 30-day scoping period which ended on February 16, 2007. Key issues identified in those letters are addressed in the EA. The pre-decisional draft EA was mailed to 58 potentially affected or interested individuals and agencies for a 30-day public comment period on September 14, 2007. In addition, a public notice was published in the Arizona Daily Star and news releases were sent to several other major media outlets serving central and southern Arizona regarding the availability of the draft EA. The draft EA was also available on Reclamation’s Phoenix Area Office web site. Five respondents submitted written comments concerning the proposed project during the 30-day public comment period. These comments and the agencies’ responses are included in Appendix G of the final EA. 3 Concurrent with development of the draft EA, Reclamation and CNF consulted with FWS under ESA Section 7(a)(2). The possible effects to listed species resulting from implementation of the Proposed Action were addressed in a biological assessment prepared by Reclamation and the Forest Service and submitted to the FWS on August 3, 2007. The biological assessment concluded the project may affect, and is likely to adversely affect, Gila topminnow, Gila chub, Sonora tiger salamander, and Chiricahua leopard frog because some may be harmed by chemical and mechanical treatments of aquatic habitat, despite salvage efforts prior to the treatments. The biological assessment also concluded that the proposed action may affect, but is unlikely to adversely affect, the lesser long-nosed bat. Despite possible adverse effects during implementation, the project is expected to have long-term, net benefits to native fish and amphibians by removing nonnative predatory fish and bullfrogs and preventing nonnative fish from reinvading stream habitat in Redrock Canyon. The FWS in its 2008 biological opinion on the Proposed Action, concurred with the effects determination of the biological assessment and required Reclamation and the Forest Service, to implement reasonable and prudent measures (RPMs) and associated terms and conditions to minimize or avoid the impact of incidental take on listed fishes (FWS 2008b). MAJOR CONSIDERATIONS The following issues that were addressed in the EA have been taken into consideration in Reclamation’s deliberation whether a Finding of No Significant Impact is appropriate, or an environmental impact statement should be prepared. 1. The Proposed Action is consistent with the direction and objectives of the CNF Plan and the 2008 CAP biological opinion. In addition, the 2008 biological opinion on the proposed action concluded that the Action is not likely to jeopardize the continued existence of Gila topminnow, Gila chub, Chiricahua leopard frog, and Sonora tiger salamander and will provide long-term benefit to these species by protecting them from the adverse effects of invasive nonnative aquatic species. Reclamation and the Forest Service will comply with the terms and conditions of the RPMs. Forest Service-sensitive species and management-indicator species known to occur in the project area would not be negatively affected by the Proposed Action. 2. Implementation of the Proposed Action will not significantly affect water resources. Potential increases in stream turbidity attributable to fish barrier construction will be short term and minor. No significant effect on stream dynamics or sediment transport will result from operation of the barrier. Application of the piscicide (antimycin A and/or rotenone) will have short-term, minor effects on water quality. Water quality certification and permit coverage under Clean Water Act, Sections 401and 404, have already been obtained. The terms and conditions of the 404 permit and 401 certification will be complied with. 4 Final Environmental Assessment Native Fish Restoration in Redrock Canyon 3. Effects to native aquatic biota will be temporary and limited to the treatment area. Application of the piscicide has the potential to temporarily reduce the abundance of certain groups of aquatic macroinvertebrates in treatment area, but long-term effects are expected to be minimal in regard to number, biomass, and diversity. Possible minor effects to other nontarget aquatic species will be limited to the treatment area. Dilution combined with the oxidation caused by sediment and organic material in the stream will detoxify all piscicide residues within a few