Southern Idaho Wildlife Mitigation

Authors(s): H. J. Hansen and C. Colter

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Publication Date: 0000-00-00

Type: proposal

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Abstract: Protect, enhance, and maintain native riparian, wetland, and shrub-steppe habitats in southern Idaho as on-going mitigation for Palisades, Anderson Ranch, Minidoka, and Black Canyon hydroelectric projects (NWPPC Program Measures 11.2D.1, 11.2E.1, 11.3D.4, 11.3D.5, 11.3D.7, and 11.3D.8). The overall objective is to provide 18,223 Habitat Units (HU?s) by acquiring fee-title or easements and enhancing a combination of 16,216 acres of priority habitats, through the year 2003. The specific FY1999 objective is to provide 4,146 HU by the protection/enhancement of 3,689 acres. Potential mitigation sites in southern Idaho were initially prioritized by interagency teams of biologists in the mid 1980's, who considered biological significance, applicable references (Boccard 1980), in-place/in-kind opportunities, and juxtaposition to other management areas. The original list of mitigation sites continues to guide mitigation implementation, with the addition of new information from more contemporary conservation site planning in Idaho, including wetland conservation strategies (Jankovsky- Jones, 1997a,b) and the recent Nature Conservancy/Idaho Department of Fish and Game process to identify a set of biodiversity conservation reserves in the Columbia Plateau ecoregion using GAP Analysis Program cover types as coarse filter targets (Moseley, pers. comm.). Each individual mitigation parcel is subjected to the CBFWA regional wildlife criteria by the interagency teams of biologists to ensure that it meets regional wildlife program standards. Progress will be monitored by measuring standardized target species habitat variables from Habitat Evaluation Procedure (HEP) models (USFWS 1980). Target species population trends also will be monitored to evaluate long-term species-habitat relationships. a. Technical and/or scientific background. The human ecology of the Pacific Northwest has been and continues to rely heavily on the Columbia River system. The development of the Columbia River Basin has provided many modern, social benefits such as hydropower, irrigation, and flood control. These benefits, however, also came with many social costs that were largely ignored for decades. A free-flowing river became a series of reservoirs. The historic salmon and steelhead runs became sparse. The timing and intensity of natural water flows were altered. Riparian corridors and adjacent uplands were inundated. Perhaps most important, yet least understood, were the cumulative impacts on both terrestrial and aquatic systems. Other land use activities also have impacted native wildlife habitat in the Columbia Basin over the last 100-200 years. Since the 1860's, when mining and farming boomed, wetlands in Idaho have decreased 56%, from about 879,000 acres to approximately 386,000 acres (Dahl 1980). The Interior Columbia Basin Ecosystem Management Project basin-wide analysis of riparian vegetation noted significant changes, including widespread declines of shrublands in riparian zones (USFS 1996). Cottonwood, aspen, and willow, typical riparian-associated species, significantly decreased in the Snake River Headwaters and the Columbia Plateau. Substantial declines in native grasslands and shrublands, mostly on non-federal lands, also have been documented (USFS 1996). Within the Columbia Basin, many wildlife species have declined because of the changes and loss of native shrublands and grasslands, including Columbian sharp-tailed grouse, sage grouse, loggerhead shrike, pygmy rabbit, white-tailed antelope squirrel, California bighorn sheep, and Washington and Idaho ground squirrels. The current extent of shrub-steppe and grassland protection in Idaho is low (Caicco et al. 1995) but is a high priority in the 1996-2000 Idaho Sage Grouse Plan (IDFG 1996). Neotropical migrants, whose populations are declining globally, also would benefit from conservation and restoration of riparian, old forest, shrub-steppe, grassland, and juniper habitats (USFS 1996). Although the obvious cost of the hydropower system was the impact on wild salmon and steelhead runs, the cumulative impacts to wildlife also were recognized. As a result of the Pacific Northwest Electric Power Planning and Conservation Act of 1980 (Public Law 96-501), the Northwest Power Planning Council (NWPPC) passed the Columbia River Basin Fish and Wildlife Program (FWP) to addresses these impacts and to ensure that wildlife receive equitable treatment in matters concerning the hydropower system. The goal of the FWP wildlife strategy is ?to achieve and sustain levels of habitat and species productivity as a means of fully mitigating wildlife losses caused by construction and operation of the federal and non-federal hydroelectric system? (Sec. 11.1, 1995 Amendments). In southern Idaho, four federal projects, including Minidoka, Black Canyon, Anderson Ranch, and Palisades, inundated a total of 36,405 acres of wildlife habitat. Using the standardized Habitat Evaluation Procedure (HEP), a measure of both the quality and quantity of wildlife habitat (USFWS 1980), biologists estimated a net loss of 54,292 habitat units (HU?s) for a variety of target species. The Southern Idaho Wildlife Mitigation Project is designed to mitigate those losses, in addition to protecting and enhancing critical habitat for a wide variety of species depending on riparian, wetland, and shrub-steppe habitats. In conjunction with the NWPPC and CBFWA?s Wildlife Caucus criteria for ranking wildlife projects, most projects are in-place, in-kind mitigation and all have addressed HU for target species (see Table 11-4 in NWPPC 1995; USFWS 1980). Each of the four facilities will be addressed separately in this section for clarity. Palisades Palisades Dam was completed in 1958, impacting 18,565 acres of wildlife habitat (Chaney and Sather-Blair 1985c) and Sather-Blair and Preston (1985) estimated a net loss of 37,068 HU. The Wildlife Protection, Mitigation, and Enhancement Plan: Palisades Project (Martin and Hansen 1986) outlined priorities for mitigation, and the Wildlife Caucus ranked the proposed South Fork Snake River as one of the highest-priority mitigation projects for the Columbia Basin. The riparian habitats along the South Fork Snake River represent one of the largest remaining cottonwood systems in the western U.S. and provides habitat for many wildlife species and for a native cutthroat trout population.. The South Fork and Upper Snake was ranked as the most important fish and wildlife habitat in Idaho (Boccard 1980) and as the highest-priority coarse filter target (seasonally/temporarily flooded cold deciduous forest) for protection within the Columbia Plateau Ecoregion (B. Moseley, IDFG, pers. comm.). The primary threat to these cottonwood systems is recreational home development spilling over from the Jackson Hole, Wyoming, and Yellowstone area fragmenting the riparian corridor, increasing human disturbance, thus losing bald eagle breeding and wintering habitat. Although much of the river corridor is currently managed by Bureau of Land Management (BLM), several key riparian parcels will imminently be subdivided if they are not protected through this program (B. Martin, IDFG, pers. comm.). A number of unprotected parcels are likely to become available for acquisition or easement within the next several years (K. Ragotzkie, IDFG, pers. comm.). Existing shrub-steppe, that provides food and cover for big game, sage grouse, and sharptailed grouse, is steadily declining. Considering the projected population growth in Idaho in the next decade (Idaho Division of Financial Management 1997), it is critical to protect and enhance the remaining shrub-steppe. The Southern Idaho Wildlife Mitigation Project is designed to protect, enhance, and maintain river and riparian corridors and shrub-steppe habitat. Focus areas for protecting river and riparian corridors include the South Fork, Henrys Fork, and Upper Snake Rivers. Focus areas for protecting shrub-steppe include the Tex Creek and Soda Springs Hills mitigation project areas, with additional opportunities in Sand Creek and Fort Hall Bottoms. In addition to the target species, many wildlife species will benefit from mitigation, including moose, elk, deer, river otters, trumpeter swans, and neotropical songbirds. The newly-discovered, listed threatened plant, Spiranthes diluvialis, may also benefit. All projects will provide in-kind mitigation.

Keywords: Idaho, wildlife, animal, mammal, management, population, mortality, habitat, Palisades Lake, human activity, fish, Pisces, Snake River, grouse, bird, Aves, ornithology, ichthyology, sharp-tailed grouse, Columbian sharp-tailed grouse, Tympanuchus phasianellus columbianus, sage grouse, Centrocercus uraphasianus, shrike, loggerhead shrike, Lanius ludovicianus, rodent, rabbit, Leporidae, pygmy rabbit, Brachylagus idahoensis, squirrel, white-tailed antelope squirrel, Ammospermophilus leucurus, ungulate, sheep, bighorn sheep, Ovis canadensis, California bighorn sheep, Ovis canadensis californiana, ground squirrel, Washington ground squirrel, Spermophilus washingtoni, Idaho ground squirrel, Spermophilus brunneus endemicus, neotropical migrant, Salmonid, trout, cutthroat trout , Oncorhynchus clarki bouvieri, salmon, Jackson Hole, Greater Yellowstone Ecosystem, Teton County, suburban area, eagle, raptor, bald eagle, Haliaeetus leucocephalus, moose, Cervidae, wapiti, elk, Cervus elaphus, deer, otter, river otter, Lutra canadensis, swan, trumpeter swan, Olor buccinator