REV103458 - Laserfiche WebLink

Home Browse Search

Biological Assessment for DMG Permit Renewals McClane Canyon & Munger Canyon Mines humpback chub (USFWS 1967), and razorback sucker (USFWS 1991). Decline of the four endangered species is due at least in part to habitat destruction (diversion and impoundment of rivers) and competition and predation from introduced fish species. In 1994, the USFWS designated critical habitat for the four endangered species (USFWS 1994), which in Colorado includes the 100-year floodplain of the upper Colorado River from Rifle to Lake Powell, and the Gunnison River from Delta to Grand Junction. None of the four endangered Colorado River fishes occur in or near the assessment areas and the assessment areas do not occur within or adjacent to designated critical habitat. The closest designated critical habitat and the closest populations of the Colorado pikeminnow, humpback chub, and razorback sucker are in the Colorado River, approximately 20 miles south of the assessment areas (Figure 1). The bonytail is presumed to be extirpated in Colorado. Potential impacts to Colorado River endangered fishes could result from water depletion in East Salt Creek, a tributary of the Colorado River (see Section 3 of this BA for depletion descriptions and Section 2 of this BA for descriptions of previous Section 7 consultations on depletions). Water depletions, although relatively small (a permitted average of 13.39 acre-feet per year), have the potential to diminish backwater spawning areas in downstream designated critical habitat in the Colorado River. The Upper Colorado River Endangered Fish Recovery Program, a partnership of public and private organizations working to recover the four species while allowing continued and future water development, was established in 1988. Recovery strategies include conducting research, improving river habitat, providing adequate stream flows, managing non-native fish, and raising endangered fish in hatcheries for stocking. As explained in Section 2 of this BA, the USFWS has determined that the Recovery Program has made "sufficient progress to be the reasonable and prudent alternative to avoid the likelihood of jeopardy to the endangered fishes and to avoid destruction or adverse modification of their critical habitat by depletions of 100 acre-feet or less." 5.3 Amphibians Nofederally-listed amphibians are affected by the proposed actions. Great Basin soadefoot (S). This toad is probably widespread in northwestern Colorado, where it is known from several scattered locations ranging from the bottoms of rocky canyons to dry basins in broad floodplains, in sagebrush, semi-desert shrublands, and pinyon-juniper woodlands (Hammerson 1999). Its status in the assessment areas is unknown. The toads are active during and after spring and summer rains from May through September. Breeding occurs primarily along permanent streams in floodwaters, in pools along intermittent streams, or in temporary pools after rainfall. Inactive periods are spent burrowed into soils. No major threats are known (Hammerson 1999). The permitted areas of surface disturbance for McClane and Munger directly affect approximately 10.5 acres of potential Great Basin spadefoot habitat (the East Salt Creek riparian corridor, the mouth of McClane Canyon, and the Munger Creek canyon bottom). Potential impacts are limited to habitat loss and fragmentation from pre-existing surface disturbance and accidental roadkill. Given the limited area pre-existing surface disturbance and level of operational activity at the mine sites, the proposed actions are not likely to produce measurable impacts on the Great Basin spadefoot. Northern leopard frog (S, SC). The northern leopard frog inhabits wet meadows, the banks and shallows of marshes, stock ponds, beaver ponds, kettle ponds, lakes, reservoirs, streams, and irrigation ditches. Formerly quite abundant in Colorado, northern leopard frog populations are thought to be in decline in the state at least partly or locally due to competition and predation March 27, 2006 11 Rare Earth Science,