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CESPK-CO-R Public No[ice Number 199475260 Once mined, the blockage fill is partially removed (concrete blocks) and breached to allow river flow to return to the pit. All available extraction sites for the Thomas Pit are further depicted on the Plan View drawing (Page 2 of 8). Normal mining operations have been restricted to the upper portion of the harvest pit in the central portion of this drawing. ALTERNAT}1VES: The no action alternative would result in permit denial and essentially require the instream operations to cease. This alternative would possibly require the applicant to mine upland areas within their permit boundaries. While mining riparian and upland areas would avoid excavation activities within the Animas River, these areas provide a finite and nonreplenishable source of material and can result in additional types of negative impacts. ,such impacts may include the loss of riparian vegetation, interception and exposing of ground water, and an increased number of other gravel mine locations and associated secondary impacts (such as habitat loss, bank destabilization, loss of flood control function, noise, traffic, dust, and visual aesthetics). Alternative methods of mining or other mining locations have not been identified by the applicant; however, six additional instream sand and gravel mining activities occur in the Animas River valley (refer to "Additional Information" section below). AREA DI~.SCRIPT'1:ON: The project area is private property leased for a commercial gravel operation by owners Donna L. Thompson and Collen J. Bryce. This site is located within and adjacent 'to the Animas River approximately 11 miles north of Durango and two miles downstream of Bakers Bridge. Affected area of the mining operation is approximately 29.8 acres permitted from the Colorado Department of Natural Resources, Division of Minerals a.nd Geolol;y, permit number M-76-020. 11113 Slle 1a luCdted Within a iTiOnntaln Valley aC an Cle`/utl.^.^ Cf approximately 6,670 feet msl. The drainage basin of the Animas River at this location is approximatley 475 square miles with an average annual bankfull discharge of approximately 3,400 cubic feet per second (cfs). High flows usually occur in the spring between the months of April through July with some increase seen during late summer rains. The high flow of record occurred on October 5, 1911 measuring 2.5,000 cfs at the USGS stream gage in Durango. Elk, mule deer, small mammals, and various waterfowl and passerine bird species frequent the area. A 1992 fish study was performed approximately two miles upstream near Bakers Bridge and reported trout (brown and rainbow), suckers (flannel mouth, bluehead, and white), mottled sculpin, and carp. The Colorado Division of Wildlife has identified heavy metals, hil;h silt load, and high water velocities as the limiting factors for fisheries in the Animas River north of Dura~lgo. Riparian plant comrrrunities occur irregularly along the river banks and are dominated by cottonwood trees with an un~ierstory of upland shrubs and grasses. Cottonwoods are also becoming established on the side slopes of the southern dike feature. River banks are steep and appea:• to be suffering from erosion. The west bank contains several small ponds fed by the Animas Valley C'onsolidtsted Ditch and a few home sites with State Highway 550 farther upgrade. Surrounding ]and use is increasingly residential, particularly on the east side of the Animas River. ~~ •