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CESPK-CO-R Public Notice Number 199475348 Some excavated materials may be temporarily stockpiled on the adjacent east river bank until the material can be hauled off-site. This stockpile site is located above the "ordinary high water mark" of the Animas River in an upland azea as shown on the attached Typical Section drawing. Excavated materials, which range between sand and silt particle size, aze usually hauled up to the Dalton Pit (also owned by the applicant) for processing, if necessary (such as wood removal). When baz excavations are completed, the perimeter berm is removed with afront-end loader and hauled from the site. The finished surface is dressed and left in a smooth configuration. The applicant states "... This method of controlled mining contributes to the stability of the river system by preventing the accumulation of sediment on the point bar, thereby decreasing the pressure of the rivers flow on the west bank with a corresponding decrease in erosion of the west bank. Additionally, this method of mining does not increzse the existing channel bank heights and so does not contribute to accelerated bank erosion ~md no detrimental impacts to local or off-site areas have been observed nor are expexted. Further, this type of mining operation does not involve the removal of existing riparian vegetation or the alluvial soil overburden." ALTERNATIVES: The no action alternative would result in permit denial ~md essentially require the instream mining operation to cease. This alternative would possibly result in the applicant mining other areas within their permit boundaries. While mining 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 or different types of negative impacts. These impacts may include the loss of riparian vegetation, interception and exposition of ground water, and an increased number of other mine locations and associated -secondary-impacts-(such-as habitat-loss,-bank-destabilization,-loss of-flood-control-function,____ noise, traffic, dust and visual aesthetics). Alternative mining methods and 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 DESCRIPTION: The project site is located at a northeast point bar of the Animas River approximately four miles north of Durango. The Animas River is at a~i elevation of 6,550 feet msl at this location and drains an approximate 656 square mile drainage area. Average annual bankfull discharge is approximately 4,260 cubic feet per second (cfs). High flows usually occur in the spring between thf: months of April through July with some peaks seen during late summer rains. The high flow of record occurred in October 1911 at 25,000 cfs, as measured at the USGS stream gage located in Durango. 2 •