Laserfiche WebLink
-17- <br />One of these areas, the Morrell Cow Camp area, although geographically <br />adjacent to the permit area, is not hydrologically adjacent to the <br />activities being reviewed in this permit application. The northerly <br />downdip of the strata, the lack of water encountered in drill holes just <br />to the North of the permit boundary, the depth of overburden <br />(1500-2000'), and the presence of a surface water divide between the <br />permit area and the Morrell Cow Camp area indicate a hydrologic <br />separation from the area to be permitted. As such, a formal <br />determination for this area will not be made at this time. When the <br />applicant submits an application that proposes mining activities within <br />either the surface watershed or ground water system for this area, the <br />Division will make the required alluvial valley floor determination. <br />A second area is located along Stevens Gulch in the W 1/2 NW 1/4 of <br />Section 13, T13S, R92W. As identified in the CWI Phase 1 AVF Study, the <br />area is approximately 2U acres in size and is composed of valley-fill <br />deposits (Qvf}. The applicant currently pumps 30,000 GPD from a <br />production well installed in this alluvium, and depth to water ranges <br />from about 7 feet in May to approximately 36 feet in February. The area <br />is high and isolated, but has been used for pasture-hay meadow. The area <br />is not flood irrigated, has not been flood irrigated, and is too high in <br />elevation to be flood irrigated. (At that elevation, the yrowing season <br />is too short for the normal flood irrigated crops.) Subirrigation is <br />limited to areas along the stream channel itself. The area is determined <br />not to be an alluvial valley floor based on its lack of flood irrigation <br />potential and lack of significant Subirrigation. <br />An additional area along Stevens Gulch, within and to the South of the <br />mine permit area, contains areas of alluvium. This area includes the <br />younger and older alluvial gravel deposits in Sections 24 and 25 (T13S, <br />R92W) and the W 1/2 of Section 30 (T13S, R91W). Four separate deposits <br />have been identified within this area, as shown on Map No. 40 of the 1981 <br />application. The two larger deposits, labeled Qagy and Qago, may meet <br />the geomorphic criteria of alluvial valley floors, but do not meet the <br />water availability criteria for either flood irrigation or <br />Subirrigation. Due to the steep slopes, rocky surface, and lack of <br />sufficient water, these areas are not capable of being flood irrigated. <br />In regards to Subirrigation potential, the filed investigation to detect <br />subirrigated species along Stevens Gulch did not identify any such <br />species within these areas. Vegetation suggestive of Subirrigation does <br />occur along portions of Stevens Gulch, but these species are confined to <br />the extreme channel bottom areas. Based upon this information, these two <br />areas are found not to meet the criteria for alluvial valley floors. <br />These are older terraced deposits which have been dissected by stream <br />channels, such that the channels have completely cut through the <br />desposit. Neither of these deposits meet the minimum size criteria of <br />the OSM alluvial valley floor technical guideline (10 acres), and these <br />areas are found not to be alluvial valley floors. The larger of the two <br />areas totals 11.5 acres, but the residential access road which passes <br />over the area reduces the acreage to below 10 acres. <br />