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-14- <br />Ground water information can be found on pages 37-42A of Section 2.04 of <br />Volume A, pages 126-153 of Section 2.05 of Volume 16, and in the ground water <br />Appendix of Volume 4 of the 1983 application; and in Sections 2.04.5 and <br />2.04.7 of the permit amendment. The operation is in compliance with the <br />requirements of this section. <br />VI. ALLUVIAL VALLEY FLOORS (2.06.8, 4.24) <br />The discussion of alluvial valley floors can be found on pages 11-20, Section <br />2.06, Volume 1B and AVF Appendix, Volume 4. <br />Identification of Alluvial Valley Floors <br />The general area in which the Orchard Valley Mine is situated contains several <br />deposits of alluvium. These alluvial deposits are made up of 3 types of <br />alluvium: 1) Flood-plain alluvium (Qal) along the North Fork of the Gunnison <br />River; 2) Valley-fill deposits (Qvf) along a portion of Steven's Gulch; and 3) <br />Alluvial gravels (Qag) divided into 3 age categories (younger (Qagy), middle <br />(Qagm) and older (Qago)). These deposits are located along the North Fork <br />Valley side slopes. <br />CWI has identified alluvial/colluvial deposits in a second area which is <br />located along Steven's Gulch in the W 1/2 NW 1/4 of Section 13, T13S, R92W. <br />As identified in the CWI Phase 1 AVF Study, the area is approximately 20 acres <br />in size and is composed of valley-fill deposits (Qvf). The applicant <br />currently pumps 30,000 GPD from a production well installed in this <br />alluvium/colluvium, and depth to water ranges from about 7 feet in May to <br />approximately 36 feet in February. The area is high and isolated, but has <br />been used for pasture-hay meadow. The area is not flood irrigated, has not <br />been flood irrigated, and is too high in elevation to be flood irrigated (at <br />that elevation, the growing season is too short for the normal flood irrigated <br />crops). subirrigation is limited to areas along the stream channel itself. <br />The area is determined not to be an alluvial valley floor based on its lack of <br />flood irrigation potential and lack of significant subirrigation. <br />An additional area along Steven's Gulch, within and to the south of the mine <br />permit area, contains areas of alluvium. This area includes the younger and <br />older alluvial gravel deposits in Sections 24 and 25 (T13S, R92W) and the W <br />1/2 of Section 30 (T13S, R91W). Four separate deposits have been identified <br />within this area, as shown on Map No. 2-2, Volume. The two larger deposits, <br />labeled Qagy and Qago, may meet the geomorphic criteria of alluvial valley <br />floors, but do not meet the water availability criteria for either flood <br />irrigation or subirrigation. Due to the steep slopes, rocky surface, and lack <br />of sufficient water, these areas are not capable of being flood irrigated. In <br />regards to subirrigation potential, the field investigation to detect <br />subirrigated species along Steven's Gulch did not identify any such species <br />within these areas. Vegetation suggestive of subirrigation does occur along <br />portions of Steven's Gulch, but these species are confined to the extreme <br />channel bottom areas. Based upon this information, these two areas are found <br />not to meet the criteria for alluvial valley floors. These are older terraced <br />deposits which have been dissected by stream channels, such that the channels <br />