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high and isolated, but has been used for pasture-hay meadow. The area is not flood irrigated, has <br />not been flood irrigated, and is too high in elevation to be flood ircigated (at this elevation, the <br />growing season is too short for the normal flood irrigated crops). Subirrigation is limited to areas <br />along the stream channel itself. The area is determined not to be an Alluvial Valley Floor based <br />on its lack of flood ircigation potential and lack of significant subircigation. <br />An additional area along Steven's Gulch which lies within and to the south of the mine permit <br />area, contains areas of alluvium. This area includes alluvial gravel deposits in Sections 24 and 25 <br />(T13S, R92W) and the W I/2 of Section 30 (TI3S, R91W). Four separate deposits have been <br />identified within this area, as shown on Map No. 2-2. The two larger deposits, labeled Qagy and <br />Qago, may meet the geomorphic criteria of Alluvial Valley Floors, but do not meet the water <br />availability criteria for either flood ircigation or subircigation. Due to the steep slopes, rocky <br />surface, and lack of sufficient water, these areas cannot be flood irrigated. Regarding <br />subirrigation potential, the field investigation to detect subircigated species along Steven's Gulch <br />did not identify any such species within these areas. Vegetation suggests subircigation does <br />occur along portions of Steven's Gulch, but these species are confined to the extreme channel <br />bottom areas. Based upon this information, these two areas are found not to meet the criteria for <br />Alluvial Valley Floors. These are older tercaced deposits that have been dissected by stream <br />channels, such that the channels have completely cut through the deposit. These areas are found <br />not to be Alluvial Valley Floors. The larger of the two areas totals II.S acres, but the residential <br />access road that passes over the area reduces the acreage to below 10 acres. <br />A third area identified as having alluvial deposits is located along the North Fork of the <br />Gunnison River. These consist of floodplain and low tercace alluvial deposits and are identified <br />as (AI) on Plate No. 2. This area meets the geologic and hydrologic criteria of an Alluvial Valley <br />Floor in having unconsolidated stream-laid deposits with water sufficient to sustain agriculture. <br />Portions of the loadout facility and rail spur have been part of the mine plan before August 3, <br />1977; therefore, their construction is grandfathered (see Alluvial Valley Floor Findings that <br />follow). <br />Adjoining these deposits on both sides of the river are deposits ofcourse-grained outwash <br />(pediment) labeled Qpc. Geomorphically the deposits form lobes and undulating topography that <br />extend down to the low alluvial terrace deposits of the identified Alluvial Valley Floor. These <br />deposits are easily identified on Map 8-3 by the abrupt change in slope as one leaves the <br />flood-plain and terrace deposits along the river. <br />The slope outwash deposits are flood ircigated, which meets the hydrologic criteria of an Alluvial <br />Valley Floor, but geologically they are mixtures Mancos shale and eroded alluvium that were <br />primarily deposited by gravity flow and sheet wash. As such, they do not meet the criteria of <br />being stream laid. During the original review of the permit application, these deposits were <br />identified as part of the AVF. But further review and interpretation of additional hydrologic and <br />geologic information during the summer of 1991 indicated that the area did not meet the strict <br />definition of an Alluvial Valley Floor. Deposits at the mouth of Steven's Gulch mapped as Qpc <br />on Plates I and 2, of the Geo-Hydro AVF Phase I study (Volume 4) are identified as slope <br />outwash deposits. As such, they also do not meet the strict definition of unconsolidated <br />stream-laid deposits. The U.S. Soil Conservation Service has identified the Aqua Fria soils in <br />this area as "Farmland of Statewide Importance" and not as prime farmland. Because much of <br />the area is occupied by flood-irrigated orchards, the Division feels these areas are worth <br />protecting for their agricultural contribution. Although these areas are not AVF's, the Division <br />will require that these areas be treated as AVF's with respect to assuring that their essential <br />hydrologic functions be restored. On the basis of the information provided, the North Fork of the <br />40 <br />