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<br /> A second area is located along Stevens Gulch in the W-�NW4 of Section 13, T13S,
<br /> R92W. As identified in the Orchard Valley permit application, the area is
<br /> approximately 35 acres in size and is composed of valley-fill deposits (Qvf) .
<br /> The applicant currently pumps 30,000 GPD from a production well installed in
<br /> this alluvium, and depth to water ranges from about 7 feet in May to approxim-
<br /> ately 36 feet in February. A letter from the Soil Conservation Service (Prime
<br /> Farmland Appendix, Volume 4) indicates that the area has not been historically
<br /> flood irrigated, and that flood irrigation has an extremely low potential due
<br /> to the location, rocky surface, and ground slope which would make the ponding
<br /> of water on the site extremely unlikely. On June 25, 1981, a field reconais-
<br /> . sance to detect subirrigated plant species was conducted, and it was found
<br /> that subirrigated tree species (pacific willow, river hawthorne, and narrowleaf
<br /> cottonwood) and herbaceous species (horsetails and rushes) exist within 4-5 feet
<br /> of either side of the drainage channel, which was dry. on the basis of infor-
<br /> mation provided, Stevens Gulch and it's associated alluvium in the W--�NW-id of
<br /> Section 13, T13S, R92W, is found to meet the criteria of alluvial valley floors.
<br /> An additional area along Stevens 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 A
<br /> of Section 30 (T13S, R91W) . Four separate deposits have been identified
<br /> within this area, as shown on Map No. 40. The two larger deposits, labeled
<br /> Qagy and Qago, may meet the geomorphic criteria of alluvial valley floors, but
<br /> do not meet the water availability criteria for either flood irrigation or
<br /> subirrigation. Due to the steep slopes, rocky surface, and lack of sufficient
<br /> water, these areas are not capable of being flood irrigated. In regards to
<br /> subirrigation potential, the field investigation to detect subirrigated species
<br /> (see AVF appendix, Volume 4) along Stevens Gulch did not identify any such
<br /> ( species within these areas. Vegetation suggestive of subirrigation does occur
<br /> along portions of Stevens 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. The two smaller deposits
<br /> adjacent to the stream channel may also meet the geomorphic criteria of
<br /> alluvial valley floors. These are older terraced deposits which have been
<br /> dissected by stream channels, such- that the channels have completely cut
<br /> through the deposit. Neither of these deposits meet the minimum size criteria of
<br /> the OSM alluvial valley floor technical guideline (10 acres) , and these areas
<br /> are found not to be alluvial valley floors. The larger of the two areas totals
<br /> 11.5 acres, but the residential access road which passes over the area reduces
<br /> the acreage to below 10 acres.
<br /> A third area identified as having alluvial deposits is located along the North
<br /> Fork of the Gunnison River. Deposits located upstream of the proposed opera-
<br /> tions are not a part of the hydrologic system that could be affected, and no
<br /> determination need be made at this time. The first area of unconsolidated
<br /> stream-lain deposits adjacent to the permit area is found at the beginning
<br /> of the loadout facility railroad spur, located in the NEfSE'r of Section 29,
<br /> T13S, R91W. At this point, the valley bottom has opened up and the deposits
<br /> extend up to 1%2 mile on either side of the river. Unconsolidated stream-lain
<br /> dep_s:=s w-=-•- _-.-- area ..-e been cl.assi=ied as Flood-plain alluvium, valley-
<br /> fill deposits, and younger alluvial gravels. Areas within Sections 29, 30,
<br /> 31 and 32 in T135, R911V and Section 36 in T13S, R92W have been identified as
<br /> currently supporting agriculture. The application, on pages 15-16, Section 2.06
<br />
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