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<br />that this ie an insufficient amount of water to support surface irrigation <br />activities. Based on the limited presence of unconsolidated deposits, <br />their location in relation to the proposed mine, and the lack of surface <br />water to support surface irrigation, No Name gulch is determined not to be <br />an AVF. <br />Unconsolidated streamlaid deposits exist in Johnson gulch within the <br />proposed permit area. These valley fill areas are all located outside of <br />the proposed disturbed area. Land use along Johnson gulch ie undeveloped <br />rangeland and cropland. The cropland consists of 725 acres of dryland <br />wheat. The upper reaches of Johnson gulch will also be mined through and <br />reconstructed during reclamation. No identified alluvial deposits will be <br />mined through. The average annual water yield ie 114 acre-ft/year. Based <br />on conversations with the local Soil Conservation Service official in <br />Craig, Colorado this is amount of water would irrigate 25-35 acres for <br />average years after evaporation losses. It would be uneconomical to <br />construct a flood irrigation system for such a limited acreage. <br />Therefore, based on the lack of irrigation potential and currently <br />irrigated cropland, Johnson gulch is determined not to be an AVF. <br />The valley associated with Pyeatt gulch contains unconsolidated streamlaid <br />deposits. All of these alluvial materials are located downstream of the <br />proposed permit area and will, therefore, not be disturbed by mining. <br />Land use along Pyeatt gulch consists of cropland and undeveloped rangeland <br />(see Map 35-8). Unirrigated wheat and native grass hay are grown along <br />Pyeatt gulch and constitute 719 acres of cropland. The average annual <br />water yield for Pyeatt gulch is 154 acre-ft. The applicant, through <br />interviews with local Soil Conservation Service officials, has determined <br />that this is an insufficient amount of water to economically practice <br />flood irrigation. Flood irrigation is occasionally practiced in the <br />Pyeatt gulch valley. The McNamara ditch ( see Map 31 ) is fed by a deep <br />bedrock well, completed to a depth of greater than 400 feet. Since this <br />ditch does not rely on surface or alluvial water, Pyeatt gulch is not an <br />AVF based on the presence o£ surface irrigation. Data supplied by the <br />applicant indicate that the depth Co the alluvial water table is 5.6-7.7 <br />feet. This water table is to deep for wheat and native grass hay to be <br />subirrigated. Therefore, based on the lack of sufficient water available <br />for agricultural benefit, Pyeatt gulch is determined not to be an AVF. ~ <br />The applicant has identified unconsolidated streamlaid deposits along the <br />valley of Flume gulch. All of these alluvial materials are located <br />downstream of any proposed mining disturbance. Land use along Flume gulch <br />consists of undeveloped rangeland and cropland. None of these crops are <br />currently or were historically flood irrigated. No irrigation ditches <br />currently exist along Flume gulch. The average annual water yield for <br />Flume gulch is estimated at less than 40 acre-ft which is an insufficient <br />amount of water to practice flood irrigation. Originally, data submitted <br />by the applicant indicated depths to the alluvial water table of <br />approximately 2 feet. Current data (Sept. 1992) indicate water levels of <br />34 feet below the surface and 16 feet below the surface at the COMB Bite <br />and the GC3 site respectively. The Soil Conservation Service conducted an <br />Order 2 Soil Survey of Flume gulch and reported the results of this survey <br />in a correspondence to Trapper Mine dated October 31, 1985. In there <br />opinion, the only portion of Flume gulch which had the potential to be an <br />AVF was the area shown on Map 58 of the Trapper permit designated with the <br />symbol 08. They also reported the area as having little agricultural <br />significance. This study included six test pits, only three of which <br />ultimately fell in the area labeled as 08. In addition, these three test <br />pits all were located in the southern or upper portion of area 08. Test <br />pit #4 showed ground water at 66 inches and some mottling indicating the <br />presence of potential subirrigation. The crop historically and currently <br />growing within the area 08 is a perennial hay crop consisting of almost <br />exclusively alfalfa in the pasture areas. Production data submitted <br />indicates 3750 pounds per acre for the pasture lands. Color infrared <br />Page 14 <br />