Laserfiche WebLink
• The area in the vicinity of New Horizon 2 has (since about 1910) had an extensive man-made <br />irrigation system. The water used for flood irrigation is diverted from the San Migue! River <br />approximately 15 miles east ofthe New Horizon Mine by the Colorado Cooperative Ditch Company. <br />The irrigation ditches transect basins and commonly run along the basin divides {see Map 2,04.7-1 <br />for the exact location of the irrigation ditches). The main irrigation ditches have a network of feeder <br />ditches running from them for irrigating outlying fields. These ditches are a source of ground water <br />recharge, causing ground water mounding in the shallow ground water aquifer system. The effects <br />of mounding near the New Horizon Mine are apparent from monitor well water levels and <br />hydrographs (see Peabody Appendix 7-2). Perennial flow occurs in Tuttle Draw as a result of <br />ground water discharge and return flow from the irrigation of the upland area. Site inspections <br />confirm that water used for irrigation is obtained from the San Miguel River and no flood irrigation <br />water is obtained from Tuttle Draw or Calamity Draw. The West Lateral Ditch crosses the proposed <br />New Horizon 2 mining area. <br />In regard to the agricultural water quality standards, the San Miguel River water delivered by the <br />irrigation ditches is more suitable for irrigation purposes than the waters in Tuttle or Calamity Draw. <br />The agricultural suitability (National Academy of Sciences, 1972) of surface water in Calamity and <br />Tuttle Draws falls within the category of water that can only be used for salt tolerant plants on <br />permeable soils with careful management practices (TDS from 2,000 to 5,000 mg/I). Using the <br />same classification system, water supplied by the West Lateral irrigation ditch (San Miguel River) <br />(TDS 500 mg/I or lower) will have no detrimental effects on plants. Waters of Tuttle and Calamity <br />Draws have commonly exceeded the manganese and PH agricultural standards. <br />Since the early part of this century, it has been a regional practice to obtain water for irrigation from <br />the San Miguel River, Because of the incised nature of the stream channel, it is diffcult to flood <br />irrigate from either Tuttle or Calamity Draw. From field reconnaissance investigations, it has also <br />been determined that water pumpage from these draws for irrigation purposes is occurring <br />infrequently. <br />Subirrigation <br />A small amount of Subirrigation does occur along the Tuttle and Calamity Draw stream channels. <br />Much of the alluvial ground water along these draws is a result of seepage from the irrigation <br />ditches. In many areas where the subirrigation occurs, the vegetation and soil quickly dry up when <br />the ditch is turned off from October to April. The subirrigation along Tuttle or Calamity Draw is not <br />considered extensive enough to support agricultural development. <br />Conclusion <br />• (REVISEO6/01j 2.05.6(3) - 13 <br />