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The combination of fractured, weathered sandstone channel bottoms in the ditch and localized <br />"flood- type" irrigation along these two gaining reaches likely resulted in the measured gains in <br />flow. <br />Flows in Calamity Draw, which is roughly parallel to the southern boundary of Mine 2, generally <br />reflect local irrigation practices. Water from the West Lateral Ditch's return irrigation flow is its <br />primary source. Very little supplemental flow is derived from precipitation and snowmelt <br />runoff. In 1987, measured flow rates in Calamity Draw varied from 0.605 cfs in April to 13.4 cfs <br />in July. Flow in Calamity Draw varied from 1.04 to 2.06 cfs during the non - irrigation period. <br />Shallow ground water alluvial sources provide a large portion of this low flow period's water. <br />This ground water flow is related to local irrigation practices but is consolidated into a more <br />uniform and regular flow by the permeability of these near surface alluvial deposits. Sediment <br />Pond 007 for the New Horizon Mine 2 mining site will contribute water to the Calamity Draw <br />system. The drainage system at the Mine 2 site has been designed to provide adequate capacity <br />and storage times to completely control a 10 -year 24 -hour precipitation event. This system will <br />collect all runoff from the mine site and should actually lower present total suspended solids <br />(TSS) contribution from this area over the life of the mine. Increased TDS levels in this water <br />from mining disturbances are expected, but are projected to be within acceptable discharge levels <br />and will be mitigated by dilution. Regular monitoring of these flow rates and water quality will <br />give adequate control of this current water source to protect water quality in Calamity Draw. <br />The discharges from the mine enter Calamity Draw at a point about 2.5 miles above the <br />confluence of Calamity Draw and the San Miguel River. <br />The above - mentioned parks consist of recent undifferentiated aeolian silts and sands overlaying <br />the Dakota and Burro Canyon Formations. The perennial flow nature of both Tuttle and <br />Calamity Draws is largely due to the local irrigation practices. Over the years this more or less <br />constant source of water in these drainage systems has encouraged the growth of vegetation. <br />This has resulted in the channels becoming more erosionally stable but more incised. <br />Surface water monitoring practices and frequencies are described within the permit application. <br />Also see Findings Section B, Item II E, of this document for a summary of surface and ground <br />water monitoring practices to which WFC has committed. <br />D. Ground Water <br />The New Horizon Mines lie in a ground water basin defined by the Nucla Syncline. This broad <br />northwest trending syncline is recharged along the Uncompahgre uplift to the northeast and <br />discharges southwest toward the major rivers flowing through the area. <br />Near surface ground water in the Nucla area is partially recharged by irrigation return flow <br />through Quaternary aeolian and alluvial deposits. The lower Dakota and underlying Morrison <br />Formations are regional aquifers, although water from the Dakota Formation is not heavily <br />utilized due to its high salinity. The Morrison Formation water is widely used for stock and <br />domestic wells. <br />13 <br />