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The flow in Tuttle Draw is primarily from irrigation return waters. Occasional precipitation and snowmelt events contribute waters to this Draw. Sediment Pond 001 discharges water to this drainage system regulazly with flows characterized by lows in April, averaging about 0.01 cfs, to highs in September of 0.9 cfs. Sediment Pond 006 discharges significant flow to Tuttle Draw beginning in May and continuing through August. Average flow for this period is 0.4 cfs. In September discharges from Sediment Pond 006 rapidly decline. In January through April the average discharge is insignificant. This dischazge has been monitored for [en years. These flows appear to be greatly influenced by local irrigation practices. Impacts on water quality from these ponds on Tuttle Draw are very limited due to the high dilution ratios. These discharges occur upstream of surface water monitoring site SW-N3. Measurements of water flow at SW-N3 show rates from 0.019 cfs to 9.35 cfs. Flows in April were measured at 0.665 cfs and at 9.35 cfs in September. The West Retum Ditch is also tributary to Tuttle Draw just upstream of SW-N3. Contributions from this source generally decline to near zero during the non-irrigation period. These flows vary from 0.006 cfs during April to 0.856 cfs in June. ~lJ The New Horizon Mine 2 site is just west of the town of Nucla and is located in the mildly sloping up an area immediately north of Calamity Draw, approximately in the middle of First Park. Especially in the New Horizon Mine 2 mining area, the surface water system is characterized by a "disjointed" tributary drainage system almost completely controlled by retum flow ditches of the local irrigation network. Flows in Calamity Draw generally reflect local irrigation practices. Water from the West Lateral Ditch's return irrigation flow is its primary source. Very little supplemental flow is derived from precipitation and snowmelt runoff. In 1987, measured flow rates in Calamity Draw varied from 0.605 cfs in April to 13.4 cfs in July. Flow in Calamity Draw varied from 1.04 to 2.06 cfs during the non-irrigation period. Shallow ground water alluvial sources provide a large portion of this low flow 4 period's water. This ground water flow is related to local irrigation practices but is consolidated into amore uniform and regular flow by the permeability of these near surface alluvial deposits. Sediment Pond 007 for the New Horizon Mine 2 mining site will contribute water to the Calamity Draw system. The drainage system at the New Horizon 2 site has been designed to provide adequate ~,,, capacity and storage times to completely control a 10-year 24-hour precipitation event. This system will collect all runoff from the mine site and should actually lower present total suspended solids (TSS) contribution from this area over the life of the mine. Increased TDS levels in this water from mining disturbances are expected but are projected to be within acceptable discharge levels and will be mitigated by dilution. Regular monitoring of these flow rates and water quality will give adequate Q control of this current water source to protect water quality in Calamity Draw. The discharges from ~ the mine enter Calamity Draw at a point about 2.5 miles above the confluence of Calamity Draw and the San Miguel River. `~ e The above-mentioned parks consist of recent undifferentiated aeolian silts and sands overlaying the Dakota and Burro Canyon Formations. The perennial flow nature of both Tuttle and Calamity Sef' Draws is largely due to the local irrigation practices. Over the years this more or less constant 'u AP source of water in these drainage systems has encouraged the growth of vegetation. This has resulted in the channels becoming more erosionally stable but more incised 5