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Creek is typical of a lowland drainage with relatively broad, shallow <br />stream channel with a base of poorly sorted colluvial/alluvial material <br />and a flow regime which is dependent upon snowmelt or major thunderstorm <br />events. <br />All of the streams discussed in this section are tributary to the Arkansas <br />River. The Arkansas River is the major perennial drainage in this region, <br />with a contributing drainage area of approximately 4,000 square miles <br />upstream of the Town of Portland, which is just east of Florence. Most <br />of the Arkansas River drainage area is heavily forested, mountainous <br />terrain on the eastern slope of the Continental Divide. Flows in the <br />Arkansas River are heavily influenced by spring snowmelt and manmade flood <br />control structures in the area west of Canon City. With drainage derived <br />primarily from forested mountain terrain, suspended solids levels in the <br />Arkansas River are relatively low over much of the year. However, <br />dissolved solids and specific chemical constituents are elevated as a <br />• result of drainage from major mining areas where extensive underground <br />mining of precious metals occurred during the mid to late 1800's and early <br />1900's. <br />Surface Water Quantity <br />Information on surface water flows in the mine, loadout, adjacent areas, <br />and the general area is generally limited to diversion records for Newlin <br />Creek, water monitoring information collected by the State of Colorado and <br />various mining companies for Magpie, Newlin and Oak Creek and USGS <br />monitoring information for the Arkansas River. With the exception of USGS <br />monitoring of the Arkansas River and diversion records for Newlin Creek, <br />no long-term historical flow information is available. <br />Of those drainages potentially effected by Southfield's mining and related <br />activities only the upper portions of Oak and Newlin Creeks and the <br />Hardscrabble Creek and Arkansas River drainage are perennial. All other <br />• drainages or portions of drainages have ephemeral flow characteristics <br />with significant runoff occurring only in response to spring snowmelt~and <br />major thunderstorm events. Generally, upland portions of drainages in <br />this area demonstrate more consistent flows due to relatively impermeable <br />2.04.7-26 <br />