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Mureb 2006 RCCD Upper Yumpu Rr'arr Burin Implementation Plan • G <br />were included on the State's 2000 303(dl list of "impaired waters", one stream segment (Dry Creek) <br />was placed on the list in 2004 due to selenium concentrations higher than the standard. In addition, a <br />• number of segments have been identified on the State's 2004 "Monitoring and Evaluation List", <br />including Middle Creek at Road 33 south of Milner (for high pH and E. coli bacteria values); <br />Stagecoach Reservoir (low dissolved oxygen concentrations); and Foidel Creek (high E coli bacteria <br />Levels). The USFS had previously (1998) identified several stream segments within the National <br />Forest as potentially subject to excessive sediment deposition. These segments remain on the <br />"Monitoring and Evaluation List" and assessments in these areas have been initiated and will likely <br />continue through 2008 (WQCD, 2000 and 2004). Parameters of concern within the basin are briefly <br />described below. <br />• Dissolved oxygen: Dissolved oxygen (DO), a measurement of the oxygen available to fish <br />and aquatic life, is affected by many factors and varies with elevation, temperature, and depth <br />of sample. It is further influenced by in-stream processes (such as photosynthesis, <br />respiration, decay of organic rriaterial, and flow) as well as watershed activities (such as <br />inflows from point and nonpoint sources). Oxygen demanding substances or processes may <br />deplete the oxygen supply necessary for fish and aquatic life. Oxygen levels may show <br />seasonal, as well as diurnal trends. In a number of instances, DO in the Yampa Basin has <br />been reported at concentrations lower than the standard. This has been noted particularly at <br />Stagecoach Reservoir and Stearriboat Lake. Occasional low concentrations have also been <br />noted on the Yampa River downstream of Stagecoach Reservoir, as well as on the Yampa <br />River at Steamboat Springs. Concentrations less than the standard are generally noted during <br />the summer months when stream levels are low and water temperatures relatively high. A <br />recent evaluation conducted by the City of Steamboat Springs (AWC, 2001) indicates that <br />DO levels fluctuate according to seasonal flow and water levels, with concentrations typically <br />• greater that 10.0 mg/1 in the spring and steadily decreasing concentrations as flow decreases <br />and temperatures rise. A recent USGS study supports these findings and further indicates <br />that diurnal fluctuations may be° due to algal photosynthesis/respiration activities (USGS, <br />2001). <br />Iron and/or manganese: Iron and. manganese are often found in relatively high <br />concentrations in Colorado streams and are generally indicative of naturally occurring <br />mineralization. Elevated levels of iron and manganese are also possible indicators of runoff <br />from mining operations, and there are several coal mines in Routt County. These <br />parameters, naturally occurring in many areas within the watershed, have been reported at <br />elevated levels or concentrations exceeding the stream standards at several monitoring <br />locations in the basin including: Yampa River upstream of Stagecoach Reservoir, Yampa <br />River downstream of Stagecoach Reservoir, Oak Creek (just upstream of its confluence with <br />the Yampa River), Yampa River at Steamboat Springs, Elk River near Milner, Lost Dog <br />Creek above mouth near Clark, Trout Creek, Yampa River near Hayden, Elkhead Creek, and <br />additional locations further downstream on the Yampa River in Moffat County. <br />Total dissolved solids: Total dissolved solids (TDS) provides a general measure of salinity <br />or matter (major ions) dissolved in a water sample. It may be used as an indicator of the <br />extent of mineralization or erosional releases in a basin and is often used as a general <br />indicator of water quality. TDS has been reported at elevated concentrations at several <br />locations in the basin (including (Jak Creek upstream of its confluence with the Yarnpa River <br />and Trout Creek) and may be associated with mining activities in the basin. <br />• pH: pH is a measurement used to determine the relative acidity of water. In the Yampa <br />River Basin, pH is generally between 6 and 9 standard units. On occasion, however, a pH <br />value less than 6 is measured. High in the watershed, this is typically due to snowmelt <br />conditions in waters of extremely low alkalinity (low buffering capacity). In other siniations, <br />RCCD * l-~75 Pure C,'rnre Rourl, Sirite 201.=1 * S'leunJLout Sprrugr, CO BO-f87 * (J70) 379-3221 <br />