MetroSouthPlatteInterimBasinWaterSupplyNeedsReport (2)

Home Browse Search

Section 3 Physical Environment of the South Platte Basin and Denver/South Metro Counties I l!l~! Figure 3-7 identifies the locations of surface waters South Platte Basin and Denver/South Metro Counties that have been listed for impairment for one or more parameters on Colorado's 2002 303(d) list. Stream segments proposed for listing via the 2004 303(d) list and the accompanying Monitoring and Evaluation list are described in Colorado Water Quality Control Commission (WQCC) Regulations 93 and 94. The state's 2004 proposed 303(d) list incorporates several additions from the 2002 list. It includes numerous surface waters that span the basin's diverse topography and land uses. Listed segments proposed for the upper South Platte and its tributaries, such as Clear Creek, are primarily listed for metals such as cadmium, copper, and zinc. Certain stream segments in urbanized areas are listed for bacteria and other constituents. A variety of constituents comprises the remainder of the listings for other parts of the basin, including several segments listed for selenium. 3.2.9 Areas of Environmental Concern, Special Attention Areas, and Threatened and Endangered Species As described above, various reaches of the South Platte River in the Denver Metro Area have water quality issues. High TDS and nitrate in the groundwater of the alluvial aquifer is also a concern. Acid mine drainage, whirling disease, sedimentation, and wetland protection in the South Platte River headwaters have been problems as well. Wetlands are important in that they "have a well-documented capacity for extracting metals, particularly uranium, from ground and surface waters containing very dilute concentrations of the metals." A 1992 USGS study, Uranium and Other Elements in Colorado Rocky Mountain Wetlands - A Reconnaissance Study, sampled 145 montane and sub- alpine wetlands in Colorado to assess the concentration of uranium and other heavy metals in the wetlands. Forty-six percent of all the wetlands that were analyzed showed moderate or greater enrichment in uranium. If a wetland is partially or completed drained, oxidation of the organic-rich sediments might liberate the heavy metals that have accumulated in the wetlands over thousands of years. Therefore, the protection of wetlands, a natural water filter, is important to prevent environmental and health concerns (Owen et al. 1992). CONI 3-10 In addition to impaired areas, threatened and endangered species and areas of high environmental or recreational value require special attention when evaluating water supply projects and water use in the South Platte Basin. For a complete list of federal and/or state listed threatened and endangered fish and other species in the South Platte Basin, along with information on recreational in-channel diversions (RICDs) in Fort Collins, Golden, and Longmont, see Appendix C of the SWSI Report. An example of an area with high-quality aquatic habitat in the South Platte Basin is the 3-mile section below Cheesman Dam that produces more than 500 pounds of fish per surface acre, mostly rainbow trout from 15 to 22 inches. Other areas that are valued for their fishing opportunities in the basin include the following Gold Medal designated segments: . The South Fork downstream from the Highway 285 bridge to the inlet of Antero Reservoir . The Middle Fork downstream from the Highway 9 Bridge (4.9 miles north of Garo) to the confluence of the Middle and South Forks and the South Platte River . From the Middle and South Forks downstream through Spinney Mountain Reservoir to the buoy line at the inlet of Elevenmile Reservoir . From Cheesman Reservoir Dam downstream to the North Fork of the South Platte River . Spinney Mountain Reservoir, on the South Platte River about 5 miles upstream from Elevenmile Reservoir Figure 3-8 shows the locations of some of the basin's key aquatic species habitat. Areas of high recreational value in the basin, including the Mount Evans Wilderness Area, Rocky Mountain National Park, and Chatfield State Park, are discussed in Section 6. 3.2.10 Energy and Mineral Resources More than 250 identifiable minerals have been located in deposits in the South Platte Basin. Other important natural resources in the basin include natural gas, petroleum, and coal. Over 130 million tons of coal was produced from the Denver Basin from 1883 to 1978 (Woodward-Clyde Consultants 1982). S:\1177\BASIN REPORTSlSOUTH PLATTE\S3_S0UTH PLATTE. DOC