7049 - Laserfiche WebLink

Home Browse Search

.,:.,.__~,~5~;.t:::,,~:-:~~!.. : . . . r v" Sediment load is a primary factor determining the qual ity of water and its suitabil ity for various uses. Sediment load also significantly influences the hydraul ic stabi I ity of a stream channel as well as the aquatic habitat. The supply of sediment to the channel network, and thus the sedi- ment lead ef the stream, is determined by IT'any factors. Of these, land use is probably the most read! ly influenced by human activities. Extensive changes in land use are anticipated in the Yampa River basin during the next 15 years, due primari ly to development of energy resources and associated econor1ic development. The ar-oU'lt Qf coal mined a';f\..r3ual1y in the Yampa River basin is expected to increase' -(fom sl ightly <,more than 6.0 million' tons'- (5.4 million tt ifT 1976' to about '29 mil1ioD. tons (18 millioil t) by J990: A-5-ubstantial part of the cQal will 'he mined from the land surface and v,ill be-convert.edwi-thin- the b-asin to electric power or possibly te synthel.J.c gases';,"'.'Other energy resources YJithin the basin include oi I and gas;-'oil shale, ura:lium, and geothermal springs. Due primari ly to the anticipated energy development, the basin population, which in 1975 was nearly 18,000 (Udis and Hess, 1976), is expected to increase 2 to 3 times during the next 15 years (Udis and others, 1977). The changes in land use associated with this development ~may increase the quantity of sediment sup- pI ied to stream channels in the Yampa River basin and thus adversely affect the qual ity of water in the basin. Puroose and Scope The purpose of this report is to describe the quantity and areal distribution of sediment loads carried by selected streams within the Yampa River basin, Colorado and \4yoming (fig. 1). Present sediment loads were computed from historical data, supplemented by data collected during 1975-77 as part of the present study. Potential increases in the sediment ioad carried by streams in the Yampa River basin due to surface mining were com- puted through analysis of the extent of land disturbance and its increased erodibility. 82sed upon these computations, probable impacts of surface mining upon sediment yield can be evaluated and the need for more intensive studies can be identified. Acknovi 1 ecgmen t s Timothy D. Steele provided some of the sediment data and numerous helpful suggestions, especially with regard to evaluating the impact of anticipated development. Dana Coffield was a cheerful field assistant and perfol-med most of the comoutations. 2