Clear Creek Sediment and Water Quality

As a result of fires, extreme precipitation events, and human activities, some reaches in the mid-part of the Clear Creek drainage basin have experienced severe erosion which has incised the stream channel and deposited sediment into lower portions of the creek. A small range fire along U.S. Highway 50 in 2003 left the slopes susceptible to increased sediment runoff. Heavy rains in December 1997 resulted in a large flood event which washed out portions of old U.S. Highway 50 in areas where the road closely parallels the stream. Construction of large commercial buildings and parking lots adjacent to and near the creek in its lower reaches may be affecting stream-water quality and sediment yield. Additional information on sediment yield and water quality in the Clear Creek drainage are needed to establish a baseline for evaluating current, as well as future changes in water quality and sediment transport related to increased urbanization and fire hazards.

Objectives

Describe the relation between suspended-sediment loading and discharge in Clear Creek, use this relation to estimate sediment yield from the Clear Creek basin and establish baseline data to evaluate future changes in water quality and sediment yield.

Strategy and Approach

Daily streamflow will be measured at the gaging station on Clear Creek near Carson City. Suspended-sediment, bedload-sediment, and water-quality samples will be collected at the site. An automatic sampler will be installed at the gaging station and set up to sample during events where the stage changes over a short period of time. Two additional sites, one pstream near Highway 50 and one downstream near Fuji Park, also will be sampled for suspended and bedload sediment and water quality. Suspended-sediment samples will be collected about every 6 weeks during moderate to low flow. Additional sediment samples will be collected during rainfall and runoff events and spring snowmelt to characterize suspended-sediment loading during high flow when the sediment load is expected to be greatest. Simple linear regression analysis of suspended-sediment load and streamflow will be done. Streamflow data from the gaging station will be used as the input variable to the regression equation to estimate daily mean suspended sediment load. Seasonal and annual loads will be estimated by summing daily loads for each season and year. Sediment yield will be calculated and compared to areas with similar hydrologic and geologic characteristics

Data availability

USGS National Water Information System website (NWISweb): Clear Creek near Carson City || Clear Creek at Fuji Park

Annual data report: Clear Creek near Carson City || Clear Creek at Fuji Park

Relevance and Benefits

The proposed study is relevant to the USGS Water Resources Discipline (WRD) goals and Nevada Water Science Center science plan issues. WRD goals to be addressed by the study include advancing understanding of hydrologic processes and providing water-resource information useful to multiple parties for planning and operation purposes. Nevada Water Science Center science plan issues addressed by the study include human health (issue 2) and quality of life (issue 4). This study should improve the understanding of sediment transport and the effectiveness of future erosion control structures in the Clear Creek Basin. The information should benefit managers tasked with making informed decisions on the design and types of structures for controlling erosion.