

Publications—Scientific Investigations Report 
Using Tracers to Evaluate Streamflow GainLoss Characteristics of Terror Creek, in the Vicinity of a MinePermit Area, Delta County, Colorado, Water Year 2003By Cory A. Williams and Kenneth J. LeibUSGS Scientific Investigations Report 20055018, 27 p., 12 figs. This document is available in pdf format: The citation for this report, in USGS format, is as follows:
AbstractIn 2003, the U.S. Geological Survey, in cooperation with Delta County, initiated a study to characterize streamflow gainloss in a reach of Terror Creek, in the vicinity of a minepermit area planned for future coal mining. This report describes the methods of the study and includes results from a comparison of two sets of streamflow measurements using tracer techniques following the constantrate injection method. Two measurement sets were used to characterize the streamflow gainloss associated with reservoirsupplemented streamflow conditions and with natural baseflow conditions. A comparison of the measurement sets indicates that the streamflow gainloss characteristics of the Terror Creek study reach are consistent between the two hydrologic conditions evaluated. A substantial streamflow gain occurs between measurement locations 4 and 5 in both measurement sets, and streamflow is lost between measurement locations 5 and 7 (measurement set 1, measurement location 6 not visited) and 5 and 6 (measurement set 2). A comparison of the measurement sets above and below the minepermit area (measurement locations 3 and 7) shows a consistent loss of 0.37 and 0.31 cubic foot per second (representing 5 and 12percent streamflow losses normalized to measurement location 3) for measurement sets 1 and 2, respectively. This indicates that similar streamflow losses occur both during reservoirsupplemented and natural baseflow conditions, with a mean streamflow loss of 0.34 cubic foot per second for measurement sets 1 and 2. Findings from a previous investigation support the observed streamflow loss between measurement locations 3 and 7 in this study. The findings from the previous investigation indicate a streamflow loss of 0.59 cubic foot per second occurs between these measurement locations. Statistical testing of the differences in streamflow between measurement locations 3 and 7 indicates that there is a discernible streamflow loss. The pvalue of 0.0236 for the parametric paired ttest indicates that there is a 2.36percent probability of observing a sample mean difference of 0.34 cubic foot per second if the population mean is zero. The pvalue of 0.125 for the nonparametric exact Wilcoxon signed rank test indicates that there is a 12.5percent probability of observing a sample mean difference this large if the population mean is zero. The similarity in streamflow gainloss between measurement sets indicates that the process controlling streamflow may be the same between the two hydrologic conditions evaluated. Gains between measurement locations 4 and 5 may be related to hyporheic flow from tributaries that were dry during the study. No other obvious sources of surface water were identified during the investigation. The cause for the observed streamflow loss between measurement locations 5 and 6 is unknown but may be related to mapped local faulting, 100 years of coal mining in the area, and aquifer recharge. ContentsAbstract Introduction Purpose and Scope Description of Study Area Geology Hydrology Previous Studies Acknowledgments Methods Streamflow Determination Discharge by ConstantRateInjection Method Measurement Location and Site Selection Accounting for Streamflow Variation WaterSample Collection and Analysis WaterSampling Techniques Analytical Techniques Error Analysis Sensitivity Analysis Error Propagation Streamflow Comparisons Graphical Comparison Statistical Comparison Evaluation of Streamflow GainLoss Characteristics Measurement Set 1, Streamflow GainLoss Characteristics Measurement Set 2, Streamflow GainLoss Characteristics Interpretation of Findings Factors Affecting Streamflow GainLoss Characteristics Hyporheic Flow System Deep Flow System Summary References Cited Supplemental Information 

AccessibilityFOIAPrivacyPolicies and Notices  
U.S. Department of the Interior, U.S. Geological Survey
Persistent URL: Page Contact Information: Contact USGS Last modified: Thursday, December 01 2016, 06:47:34 PM 