Skip Links

USGS - science for a changing world

Scientific Investigations Report 2010–5198

Prepared in cooperation with the Colorado Water Conservation Board, Colorado River Water Conservation District, Upper Colorado River Endangered Fish Recovery Program, Colorado Division of Water Resources, and City of Craig

Streamflow Gain-Loss Characteristics of Elkhead Creek Downstream from Elkhead Reservoir near Craig, Colorado, 2009

By Barbara C. Ruddy

Abstract

Thumbnail of and link to report PDF (4.6 MB)

The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board, the Upper Colorado River Endangered Fish Recovery Program (UCREFRP), Colorado Division of Water Resources, and City of Craig studied the gain-loss characteristics of Elkhead Creek downstream from Elkhead Reservoir to the confluence with the Yampa River during August through October 2009. Earlier qualitative interpretation of streamflow data downstream from the reservoir indicated that there could be a transit loss of nearly 10 percent. This potential loss could be a significant portion of the releases from Elkhead Reservoir requested by UCREFRP during late summer and early fall for improving critical habitat for endangered fish downstream in the Yampa River. Information on the gain-loss characteristics was needed for the effective management of the reservoir releases.

In order to determine streamflow gain-loss characteristics for Elkhead Creek, eight measurement sets were made at four strategic instream sites and at one diversion from August to early October 2009. An additional measurement set was made after the study period during low-flow conditions in November 2009. Streamflow measurements were made using an Acoustic Doppler Velocimeter to provide high accuracy and consistency, especially at low flows. During this study, streamflow ranged from about 5 cubic feet per second up to more than 90 cubic feet per second with step increments in between. Measurements were made at least 24 hours after a change in reservoir release (streamflow) during steady-state conditions.

The instantaneous streamflow measurements and the streamflow volume comparisons show the reach of Elkhead Creek immediately downstream from Elkhead Reservoir to the streamflow-gaging station 09246500, Elkhead Creek near Craig, CO, is neither a gaining nor losing reach. The instantaneous measurements immediately downstream from the dam and the combined measurements of Norvell ditch plus streamflow-gaging station 09246500 are mostly within the plus or minus 5-percent measurement error of each other. The variability of data is such that sometimes the streamflow is greater upstream than downstream and sometimes the streamflow is greater downstream than upstream. Streamflow volumes were calculated for multiple time periods as determined by a change in release from the reservoir. Streamflow volumes were greater downstream than upstream for all but one time period. The predominance of greater streamflows downstream is due to the difference between the USGS instantaneous measurements and record computation with the Supervisory Control and Data Acquisition (SCADA) record at the dam. Immediately following an increase in streamflow from the reservoir, the downstream volume was smaller than the upstream volume, but this was an artifact of the traveltime between the two sites and possibly small amounts of water entering the streambank. Traveltimes were shorter at higher streamflows and when streamflow was increasing.

First posted December 29, 2010

For additional information contact:

Director, USGS Colorado Water Science Center
Box 25046, Mail Stop 415
Denver, CO 80225

http://co.water.usgs.gov

This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.


Suggested citation:

Ruddy, B.C., 2010, Streamflow gain-loss characteristics of Elkhead Creek downstream from Elkhead Reservoir near Craig, Colorado, 2009: U.S. Geological Survey Scientific Investigations Report 2010–5198, 14 p.



Contents

Abstract

Introduction

Methods

Streamflow Characteristics of Elkhead Creek

Summary

Acknowledgments

References Cited


Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://pubsdata.usgs.gov/pubs/sir/2010/5198/index.html
Page Contact Information: GS Pubs Web Contact
Page Last Modified: Monday, 07-Mar-2016 13:43:58 EST