Scientific Investigations Report 2007–5164
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2007–5164
Influence of Cougar Reservoir Drawdown on Sediment and DDT Transport and Deposition in the McKenzie River Basin, Oregon, Water Years 2002–04
Prepared in cooperation with the U.S. Army Corps of Engineers
By Chauncey W. Anderson
Table of Contents
Conversion Factors, Datums, and Abbreviated Water-Quality Units
Abstract
Introduction
Methods
Transport and Deposition of Sediment and DDT
Influence of Drawdown on Sediment and DDT Transport and Deposition
Summary and Conclusions
Acknowledgments
References Cited
Appendixes
Figures
Figure 1. Location of study area with sampling locations, McKenzie River basin, Oregon.
Figure 2. Aerial view of Cougar Reservoir during drawdown, with exposed upstream deltaic sediments, during the summer of 2002.
Figure 3. Discharge and turbidity at South Fork McKenzie River near Rainbow (CGRO) downstream of Cougar Reservoir, Oregon, spring and summer of 2002.
Figure 4. Installation process for infiltration bags for estimation of fine sediment deposition in the McKenzie River, Oregon.
Figure 5. Infiltration bag retrieval process for measurement of deposition of fine sediment and DDT plus metabolites in the McKenzie River, Oregon, August 2004.
Figure 6. Discharge and turbidity at sampling sites in the McKenzie River basin, Oregon, water years 2002–04.
Figure 7. Median percentage of fine material (less than 0.063 millimeter) and standard deviation in percentage of fine material of suspended sediment at gaging stations in the McKenzie River basin, Oregon, 2003–04.
Figure 8. Regression using linear, and power-function regression lines for turbidity and concentration of suspended sediment at study sites in the McKenzie River basin, Oregon, water years 2002–04.
Figure 9. Channel changes in the South Fork McKenzie River within the Cougar Reservoir drawdown area, January 29–31, 2003, as seen from the Terwilliger Hot Springs parking area.
Figure 10. Annual load and discharge-weighted concentration of suspended sediment at the inflow to and outflow from Cougar Reservoir, Oregon.
Figure 11. Percentage of sediment less than 0.063 millimeters in diameter in infiltration bags after 1 year deployment in the McKenzie River, Oregon, 2004.
Figure 12. Relation of sand, silt, and clay fractions recovered from infiltration bags and freeze cores in the McKenzie River, Oregon.
Tables
Table 1. Stations used to monitor discharge, turbidity, and sediment in the McKenzie River basin, Oregon, 2002–04.
Table 2. Suspended-sediment concentrations and associated turbidity during storm sampling in the McKenzie River basin, Oregon, 2003–04.
Table 3. Regression equations and correlation coefficients for relations between turbidity and suspended-sediment concentrations, McKenzie River basin, Oregon.
Table 4. Estimated annual discharge, suspended-sediment load, and discharge-weighted suspended-sediment concentrations at gaging stations in the McKenzie River, Oregon, water years 2002–04, as derived from continuous measurements of discharge and turbidity, and regressions of turbidity and suspended-sediment concentration.
Table 5. Concentrations of suspended sediment, suspended organic carbon, and DDT and metabolites transported during storms in the McKenzie River basin, Oregon, 2003.
Table 6. Total mass of sediment and percent of fine materials, and concentrations of DDT and metabolites, in infiltration bags deployed in the McKenzie River, Oregon, August 2003–July 2004.
Table 7. Comparison of fine material deposition in McKenzie River bed sediment measured from freeze cores during July 2002 and infiltration bags deployed from August 2003–July 2004.
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Send questions or comments about this report to the author, Chauncey W. Anderson, (503) 251-3206.
For more information about USGS activities in Oregon, visit the USGS Oregon Water Science Center home page.
U.S. Department of the Interior | U.S. Geological Survey