Prepared in cooperation with Douglas County, Nevada Precipitation and Runoff Simulations of the Carson Range and Pine Nut Mountains, and Updated Estimates of Ground-Water Inflow and the Ground-Water Budget for Basin-Fill Aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California Scientific Investigations Report 2007–5205 U.S. Department of the Interior U.S. Geological Survey Cover: Looking west from Ambrosetti Pond towards the Carson Range. Photograph taken by Laurie Bonner, U.S. Geological Survey, October 27, 2004. Precipitation and Runoff Simulations of the Carson Range and Pine Nut Mountains, and Updated Estimates of Ground-Water Inflow and the Ground-Water Budget for Basin-Fill Aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California By Anne E. Jeton and Douglas K. Maurer Prepared in cooperation with Douglas County, Nevada Scientific Investigations Report 2007–5205 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Myers, Director U.S. Geological Survey, Reston, Virginia: 2007 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Jeton, A.E., and Maurer, D.K., 2007, Precipitation and runoff simulations of the Carson Range and Pine Nut Mountains, and updated estimates of ground-water inflow and the ground-water budget for basin-fill aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California: U.S. Geological Survey Scientific Investigations Report 2007–5205, 56 p. iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................2 Purpose and Scope ..............................................................................................................................4 Geographic Setting ...............................................................................................................................4 Geologic Setting ....................................................................................................................................6 Hydrologic Setting ................................................................................................................................8 Components of the Ground-Water Budget for Basin-Fill Sediments of Carson Valley ....8 Description of Watershed Models ............................................................................................................11 Precipitation-Runoff Modeling System ...........................................................................................13 Model Development ...........................................................................................................................15 Basin Characterization and Delineation of Hydrologic Response Units ..........................15 Runoff and Climate Data ...........................................................................................................16 Model Sensitivity........................................................................................................................21 Model Calibration................................................................................................................................22 Error Analysis ......................................................................................................................................22 Carson Range Perennial Watersheds ....................................................................................23 Daggett Creek Watershed ...............................................................................................23 Fredericksburg Canyon Watershed ...............................................................................27 Pine Nut Mountains Perennial Watersheds ..........................................................................27 Pine Nut Creek Watershed ..............................................................................................27 Buckeye Creek Watershed .............................................................................................32 Model and Data Limitations ..............................................................................................................32 Results of Watershed Modeling and Comparison with Previous Estimates ......................................33 Perennial Watersheds .......................................................................................................................33 Ephemeral Watersheds .....................................................................................................................44 Ground-Water Inflow Simulated from Watershed Models and Variation from Dry to Wet Conditions. ..............................................................................................................................46 Uncertainty in Estimates of Simulated Ground-Water Inflow .....................................................47 Ground-Water Inflow Simulated from Watershed Models Compared with Previous Estimates ...48 Updated Ground-Water Budget for Basin-fill Aquifers of Carson Valley ...........................................50 Summary and Conclusions .........................................................................................................................51 Acknowledgments .......................................................................................................................................53 References Cited..........................................................................................................................................53 iv Figures Figure 1. Map showing location of the Carson River Basin and the Carson Valley hydrographic areas, Nevada and California ……………………………………… 3 Figure 2. Map showing location of the Carson Valley study area and depth to water table, Nevada and California, June 2005 ………………………………………… 5 Figure 3. Map showing surficial geologic units and faults in Carson Valley, perennial and ephemeral watersheds, and the locations of precipitation and runoff gaging or measurement stations used in watershed model development, Nevada and California …………………………………………………………… 7 Figure 4. Graphs showing annual precipitation at Minden, Nevada, and Heavenly Valley, California, and Palmer Drought Severity Index for western Nevada ……… 9 Figure 5. Conceptual diagram showing components of ground-water recharge to and discharge from basin-fill aquifers of Carson Valley, Nevada and California ……… 10 Figure 6. Schematic diagram of processes simulated by the Precipitation-Runoff Modeling System ………………………………………………………………… 14 Figure 7. Maps showing HRU delineation and distribution of slope, aspect, land cover, and land-surface altitude zones in the Daggett Creek watershed, Carson Valley, Nevada …………………………………………………………………… 17 Figure 8. Graphs showing simulated and measured daily mean runoff for Daggett Creek and Fredericksburg Canyon watersheds, Carson Valley, Nevada and California, water years 1990–2002 ………………………………………………… 24 Figure 9. Graph showing simulated and measured annual mean runoff and ground-water inflow for Daggett Creek, water years 1990–2002, Fredericksburg Canyon, water years 1990–2001, and Pine Nut Creek and Buckeye Creek watersheds, water years 1981–97, Carson Valley, Nevada and California ………………………………………………………………………… 25 Figure 10. Graphs showing simulated and measured daily mean runoff for Pine Nut Creek and Buckeye Creek watersheds, Carson Valley, Nevada, water years 1981–97 …………………………………………………………………………… 28 Figure 11. Graphs showing simulated and reconstructed daily mean runoff for 10 ungaged perennial watersheds in Carson Valley, Nevada and California, water years 1990–2002 …………………………………………………………… 34 Figure 12. Graphs showing simulated and reconstructed annual mean runoff and ground-water inflow for 10 ungaged perennial watersheds in Carson Valley, Nevada and California, water years 1990–2002 …………………………………… 39 v Tables Table 1. Major bedrock type, runoff as a percentage of precipitation, index model, and precipitation stations used for model development of perennial gaged and ungaged watersheds, Nevada and California …………………………………… 12 Table 2. Precipitation and streamflow-gaging stations, period of record, and altitude, Carson Valley, Nevada and California …………………………………………… 21 Table 3. Calibration statistics for PRMS watershed models of gaged watersheds of the Carson Range and Pine Nut Mountains, Carson Valley, Nevada and California ………………………………………………………………………… 23 Table 4. Summary of model results for 14 perennial watersheds in Carson Valley, water years 1990–2002, and comparison with estimates from Maurer and Berger (2007) ………………………………………………………………………