Prepared in cooperation with the Albuquerque–Bernalillo County Water Utility Authority Water Quality, Streamflow Conditions, and Annual Flow- Duration Curves for Streams of the San Juan–Chama Project, Southern Colorado and Northern New Mexico, 1935–2010 Scientific Investigations Report 2013–5005 Revised May 2013 U.S. Department of the Interior U.S. Geological Survey Cover: Left, Gage at Azotea Tunnel outlet near Chama, New Mexico, June 2, 2008. Right, Gage at Azotea Tunnel outlet near Chama, New Mexico, September 23, 2008. Water Quality, Streamflow Conditions, and Annual Flow-Duration Curves for Streams of the San Juan–Chama Project, Southern Colorado and Northern New Mexico, 1935–2010 By Sarah E. Falk, Scott K. Anderholm, and Katya A. Hafich Prepared in cooperation with the Albuquerque–Bernalillo County Water Utility Authority Scientific Investigations Report 2013–5005 Revised May 2013 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2013 Revised: May 2013 This and other USGS information products are available at http://store.usgs.gov/ U.S. Geological Survey Box 25286, Denver Federal Center Denver, CO 80225 To learn about the USGS and its information products visit http://www.usgs.gov/ 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: Falk, S.E., Anderholm, S.K., and Hafich, K.A., 2013, Water quality, streamflow conditions, and annual flow-duration curves for streams of the San Juan–Chama Project, southern Colorado and northern New Mexico, 1935–2010: U.S. Geological Survey Scientific Investigations Report 2013–5005, 50 p., 1 app. (Revised May 2013.) iii Acknowledgments The authors thank John Stomp and David Price of the Albuquerque–Bernalillo County Water Utility Authority for providing guidance and support for this investigation to improve understanding of the water resources available to the Albuquerque and Bernalillo County area. v Contents Acknowledgments .......................................................................................................................................iii Abstract ..........................................................................................................................................................1 Introduction ....................................................................................................................................................2 Purpose and Scope .............................................................................................................................2 Description of Study Area ..................................................................................................................5 San Juan–Chama Project ...................................................................................................................5 Previous Studies ................................................................................................................................12 Method of Analysis ............................................................................................................................14 Water Quality ...............................................................................................................................................18 Streamflow Conditions and Annual Flow-Duration Curves .................................................................23 Seasonal and Annual Variations in Streamflow Conditions ..............................................27 Trends in the Seasonal Distribution of Streamflow ....................................................34 Time Series of the Indicators of the Seasonal Distribution of Streamflow .................................................................................................36 Indicators of the Seasonal Distribution of Streamflow Compared to Annual Discharge ......................................................................................36 Probability of Annual and Monthly Availability of Water ...................................................42 Summary .......................................................................................................................................................46 References Cited .........................................................................................................................................48 Appendix 1. Water-Quality Data for Streams of the San Juan–Chama Project, Southern Colorado and Northern New Mexico, 1958–2009 (available at http://pubs.usgs.gov/sir/2013/5005/) Figures 1. Map showing location of the study area, hydrographic areas within the study area, selected geographic features, and climate stations, southern Colorado and northern New Mexico ................................................................................................................3 2. Schematic of the San Juan–Chama Project and location of streamflow-gaging stations and water-quality sampling sites in the study area, southern Colorado and northern New Mexico .........................................................................................................4 3. Graphs showing temperature and precipitation data for climate station Upper San Juan (Natural Resources Conservation Service SNOwpack TELemetry site), in the southern Colorado portion of the study area .....................................................8 4. Graphs showing temperature and precipitation data for climate station Chama (National Weather Service Cooperative Observer Program weather station), in the northern New Mexico portion of the study area, 1905–2009 .........................................9 5. Map showing surface geology of the study area, location of selected streamflow-gaging stations, and the boundary of selected watersheds, southern Colorado and northern New Mexico .....................................................................10 6. Graph showing conceptual model of streamflow for small volume of annual discharge (low flow) and large volume of annual discharge (high flow) with the same base flow ..........................................................................................................................14 vi 7. Graph showing relative percent difference of discharge between the discharge at the streamflow-gaging station at Azotea and the summed discharge of the streamflow-gaging stations at Blanco Diversion, Little Oso Diversion, and Oso Diversion, southern Colorado and northern New Mexico, 1975–2009 ....................................................................................................................................16 8. Graphs showing calculated daily mean streamflow compared to the measured discharge from the streamflow-gaging stations plus the measured diversion discharge at the points of diversion on the Rio Blanco, Little Navajo River, and Navajo River, in the southern Colorado portion of the study area, 1974–2010 ................17 9. Trilinear diagram of representative water composition from selected water- quality sampling sites in the study area, southern Colorado and northern New Mexico ...............................................................................................................................19 10. Graphs showing variation of water-quality conditions at water-quality sampling sites in the study area, southern Colorado and northern New Mexico, 1958–2009 .......21 11. Graphs showing monthly variation in specific-conductance values for selected water-quality sampling sites and comparison of the variation of the average monthly specific conductance to the median monthly discharge, with monthly discharge categorized as high-flow or base-flow conditions, for selected water-quality sampling sites in the study area, southern Colorado and northern New Mexico, 1958 to 2009 ........................................................................................................22 12. Graphs showing distribution of annual discharge, median annual discharge, and annual flow-duration curves for selected for streamflow-gaging stations in the southern Colorado portion of the study area, 1975–2010 .............................................25 13. Graph showing annual discharge at streamflow-gaging stations in the northern New Mexico portion of the study area, 1943–2009 ..............................................................28 14. Graph showing distribution of annual discharge, median annual discharge, and annual flow-duration curves for the period of record for the streamflow- gaging station Willow Creek near Park View, in the northern New Mexico portion of the study area, 1943–69 ..........................................................................................28 15. Graphs showing median monthly discharge for selected for streamflow-gaging stations over the period of record in the study area, southern Colorado and northern New Mexico, 1943–2010 ...........................................................................................29 16. Graph showing annual discharge at streamflow-gaging station Navajo River at Banded Peak Ranch, in the southern Colorado portion of