Streamflow Statistics for the Paradise and Pocono Creek Watersheds and Selected Streamflow-Gaging Stations in Monroe County, Pennsylvania by Ronald E. Thompson and Gregory J. Cavallo In cooperation with the Delaware River Basin Commission and the Brodhead Watershed Association Scientific Investigations Report 2005-5162 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia: 2005 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 For more information about the USGS and its products: Telephone: 1-888-ASK-USGS World Wide Web: http://www.usgs.gov/ Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. 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Suggested citation: Thompson, R.E., and Cavallo, G.J., 2005, Streamflow statistics for the Paradise and Pocono Creek Watersheds and selected streamflow-gaging stations in Monroe County, Pennsylvania: U.S. Geological Survey Scientific Investi- gations Report 2005-5162, 21 p. iii Contents Abstract. 1 Introduction . 1 Purpose and Scope . 1 Study Area. 1 Hydrogeologic Setting . 1 Previous Investigations . 3 Continuous- and Partial-Record Stations . 3 Methods For Determining Streamflow Statistics at Continuous- and Partial-Record Stations. 4 Streamflow Statistics for Monroe County, Pennsylvania . 6 Subbasin Yields in the Paradise and Pocono Creek Watersheds. 6 Observed Streamflow Statistics for Continuous-Record Stations . 6 Predicted Streamflow Statistics for Partial-Record Stations . 6 Comparison of Predicted and Observed Streamflow Statistics for Continuous-Record Stations . 13 Regression Analyses of Continuous-Record Station Data . 13 Differences in Predicted and Observed Streamflow Statistics for Continuous-Record Stations. 13 Limitations of the Investigation and Statistics . 19 Summary and Conclusions . 19 Acknowledgments . 19 Selected References. 19 Figures 1. Map showing bedrock geology, Paradise and Pocono Creek watershed boundaries, and selected streamflow-gaging stations in Monroe County, Pennsylvania . .2 2. Graph showing concurrent daily mean flows at Brodhead Creek near Analomink, Pa., and intermittent measurements at Pocono Creek near Stroudsburg, Pa. .5 3. Graph showing log 10-transformed concurrent daily mean flows at Brodhead Creek near Analomink, Pa., and intermittent measurements at Pocono Creek near Stroudsburg, Pa. .5 4. Map showing bedrock geology and base-flow measurement locations in the Paradise and Pocono Creek watersheds, Monroe County, Pennsylvania. .7 5. Graph showing observed and predicted streamflow statistics for Lehigh River at Stoddartsville, Pa. 13 iv Tables 1. Selected continuous- and partial-record stations in Monroe County, Pennsylvania.. 4 2. Locations in downstream order, base flows measured, and subbasin yields for the Paradise and Pocono Creek watersheds, Monroe County, Pennsylvania: October 25-27, 2000; May 2-3, 2001; and July 8-9, 2003. 8 3. Observed streamflow statistics for continuous-record stations in Monroe County, Pennsylvania. 11 4. Regression coefficients and equations for predicting 7-day, low-flow recurrence-interval statistics at partial-record stations in Monroe County, Pennsylvania.. 12 5. Predicted streamflow statistics for partial-record stations in Monroe County, Pennsylvania. 14 6. Regression coefficients and equations for predicting 7-day, low-flow recurrence-interval statistics at continuous-record stations (treated as partial-record stations) in Monroe County, Pennsylvania. 16 7. Predicted streamflow statistics and percent differences from observed statistics for continuous-record stations in Monroe County, Pennsylvania. 17 Conversion Factors and Datum Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Area square mile (mi2) 259.0 hectare (ha) square mile (mi2) 2.590 square kilometer (km2) Flow rate cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) cubic foot per second per square mile cubic meter per second per square [(ft3/s)/mi2] 0.01093 kilometer [(m3/s)/km2] cubic foot per second per square mile million gallons per day per square mile [(ft3/s)/mi2] 0.6463 [(Mgal/d)/mi2] Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27). Temperature in degrees Fahrenheit (˚F) may be converted to degrees Celsius (˚C) as follows: ˚C = (˚F - 32) / 1.8 Streamflow Statistics for the Paradise and Pocono Creek Watersheds and Selected Streamflow-Gaging Stations in Monroe County, Pennsylvania by Ronald E. Thompson and Gregory J. Cavallo Abstract agement area outlets (pour points) and to determine stream reaches that are gaining or losing flow. A suite of 36 observed streamflow statistics, ranging from high to low flows, were computed for 7 continuous-record and Purpose and Scope predicted for 12 partial-record streamflow-gaging stations in Monroe County, Pa. The predicted statistics for the partial- This report presents observed and predicted streamflow record stations were determined from regression analyses of statistics for selected streamflow-gaging stations (stations) in intermittent streamflow measurements made at the partial- Monroe County, Pa., and subbasin yields for the Paradise and record stations and concurrent daily mean flows at index con- Pocono Creek watersheds. The report also discusses the meth- tinuous-record stations. The prediction methodology has been ods used to determine the streamflow statistics, an analysis of previously used only for estimating low-flow statistics. Results the prediction methodology, and limitations of the methods and from this study indicate the methodology may have applicabil- the statistics. Thirty-six streamflow statistics were computed ity for predicting high- and intermediate-flow statistics as well. for 7 continuous-record stations and predicted for 12 partial- Three sets of base-flow measurements were made at 40 sites in record stations. The statistics computed at the continuous- the Paradise and Pocono Creek watersheds to determine subba- record stations are referred to as “observed” in this report. Sub- sin yields and stream reaches gaining or losing flow. Subbasin basin yields were determined at 29 sites in the Pocono Creek yields, the base-flow measurements normalized to respective watershed during 2000 and 2001 and at 11 sites in the Paradise drainage areas, were consistent for each measurement period. Creek watershed during 2003. Introduction Study Area Monroe County is in the Pocono Mountains area of north- The Delaware River Basin Commission (DRBC) has eastern Pennsylvania and, for the period 1931-2000, had an established a “Goal-Based Planning Approach” targeted for use average annual temperature of 47°F and average annual precip- by watershed groups in the basin. These groups are starting or itation of 44 in. (National Climatic Data Center, 2002). Average have started an inventory of water resources and will use the annual potential evaporation ranges from 25 to 27 in. (Flippo, inventory as part of a comprehensive process for planning 1982a). development. The U.S. Geological Survey (USGS), the DRBC, The Lehigh River flows along the northwestern boundary and the Brodhead Watershed Association cooperated in a study of the county, and the Delaware River is part of the southeastern to determine streamflow statistics in the Paradise and Pocono boundary. The Borough of Stroudsburg, on the south-central Creek watersheds and surrounding parts of Monroe County, Pa. boundary, is the county seat. Paradise and Pocono Creeks, The technical information developed for this study will help which flow in an easterly direction and share a common water- form a basis for evaluating the effects of competing water uses shed divide, are tributaries to Brodhead Creek, which flows in on water quantity in the Pocono and Paradise Creek watersheds a southerly direction (fig. 1). and other parts of Monroe County. The Pocono Creek water- shed planning effort served as a pilot project for the DRBC approach, and the Paradise Creek watershed planning effort is Hydrogeologic Setting following the same process. Streamflow statistics are needed in Monroe County to quantify surface-water resources and to The surficial geology in Monroe County includes glacial serve as input for ground-water models. Subbasin yields for the deposits, sandstones, conglomerates, siltstones, shales, and Paradise and Pocono Creek watersheds also are needed at man- small amounts of carbonate rock that have been deformed by 2 Streamflow Statistics for the Paradise and Pocono Creek Watersheds, Monroe County, Pennsylvania Figure 1. Bedrock geology, Paradise and Pocono Creek watershed boundaries, and selected streamflow-gaging stations in Monroe County, Pennsylvania Introduction 3 intense folding in the southeastern third of the county and gentle tistic(s) from the continuous-record station (U.S. Geological folding throughout the remainder of the county. Parts of the Survey, 2002). Upper, Middle, and Lower Series of the Devonian System are A second approach used graphical correlation analysis of all exposed in the landscape. Carswell and Lloyd (1979) identi- intermittent measurements at