1. MA BF REFERENCE CURVES Objective Develop bankfull regional curves and equations for estimating bankfull width, mean depth, cross-sectional area, and discharge in Massachusetts

2. BF REFERENCE STREAMGAGES USGS streamflow-gaging stations with 10 or more years of record Relatively natural flow, with little to no high- flow regulation dams, diversions, etc. Drainage areas of varying sizes Less than 25 percent urban land use Wadeable for surveying Identifiable bankfull indicators

3. BF REFERENCE STUDY SITES OTHER STUDY

4. APPROACH Rosgen stream classification method (1994) Identify BF indicators - primarily the active floodplain, where the stream overtops its banks BF indicator elevations were compared to the streamgage stage of the 1.05 to 2-yr recurrence interval peakflows BF indicator, water surface, and thalweg elevations were surveyed at 20 longitudinal locations about one BF width apart to the USGS streamgage datum At 2 (riffle section) of the 20 locations detailed cross sections were surveyed Wolman (1954) pebble count for each stream reach

5. FIELD WORK 27 USGS streamgage stream channels were surveyed Surveyed over 6,000 elevation points Surveyed about 36,750 ft (about 7 miles) of stream channel Measured the median axis of 4,860 pebbles 6 additional BF Reference Study Sites –1 VT site – VT ANR, 2 MA sites – NRCS, and 3 sites – NY USGS –All used similar methods to this study’s work

6. BANKFULL ASSESSMENTS A B B A AB

7. MA BF REFERENCE CURVES WIDTH DEPTH X-SEC FLOW DRAFT – SUBJECT TO REVISION DO NOT COPY OR RELEASE

8. MA BANKFULL MULTIPLE REGRESSION EQUATIONS BF Width = 10.84 (drainage area) 0.39 (mean basin slope) 0.19 –R 2 =0.91 BF Mean Depth = 0.77 (drainage area) 0.28 (mean basin slope) 0.13 –R 2 =0.85 BF XSEC Area = 8.26 (drainage area) 0.67 (mean basin slope) 0.32 –R 2 =0.95 BF Discharge = 8.83 (drainage area) 0.75 (mean basin slope) 0.77 –R 2 =0.92 DRAFT – SUBJECT TO REVISION DO NOT COPY OR RELEASE

9. MA BF EQUATIONS - STREAMSTATS Currently working on integrating the bankfull equations into the USGS StreamStats application http://water.usgs.gov/osw/streamstats/massachusetts.html http://water.usgs.gov/osw/streamstats/massachusetts.html Streamstats is a web-site that allows the user to click any stream location and calculate selected flow and basin characteristics

10. OTHER AVAILABLE FG DATA Bridge Scour database –2,400 bridge crossing longer than 20 ft –Type, dimensions, x-sec data, bed material, etc. NAWQA database –Some geomorphic data Hydraulic structures and stream cross- sections surveyed for FEMA flood studies –Taunton River Basin (Spring 2010 flood) –Deerfield River Basin (T.S. Irene 2011 flood) –Hoosic River Basin (T.S. Irene 2011 flood)