USGS Water-Year Summary 2024
01417000 EAST BRANCH DELAWARE RIVER AT DOWNSVILLE, NY
LOCATION - Lat 42°04'30.1", long 74°58'34.6" referenced to North American Datum of 1983, Delaware County, NY, Hydrologic Unit 02040102, on left bank 0.5 mi downstream from Downsville Dam, at downstream end of outlet channel of Pepacton Reservoir, and 1.0 mi east of Downsville.
DRAINAGE AREA - 372 mi².
REVISIONS HISTORY - WDR NY-82-1: Drainage area. WDR-US-2006: 2004-05 (M). Datum of gage was corrected on Feb. 7, 2022, from 1,094.92 ft above NGVD of 1929 (levels by Board of Water Supply, City of New York) to 1,094.92 ft above Mean Sea Level Datum of Board of Water Supply, City of New York (levels by Board of Water Supply, City of New York).
SURFACE-WATER RECORDS
PERIOD OF RECORD - July 1941 to current year.
GAGE - Water-stage recorder and concrete control. Datum of gage is 1,094.92 ft above Mean Sea Level Datum of Board of Water Supply, City of New York (levels by Board of Water Supply, City of New York) and 1,093.67 ft above NAVD of 1988. Prior to Sept. 26, 1941, nonrecording gage, and Sept. 26, 1941 to June 27, 1955, water-stage recorder, at site 0.8 mi downstream at datum 7.03 ft lower.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Oct. 9, 1903, reached a stage of about 16 ft (at former site and datum).
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, since construction of Pepacton Reservoir in 1954, 20,200 ft³/s, Sept. 18, 2004, gage height, 12.08 ft; minimum discharge, 0.3 ft³/s, Oct. 11, 1954; minimum gage height, 1.39 ft, Jan. 17, 1964.
EXTREMES FOR PERIOD PRIOR TO REGULATION - Maximum discharge, prior to construction of Pepacton Reservoir in 1954, 23,900 ft³/s, Nov. 26, 1950, gage height, 14.52 ft, site and datum then in use.
WATER-QUALITY RECORDS
PERIOD OF DAILY RECORD - WATER TEMPERATURE: July 2019 to current year.
INSTRUMENTATION - Water-temperature recorder provides 15-minute-interval readings.
EXTREMES FOR PERIOD OF DAILY RECORD - WATER TEMPERATURE: Maximum, 16.4 °C, July 18, 2021; minimum, 2.2 °C, Mar. 1, 2020.