USGS Water-Year Summary for Site 01417000

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	Available Parameters
	00010 Temperature, water(Max.,Mean,Min.)
	00060 Discharge(Mean)

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Water year 2023: 2022-10-01 to 2023-09-30

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USGS Water-Year Summary 2023

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.

REMARKS - Subsequent to September 1954, entire flow from drainage area controlled by Pepacton Reservoir (station 01416900). Part of flow diverted for New York City municipal supply. Remainder of flow (except for conservation releases and spill) impounded for release during periods of low flow in the lower Delaware River basin, as directed by the Delaware River Master.
Water Years 2014-22: Records good.

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.