LOCATION.--Lat 41°49'40.4", long
74°38'20.1" referenced to North American Datum of
1983, Sullivan County, NY, Hydrologic Unit 02040104, at a
gatehouse at Neversink Dam on Neversink River, and 2 mi
southwest of Neversink.
DRAINAGE AREA.--92.5 mi².
PERIOD OF RECORD.--June 1953 to September 2013
(furnished month-end elevations, contents, and diversions),
October 2013 to current year (furnished daily observation
elevations in NGVD of 1929), October 2019 to current year
(continuously recorded elevations in NAVD of 1988).
REVISIONS HISTORY.--WDR NY-85-1: Drainage area. WDR
NY-82-1: 1976 and 1977-Diversion.
GAGE.--Water-stage recorder. Datum of gage is NAVD of
1988. Datum of furnished elevations is NGVD of 1929
(levels by Board of Water Supply, City of New York).
COOPERATION.--Daily observation records of elevation and
capacity table provided by New York City Department of
Environmental Protection.
REMARKS.--Reservoir is formed by an earthfill rockfaced
dam. Storage began June 2, 1953. Usable capacity 34,941 mil gal
between minimum operating level, elevation 1,319.0 ft, NGVD of
1929, and crest of spillway, elevation 1,440.0 ft, NGVD of
1929. Capacity at crest of spillway 37,146 mil gal; at minimum
operating level, 2,205 mil gal; dead storage below diversion
sill and outlet sill, elevation 1,314.0 ft, NGVD of 1929, 1,680
mil gal. Figures given herein represent total contents.
Reservoir impounds water for diversion (01435800) through
Neversink-Grahamsville Tunnel to Rondout Reservoir on Rondout
Creek, in Hudson River basin, for water supply of City of New
York; for release during periods of low flow in the lower
Delaware River basin, as directed by the Delaware River Master;
and for conservation release. No diversion prior to Dec. 3,
1953.
Capacity table (elevation, in NGVD of 1929, in feet, and total contents, in millions of gallons)
Elevation Contents Elevation Contents
1,314.0 1,680 1,390.0 17,011
1,330.0 3,544 1,410.0 24,023
1,350.0 6,901 1,430.0 32,400
1,370.0 11,370 1,445.0 39,666
EXTREMES FOR PERIOD OF RECORD.--Maximum contents
observed, 38,983 mil gal, Apr. 3, 2005, elevation, 1,443.66 ft,
NGVD of 1929; minimum contents observed (after first filling),
1,985 mil gal, Nov. 25, 1964, elevation, 1,316.98 ft, NGVD of
1929. Maximum elevation since October 2019, 1,441.16 ft, NAVD
of 1988, Apr. 13, 2020; minimum elevation since October 2019,
1,416.46 ft, NAVD of 1988, Sept. 5, 2022.
PERIOD OF DAILY RECORD1.--WATER TEMPERATURE
AT 1,355 FT ABOVE NAVD OF 1988: October 2019 to current
year. WATER TEMPERATURE AT 1,383 FT ABOVE NAVD OF
1988: October 2019 to current year. WATER TEMPERATURE AT
1,425 FT ABOVE NAVD OF 1988: October 2019 to current
year.
INSTRUMENTATION1.--Water-temperature recorder
provides 15-minute-interval readings.
REMARKS1.--Interruption of record may occur
due to water levels falling below the elevation of the
sensor.
EXTREMES FOR PERIOD OF DAILY RECORD1.--WATER
TEMPERATURE AT 1,355 FT ABOVE NAVD OF 1988: Maximum, 12.8
°C, Nov. 1, 2019, Oct. 20, 2021; minimum, 1.6 °C,
Mar. 1, 2020, Jan. 30, Feb. 3, 4, 8, 2021. WATER TEMPERATURE AT
1,383 FT ABOVE NAVD OF 1988: Maximum, 20.3 °C, Sept. 22,
23, 2022; minimum, 1.4 °C, Jan. 30, 2021. WATER
TEMPERATURE AT 1,425 FT ABOVE NAVD OF 1988: Maximum, 28.4
°C, July 23, 2022; minimum, 0.5 °C, Feb. 29, Mar. 1,
2020.
1 Water-Quality Records