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LOCATION.--Lat
42°00'08", long 76°38'05" referenced to North
American Datum of 1983, Chemung County, NY, Hydrologic Unit 02050105,
on right bank 100 ft upstream from bridge on State Highway 427, 0.7 mi
southwest of Chemung, and 10.0 mi upstream from mouth.
DRAINAGE AREA.--2,506 mi².
PERIOD OF RECORD.--September 1903 to current year (gage heights
only for some winter periods).
REVISIONS HISTORY.--WSP 891: 1935-39. WSP 1432: 1904, 1907,
1915. WSP 2103: Drainage area. WDR NY-74-1: 1973.
GAGE.--Water-stage recorder. Datum of gage is 778.63 ft above
NGVD of 1929 (levels by Corps of Engineers) and 778.07 ft above NAVD of
1988 (VERTCON). Prior to Jan. 10, 1930, nonrecording gage on highway
bridge 60 ft upstream at same datum.
REMARKS.--High flows significantly regulated by upstream
reservoirs: since March 1940, by Arkport Reservoir (01521000); since
June 1949, by Almond Lake (01523000); since Nov. 1979, by Tioga Lake
(01517900) and Hammond Lake (01518498); and since Dec. 1979, by
Cowanesque Lake (01519995). From 1931-98, a large part of flow from
45.5 mi² of drainage area upstream from Lamoka Lake on Mud Creek, an
upstream tributary, had been diverted into Keuka Lake (Oswego River
basin) for power development.
Water Year 2014: Records good except those for estimated daily
discharges, which are fair, and those for May 17 to Aug. 18, which are
poor (due to sluggish intakes).
Water Years 2015-17: Records good except those for estimated daily
discharges, which are poor.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, since
construction of Tioga, Hammond and Cowanesque Lakes in 1979, 77,800
ft³/s, Jan. 20, 1996, gage height 19.71 ft; minimum discharge, 104
ft³/s, Sept. 3, 1991; minimum gage height, 2.61 ft, Aug. 9, 10,
2016.
EXTREMES FOR PERIOD PRIOR TO REGULATION.--Maximum discharge,
prior to construction of Tioga, Hammond and Cowanesque Lakes in 1979,
189,000 ft³/s, June 23, 1972, gage height, 31.62 ft, from floodmark,
from rating curve extended above 65,000 ft³/s on basis of slope-area
and velocity-area studies at gage height 19.57 ft, and slope-area and
contracted-opening measurements at gage heights 23.97 ft and 31.62 ft,
respectively; minimum discharge, 49 ft³/s, Aug. 14, 1911, gage height,
1.47 ft.
PERIOD OF DAILY RECORD1.--SUSPENDED-SEDIMENT
DISCHARGE: March 1962 to March 1964, August 1974 to September
1977.
EXTREMES FOR PERIOD OF DAILY
RECORD1.--SUSPENDED-SEDIMENT CONCENTRATION: Maximum
daily mean, 3,050 mg/L, June 20, 1976; minimum daily mean, 1 mg/L, on
several days. SUSPENDED-SEDIMENT DISCHARGE: Maximum daily, 402,000
tons, Sept. 26, 1975; minimum daily, 0.85 ton, Sept. 20, 1974, Oct. 13,
1975.
1 Water-Quality Records
Peak Flow and Stage Information
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