LOCATION.--Lat 40°50'59.7", long
73°13'27.2" referenced to North American Datum of
1983, Suffolk County, NY, Hydrologic Unit 02030201, on left
bank 0.5 mi downstream from New Mill Pond, 1.0 mi southwest of
Smithtown, and 1.5 mi southwest of Village of Smithtown
Branch.
DRAINAGE AREA.--27 mi².
PERIOD OF RECORD.--October 1943 to September 2019,
October 2020 to October 2022 (discontinued).
REVISIONS HISTORY.--WSP 1141: Drainage area.
GAGE.--Water-stage recorder and concrete control. Datum
of gage is 9.59 ft above NGVD of 1929 and 8.52 ft above NAVD of
1988 (VERTCON).
REMARKS.--Occasional regulation caused by cleaning of
fish screens and trash racks at outlet of New Mill Pond on main
stream and ponds on tributaries above station.
Water Years 2014-19, 2021-22: Records good except those for
estimated daily discharges, which are fair.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 952
ft³/s, Jan. 22, 1979, gage height, 3.22 ft, result of dam
failure; minimum discharge, 16 ft³/s, June 5, 6, 1967; minimum
gage height, 0.46 ft, Feb. 9, 1951.
PERIOD OF DAILY RECORD1.--WATER TEMPERATURE: April 2021 to
October 2022. SPECIFIC CONDUCTANCE: April 2021 to October
2022. DISSOLVED OXYGEN: April 2021 to October
2022.
EXTREMES FOR PERIOD OF DAILY RECORD1.--
WATER TEMPERATURE:
Maximum, 27.2°C, June 30, 2021; minimum
0.1°C,
Jan. 15, 2022.
SPECIFIC CONDUCTANCE: Maximum, 430
uS/cm @ 25°C, Feb. 10, 2022; minimum, 120 uS/cm @ 25°C, Sept.
2, 2021.
DISSOLVED OXYGEN: Maximum, 14.9
mg/L, Jan. 16, 2022 ; minimum, 6.3 mg/L Sept. 22,
2022.
1 Water-Quality Records