Millstone River at Blackwells Mills, Somerset County NJ (BKWN4)
Gage Location: Somerset County, New Jersey	Site Location: Somerset County, New Jersey
Latitude: 40.475	Longitude: -74.576	Elevation: 26.97 ft. MSL	Drainage Area: 258 Sq. Mi.
Minor Stage: 9 ft.	Moderate Stage: 10 ft.	Major Stage: 15 ft.
First Flood: 1924-04-07	Last Flood: 2011-12-08 Crest: 10.79 ft.	Datum change: 1928-08-17	Number of Floods: 144

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Year Before Datum Change Number of Floods 1924 1 1925 1 1926 1 1927 2

Year After Datum Change Number of Floods 1928 0 1929 0 1930 0 1931 0 1932 3 1933 1 1934 1 1935 0 1936 2 1937 0 1938 2 1939 1 1940 2 1941 0 1942 1 1943 0 1944 3 1945 0 1946 1 1947 0 1948 1 1949 0 1950 1 1951 1 1952 2 1953 2 1954 0 1955 3 1956 0 1957 0 1958 1 1959 0 1960 1 1961 2 1962 2 1963 0 1964 0 1965 0 1966 2 1967 2 1968 1 1969 2 1970 1 1971 2 1972 2 1973 4 1974 1 1975 4 1976 1 1977 4 1978 3 1979 6 1980 1 1981 0 1982 2 1983 4 1984 4 1985 0 1986 4 1987 3 1988 0 1989 4 1990 0 1991 0 1992 2 1993 2 1994 2 1995 0 1996 6 1997 1 1998 4 1999 2 2000 0 2001 1 2002 0 2003 5 2004 2 2005 3 2006 1 2007 2 2008 3 2009 3 2010 2 2011 8 2012 0 2013 0

Codes and description

C1|Crest information looks unreliable and incomplete and not used in frequency calculations. Some of the floods are based on current flood stage and nearby gage information.
C2|Crest information looks reliable despite potential problems. This data was used in frequency calculations.
C3|Crest height estimated by the USGS.
C4|Crest height is from the National Weather Service.
C5|Crest height affected by backwater.
C6|Crest occurred at a previous flood stage that is lower than the current flood stage. The crests below the new flood stage are not used in flood frequency calculations.
C7|Crest from USGS yearly peak and/or date is different than the crest we provide. In many cases MARFC uses crest based on backwater or ice effects.
C8|Crest month or day of occurrence has been estimated by The Middle Atlantic River Forecast Center usually based on nearby gage information.
C9|Crest date (day) in the month is unknown.
F1|Flow is an estimate.
F2|Flow affected by regulation or diversion and in some cases to an unknown degree.
F3|Flow effected by snow-melt, ice jam or debris jam break up.
F4|Flow affected by dam failure.
F5|Flow - All or part of the record affected by urbanization, mining, agricultural changes, channelization or other factors.
G1|Gage height at a different site and/or datum.
G2|Gage is not an official USGS gage with crests provided by the NWS. Crest information looks unreliable and incomplete and not used in flood frequency calculations.
G3|Gage datum changed during this year.
none,No code; Good Data

Updated: 08:09 AM Feb 08, 2013