South Branch Potomac River near Petersburg, Grant County WV (PETW2)
Gage Location: Grant County, West Virginia	Site Location: Grant County, West Virginia
Latitude: 38.991	Longitude: -79.176	Elevation: 968.34 ft. MSL	Drainage Area: 651 Sq. Mi.
Minor Stage: 14 ft.	Moderate Stage: 15 ft.	Major Stage: 17 ft.
First Flood: 1877-11-24	Last Flood: 2010-01-25 Crest: 14.86 ft.	Datum change: 2011-03-16	Number of Floods: 29

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Year Before Datum Change Number of Floods 1877 1 1878 0 1879 0 1880 0 1881 0 1882 0 1883 0 1884 0 1885 0 1886 0 1887 0 1888 0 1889 0 1890 0 1891 0 1892 0 1893 0 1894 0 1895 0 1896 0 1897 0 1898 0 1899 0 1900 0 1901 0 1902 0 1903 0 1904 0 1905 0 1906 0 1907 0 1908 0 1909 0 1910 0 1911 0 1912 0 1913 0 1914 0 1915 0 1916 0 1917 0 1918 0 1919 0 1920 0 1921 0 1922 0 1923 0 1924 1 1925 0 1926 0 1927 0 1928 0 1929 0 1930 0 1931 0 1932 1 1933 0 1934 0 1935 0 1936 1 1937 0 1938 0 1939 1 1940 1 1941 0 1942 2 1943 0 1944 0 1945 0 1946 0 1947 0 1948 0 1949 1 1950 0 1951 0 1952 0 1953 0 1954 1 1955 0 1956 0 1957 0 1958 0 1959 0 1960 0 1961 0 1962 0 1963 1 1964 0 1965 0 1966 0 1967 1 1968 0 1969 0 1970 0 1971 0 1972 1 1973 1 1974 1 1975 1 1976 1 1977 0 1978 1 1979 0 1980 0 1981 0 1982 1 1983 0 1984 1 1985 1 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 3 1997 0 1998 0 1999 0 2000 0 2001 0 2002 0 2003 1 2004 0 2005 0 2006 0 2007 2 2008 1 2009 0 2010 1

Year After Datum Change Number of Floods 2011 0 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