Potomac River at Point of Rocks, Frederick County MD (PORM2)
Gage Location: Frederick County, MarylandSite Location: Frederick County, Maryland
Latitude: 39.274Longitude: -77.543Elevation: 200.63 ft. MSLDrainage Area: 9651 Sq. Mi.
Minor Stage: 16 ft. Moderate Stage: 20 ft.Major Stage: 25 ft.
First Flood: 1889-06-02Last Flood: 2014-05-17 Crest: 22.62 ft.Datum change: 1929-10-28Number of Floods: 115

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Date of FloodCrest(ft)Streamflow(cfs)CategoryCode
1889-06-0240.2460000MajorC1 G1
1896-10-0127.2204000MajorC1 G1
1898-08-1218127000MinorC1 G1
1899-03-0618.1128000MinorC1 G1
1901-04-2222161000ModerateC1 G1
1902-03-0229219000MajorC1 G1
1903-03-0116.6110000MinorC1 G3
1907-03-1517.6119000MinorC1
1908-01-1321.6152000ModerateC1
1910-06-1823.5168000ModerateC1
1911-09-0116.1106000MinorC1
1913-03-2820139000ModerateC1
1915-06-0420139000ModerateC1
1916-03-2918.3124000MinorC1
1917-03-1318.1123000MinorC1
1918-04-1618.6127000MinorC1
1920-03-0616.4109000MinorC1
1924-05-1332.2277000MajorC1
1928-05-0221.3145000ModerateC1
1929-04-1824.94180000ModerateC1
1929-10-2317.4110000MinorC1
1932-05-1423.34158000Moderatenone
1933-04-2119.3123000Minornone
1934-12-0219.78128000Minornone
1936-02-2818.13113000Minornone
1936-03-1941.03480000Majornone
1937-04-2733.86310000Majornone
1937-10-3024.93175000Moderatenone
1939-02-0519.39124000Minornone
1942-05-2421.13125000Moderatenone
1942-10-1640.43418000Majornone
1942-12-3120.47126000Moderatenone
1945-09-2021.98139000Moderatenone
1948-04-1516.0487000Minornone
1949-06-2021.2132000Moderatenone
1950-12-0520.75128000Moderatenone
1950-12-0918.42107000Minornone
1951-06-1517.5299000Minornone
1952-03-1317.1295800Minornone
1952-04-2920.67127000Moderatenone
1952-11-2319.68118000Minornone
1954-03-0318.65109000Minornone
1954-10-1721.02130000Moderatenone
1955-08-2029.08214000Majornone
1960-04-0117.3597800Minornone
1960-04-0618.25105000Minornone
1960-05-1020.28124000Moderatenone
1961-02-2117.9102000Minornone
1961-02-2716.691800Minornone
1962-03-2319.45116000Minornone
1963-03-0717.699800Minornone
1963-03-2120.47125000Moderatenone
1964-03-061687000Minornone
1965-03-0617.3597800Minornone
1967-03-0822.53144000Moderatenone
1970-04-0316.6492100Minornone
1972-06-2337.43347000Majornone
1972-10-0818.28106000Minornone
1973-04-2916.5891600Minornone
1973-12-2821.27132000Moderatenone
1975-03-2126.15181000Majornone
1975-09-2624.35126000Moderatenone
1976-01-0218.71109000Minornone
1976-10-1127.25193000Majornone
1978-01-2821.22132000Moderatenone
1978-03-1622.01139000Moderatenone
1978-03-2818.43107000Minornone
1978-05-1717.67100000Minornone
1979-01-2517.2996900Minornone
1979-02-2725.94178000Majornone
1979-09-0716.1987800Minornone
1982-06-1516.6692000Minornone
1983-04-2619.21115000Minornone
1984-02-1628.14199000Majornone
1984-03-3020.8128000Moderatenone
1984-04-0619.49117000Minornone
1985-11-0736.28309000Majornone
1986-03-1619.35116000Minornone
1987-04-1823.49153000Moderatenone
1988-05-2017.0196100Minornone
1992-04-2316.2590000Minornone
1993-03-0624.94167000Moderatenone
1993-03-2518.12105000Minornone
1993-04-0318.19106000Minornone
1993-04-1820.17123000Moderatenone
1993-11-2919.25115000Minornone
1994-02-2516.0388200Minornone
1994-03-1117.78102000Minornone
1994-03-3019113000Minornone
1996-01-2136.34310000Majornone
1996-01-2816.5392200Minornone
1996-03-2116.692800Minornone
1996-09-0836.26309000Majornone
1997-11-0917.3799100Minornone
1998-01-1020.07122000Moderatenone
1998-02-0617.99104000Minornone
1998-02-1918.23106000Minornone
1998-03-2220.24123000Moderatenone
2003-01-0316.2589970Minornone
2003-02-2416.591990Minornone
2003-03-2216.8594820Minornone
2003-09-2123.12150000Moderatenone
2003-12-1219.5818000Minornone
2004-09-3017.2598100Minornone
2005-03-3019.37116000Minornone
2007-04-171796000Minornone
2008-05-1316.9996000Minornone
2009-05-0617.5100000Minornone
2010-01-2621.42134000Moderatenone
2010-03-1525.52172000Majornone
2011-03-1219.92121000Minornone
2011-04-1822.52144000Moderatenone
2011-05-1922.15141000Moderatenone
2012-10-3118.19106000Minornone
2014-05-1722.62145000Moderatenone



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: 08:00 PM May 28, 2014