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
2014-05-1722.6214500Moderatenone



Codes and description

C1|Crest information during this period may be incomplete and therefore was not used in frequency calculations. Some of the floods are based on current flood stage and nearby gage information.
C2|Crest information during this period 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: 07:31 AM Dec 19, 2014