Susquehanna River at Conowingo, Harford County MD (CNWM2)
Gage Location: Harford County, MarylandSite Location: Cecil County, Maryland
Latitude: 39.659Longitude: -76.174Elevation: 5 ft. MSLDrainage Area: 27100 Sq. Mi.
Minor Stage: 23.5 ft. Moderate Stage: 28 ft.Major Stage: 33 ft.
First Flood: 1970-02-04Last Flood: 2014-04-18 Crest: 27.8 ft.Datum change: 1967-10-01Number of Floods: 27

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Date of FloodCrest(ft)Streamflow(cfs)CategoryCode
1970-02-0426.4434000ModerateF2
1972-06-2436.831130000MajorF2
1975-09-2730.92710000MajorF2
1976-01-2824.65338000MinorF2
1976-10-1023.99306000MinorF2
1978-01-2825.64377000ModerateF2
1979-03-0728.04499000ModerateF2
1981-02-2525.18355000ModerateF2
1984-02-1628.08501000ModerateF2
1986-03-1626.17403000ModerateF2
1993-04-0228.06500000MajorF2
1994-03-2326.16403000ModerateF2
1996-01-2034.18909000MajorF2
1996-11-1124.04303000MinorF2
1998-01-1025.55372000ModerateF2
2003-03-2224.15308000MinorF2
2004-01-1623.88-9999MinorF2
2004-09-1930.07620000MajorF2
2005-04-0426.7430000ModerateF2
2006-06-2927.31461000MinorF2
2008-03-0625.64379000MinorF2
2010-01-2724.37325000MinorF2
2011-03-0824.17317000MinorF2
2011-03-1227.79487000MinorF2
2011-04-2925.06354000ModerateF2
2011-09-0932.41778000MajorF2
2014-04-1827.8487000Minornone



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: 02:58 PM Apr 18, 2014