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: 2011-09-09 Crest: 32.41 ft.Datum change: 1967-10-01Number of Floods: 26

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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



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