Perkiomen Creek at Graterford, Montgomery County PA (GRAP1)
Gage Location: Montgomery County, PennsylvaniaSite Location: Montgomery County, Pennsylvania
Latitude: 40.229Longitude: -75.452Elevation: 112.66 ft. MSLDrainage Area: 279 Sq. Mi.
Minor Stage: 11 ft. Moderate Stage: 13 ft.Major Stage: 16 ft.
First Flood: 1915-01-07Last Flood: 2014-05-01 Crest: 16.2 ft.Datum change: 1927-09-14Number of Floods: 82

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Date of FloodCrest(ft)Streamflow(cfs)CategoryCode
1915-01-0714.3319800ModerateC1
1915-01-1313.9818900ModerateC1
1915-02-0114.8321300ModerateC1
1915-08-04-999924900MissingC1
1918-02-15-999915600MissingC1
1918-02-2012.715600MinorC1
1919-07-21-999917400MissingC1
1928-07-1413.3621200Moderatenone
1929-02-2611.2214700Minornone
1929-10-0211.6215800Minornone
1933-08-2316.6534600Majornone
1934-09-3012.3419100Minornone
1935-07-0918.2639900Majornone
1935-09-0411.5515800Minornone
1936-01-0311.416400Minornone
1938-09-2113.514000ModerateC7
1940-03-1512.7119100Minornone
1940-05-2013.2822100Moderatenone
1942-08-0915.530200Moderatenone
1943-06-1811.6217000Minornone
1943-11-0911.4316400Minornone
1945-01-0111.9417900Minornone
1946-06-0216.2331700Majornone
1946-07-2312.1818900Minornone
1948-12-3011.8517800Minornone
1950-11-2514.626100Moderatenone
1952-04-2811.2116100Minornone
1952-07-1011.1516100Minornone
1952-11-2213.3622400Moderatenone
1952-12-1112.4919700Minornone
1953-01-2411.3116400Minornone
1955-08-1314.2624200Moderatenone
1955-08-1914.0823600Moderatenone
1955-10-1512.7219100Minornone
1958-02-2811.2314700MinorF2
1960-09-1214.5525400ModerateF2
1965-02-0811.1114500MinorF2
1967-03-0711.8616600MinorF2
1968-05-3111.7516300MinorF2
1969-07-2911.1714600MinorF2
1970-04-0212.217600MinorF2
1971-09-1414.6725600ModerateF2
1972-06-2217.0835800MajorF2
1972-11-1411.817400MinorF2
1973-12-2113.0421100ModerateF2
1975-07-1412.3919200MinorF2
1977-03-2312.1918600MinorF2
1978-01-2613.0321100ModerateF2
1979-01-2514.7926400ModerateF2
1982-01-0411.115100MinorF2
1983-04-1011.716700MinorF2
1984-07-0715.0627400ModerateF2
1985-09-2713.1921200ModerateF2
1989-09-2011.0815000MinorF2
1990-05-301320600ModerateF2
1993-12-0514.6526000ModerateF2
1995-03-0913.2921500ModerateF2
1996-01-1916.4532500MajorF2
1996-10-1915.6729600ModerateF2
1999-09-1616.5933700MajorF2
2000-03-2211.8917300MinorF2
2000-12-1713.7122800ModerateF2
2002-05-1412.5219100MinorF2
2003-06-2113.7823100ModerateF2
2003-09-1512.4318850MinorF2
2003-10-2712.0817815MinorF2
2004-07-2812.4919030MinorF2
2004-09-1814.826500ModerateF2
2004-09-2912.5319200MinorF2
2005-03-2811.1815300MinorF2
2005-04-0314.1724400ModerateF2
2005-10-0814.926800ModerateF2
2006-06-2813.6622700ModerateF2
2007-04-1512.4318900MinorF2
2008-02-1312.0817800MinorF2
2008-12-1212.9121400MinorF2
2010-10-0114.1827700ModerateF2
2011-08-2818.239600MajorF2
2011-09-0713.9324600ModerateF2
2011-11-2312.6118300MinorF2
2013-01-3112.4918000MinorF2
2014-05-0116.230200MajorF2



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