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: 2013-01-31 Crest: 12.49 ft.Datum change: 1927-09-14Number of Floods: 81

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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



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: 07:20 AM Nov 12, 2013