Perkiomen Creek at Graterford, Montgomery County PA (GRAP1)
Gage Location: Montgomery County, Pennsylvania	Site Location: Montgomery County, Pennsylvania
Latitude: 40.229	Longitude: -75.452	Elevation: 112.66 ft. MSL	Drainage Area: 279 Sq. Mi.
Minor Stage: 11 ft.	Moderate Stage: 13 ft.	Major Stage: 16 ft.
First Flood: 1915-01-07	Last Flood: 2013-01-31 Crest: 12.49 ft.	Datum change: 1927-09-14	Number of Floods: 81

Click on table headers to sort

Date of Flood Crest(ft) Streamflow(cfs) Category Code 1915-01-07 14.33 19800 Moderate *** 1915-01-13 13.98 18900 Moderate *** 1915-02-01 14.83 21300 Moderate *** 1915-08-04 -9999 24900 Missing *** 1918-02-15 -9999 15600 Missing *** 1918-02-20 12.7 15600 Minor *** 1919-07-21 -9999 17400 Missing *** 1928-07-14 13.36 21200 Moderate none 1929-02-26 11.22 14700 Minor none 1929-10-02 11.62 15800 Minor none 1933-08-23 16.65 34600 Major none 1934-09-30 12.34 19100 Minor none 1935-07-09 18.26 39900 Major none 1935-09-04 11.55 15800 Minor none 1936-01-03 11.4 16400 Minor none 1938-09-21 13.5 14000 Moderate none 1940-03-15 12.71 19100 Minor none 1940-05-20 13.28 22100 Moderate none 1942-08-09 15.5 30200 Moderate none 1943-06-18 11.62 17000 Minor none 1943-11-09 11.43 16400 Minor none 1945-01-01 11.94 17900 Minor none 1946-06-02 16.23 31700 Major none 1946-07-23 12.18 18900 Minor none 1948-12-30 11.85 17800 Minor none 1950-11-25 14.6 26100 Moderate none 1952-04-28 11.21 16100 Minor none 1952-07-10 11.15 16100 Minor none 1952-11-22 13.36 22400 Moderate none 1952-12-11 12.49 19700 Minor none 1953-01-24 11.31 16400 Minor none 1955-08-13 14.26 24200 Moderate none 1955-08-19 14.08 23600 Moderate none 1955-10-15 12.72 19100 Minor none 1958-02-28 11.23 14700 Minor (A) 1960-09-12 14.55 25400 Moderate (A) 1965-02-08 11.11 14500 Minor (A) 1967-03-07 11.86 16600 Minor (A) 1968-05-31 11.75 16300 Minor (A) 1969-07-29 11.17 14600 Minor (A) 1970-04-02 12.2 17600 Minor (A) 1971-09-14 14.67 25600 Moderate (A) 1972-06-22 17.08 35800 Major (A) 1972-11-14 11.8 17400 Minor (A) 1973-12-21 13.04 21100 Moderate (A) 1975-07-14 12.39 19200 Minor (A) 1977-03-23 12.19 18600 Minor (A) 1978-01-26 13.03 21100 Moderate (A) 1979-01-25 14.79 26400 Moderate (A) 1982-01-04 11.1 15100 Minor (A) 1983-04-10 11.7 16700 Minor (A) 1984-07-07 15.06 27400 Moderate (A) 1985-09-27 13.19 21200 Moderate (A) 1989-09-20 11.08 15000 Minor (A) 1990-05-30 13 20600 Moderate (A) 1993-12-05 14.65 26000 Moderate (A) 1995-03-09 13.29 21500 Moderate (A) 1996-01-19 16.45 32500 Major (A) 1996-10-19 15.67 29600 Moderate (A) 1999-09-16 16.59 33700 Major (A) 2000-03-22 11.89 17300 Minor (A) 2000-12-17 13.71 22800 Moderate (A) 2002-05-14 12.52 19100 Minor (A) 2003-06-21 13.78 23100 Moderate (A) 2003-09-15 12.43 18850 Minor (A) 2003-10-27 12.08 17815 Minor (A) 2004-07-28 12.49 19030 Minor (A) 2004-09-18 14.8 26500 Moderate (A) 2004-09-29 12.53 19200 Minor (A) 2005-03-28 11.18 15300 Minor (A) 2005-04-03 14.17 24400 Moderate (A) 2005-10-08 14.9 26800 Moderate (A) 2006-06-28 13.66 22700 Moderate (A) 2007-04-15 12.43 18900 Minor (A) 2008-02-13 12.08 17800 Minor (A) 2008-12-12 12.91 20300 Minor (A) 2010-10-01 14.18 27700 moderate none 2011-08-28 17.76 38100 Major none 2011-09-07 13.93 24600 Moderate none 2011-11-23 12.61 20500 Minor none

MARFC Codes
Code Description
(!!!) Datum changed during this year.
(1) Backwater Effect.
(2) 15.77 ft also occurred on 11/25/1950 but only counted as one flood.
(3) Estimated from currrent USGS rating table.
(4) Estimated height from the USGS.
(5) Gage height at a different site and/or datum
(6) Discharge affected by Regulation or Diversion
(7) Due to changes, prior floods were based on present flood stage. Therefore, flood data could possibly be incomplete.
(8) Gage is a staff gage and not the offical USGS gage. Therefore, some floods may be missing from our study.
(9) Discharge effected by snow-melt, ice jam or debris jam break up
(A) Discharge affected to unknown degree by regulation or diversion.
(B) Month or day of occurrence is unknown or not exact.
(C) All or part of the record affected by urbanization, mining, agricultural changes, channelization, or other factors.
(D) Crest height adjusted to current datum.
(E) Estimated discharge.
(F) Only annual maximum peak available for this year.
(O) This flood occurred at a previous flood stage that is lower than the current flood stage. This is only a historical flood.
** Crest information looks reasonable despite potential problems. This data was used in our study.
*** Crest information looks unreliable and incomplete and was not used in our flood frequency study.
**** Gauge was discontinued in 2004. 2004 and later was not used in our study.
none No code

Updated: 08:58 AM Jun 28, 2012