Potomac River at Hancock, Washington County MD (HNKM2)
Gage Location: Washington County, Maryland	Site Location: Washington County, Maryland
Latitude: 39.698	Longitude: -78.178	Elevation: 383.68 ft. MSL	Drainage Area: 4064 Sq. Mi.
Minor Stage: 30 ft.	Moderate Stage: 33 ft.	Major Stage: 35 ft.
First Flood: 1889-06-01	Last Flood: 1996-09-08 Crest: 35.81 ft.	Datum change: 1937-01-21	Number of Floods: 13

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Date of Flood Crest(ft) Streamflow(cfs) Category Code 1889-06-01 40 220000 Major *** (B) 1924-03-30 32.4 130000 Minor *** (B) 1924-05-13 35 160000 Major *** 1929-04-17 30.3 110000 Minor *** (B) 1936-03-18 47.6 340000 Major *** 1937-04-27 35.7 153000 Major none 1937-10-29 31.8 122000 Minor none 1942-10-16 36.63 155000 Major none 1955-08-19 32.4 123000 Minor none 1972-06-23 30.79 112000 Minor none 1985-11-06 41.2 207000 Major none 1996-01-20 36.26 152000 Major none 1996-09-08 35.81 148000 Major 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