West Branch Susquehanna River at Williamsport, Lycoming County PA (WILP1)
Gage Location: Lycoming County, Pennsylvania	Site Location: Lycoming County, Pennsylvania
Latitude: 41.236	Longitude: -76.907	Elevation: 494.98 ft. MSL	Drainage Area: 5682 Sq. Mi.
Minor Stage: 20 ft.	Moderate Stage: 21 ft.	Major Stage: 30 ft.
First Flood: 1865-03-17	Last Flood: 2011-04-28 Crest: 20.27 ft.	Datum change: 1928-10-01	Number of Floods: 39

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Month Number of Floods After Datum Number of Floods Total Cumulative Total After Datum Cumulative Total January 3 3 3 3 February 2 3 5 6 March 7 15 12 21 April 5 5 17 26 May 1 4 18 30 June 1 3 19 33 July 0 0 19 33 August 0 0 19 33 September 2 2 21 35 October 0 0 21 35 November 1 1 22 36 December 2 3 24 39 Seasonal Totals Winter (Dec-Jan-Feb) 9 Spring (Mar-Apr-May) 24 Summer (Jun-Jul-Aug) 3 Fall (Sep-Oct-Nov) 3

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: 08:09 AM Feb 08, 2013