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

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Height Above Flood Stage for Entire Period of Record
Height Above FSTotal OccurencePercent of Crest OccurrenceCumulative Total Flood OccurrencePercent of Floods above Listed Value
20 ft to 21 ft1230.820 ft or above 39100.0
21 ft to 22 ft820.521 ft or above 2769.2
22 ft to 23 ft37.722 ft or above 1948.7
23 ft to 24 ft37.723 ft or above 1641.0
24 ft to 25 ft25.124 ft or above 1333.3
25 ft to 26 ft12.625 ft or above 1128.2
26 ft to 27 ft12.626 ft or above 1025.6
27 ft to 28 ft37.727 ft or above 923.1
28 ft to 29 ft12.628 ft or above 615.4
29 ft to 30 ft12.629 ft or above 512.8
30 ft to 31 ft00.030 ft or above 410.3
31 ft to 32 ft12.631 ft or above 410.3
32 ft to 33 ft12.632 ft or above 37.7
33 ft to 34 ft12.633 ft or above 25.1
34 ft to 35 ft12.634 ft or above 12.6
Height Above Flood Stage After Datum Change
Height Above FSTotal OccurencePercent of Crest OccurrenceCumulative Total Flood OccurrencePercent of Floods above Listed Value
20 ft to 21 ft729.220 ft or above 24100.0
21 ft to 22 ft14.221 ft or above 1770.8
22 ft to 23 ft312.522 ft or above 1666.7
23 ft to 24 ft312.523 ft or above 1354.2
24 ft to 25 ft28.324 ft or above 1041.7
25 ft to 26 ft14.225 ft or above 833.3
26 ft to 27 ft14.226 ft or above 729.2
27 ft to 28 ft28.327 ft or above 625.0
28 ft to 29 ft14.228 ft or above 416.7
29 ft to 30 ft14.229 ft or above 312.5
30 ft to 31 ft00.030 ft or above 28.3
31 ft to 32 ft00.031 ft or above 28.3
32 ft to 33 ft00.032 ft or above 28.3
33 ft to 34 ft14.233 ft or above 28.3
34 ft to 35 ft14.234 ft or above 14.2





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