Potomac River at Williamsport, Washington County MD (WLLM2)
Gage Location: Washington County, MarylandSite Location: Washington County, Maryland
Latitude: 39.609Longitude: -77.848Elevation: 327.7 ft. MSLDrainage Area: 4943 Sq. Mi.
Minor Stage: 23 ft. Moderate Stage: 25 ft.Major Stage: 28 ft.
First Flood: 1936-03-18Last Flood: 1996-09-08 Crest: 31.1 ft.Datum change: 1932-01-01Number of Floods: 8

Click on table headers to sort
Height Above Flood Stage for Entire Period of Record
Height Above FSTotal OccurencePercent of Crest OccurrenceCumulative Total Flood OccurrencePercent of Floods above Listed Value
25 ft to 26 ft112.525 ft or above 8100.0
26 ft to 27 ft00.026 ft or above 787.5
27 ft to 28 ft00.027 ft or above 787.5
28 ft to 29 ft00.028 ft or above 787.5
29 ft to 30 ft00.029 ft or above 787.5
30 ft to 31 ft00.030 ft or above 787.5
31 ft to 32 ft112.531 ft or above 787.5
32 ft to 33 ft00.032 ft or above 675.0
33 ft to 34 ft00.033 ft or above 675.0
34 ft to 35 ft225.034 ft or above 675.0
35 ft to 36 ft00.035 ft or above 450.0
36 ft to 37 ft225.036 ft or above 450.0
37 ft to 38 ft112.537 ft or above 225.0
38 ft to 39 ft00.038 ft or above 112.5
39 ft to 40 ft00.039 ft or above 112.5
40 ft to 41 ft00.040 ft or above 112.5
41 ft to 42 ft00.041 ft or above 112.5
42 ft to 43 ft00.042 ft or above 112.5
43 ft to 44 ft00.043 ft or above 112.5
44 ft to 45 ft00.044 ft or above 112.5
45 ft to 46 ft00.045 ft or above 112.5
46 ft to 47 ft00.046 ft or above 112.5
47 ft to 48 ft00.047 ft or above 112.5
48 ft to 49 ft112.548 ft or above 112.5
Height Above Flood Stage After Datum Change
Height Above FSTotal OccurencePercent of Crest OccurrenceCumulative Total Flood OccurrencePercent of Floods above Listed Value
23 ft to 24 ft00.023 ft or above 8100.0
24 ft to 25 ft00.024 ft or above 8100.0
25 ft to 26 ft112.525 ft or above 8100.0
26 ft to 27 ft00.026 ft or above 787.5
27 ft to 28 ft00.027 ft or above 787.5
28 ft to 29 ft00.028 ft or above 787.5
29 ft to 30 ft00.029 ft or above 787.5
30 ft to 31 ft00.030 ft or above 787.5
31 ft to 32 ft112.531 ft or above 787.5
32 ft to 33 ft00.032 ft or above 675.0
33 ft to 34 ft00.033 ft or above 675.0
34 ft to 35 ft225.034 ft or above 675.0
35 ft to 36 ft00.035 ft or above 450.0
36 ft to 37 ft225.036 ft or above 450.0
37 ft to 38 ft112.537 ft or above 225.0
38 ft to 39 ft00.038 ft or above 112.5
39 ft to 40 ft00.039 ft or above 112.5
40 ft to 41 ft00.040 ft or above 112.5
41 ft to 42 ft00.041 ft or above 112.5
42 ft to 43 ft00.042 ft or above 112.5
43 ft to 44 ft00.043 ft or above 112.5
44 ft to 45 ft00.044 ft or above 112.5
45 ft to 46 ft00.045 ft or above 112.5
46 ft to 47 ft00.046 ft or above 112.5
47 ft to 48 ft00.047 ft or above 112.5
48 ft to 49 ft112.548 ft or above 112.5