Preliminary stage and streamflow data at selected U.S. Geological Survey streamgages in New England for the floods of April 2019

The combination of rainfall and snowmelt in northern New England and rainfall in southern New England resulted in minor to major flooding from April 15 to 24, 2019, according to stage and streamflow data collected at 63 selected U.S. Geological Survey (USGS) streamgages. A typical USGS streamgage measures and records stream stage and estimates streamflow based on a relation (rating curve) of discrete measurements of streamflow and the recorded stage. USGS hydrographers were deployed during and after these storms to measure the streamflow of the flooded rivers and confirm streamgage rating curves.

Preliminary Data Indicate...

• The National Weather Service flood stage was reached at 36 USGS streamgages selected for monitoring; the minor flood stage category was reached at 30 streamgages, moderate flood stage category at 5 streamgages, and major flood stage category at 1 streamgage.
• Peak streamflows for the period of record occurred at three streamgages in Maine. Of these, the peak at the St. John River at Ninemile Bridge, Maine streamgage was the highest in its 67-year period of record.
• A total of 30 streamgages—15 streamgages in Maine, 9 in Vermont, 4 in New Hampshire, and 1 each in Connecticut and Massachusetts—recorded peak streamflows within the top 10 for their period of record. Two of these streamgages, the Clyde River at Newport, Vermont and the Saco River at Cornish, Maine, have periods of record greater than 100 years.
• In total, USGS hydrographers made more than 210 streamflow measurements during the April 15–24 floods in New England.