In times of floods and droughts, immediate access to river level data is important to officials charged with the responsibilities of protecting lives and property by taking actions to diminish the adverse effects of the emergency. The U.S. Geological Survey (USGS), in cooperation with many Federal, State, and local agencies, is the Nation's principal collector of accurate and unbiased streamflow data, and thus is the agency emergency officials rely on to provide the needed river data. The USGS operates and maintains more than 7,000 continuous-record streamflow-gaging stations on rivers in the United States; 84 of these stations are in Massachusetts and Rhode Island (see fig. 1). The river levels are recorded every 15 minutes at most of the stations; the river level data are then converted to streamflow data. Recorders equipped with telemetry (satellite radios or telephone modems) can provide almost immediate access to vital river levels.