The federal spending cuts, known as sequester, have forced the U.S. Geological Survey to begin turning off some 150 stream gauges that monitor water levels on the nation's rivers and streams, CNN reported Friday.
And funding cutbacks at states, cities and towns struggling with their own budget crises could mean a further 200 gauges being turned off, water science experts said.
"We're trying to be very careful about which ones we say aren't going to receive funding," Michael Norris, coordinator for the National Streamflow Information Program, said.
The program, one of thousands of federal programs facing federal budget cuts, suffered a $2 million reduction in its 2013 funding.
"The last thing we want to do is put anyone's life or property in danger," said Norris, whose group has spent months deciding which gauges are the least critical.
The gauges allow the National Weather Service to forecast floods in advance.
"Without these observations, (our) forecast and warning operations will be impaired, reduced, or discontinued on a location-by-location basis," Christopher Vaccaro, a weather service spokesman, said.