With winter's snow about to melt away into lakes and streams, spring flood forecasting could be compromised by federal budget cuts.

The U.S. Geological Survey (USGS), which manages more than 100 gauges that measure flow rates and heights on rivers and streams across Minnesota, could pull the plug on as many as 10 percent of the devices. The move would be taken as a small part of sequestration, the automatic federal budget reductions that began taking effect March 1. Nationally, 375 gauges could be sidelined.

James Fallon, hydrologic networks and data chief for the USGS in Minnesota, said the agency is still working out how to trim its operations, so he couldn't specify which gauges might have to be shut down, or when. But with gauge information already providing key data for flooding outlooks around the region, "the timing is horrible," Fallon said.

USGS gauges are located on large rivers and key tributaries, including the Mississippi River at St. Paul and dozens of communities along the Minnesota River. They're also at other spots that gain particular prominence during flood season, such as the Red River at Fargo and more than 40 other locations in the Red watershed.

Most of the gauges transmit river levels and flow rates to satellites nearly continuously. Although they are automated, the gauges require regular visits for maintenance and calibration, Fallon said. In addition, spring ice breakup and flooding can destroy or wash them away, requiring more intervention, he said.

'We're really concerned about this'

The continual maintenance and calibration is needed to keep flood forecasts accurate by matching river height to flow rates, said Diane Cooper, hydrologist with the North Central River Forecast Center, the Chanhassen-based NOAA agency that monitors flood dynamics in Minnesota, seven other states and parts of two Canadian provinces.

"We're really concerned about this," said Cooper said. "It's not good."

One possible target for shutdown could be a gauge on the Root River near Pilot Mound in southeast Minnesota, Fallon said. Ferris Chamberlin, chief of water management for the St. Paul District of the U.S. Army Corps of Engineers, said that gauge is so remote that it's expensive to send people out to check it, even though it's in an area prone to flash flooding.

"If we have a big rainstorm on the Root and it spikes up, I'm not going to know," Chamberlin said, describing the effect of a gauge shutdown.

The Minnesota Department of Natural Resources also has a network of 260 river gauges, noted Greg Kruse, supervisor of the DNR's water monitoring surveys unit. But relatively few transmit real-time data. Also, many do not play a role in flood forecasting, instead providing information on water quality and other concerns.

Although the gauge network is far more extensive than it was in the past, Kruse added, planners, forecasters and community leaders have simply come to rely on it in its current state.

"The expectation is that you're going to have instantaneous information at your fingertips," he said.

Bill McAuliffe • 612-673-7646