Pennsylvania has lost nearly half of its most reliable precipitation gauges that the National Weather Service uses for forecasting floods.
Forty-seven of the 104 rain gauges were closed by the U.S. Geological Survey on March 1 because of a $206,000 funding shortfall. USGS maintains the gauges.
One was in Ephrata, where the gauge at the borough sewage treatment plant had been temporarily taken out of service in March 2012 because of construction at the plant. It will not be redeployed.
That leaves only one state-of-the-art USGS gauge in Lancaster County – along the Conestoga River at Lancaster city’s water-treatment plant.
All the gauges are part of the Weather Service’s Susquehanna Flood Forecast and Warning System that involve the NWS and USGS. The gauges report precipitation amounts every 15 minutes.
There are hundreds of other precipitation gauges across the state that NWS can draw on, but the USGS system is important because the gauges are sophisticated, report nearly real-time amounts, are heated for year-round use and are regularly maintained by technicians.
The Lancaster County Emergency Management Agency has a network of 17 less sophisticated rain gauges, called Iflows, that it maintains and NWS also uses.
“We have a job to do here to put out flash flood and flood warnings as quick as possible. Will it be as easy? Of course not,” says Charles Ross, NWS hydrologist at the Mid Atlantic River Forecast Center in State College.
The key tool used in making flood forecasts is radar, he emphasizes. But rain gauges “are the ground troops,” he says, used to check the accuracy of what radar is showing.
“I’d like to have three times as many. It’s just the reality of the situation,” he says.
“We’ve always had (funding) issues, but it seems to me this if by far the most impacts we’ve seen from the loss of gauges.”
Since record-keeping began 200 years ago, the Susquehanna River Basin has been one of the most flood-prone watersheds in the nation. The region also is characterized by localized flooding of small streams with little advance warning.
Funding for the forecast system has previously been strained, but in the past some agency or group has come forward to fill the gap.
For much of its existence, the flood forecasting system was primarily funded by a Congressional earmark championed by U.S. Sen. Barbara Mikulski, a Maryland Democrat. But in 2011, such add-on funds, considered “pork” by some, were banned by a Republican initiative.
The funding gap initially was filled by NWS, but not this year.
The USGS has left the rain gauges in place, ready to be turned back on if someone steps forward.
“I don’t know there’s a lot of hope right now,” says Ben Pratt, hydraulic engineer for the Susquehanna River Basin Commission.
Ross said the NWS will now rely more on volunteer weather “spotters,” who report precipitation measurements at their homes. For example, many report rain totals to the NWS State College Facebook page. Others send in totals via Twitter.
A separate network of 416 stream gauges are instrumental in forecasting floods. Those gauges also are operated by USGS and used by the NWS.
Funding cutbacks caused by the sequester will result in two or three stream gauges being shut down in Pennsylvania.
Those gauges will be chosen in the next two or three weeks, according to Marla Stuckey, associate director of the USGS Pennsylvania Water Science Center in New Cumberland.
Stuckey said it is “unlikely” any of the gauges to be taken out of service would come from Lancaster County’s network of 10 stream gauges.
The ones closed would be least likely to impact lives and property, said Stuckey, adding, “Every gauge is important to someone.”
Besides their forecasting function, the network of rain gauges across Pennsylvania provides the public with a free source of rainfall totals, posted on websites. Some are used by the media for local weather pages.