NewsFebruary 10, 2012

Flood Warnings at Risk as Cuts to Critical Gauges Loom

Search results placeholder
Andrew Freedman

By Andrew Freedman

This is the first in an occasional Climate Central series on how reduced funding for scientific observations is affecting climate and weather research and forecasting.

On Sept. 7, 2011, a record deluge associated with Tropical Storm Lee struck Binghamton, N.Y., dumping 7.5 inches of rain in a 24-hour period—the most the city had ever seen in such a short time. Weather forecasters, emergency managers and rescue teams knew the nearby Susquehanna River was already rising from an unusually wet summer, and that this would further swell the engorged river. To predict the flooding and aid critical rescue efforts, they counted on a crucial network of rain and stream gauges positioned at various points along the river.

Data from these gauges was fed into the National Weather Service’s computer models, and as the waters rose and threatened to spill into Binghamton’s central business district, the forecasts enabled emergency managers to order the timely evacuation of 20,000 residents.

Aerial photo of a flooded Binghamton. Credit: Bill Walsh via NOAA.

In the end, the river crested at a record 25.71 feet, beating the old high water mark of 25.0 feet, set in 2006. And in large part because of stream gauges and accurate forecasts, Binghamton was spared from a worst-case scenario, and no deaths occurred in the city. Still, the damage estimate for Broome County alone stands at $513 million, rising to nearly $1 billion when damage in neighboring Tioga County is included.

If a similar event were to happen this year, though, the officials may have to rely on less accurate information, as budget cuts are forcing the shutdown of 19 stream gauges in New York’s portion of the flood-prone Susquehanna River Basin. These cuts would significantly reduce the accuracy of flood warnings and streamflow forecasts, according to water officials at the National Weather Service, U.S. Geological Survey (USGS), and Susquehanna River Basin Commission.

The timing of such cutbacks couldn’t be any worse. Global warming is increasing the frequency and severity of heavy rainfalls in the Northern Hemisphere, tilting the odds in favor of extreme events. This makes monitoring networks like stream gauges even more valuable.

The Empire State is not alone in facing the prospect of losing the gauges, either. The USGS operates a national network of about 7,800 gauges, funded with federal dollars and through partnerships with state, local and regional entities. While the total number of stream gauges has been increasing, many states are having an increasingly difficult time coming up with their share of the $17,000 to $18,000 per year required to operate each one, leading to significant losses of data in some areas.

Nationally, the USGS currently lists 112 stream gauges as “threatened,” due to potential insufficient funding, 74 gauges as “endangered,” meaning that the USGS has been notified of a definite lack of funding, and 449 gauges as recently discontinued. Most of the discontinued stream gauges were located in Florida and New Mexico.

USGS Map of threatened (orange), endangered (red) and recently discontinued (black) stream gauges.

While scientists say it’s impossible to blame any single weather event on global warming, studies show the warming climate likely has increased the odds in favor of extreme rainfall, including a major flooding event in the U.K. in 2000. Research also shows that precipitation-related impacts may worsen as the atmosphere and oceans continue to warm, releasing more water vapor into the atmosphere that can be wrung out by storm systems. On average, there is about 4 percent more water vapor in the atmosphere now than there was in the 1970s.

In 2011, the U.S. set a record for precipitation extremes, as 56 percent of the country experienced either very wet or very dry conditions. Pennsylvania and New York had their wettest years since records began in the late 19th century.

Unless new funding can be found from federal, state, or local sources, New York stands to lose a total of 30 stream gauges and seven rain gauges statewide as of March 1. One of the stream gauges on the USGS’ “endangered list” is located on the Susquehanna River in Binghamton, and it provided crucial data during the 2011 flooding.

Ben Pratt, a hydrologist with the Susquehanna River Basin Commission, said flood forecasts and routine river forecasts will suffer with the loss of data.

“You can’t forecast what a river is going to do without this information,” he said.

Pratt said forecasting improvements lowered the death toll from Tropical Storm Lee in the Susquehanna River Basin compared to the death toll from past storms in the area, such as Hurricane Agnes in 1972, which killed dozens from flooding rains in Pennsylvania and New York.

Graph showing the steep rise and 25.71 ft. record crest reached by the Susquehanna River at Binghamton. The stream gauge that provided the data for this graph is currently slated to be discontinued on March 1 due to a lack of funding. Credit: NOAA/AHPS.

Weather forecasters like George McKillop, who serves as the deputy chief of hydrologic services for the National Weather Service’s eastern region, consider stream gauge data to be vitally important, because the readings are fed into computer forecast models to predict streamflow and how high rivers will crest. He said the prospect of losing so many stream gauges across the country “impacts all of our operations nationwide.”

“The bottom line is that it’s data, it’s initial data that has to go into our sophisticated models. Without that data the input from our models suffer,” he said.

Stream gauge data also helps water managers determine how to allocate water resources and enables engineers to determine what a 100-year flood would be at a specific location, which is important for designing construction projects, such as bridges and dams, as well as setting insurance rates. This is especially important now that global warming may be starting to change the frequency of 100-year floods.

To determine 100-year flood levels, a long record of data is required and many of the endangered stream gauges have provided data nonstop for several decades. One stream gauge scheduled to be shut down on March 1 is located in Owego Creek near Owego, N.Y.,which has been recording data for 82 years. Such long-time series are helpful for climate scientists seeking to understand how global warming is altering rainfall and floods in different regions.

“When you think of this increased frequency of these big [rainfall] events throughout this nation, and we’re already seeing it . . . it just reinforces how critical this data is,” McKillop said.

Partnerships Under Stress

The funding shortfall stems from the unique way stream gauges are supported, according to Robert Mason, USGS’ acting director of surface water. While the agency got a nearly $5 million boost in its stream gauge budget for fiscal year 2012, it still cannot cover all the costs for the nationwide program and must rely on state governments and other entities to make up the difference.

In all, non-federal sources contribute more than half of the funding for the stream gauge program. Thanks in part to cutbacks in federal assistance for state programs, state and local governments have been forced to slash their budgets, often including their water resources budgets. Florida, for example, cut $700 million in water management funding last year, resulting in the discontinuation of dozens of stream gauges.

Radar estimated precipitation totals showing the heavy rainfall that fell near Binghamton on Sept. 7, 2011. Credit: NOAA.

Mason said many sites are endangered even though there has been an increase in the number of operational stream gauges nationwide. “We are very concerned about it. The loss of some gauging stations, particularly the stations that have long periods of record, is a tragedy,” he said.

Pratt said he remains optimistic for the future of the threatened Susquehanna River Basin gauges. “As of now I’m fairly confident that we’re going to be able to fund those 19 stream gauges through one mechanism or another,” he said. The future of the program, though, is uncertain because the same funding issues are going to arise again next year. Pratt said a steadier stream of funding is needed to avoid “that doomsday scenario where we’re going to have 15 inches of rain in the Susquehannah River Basin and not know how the river is going to respond.”

Senators Patrick Leahy of Vermont and Chuck Schumer of New York, both Democrats, were able to secure funding from the Great Lakes Fishery Commission to prevent the shutdown of 18 stream gauges in the Lake Champlain basin. That region was also hit hard by record flooding last year following Tropical Storms Irene and Lee.

“Flipping off these gauges would have forced us to tie one hand behind our back to fight flooding, when we really need all hands on deck,” Schumer said in a Jan. 15 press release.

Ward O. Freeman, director of the USGS’ New York Water Science Center, said he hopes funding will be found to keep some Susquehanna River Basin stream gauges open. According to him, one way to ensure consistently adequate levels of funding for the program would be for Congress to fully fund the agency’s National Streamflow Information Program, which currently only provides a piece of the funding for most stream gauges.

“Obviously, our goal is to fund them all, but cobbling together funds like we are is not a long-term solution,” Freeman said.

NEXT: How cuts to scientific programs within the National Oceanic and Atmospheric Administration (NOAA) may affect the accuracy of weather and climate forecasts.