The U.S. Capitol is reflected in a puddle after a rainy day in Washington, D.C. (Oliver Contreras for The Washington Post)

On Thursday afternoon, a bipartisan weather bill years in the making quietly died on the floor of the House of Representatives. Supporters of the bill say it was necessary to maintain U.S. excellence in research and forecasting and the National Weather Service’s ability to issue lifesaving warnings. It also would have bridged federal agencies and private companies in a discipline where advances are being made across all sectors.

The Weather Research and Forecasting Act of 2015 — which had Democrat, Republican, bicameral and weather enterprise support — passed the Senate by unanimous consent on Dec. 2 but was left withering on the vine in the House, ostensibly because of a decades-old water dispute in the South.

The bill would have been the first major piece of weather legislation since the early 1990s. It prioritizes accurate forecasts and warnings and collaboration with the private sector through competitive grants. It aims to improve tornado warnings, including the ability to warn of a tornado more than one hour in advance. It continues the Hurricane Improvement Forecast Program, which saw its funding slashed in 2015, much to the disappointment of the weather community and Sens. Marco Rubio (R-Fla.) and Bill Nelson (D-Fla.).

In what would have been a major win for commercial weather companies, the bill would have allowed the National Oceanic and Atmospheric Administration to purchase high-quality data from the private sector, including businesses that are launching their own satellites.

The Senate Commerce Committee put a strong emphasis on seasonal forecasting — not only improving long-range predictions of temperature and precipitation but also determining how those factors will influence the severity of drought, wildfires, tornadoes, hurricanes, etc.

None of that was a problem for the House, though. The issue came in an amendment added by Nelson over a year ago in May 2015, which would have authorized funding for a NOAA National Water Center to facilitate collaboration across water management agencies.

In particular, the key issue for the Georgia delegation was a study on water resources and predictability. To understand why this was enough to topple a 96-page weather bill, you have to go back to 1990, when lawsuits over water resources were first filed by the states of Georgia, Alabama and Florida.

Much like the Colorado River basin supplies water for nearly 40 million people in the West, the Chattahoochee River is one of the major sources of water for the three Southern states. From drinking water for Atlanta to the environmental viability of the Apalachicola Bay and its oyster industry, the Chattahoochee and surrounding rivers are critically important to each of these states, and there simply isn’t enough water to go around.

Despite the decades-long feud, there had been no sign of anxiety over Nelson’s amendment until it reached the House floor on Thursday, when the delegation from Georgia objected to the National Water Center’s study.

The House majority removed the offending language and tried to pass the bill by unanimous consent, but the Senate minority indicated that it would object if the bill was returned without Nelson’s amendment. The House Subcommittee on the Environment tried to negotiate an acceptable compromise between the Georgia and Florida delegations to no avail, said Taylor Jordan, a committee aide.

“The roadblock is very much the study, but there wasn’t enough time to come to a conclusion,” said Jordan, who emphasized that Nelson acted in bad faith when he included language that he knew could derail the bill.

Nelson’s “language was always posed to us as, ‘this is already what NOAA is doing,’” Jordan told The Post, “and that’s a bad faith effort in our opinion.”

Nelson’s office adamantly disagrees with that characterization.

“It’s disingenuous to say this was bad faith,” said Bryan Gulley, a spokesman for Nelson, who pointed out that it was approved by the two Georgia senators via unanimous consent on Dec. 2. The amendment “was there since the beginning. This was not some sneak attack in the dark of night. It was nothing of that sort.”

Many people familiar with Thursday’s deliberations told The Post that the Georgia delegation was alerted to Nelson’s water amendment by Gov. Nathan Deal (R-Ga.), who was tipped off by the Atlanta Regional Commission. Neither the Atlanta Regional Commission nor Deal’s office immediately responded to requests for comment.

The 114th Congress essentially ended on Friday afternoon when members left town — they won’t return before it is scheduled to convene on Jan. 3. The bill could technically be passed in any of three pro-forma sessions over the next week, but “it isn’t a likely option,” Jordan told The Post.

“It would be a disappointment if Georgia Republicans are successful in taking down the weather bill at the last second,” said Nelson in a statement to The Washington Post. “A carefully balanced version that was negotiated with the House Science Committee and unanimously approved by the Senate sits in the House awaiting action. All the House has to do now is take it up in the pro-forma session and pass it.”

If the weather bill is not passed pro-forma, the end of this week resets the clock.

“I am disappointed that this important legislation ultimately did not pass due to an issue unrelated to improving weather forecasting,”  Rep. Jim Bridenstine (R-Okla.), the chair of the House Subcommittee on the Environment, said in a statement. “The importance of accurate forecasts cannot be overstated. The Environment Subcommittee stands ready to move this legislation early in the next Congress. Our aim is to achieve zero deaths from tornadoes and other severe weather events.”

What the bill looks like in the 115th Congress remains to be seen. The House science committee expects the path to be more straightforward given the months of negotiations that both parties have already put in, said Jordan, though he admitted it could be burdened again by Nelson’s water amendment.

“If he wants to do that, he should do a stand-alone bill,” said Jordan, “instead of doing it to a weather bill that for 99 pages has nothing to do with water.”

A previous version of this story suggested the Everglades were affected by this water dispute. This has been corrected to note that the Apalachicola Bay and the oyster industry is impacted.