American Rivers, a Washington, D.C.-based advocacy group that has turned out most-endangered lists since 1986, put the Catawba at the top of its 2008 list to be released today.

The group accused Carolinas decision-makers of "sucking their rivers dry" to continue development as an historic drought lingers over the Catawba basin. Neither state, it said, has a long-term water plan to ensure the river survives future growth.

But some public officials say the Catawba, the subject of detailed studies and the beneficiary of new conservation efforts, has been far from ignored.

The amount of water pulled from the Catawba is projected to more than double over the next 50 years, one of those studies shows. Charlotte's chief water supply, Mountain Island Lake, could struggle to meet demand during a severe drought by 2048.

"The worst-case scenario is we'll have the same problems seen out West: We run our rivers dry. The river will no longer flow to its end," said Catawba Riverkeeper David Merryman. "We need year-round regulations of water supply. ... We can't keep sticking straws in the river."

Rick Gaskins, executive director of the Catawba Riverkeeper Foundation, which nominated the Catawba to the endangered list, said the biggest threat to the river is population growth and development.

"It's not that you can't have growth and development with good environmental quality. It's that if we continue on the course we're on, we're headed for trouble," he said.

Satisfying the growing clamor for water has strained the Catawba in recent years.

Last year was the driest on record in the basin, and it followed a four-year drought that ended in 2002. Public opposition to the quest for Catawba water from distant North Carolina cities Concord and Kannapolis -- "stealing," American Rivers said -- focused attention on water rights. South Carolina sued North Carolina before the Supreme Court on that question.

"This is the bottom line, in my opinion: If your resources are stretched to the limit, your growth period is over," said Paul Braun, a long-time river advocate in Morganton, N.C. "Every summer, if it weren't for these lakes, that river would be bone dry."

Duke Energy's renewal of its federal license to manage the Catawba, to expire this year, focused attention on the basin's future.

Fifty-year projections of water supplies and demand are the most extensive analyses in the state. Local communities last year put into action a new drought-response plan, created by the license terms, that is credited with keeping lake levels high as the dry spell continues. A water-management board, paid for by local water agencies in both Carolinas, was created in December.

"I look at this proposed new license as a really big improvement in the sustainable management of the river," said John Morris, director of the N.C. Division of Water Resources. "I see all those as positive things."

Year-round conservation programs -- American Rivers criticized a lack of them -- now have residential customers of Charlotte-Mecklenburg Utilities using less water than at any time in recent history, said utility conservation manager Maeneen Klein.

In Rock Hill, officials credited consumers with reducing water usage by up to 30 percent during the peak of the drought.

"Nobody turned on their tap and didn't have water" during the record-dry 2007, Klein said. "If anything, this year has proved that we probably lead the state in protecting our water supplies."

American Rivers said the endangered list is meant to depict rivers "at a crossroads" in public policy, not necessarily those with the most severe problems.

"These aren't 10 hopeless rivers," spokesman Garrett Russo said. "These are things that can be fixed."

The Catawba's problems are far from solved, said York County Councilman Rick Lee, who agrees with the "endangered" label. Lee has been an outspoken critic of the interbasin transfer (IBT) proposed by Concord and Kannapolis to siphon water from the Catawba, a plan now held up by the lawsuit before the U.S. Supreme Court.

"I'm glad to see the report," Lee said. "It comes at a good time, and it might help things at the Supreme Court level."

Lee said the overuse of the Catawba's water supply and the past year's drought should be a "wake-up call" to legislators and constituents that there is a need for a bi-state water use plan in the Carolinas. He said limits need to be put in place that officials in both Carolinas follow.

"We have to draw a line in the sand," Lee said. "We've been convinced of the risk the Catawba faces for years. That's why we've been intense with our fight against the IBT."

The "endangered" designation of the Catawba helps South Carolina's claim before the Supreme Court that the two states need a fairer way to share the water, said Mark Plowden of the S.C. Attorney General's office.

"When a national organization of that size and recognition singles out that very same river, it lends a great deal of credence to what we've been saying for two years."

Bill Holman, a former state environment secretary now advising a legislative study commission on water issues, said other N.C. rivers share the Catawba's problems. The Neuse River's appearances on the endangered-rivers list, he said, spurred policies to reduce nutrient pollution.

"I thought it helped move the debate at that time," Holman said.

The study commission now under way is designed only to look at the state's options in allocating water. Controlling growth, Holman said, remains a local issue.

South Carolina's legislature also is debating water issues, including a bill that would regulate withdrawals from rivers and lakes. The bill's chances of being enacted before the legislature recesses in early June are uncertain, observers say.

"I feel it's our turn to look after the river. It's looked after us for 300 years," said Lee, the York County councilman. "We need to deal with the reality that our water is not infinite."