[COMMENT: This article is accompanied by a half-page map showing Marvin Nichols in comparison to all the other reservoirs of North Texas. R]

Providing a reliable source of water for urban North Texas' surging population could take a dramatic turn away from a century-old, tried-and-true tactic of damming rivers and flooding landscapes. The Dallas City Council refused on January 7 to join in planning for a huge and hugely controversial northeast Texas reservoir, embracing instead environmental groups' alternatives: tapping existing lakes and demanding tougher measures to conserve water.

There's no guarantee that those steps would replace the proposed Marvin Nichols Reservoir as the main long-term water supply option for North Texas. The Sulphur River project's other backers, major water providers outside Dallas, said last week that planning would continue and that they could build the reservoir without Dallas' help. But with Dallas' support in doubt, and with opposition to Marvin Nichols strengthening, regional water managers also began discussing a new approach that could significatnly lessen the importance of the reservoir.

Water system officials from urban North Texas and northeast Texas met on Monday to discuss other ways to move water from the Sulphur River Basin to the Dallas-Fort Worth area. They are looking to the U.S. Army Corps of Engineers for help. The outcome still could be a recommendation to build Marvin Nichols, especially if other water sources proved inadequate or too expensive. Planners say Marvin Nichols would cost about $1.7 billion.

Other reservoir projects are possible. Or a new study might find that a combination of other ideas, including manipulating water levels in existing reservoirs such as Wright Patman near Texarkana, could reduce or eliminate the need for a new reservoir. The unexpected political strength of those opposed to Marvin Nichols -- northeast Texas landowners, timber companies, environmental agencies, environmental groups and U.S. Rep. Max Sandlin, D-Marshall -- has the project's most ardent backers talking about alternatives.

"We still believe that [Marvin Nichols] is a good, viable project," said Mike Burke, administrator of the Sulphur River Basin Authority, which is leading planning for the reservoir. "But to be honest with you, we also believe now that we need to look at the entire basin," Mr. Burke said. "We're now asking, would there be an interest in the Dallas area in looking at a basinwide approach other than Marvin Nichols. So far, it appears that there is."

Environmentalists who have battled Marvin Nichols because it would flood more than 60,000 acres of habitat said they questioned whether planners were really changing their focus. "The term 'basinwide' is one of those red-flag words to those of us who follow the water hustling industry," said Beth Johnson, a Dallas-based consultant to the coalition fighting Marvin Nichols. "It's a way of keeping the thing alive while they appear to be studying something different," she said. "If that is what they mean, we oppose it."

Marvin Nichols has appeared in state water plans for decades, but in 2001 a North Texas water planning group established by the state made it the cornerstone of a 50-year water supply plan. The reservoir would cover about 100 square miles of river bottom and floodplain along the Sulphur River near Mount Pleasant. Water would come to Dallas-Fort Worth through pipes.

The project's North Texas supporters have included officials from Dallas and other water suppliers in the metropolitan area. Partners other than Dallas have been financing a $4 million feasibility study and engineering work in advance of a possible permit application. Dallas staff members asked the City Council on Jan. 7 to pay Dallas' 15 percent share of the study costs, $600,000. They told the council that the city would need to add new water supplies by about 2025, a few years before the first water from Marvin Nichols could arrive.

But representatives of environmental groups, landowners and timber companies said water planners had played down other options, including slashing Dallas' high per-capita water-use rate. They also pushed for greater use of existing reservoirs, including lakes Texoma, Wright Patman and Cooper, also called Jim Chapman.

Most council members sided with the environmentalists. They said they want the city to adopt a much tougher water conservation goal. The existing goal foresees a 5 percent cut in water use. And they wanted a clear comparison of costs for Marvin Nichols and other options before they committed to this project. Council members acknowledged that they could keep Marvin Nichols at arms' length only because past leaders built other reservoirs during the 20th century.

That campaign of dam building turned a semi-arid region into an area that is water-rich. The 19 reservoirs that supply urban North Texas can hold nearly 3.3 trillion gallons of water for cities, industries, agriculture and other uses. They also cover more than a half-million acres throughout the region and into East Texas. Altogether, reservoirs have claimed about 1 million acres of bottomland hardwood forests in Texas, dramatically reducing one of the state's most valued habitats.

Building a reservoir today requires land to mitigate the reservoir's impact. That means setting aside additional land for permanent preservation, taking it off local tax rolls and keeping out commerce such as ranching and logging. There's no firm figure on how much mitigation land Marvin Nichols would require.

It's still possible that Dallas will wind up backing Marvin Nichols. Jim Oliver, general manager of the Tarrant Regional Water District, said Dallas' decision not to take part in the planning now makes no difference. "It's not going to slow it down a bit," he said. "We can absorb their 15 percent of the planning." Even if Dallas decides not to help fund the reservoir, he said, other water systems would build it.

Mr. Oliver said political opposition to the project -- including strong words to the Dallas council from Mr. Sandlin, the northeast Texas congressman -- wouldn't stop the project if backers decide to build it. He recalled opposition to Richland Chambers Reservoir south of Dallas-Fort Worth, which the Tarrant district completed in 1983. The number of dedicated opponents was about the same as for Marvin Nichols, he said, but that didn't stop the project.

He acknowledged that the Marvin Nichols opposition has better organization and funding, including strong support from such unusual partners as timber companies and environmental groups. Chief among those are the Sierra Club and the National Wildlife Federation. "I bet for every Max Sandlin, we could get 10 other congressmen to do something different," Mr. Oliver said. "If we want this reservoir built, it will get built."

Ms. Johnson, the opponents' consultant, said Dallas' skepticism about Marvin Nichols showed that opponents are making logical arguments: Before spending money on new water, make better use of existing sources. That could include water from Wright Patman or other existing northeast Texas reservoirs, or from Lake Texoma on the Texas-Oklahoma line. There's enough unclaimed water, environmentalists say, to make new lakes superfluous.

"Plannning new reservoirs would be completely at odds with the common-sense approach that the citizens' coalition put before the council," Ms. Johnson said. "The common-sense approach means using every available gallon from those existing resources."