Elsewhere: Cities Look to Rivers As Key to Redevelopment

But now the river that Dallas has for much of the past century both controlled and neglected is at the center of a $1 billion plan to revitalize the city's downtown. Leaders envision bridges soaring above a vast greenway, with lakes, parks and a waterfront promenade. The city already has raised well over a third of the money it needs, and is ready to begin construction on the first bridge.

Dallas Mayor Laura Miller says the overhaul is the most important project the city will ever undertake. "I believe that," she says.

Increasingly, the nation's cities are viewing rivers as economic assets that will attract tourists and locals alike rather than as polluted, flood-prone liabilities. In cities east of the Mississippi River with substantial waterways, such as Detroit, that often means reclaiming sites on the banks that were once used by factories or mills. But in the West, cities often have to revive the river itself.

Houston is pursuing an $800 million plan to restore Buffalo Bayou, a sullied creek with eroding banks that is obscured by freeways. In May, a 23-acre portion of the project is set to open, featuring native landscaping, hiking and bike trails, and a dozen new access points. And in Southern California, local officials are working on a $3 million master plan to rehabilitate about 32 miles of the Los Angeles River, a waterway almost entirely lined with concrete that often resembles a deserted freeway.

The transformation of such urban waterways isn't necessarily new. San Antonio's famous River Walk, the backbone of the city's tourism industry, dates back to the 1930s, when city leaders built walkways, footbridges and stairways on the banks of a stream once prone to flooding. More recently, Denver transformed its South Platte River, formerly a poster child for industrial blight, into a 10.5-mile greenbelt.

Now, a number of other Western cities are reconsidering their rivers. But restoring them to something akin to their natural state is a costly proposition and one that poses challenges for cities that have for years favored growth at the expense of the environment. Urban planners who submitted proposals for the Los Angeles project, for example, say it would take the better part of a century to complete. Development along the banks is a challenge, too. In Houston, a city with no zoning ordinance, leaders are already fretting over how to execute a master plan that calls for mixed use and affordability.

"It's a tough political slog," says Patrick Phillips, an economist at Economic Research Associates, a Washington firm, and consultant to the Buffalo Bayou Partnership, which is leading the Houston effort.

In Dallas, there is considerable damage to undo. After a devastating flood in 1908, the Trinity River was confined to a channel. Its flood plain was long used for dumping. Even now, much of the water flowing down the Trinity is treated wastewater, though it is considered much cleaner than in past years.

In 1998, after a political battle, Dallas voters narrowly passed a $246 million bond package to redevelop the Trinity, which flows just west of the city's downtown. But money remains an issue. Dallas has raised an additional $184 million through federal, state and private channels, but the project's completion is contingent on the ability of local leaders to keep tapping these sources.

Nor is the project without opposition, having generated three lawsuits, mostly on environmental grounds. In each case, courts allowed the project to proceed.

The focus of the project, which will encompass 10,000 acres, is the half-mile-wide flood plain that extends some 20 miles from northwest Dallas and past downtown to the 6,000-acre Great Trinity Forest.

Ultimately, officials envision retail and residential development rising skyward on both sides of the 30-foot levees.

Ms. Miller sees development along the Trinity as part of a push by local leaders to reinvigorate Dallas's downtown, one that includes an arts district and the conversion of office space to residential space. "People say there's nothing happening here," she says. "That's got to change."

Late last year, the city broke ground on the first of three proposed suspension bridges designed by Spaniard Santiago Calatrava.

"Dallas has land," says Alex Krieger, a professor at the Harvard Graduate School of Design and co-founder of Chan Krieger & Associates, a Cambridge, Mass., architecture and urban-design firm, who was a consultant on the project. "What it wants is culture, recreation and beauty."