'Water Taxi! Water Taxi!'

Here's an idea that could boost the tourist industry, alleviate traffic, encourage smart growth and open neglected urban areas for development while helping to unify an often fractured region:

Water taxis.

Just imagine stepping off a plane at National Airport and hopping on the water shuttle to Maine Avenue, or downriver to the new Gaylord's convention resort at National Harbor.

Or imagine taking in a Nationals game by stepping off the ferry from Georgetown or Alexandria at a pier along the Anacostia and walking a block to the new stadium.

Worried about the traffic problems at the new, expanded Fort Belvoir? No problem. Avoid it all by moving to Charles County and commuting to work by boat.

Or maybe your commute is from Woodbridge to the Pentagon. You could leave the gas guzzler at home and spend your commuting time on the upper deck, reading the newspaper and answering e-mails rather than fuming in bumper-to-bumper traffic on I-95.

And what better way for tourists to experience the nation's capital as the Founding Fathers might have, traveling up the Potomac from Mount Vernon to Old Town to the Tidal Basin, where President John Adams might have bathed on a warm summer afternoon.

Transportation planners have been talking for decades about water transport, but it's been slow going. There are the charter cruises from the Southwest waterfront up and down the Potomac, the daily cruises down to Mount Vernon and more regular service from Georgetown to Old Town. And starting next April, with the opening of the first phase of National Harbor, there will be regular service across the Potomac to Alexandria and back.

But it's a big leap from these limited tourist-oriented offerings to a full regional water transport service that locals could rely on to move around the region. Such a system would need to operate 18 hours a day, every day except when the river freezes, and would require a fleet of maybe two dozen vessels shuttling among 15 different stops from Quantico to the south to Georgetown and the Navy Yard to the north. To succeed, it would need to be fast, dependable and affordable.

Other metropolitan areas have more experience and success integrating water transport into daily life. Think of New York, London, Paris, Istanbul, Hong Kong, Sydney and Vancouver, to name a few. Their networks of ferries and water taxis not only provide pleasant and convenient alternatives to cars, buses and subways, but like highway exits and train stations, act as magnets for development or recreation. They have helped to reorient life in cities that had turned their backs on waterfront areas and allowed them to decay.

All of that could happen here as well, but only if the various levels of government are willing to hand over some power and prerogatives to a regional port or waterways authority. Such an authority would require the ability to raise and borrow money to build the terminals and subsidize service. Although the authority would not have to own and operate the boats, it would need to have the power to contract with private companies that would.

Most importantly, it would require the ability to expedite the scores of licenses and regulatory approvals that would be required to dredge shorelines, construct terminals on federal lands or protected wetlands, operate near security-sensitive facilities, and get around current rules governing how fast boats can travel and how much wake they can create.

This is a regional opportunity that demands a regional, public-sector solution. Although the basic outlines can be sketched by the Council of Governments or the National Capital Planning Commission, the political will can come only from Mayor Adrian Fenty, the governors of Virginia and Maryland and the region's congressional delegation. And without the strong support of the business community, you can be pretty sure the whole effort would get pecked to death by local politicians, federal bureaucrats, neighborhood activists, environmental groups, unions, pleasure boaters, competitive rowers, fishermen and tour bus operators.

Right now, much of the impetus is coming from National Harbor developer Milt Peterson, who has an obvious commercial interest in providing water transport for 6,000 hotel guests, 8,000 residents and hundreds of shoppers and diners he hopes to have at the project every day. But Peterson didn't get to be one of the region's most successful developers without a knack for imagining what Washington could become. And like anyone who has spent time out on the river taking in the skyline and the monuments and the green spaces, Peterson knows how under-used and under-appreciated Washington's liquid assets have become.

"For too long, the rivers here have been dividers -- borders, barriers, things to get over," Peterson says. "We need to turn them into connectors."

Steven Pearlstein can be reached at pearlsteins@washpost.com.