Some people have a hard time admitting mistakes, but I'm going to come right out and acknowledge one, so brace yourself. A couple weeks ago I wrote a Sunday column about the proposed new baseball stadium on the Anacostia River. It was just plain wrong.

The thrust of the column was that it's probably good that the city wants to spend $440 million to welcome baseball back by building a new stadium on the river, because it might shine a spotlight on the mess city officials have made of the Anacostia and eventually induce policymakers to fix it. In hindsight, that's nonsense.

I guess I was swept up in the euphoria about baseball's return, with all those bigwigs and sports icons sporting red caps at a pep rally and crowing about how great it's going to be. I took a boat ride on the river with some Anacostia supporters who pointed out that a big construction project wouldn't really harm the river environmentally because it's already ruined. Talk about the tyranny of low expectations!

I've been scratching my head and kicking myself ever since. Here's why. The Anacostia River is a diamond in the rough, a deep, protected, forested river that winds for 10 scenic miles from Hains Point past the National Arboretum to the old port of Bladensburg, where ships used to come before it got so silted-up, now you're lucky to get a canoe up there on low tide. Still, even though it's choked by revolting sewage spills about 75 times a year, the few who use the river know it remains a beautiful place to look at, ideally situated for small boats or hikers to explore if they dare.

The 1,200-acre Anacostia National Park that runs along the river's western shore near the mouth is one of the largest parcels of open land in the metropolitan area and offers a fabulous nighttime view of the floodlit Capitol and the Washington Monument.

But the river and the park are little used, all but abandoned by people who know the Anacostia is poisoned by sewage every time there's a hard rain and the District's combined sanitary and storm sewers overflow, flushing pungent crud directly into the river. Two billion gallons of raw sewage wash into it every year during storms, according to Anacostia Watershed Society Director Robert Boone. Would you go there for a Sunday picnic?

This appalling situation has been going on for decades because the local and federal governments are unwilling to spend the $1.2 billion or so it would cost to build and install holding tanks or large-diameter sewer pipes that would retain excess runoff during big rains, then pipe it gradually to Blue Plains, the city's first-rate sewage treatment plant near Oxon Hill.

While the District and federal governments drag their feet on this basic civic obligation, Milwaukee, Boston, New York and Chicago have tackled the same problem and fixed it. Why not here? "It's pretty simple," says Lawrence Silverman, an environmental lawyer who works with Boone on river issues. "The Anacostia runs through the poor side of town."

Basically, nobody in power cares.

Okay, so the thinking then goes, let's spend $440 million to bring rich people and congressmen, lobbyists and lawyers down to this side of town to sit in overpriced, tax-deductible corporate suites and watch millionaire ballplayers cavort around, and maybe while they're nibbling their sushi they'll get a whiff of what residents of Anacostia have been inhaling for 50 years and demand a fix.

This is the sort of twisted thinking I got swept up in during the hoopla over Major League Baseball's heralded announcement. Then some brighter lights, including that old sewage-stirrer Marion Barry, piped up with objections to the use of precious tax dollars to promote private entertainment and the picture got a lot less murky.

Putting a $440 million, publicly financed baseball stadium on the banks of the stinky Anacostia River is like parking a shiny new official Cadillac in front of a tarpaper City Hall. The long-suffering residents of Anacostia, the District's poorest neighborhood, deserve better.

People who live in the capital of the world's richest nation in the 21st century ought to expect the river that runs through it to be clean, fishable, boatable and even swimmable, and the federal government, which contributes plenty of its own effluent to the troubled waterway, ought to pay its fair share of the cost.

If Mayor Anthony A. Williams thinks he can raise $440 million in taxes without damaging the District's business climate he ought to do it, and then spend it on something of importance to the working people who live here, not to please power brokers from Avenel and Great Falls and their clients.

The fact is, very few Anacostia residents will ever have the money to buy season tickets to the Expos, or whatever they're to be called, but everyone in Anacostia and in the city at large can benefit from a clean, picturesque river full of fish, birds and boats, with little kids in rolled-up pants dipping for minnows in the shallows on summer weekends.

That's what we could have if we spent our money wisely -- a vibrant, healthy resource bringing pleasure to city dwellers for centuries to come. Or we can provide champagne and circuses for the well-to-do till they get bored. Our choice.

A worker for the D.C. Water and Sewer Authority tries to clean up debris that contributes to an overly polluted Anacostia River.