As a transplant to Oregon, I quickly learned to make peace with the falling rain. Far tougher was accepting what happens once it hits the ground. The roof of one 1,000-square-foot house can send up to 22,500 gallons of rainwater to the sewers each year via its downspouts, which funnel water to the storm drains in the street. Most Portland homes connect to a single set of pipes that mix clean rainwater with the waste from our hoses, sinks and toilets on the way to the treatment plant. On dry days, no problem. But virtually any measurable rainfall floods the system, sending a rich stew of rainwater and sewage into overflow pipes. Destination: the lower Willamette River.

Historically, Portland has dumped as much as six billion gallons of this muck per year into the city’s rivers. With the completion of the $306 million West Side CSO (combined sewer overflow) project in 2006 (better known as the “Big Pipe” project), we’re down to about 2.1 billion gallons per year. By 2011, $426 million of additional East Side pipe will cut the flush by 80 percent—down to a mere 400 million gallons each year.

But even if you find that much sewage in your local river acceptable, keep in mind that we, the taxpayers, are now bankrolling the unnecessary treatment of billions of gallons of rainwater from our homes’ downspouts—an urban surcharge every homeowner can help reduce with a simple, stylish addition: rain chains.