In 2013, Cheryl Tyiska started work as the new manager at the historic Mount Olivet Cemetery in Washington, D.C. One day, she sat down at her desk, opened the monthly water bill and was stunned into silence. The bill was $6,000 for the 88-acre pre-Civil War cemetery, which employed only a skeleton crew and didn’t even water the grass.

“Our actual water usage, the water that we actually flush toilets with or run the sink with or whatever, runs about $100 a month,” she says. “But our water bill and all the associated fees that go with it was about $6,000 a month.”

Tyiska began looking for an answer. It wasn’t a mistake on the water meter or a clerical slip of the decimal point. The answer lay in a utility program, similar to ones popping up in cities nationwide, that charges landowners not only for their water usage but for treatment costs for stormwater and associated pollution that runs off their property. More precisely, the fee is based on the square footage of paved, roofed or otherwise “impervious” surface on the property. And that 88-acre cemetery had a lot of roads and pathways—almost 10 acres in fact.

After the stormwater fee program went into effect in 2009, all landowners started getting higher water bills from the local utility, DC Water. The fees help pay for a major project to clean the water running into nearby rivers. That’s because water picks up pollutants when it runs across streets, gutters and sidewalks. And each time a storm hits, water runs off hard surfaces and into the sewers, overwhelming the system or running untreated into rivers.

Rain that falls on Mount Olivet and the city’s east side flows to the Anacostia River and eventually ends up in the Chesapeake Bay—the country’s largest estuary, home to bottlenose dolphins, eastern oysters and blue crabs. As more land is developed upstream of the bay, there’s less soft ground for rainwater to seep into, causing runoff—a problem the Environmental Protection Agency (EPA) is requiring cities to address.

When Mount Olivet’s water bill later climbed to $10,000 a month, Tyiska called DC Water. “I said to them, ‘We might have to close our doors because we can’t afford $120,000 a year.’” But even if the cemetery closed, the Catholic Archdiocese of Washington, which owns the land, would still have to pay the fees if nothing changed on the property.

Tyiska began looking for a way out. The only solution, she eventually concluded, was to remove as much paved surface as possible.

To help facilitate those kind of retrofits, the city has created a stormwater credit trading market to encourage landowners to reshape their properties so that the buildings and grounds retain and absorb more water. Stormwater fees aren’t new, but a market-based approach to changing an entire city landscape is—and municipal governments throughout the United States are watching to see how Washington’s policy shakes out.