The Environmental Protection Agency announced Wednesday that it renewed the District’s permit to discharge stormwater into local waterways, but only under the condition that it significantly reduce rainwater runoff and the huge amount of garbage that comes with it.

Under the terms of the permit, the District is required to add a minimum of 350,000 square feet of green roofs on city properties, plant at least 4,150 trees yearly, and assure that new properties of 5,000 square feet soak up more than an inch of rainwater over a 24-hour rainfall to keep it from flowing into sewers and into rivers, streams and ultimately the Chesapeake Bay.

The city will have a year and a half to carry out the measures. The requirements are partly the result of the EPA’s strict new pollution diet placed on six states and the District in the Chesapeake Bay watershed.

To reduce the amount of nitrogen, phosphorus and sediment that pollute the bay, the states, including Virginia and Maryland, are required to upgrade wastewater treatment centers and take other conservation measures that cost billions of dollars.

“It’s a big deal for D.C.,” said Rebecca Hammer, an attorney for the water program of the Natural Resources Defense Council, which pushed for stronger clean water requirements during the permitting process. “Every city of this size has to have a permit, but most permits don’t have these requirements. It’s going to green the city.”

The green implementations the District will undertake have been applied in smaller municipalities, but not in a city of equal size, Hammer said. The District will have six months to assess government properties and work with local environmental groups, as well as other agencies, to implement the changes.

In addition to the other changes, the city must stop more than 100,000 pounds of trash per year from being discharged into the Anacostia River. During small and big rains such as from Hurricane Irene, the river becomes a slow-flowing landfill, with garbage such as styrofoam, aluminum cans, plastic jugs and motor oil fouling it for days.

The Anacostia watershed is one of the most developed and dirtiest in the nation. After every rain, DC Water, the agency that runs city sewers, strongly advises residents against swimming in the river.

EPA Regional Administrator Shawn M. Garvin said the intent of the green performance measures is to keep more dirty stormwater out of local waterways. “This builds on efforts the District has already undertaken and is a major step forward in reaching our goals for restoring the Anacostia River and Chesapeake Bay,” he said.

The five-year permit only governs the part of the District’s sewer system that separates stormwater and wastewater in two-thirds of the city.

An older combined sewer system operates in the other third of the city, frequently dumping untreated stormwater and sewage in waterways when it threatens to back up into homes and businesses during rains.