The Falk roof has multiple layers, with only the plant layer visible. Below it are layers of growth-supporting nutrients and materials designed to keep moisture from seeping into the building.

Perhaps you noticed the ladders leaning against the side of the Anne and Isidore Falk Recreation Center. Maybe you spotted hoses going up to the roof. What on earth is going on?

Earth actually has a lot to do with it. Einstein engineers have covered the flat roof with a membrane and a five-inch “nutrient layer” (dirt) and planted native wetland grasses and other plants. This “green roof” will absorb storm water and backwash pumped up from the Falk pool and Jacuzzi, says Salvatore P. Ciampo, senior director of facilities management at Einstein. “The goal is to minimize surge in the sewer system, which wasn’t built for the development that exists now,” he says. It’s a major reason that the New York City Department of Environmental Protection was eager to support the project as part of its Green Infrastructure Grant Program. The Falk roof is the only known green roof to be irrigated using water from a swimming pool. (What about the chlorine? “This water has less chlorine than the water on our coastline where these wetland plants usually grow,” says Mr. Ciampo.)

The green roof will also reduce the Falk’s energy bill in summer by blocking the sun and by cooling through water evaporation.

The innovative roof is expected to be sustainable, cost-effective and attractive to look down upon from the surrounding residence halls, labs and office buildings, says Mr. Ciampo.