The University of Iowa has added its second green roof.

The Seamans Center’s green roof, which was built in a courtyard area, was proposed by UI engineering students, said Darice Baxter, a UI Facilities Management environmental specialist.

The addition was completed Sept. 5.

The UI’s first green roof, built during this summer, is on top of the Pappajohn Biomedical Discovery Building, and it has been a tremendous success for the aquatic ecosystems in Iowa City.

Baxter said the biomedical building’s green roof has been beneficial because through the green roof, storm water could be absorbed and stored. The green roof could also reduce toxic pollutants, such as lead and zinc.

Without a garden, hot rooftop surface of a building transfer its excess heat to the rainwater, which then drains into storm sewers and raises water temperatures as it is released into rivers, ponds, and lakes.

Baxter said when warmer waters are mixed with those waterways, the rapid temperature change could be detrimental to aquatic ecosystems.

“Installing a green roof helps to lessen the heat-island effect and this building is one block from the nearest waterway, which happens to be the Iowa River,” Baxter said.

The new green roof on Seamans Center is 600 square feet; the biomedical building’s garden is 6,440 square feet.

However, Baxter said that just because it is smaller doesn’t mean it won’t be effective.

“While the engineering building green roof is mainly for aesthetic purposes, it also provides the same benefits, just at a much smaller scale,” Baxter said.

Jill McNamara, the assistant to the dean of the College of Engineering, said the project was made possible through donors and cost around $25,000.

Baxter said the green roof on the Seamans Center will eventually be expanded, and more green roofs plans are being made for other campus buildings as well.

“The next green roof system that will be installed [will be] at the new visual-arts building,” she said.

“The new Hancher will feature a large bioretention and bioswale component along the riverside of the new entrance road along to pre-treat road water prior to it entering the nearest waterway, which happens to be the Iowa River.”

Liz Christiansen, director of the University of Iowa Office of Sustainability, noted not only the environmental impact of green roofs but also how they benefit students.

“Green roofs provide many environmental benefits, but people often overlook the social and health benefits of these spaces,” Christiansen said. “Exposure to nature, even for just a little bit every day, improves individual physical and mental health, as well as community social health.”