Picture a rainstorm.

The water falls, hits the roof, bounces off, collects pet waste, fertilizers, pesticides, leaves, trash, cigarette butts, and flows into waterways.

But one University of Iowa initiative hopes to contain the pollutants associated with rain.

The UI’s 7,800 square-foot new bio-retention cell is located at the Facilities Management’s data center on the Oakdale campus.

Darice Baxter, a UI environmental specialist, said that like a garden, the cell has more than 1,500 plantings that absorb polluted rainwater. But unlike a typical garden, the $40,000 cell is engineered with 5 to 6 feet of soil and "feels like you’re walking on marshmallows," she said.

Construction on the cell was completed last week, Baxter said.

In the cell, water sifts through the soil, which removes pollutants and prevents them from entering Iowa’s waterways.

"A lot of people don’t realize storm water is not treated when it comes off roads and goes straight to the rivers and streams," Baxter said.

David McClain, the water-utilities manager for UI Facilities Management, said the university has a MS4 permit — Municipal Separate Storm Sewer Systems — for storm-water runoff that requires the school to capture the runoff, and the bio-retention cell is effective in doing that.

The initiative is not new. It has been implemented in other states and universities in the nation, the University of Northern Iowa being one example, Baxter said.

"It’s something we’re doing more and more of, and we don’t have any problems with them," said Bob Brooks, an associate director of Facilities Management’s building and landscape services.

Baxter said the cell was constructed because the back hillside of the data center is a highly erodible soil and roof drains would have caused erosion over time. Besides, building one is the right thing to do, she said.

"It’s beautiful,"she said. "It does what nature did before we disturbed it and built a bunch of impervious structures."

If the project succeeds, 23,000 gallons of water will be treated and waterways will be less polluted. 

"Water running off parking lots is super hot and kills the wildlife in the waterways," she said. "The cell cools the water."

Ryan Companies construction manager Tom Sahlmen, said the data center retention cell is working well because it is built with ideal conditions — pea gravel and sand beneath the cell. He noted that the cell makes people more aware of their water cleaning habits.

"People are finally realizing what they do affects water quality down the line," he said.

Baxter said city residents can build their own bio-retention cells — with compost and mulch — to enhance efforts to keep waterways clean. She hopes this method will continue to spread across campus.

"We’re hoping we can retrofit all building on campus some day," she said. "We’re trying to use more innovative practices."