U garden attempts to clean up groundwater

Tom Ford

The St. Paul campus is using prairie grass and wildflowers to prevent contaminated water runoff from entering the Mississippi River.

A rain garden – a low area planted with native, water-tolerant plants and designed to reduce runoff and absorb contaminants in the storm water – was installed Tuesday along Commonwealth Avenue across from the Facilities Management Building.

While officials hope this and future gardens will significantly decrease runoff problems, upcoming construction projects and the landscape structure of the St. Paul campus present barriers to storm water management efforts.

“(The rain garden) is an inexpensive way of dealing with storm water,” said Suzanne Savanick, coordinator of the Sustainable Campus Initiative Committee. “It’s the first one in a whole series, we hope.”

Located in front of a parking lot, the garden enjoys a visible locale and was placed there largely because the impermeable asphalt surface of parking lots does not allow water to be absorbed, creating high amounts of runoff that carry oil and several other contaminants.

This garden, the first of its kind at the University, will be used as a test project to determine how effective it is, whether it stays intact in large rains and how much maintenance is required, Savanick said.

Stanley Asah, a graduate student in water resource sciences, said there were plans to build more gardens this fall but other possible locations on the campus were either reserved for future construction projects or were on top of underground wires.

“(The garden) might not be a significant contribution,” Asah said. “It’s going to take a lot more than one.”

In the next 10 years several new buildings are going to be built on the campus, said Tara Carson, a University graduate student and research assistant in the department of soil, water and climate.

Besides taking up prospective sites for more gardens, she said more buildings typically increase runoff.

She said in order to keep from adding to already high runoff levels, it will be necessary for SCIC members and water resource students and faculty to be involved with the design of the new projects.

“If (water management techniques) are included in designs, there’s ways to reduce runoff,” Carson said.

Lester Potts, grounds superintendent in the facilities management office, said most buildings on the campus were designed so storm water will flow away toward curbs and gutters and into storm sewers.

He said runoff is best directed toward spaces with vegetation, which slows down water and allows it to be absorbed by plants or into the ground. But this design sends runoff in several directions, he said, and keeps the sediment and oils in the water from being filtered.

Unless some of the buildings are renovated and the campus landscape is greatly altered, Potts said, the rain garden projects could be largely ineffective.

Gregg Thompson, urban technician with the Metropolitan Soil and Water Conservation Districts, said there should be gardens near every campus parking lot and building to adequately control runoff problems.

Thompson designed the garden, composed of a small depression in the land that can collect larger amounts of water, and 37 species of native prairie grasses and wildflowers that absorb much more water than lawn grass.

The plants, whose root systems grow many feet into the ground, absorb and slow down initial water flow and improve water quality, he said. The vegetation attracts heavy metals, such as arsenic and lead, and traps phosphorus, which build up in waterways and causes algae blooms.

Thompson said the gardens don’t require watering or much maintenance, especially after the first couple years.

Funding for the garden came primarily from the Beautiful “U” Day committee and covered the cost of the plants.

As part of Beautiful “U” Day events, around 25 students, faculty, staff and community volunteers arrived to plant the vegetation.

The idea for the project arose out of student papers in a University water quality class last spring.

Several University classes, such as water quality and storm water courses, will use the garden for assignments and research.

The gardens are a part of the Sarita Wetland Restoration, started in 2000 by the SCIC – a small group of University students, faculty and staff.

As their pilot project, the SCIC has thus far worked to restore the Sarita wetland, which receives campus runoff and improve its capacity to clean water before entering the Mississippi River.