Constructed wetlands can help Iowa cities and towns manage storm runoff from both farm fields and new development sites, according to researchers who looked at the opportunities offered by urban wetland projects.
Constructed wetlands can reduce nutrients, collect sediment, slow flood water and improve biodiversity, said co-author J. Elizabeth Maas of Iowa City, a landscape consultant and restoration ecologist.
In a report for the nonpartisan Iowa Policy Project, Maas and co-author E. Arthur Bettis, associate professor of soils geomorphology at the University of Iowa, said constructed wetlands in urban settings also can improve aesthetics and expand recreational opportunities.
“They are a great way to add beauty and biodiversity.” Maas said Wednesday morning in a telephone news conference to announce the study, “Managing Water Pollution With Urban Wetlands.”
Maas, who teaches biology at Kirkwood Community College, said her own consulting work during the past 11 years impressed upon her the need for the 35-page report.
“I work with landowners, developers and municipalities who want to manage water correctly and build something beautiful,” she said. “I hope this report will improve the basic understanding of how constructed wetland systems work, their value, and increase their employment in managing water.”
The report, along with case studies of projects in Iowa City and Tipton, offers a how-to guide for local officials and developers to consider wetland options and funding possibilities, the authors said.
David Osterberg, the Iowa Policy Project’s founding director, acknowledged that runoff from farm fields contributes most of the nitrogen and phosphorus loading that constitutes the chief pollutant of Iowa waters.
“Municipalities aren’t going to solve that problem, but every little bit helps,” he said.
Bettis said the recent climate shift toward more extreme rainfall events accentuates the need for measures to control runoff.
Bettis said Iowans are becoming more aware that surface water quality is not improving . Given the lack of progress on state and federal levels, “municipalities are realizing they have to step up and do what they can,” he said.
“It comes down to the good old Iowan quality of trying to be neighborly” to downstream residents, Maas said.
The report looks at four projects — three in Iowa City and one in Tipton — all using wetlands in various ways to manage runoff from new development or the countryside.
The Iowa Policy Project is a nonpartisan, not-for-profit public policy research organization based in Iowa City. Its reports are available to the public at www.iowapolicyproject.org.