Patty Loew:
The University of Wisconsin arboretum is celebrating 75 years of innovative research in its world-class collection of restored ecosystems. But with all of this success, the arboretum now faces an environmental quandary, a challenge that faces many cities in Wisconsin. The scientific minds are looking for answers and turning to native plants in the hopes of a solution in Madison.

Liz Koerner:
People are drawn to the university arboretum for many reasons. A walk in the woods, a stroll through a prairie or a bike ride along the tree lined drive. It's an island of nature surrounded by city.         

Kevin McSweeney:
We've got nearly two square miles. 1200 acres, right in the middle of a medium sized city.

Liz Koerner:
The arboretum staff welcomes visitors but their primary mission, in addition to research, is to restore and conserve this rare collection of historic plant communities. It's a mission that's become harder since they started back in 1934, especially when it rains. The cities around them have grown larger, adding rooftops, sidewalks, driveways and parking lots. Today, rain water no longer soaks into the ground where it falls.

David Liebl:
The arboretum is downhill and water flows downhill so there is some inevitable consequence of being at the bottom of a water shed surrounded by an urban area.

Liz Koerner:
An estimated 470 million gallons of storm water pours into the arboretum every year. This storm water carries with it a whole host of problems.

David Liebl:
We're especially concerned about sediment and nitrogen and minerals, salts and other contaminants from around the water shed entering into the wetlands of the natural areas of the arboretum.

Liz Koerner:
Erosion is also a concern. Curtis Prairie is considered by many to be the jewel of the arboretum because it's the oldest restored prairie in the world. Snaking through the center is a deepening trench carved out by storm water. Even worse, an invasive species called reed canary grass seems to thrive in storm water and now grows along this trench, threatening to crowd out the native species that belong here. This aerial photo shows how the green swath of reed canary green survived even the fire used to control weeds in the prairie.

Kevin McSweeney:
The recipe is right for the growth of the canary grass.

Liz Koerner:
Another set of environmental problems has crept up downstream. Storm water flowing through the arboretum ends up in Lake Wingra.

David Liebl:
The west end of Lake Wingra is filling up with sediment from storm water from the west side of Madison and you can see in the lily pads and the fact that fish and other species can't move into the area anymore that it's choking off that part of the lake.

Liz Koerner:
State storm water rules require that the arboretum capture much of this sediment and the phosphorus that comes along with it in detention ponds. Phosphorus is a problem because it feeds algae in lakes. Old detention ponds are scattered around the perimeter of the arboretum but they’re no longer up to the job. So a large group of stakeholders, including the city of Madison, committed to spending some $6 million in a five-year effort to address the problem. One of the newly dredged ponds has features designed specifically for urban settings.

David Liebl:
It's a containment forebay that's designed to collect any kinds of petro chemical spills that might come from a trailer tipping over on the Beltline, for example, gasoline or diesel fuel. And we can collect that in the forebay behind me and remove it before it gets into the pond itself and onward into the arboretum.             

Liz Koerner:
In addition to the ponds, the arboretum is working on an unconventional element. It's a wetland basin that will serve as the first stop for storm water. Here they're planting seeds for an experiment using native plants.         

Brad Herrick:
The general question, is can native plants be used in storm water structures like we have at the arboretum to improve water quality and decrease water quantity that eventually goes into Lake Wingra.

Liz Koerner:
They want to find out if the plants can perform specific functions like crowding out invasive species, soil retention and the ability to quickly channel water deep into the ground. One plant in the mix is false sunflower.

Brad Herrick:
And this actually is fairly good at all of the functions, potentially. It has a fair amount of above ground biomass, a lot of leaves growing. A fair amount of roots in the upper six inches of the soil and then also a fairly deep root system itself. So this one might be sort of the ultimate storm water plant potentially and we'll find out from the research.

Liz Koerner:
The seed mix includes a total of 27 native species planted in different densities in a grid pattern. It will take more than a year to learn the initial results from this research. Information that will help other Wisconsin communities struggling with the negative effects of storm water runoff.

Kevin McSweeney:
There are lots of other green spaces around the country, around the world, that face similar issues so again, if we can find creative solutions to these impacts, then I think there's a real upside to that.

Patty Loew:
Natural solutions to storm water are more important than ever. Consider this recent report by the Wisconsin Initiative on Climate Change Impacts. It projects in the next 45 years, extreme storms that dump two or more inches of rain will increase in Wisconsin, resulting in more flooding. Homeowners can also take steps to reduce storm water runoff. Just log on to our website at wpt.org, then scroll down and click on "In Wisconsin" for more information.