The recent development of the Town of Normal’s Constitution Trail, through the campus of Illinois State University, provided the Grounds department an opportunity to install the campus’s first Bio-swale to handle water runoff. The Trail runs through the parking lot behind Redbird Baseball field, which sheet drains into nearby Sugar Creek. A 10’ wide by 150’ long strip of asphalt was excavated, and two and half feet of sandy soil mix was installed in its place. Both an erosion control and wet-meadow seed mix was specifically selected and sown. The bio-swale is slightly concave in an effort to store some runoff as water percolates into the soil.
The picture above was taken in fall 2007, near the end of completion.
The sign above is located off of the Constitution trail and reads:
A bioswale is a low-gradient basin system which contains a dense cover of vegetation and is used to maintain and clean runoff during storm events. The gentle grade of the land slows the water flow, while the soil and vegetation filter and store runoff, removing 30% to 80% of pollutants such as petroleum products, excess nutrients, metals and sediments that may be found in stormwater. In other words, the bioswale acts like a sponge, absorbing rain water and slowly filtering and releasing it further into the ground. This promotes ground water recharge through infiltration and in turn minimizes stormwater runoff into streams and rivers. It is an environmentally sensitive approach to pollution control that adds natural beauty to the community and provides a haven for many mammals and birds.
