The goal of the Greenhouse Rain Garden Project was to design and build a rain garden south of the campus greenhouse. Precipitation and snow‐melt from the greenhouse roof was discharged on an embankment which, as a result, was prone to soil erosion. There was a bed of rocks surrounding the outflow pipes. This riprap only slowed down the water flow. A rain garden in that location allows the water to infiltrate the soil so that it will not further erode the hill.
A major issue in the spring is the melting snow runoff onto the bike path at the bottom of the hill. The runoff freezes at night and may present a slipping hazard to foot and bicycle traffic. The rain garden also reduces warm water runoff into the Kinnickinnic River, which is a Class I trout stream, meaning the water needs to be cooler when entering the river. Another benefit of having a rain garden is that it helps to enhance the appearance of the area. The rain garden will include many colorful plants that will attract birds, butterflies, and other pollinators.
During construction we removed the rock bed and dug a trench to extend the pipe down to the rain garden. We then began digging the garden, laid a gravel base for the blocks, and built the wall with the retaining wall blocks. The final part of construction was to plant and add mulch. To prevent any further erosion a silt fence was put up and erosion control mats were laid on the bare soil with grass seed on top.
Agricultural engineering technology majors Nicholas Frazer, Alexus Heldt, Matthew Peterson, Austin Hausladen, Dylan Heimmermann, Jenna Schauer, Megan Beisner, Brett Breitenfeldt, and Mitchell Earll all worked on various portions of the project. The project also included input from CAFES Professors Dr. David Zlesak, Dr. Sonja Maki, Dr. Joel Peterson and Dr. Joe Shakal, as well as Joe McIntosh in UWRF Facilities Management.
For more information about the Greenhouse Rain Garden Project, see the group's research poster.