Rain gardens poured to manage runoff

Editor's note: The Hammonds have finished their house. Go to www.startribune.com/newhouse to visit their blog and see pictures. Our concrete guys, Fred Lutz and his sons, were back this week to frame and pour our rain gardens. Rain gardens typically are kidney shaped, organic depressions cut into the ground. However, in an effort to match our geometric theme, our architect, Michael Huber, had designed the rain gardens to be a series of step-downs poured from concrete.

The purpose of the rain gardens is to manage rainwater runoff from the two largest surfaces of our house -- the roof and driveway. By guiding the water from these two areas into the garden, we help minimize erosion, flooding and pollutants that reach ponds, streams and ultimately our drinking water.

The gardens had been designed with an overflow spout at the front of the forms. But we were concerned that the spout would need to be very deep to hold a fair amount of water and not dump it back onto the driveway. The result was that the overflow spout was starting to look a bit too exaggerated. As a solution, one of Fred's sons suggested we use a piece of rigid foam insulation and create a scupper-like opening at the mouth of the garden that I can't wait to see once the forms come off this weekend.