The heavy rain event during the July 3 night allowed us a golden opportunity to see a superior and persuasive case for raingardens.
Rain was still coming down heavily at 2 a.m. on the 4th and some continued until well after daylight. Over four inches fell in one event.
Raingardens are functional. They filter polluted water from streets and parking lots and make the water clean enough to respectably return to our lakes and streams, something that storm sewers just don't accomplish. Raingardens' native plants are carefully selected because, among other things, they have deep roots, some going down 70 inches, making them blessed with phenomenal absorption abilities. Kentucky bluegrass roots cannot begin to compete with native grasses and wildflowers for holding water.
Raingardens are built to alleviate water ponding because of nearby impervious surfaces. An impervious surface is any surface that does not allow the water to soak into the ground -- houses, garages, hard surface driveways and roads for examples. Built correctly, a raingarden will hold water 48 hours and less, saving us the concern that mosquitoes can reproduce there.
OK, so what was the state of the City of Detroit Lakes' flagship Raingarden at the Pavilion? I was there at 4 p.m. on July 4, less than 12 hours after the rain finally quit. Water had been flooding Washington Avenue during the night and a sizeable pond remained right across the park lot north from the raingarden. But the raingarden? It was without water! We had allowed a French drain to remain within it. A French drain in a raingarden is to take up exceptionally heavy rains, in the case of the Flagship Raingarden, over three inches. The French drain had seen use during the night. The plants looked a bit beaten down, but after four inches of rain, what plants don't?
The City of Detroit Lakes Parks and manager Tom Gulon can be mighty proud of our accomplishment. Now into its third season, the Flagship did exactly what it was meant to do.
-- Sally Hausken, Detroit Lakes