Hope Lutheran High School students braved the wet weather to help the City of Winona, Winona County, the Winona County Extension Master Gardeners, Prairie Smoke, and Healthy Lake Winona volunteers to revitalize 2 rain gardens (AKA Vegetative Swales) in City parking lot #17 next to the Winona County Government Center on Wednesday May 25th, 2016.
Earlier in May, a city crew cleared the rip-rap, sediment, and debris out of the existing swales in preparation for native plantings. Over time sediment had blocked the curb cuts, leading to pooling of water in the parking lot, and ice buildup in the winter. Water now flows freely into the swale, and up to 6 inches can pool and percolate into the soil, while native plants will grow and their roots will help form channels to help with water infiltration. In an extremely heavy rain, a storm drain at one end can channel excess to keep the garden from over flowing.
Earlier in May, a city crew cleared the rip-rap, sediment, and debris out of the existing swales in preparation for native plantings. Over time sediment had blocked the curb cuts, leading to pooling of water in the parking lot, and ice buildup in the winter. Water now flows freely into the swale, and up to 6 inches can pool and percolate into the soil, while native plants will grow and their roots will help form channels to help with water infiltration. In an extremely heavy rain, a storm drain at one end can channel excess to keep the garden from over flowing.
Rain gardens such as these have been proven to be extremely effective at removing and keeping nitrogen, phosphorus, and plant debris out of surface water. In a city like Winona with a municipally separated storm sewer system, water entering storm drains flows into surface waters (Lake Winona or the Mississippi River) without treatment. Holding stormwater on site and allowing it to move through the soil back into the water table cleans the water and keeps pollutants out of these waters.
Thanks to everyone who helped to bring these rain gardens back to function at cleaning our waters.
Thanks to everyone who helped to bring these rain gardens back to function at cleaning our waters.