Rain is natural. Before we built roads and buildings, it would fall on deep-rooted native plants that helped it infiltrate into the ground, to be naturally cleaned and cooled before entering the water table. As we’ve developed the landscape, we’ve also dramatically altered the path those raindrops follow. Now they fall on roofs, continue over driveways and lawns, down sidewalks, streets and other impervious surfaces. Rain turns to runoff, picking up pollutants all along the way before entering storm drains that lead to nearby bodies of water. Over half of Minnesota’s lakes, rivers, and streams are impaired, and runoff is a major contributor.
Blue Thumb–Planting for Clean Water looks for solutions by mimicking the historic hydrology of undeveloped land; specifically, by helping rain filter into the ground close to where it falls, rather than running off the land and carrying pollution into the water. We can achieve this by shaping the land to divert and collect water (as in the basin of a raingarden), and covering it in deep-rooted native plants that slow down, soak up, and infiltrate runoff. This also reduces the wear-and-tear of our aging storm sewers, and helps protect low-lying neighborhoods from flooding. As we see more and stronger rains year after year, this work is only becoming more important.