Rain gardens are shallow depressions in the landscape designed to catch runoff (usually from the roof, but they can catch runoff from other hard surfaces such as driveways too) after a storm. The water slowly filters into the ground rather than running into a storm drain. Compared to a conventional lawn, a rain garden allows about 30 percent more water to soak into the ground. Most rain gardens are planted with native perennials that are adapted to alternate wet and dry cycles. As more and more land is paved for driveways, sidewalks, parking areas, and buildings, these small garden patches contribute significantly to preventing pollution from runoff, decreasing flooding, increasing aquifer recharge, enhancing the beauty of your yard, and increasing habitat for wildlife. Make your rain garden 4-8 inches deep. Deeper gardens catch more water, but it may take too long to soak in, and in the process may provide a breeding ground for mosquitoes. A rain garden in the sun is more effective than one in the shade. And keep the rain garden at least 10 feet away from the house, to keep the water from seeping into the foundation. If your soil is poorly drained, the rain garden may be less feasible. The size of your rain garden depends on several factors-the size of the area drained, the type of soil in the yard, and the depth you'd prefer for the rain garden. Check with your local cooperative extension service, state department of natural resources, or state conservation department for assistance in determining what's best for your specific site.