Preservation 2: Replace paved driveways and sidewalks with permeable pavers Sidewalks and driveways are typically paved, “impervious” surfaces that do not allow rainwater to soak into the ground. Instead, it runs off, picking up pollutants such as oil, fertilizer and dog waste on its way to the nearest stream or storm drain. Permeable surfaces, such as pavers, allow storm water to slowly soak into the ground, reducing flooding and polluted runoff. Check with your local landscaping company; most offer porous paver options.