Rainwater harvesting makes perfect sense. From the roof to barrels or cisterns, over time, a small investment can help keep thousands of gallons of potable groundwater for uses that actually require potable water (drinking, cooking, etc.). A supply of rainwater, stored onsite, can be used to irrigate garden and lawn, wash cars, feed water fountains, fill pools, and many other uses that don’t merit pumping the liquid from an aquifer. The Chesapeake Stormwater Network offers these Rainwater Harvesting Design Specifications.