Rainwater Harvesting: What is a Dry System?

There are a few types of Rainwater Harvesting Systems. I expect that there will be more variations as we learn more in the future. In a nutshell, a Dry Harvesting System takes water from one downspout on a partial roof area of the catchment surface. A catchment surface is most often a roof. It can be any type of roof: on a home, on a barn, an area over a bench to shield from water. Any surface that can be guttered can effectively harvest rainwater.