What are some resources for designing and connecting rain barrel systems?

D.S.WisconsinAnswer: Thank you for your inquiry to ATTRA the Sustainable Agriculture Information service regarding rainbarrel water catchment and overflow illustrations. The following link is a great resource for strategies for developing alternative flow options other then your roof. This might be helpful as you plan catchment along your fence. http://www.oas.org/dsd/publications/Unit/oea59e/ch10.htmThe image below shows 8 rainbarrels connected an overflow system. They are not set up for a gravity system, but apparently this system is effective for this gardener.http://www.emmitsburg.net/gardens/articles/adams/audrey/water_barrel.htmThe online resource, Rainbarrel Resources, suggests when using multiple barrels to position the next barrel slightly lower than the first to take advantage of the Earth’s gravity to aid your rain-harvesting. Depending on the design of the rain barrel, the overflow connections can either be near the top or on the bottom of a rain barrel. The rain barrel that initially in-takes the water from the downspout must have all other ports closed besides the overflow connector. Their picture has the barrels connected via the top of each barrel.http://www.rainbarrelresource.com/2009/02/rain-barrel-how-to.htmlAlso the following guide to designing a rainbarrel system illustrates and describes some different systems for connecting multiple barrels on page 17. Note the illustration with multiple barrels using gravity. http://www.swfwmd.state.fl.us/publications/files/rain_barrels_guide.pdf