Rainwater Harvesting Handbook

Chapter 1: Why Rainwater? The Case for Harvesting

The first barrel was a disappointment. I had set it up with the kind of optimism that only a first-time installer can possess, positioning it under a downspout with a length of flexible downspout pipe and a prayer. It rained that night—a solid, steady soaker that had me checking the barrel with a flashlight before the sun was fully up. I expected it to be full, or nearly so. What I found was a foot of murky water at the bottom, a slick of roof debris floating on top, and a downspout that had already managed to clog with a single maple key. The rest of the rain had simply sheeted off the roof and onto the lawn, carrying my hopes with it into the storm drain.

That was nearly two decades ago. I have since built, designed, or maintained well over a hundred rainwater harvesting systems, ranging from a single 55-gallon drum for a suburban garden to a 10,000-gallon steel tank feeding livestock and a workshop. I have made almost every mistake you can make with gutters, pumps, and tank fittings. I have also watched the moment when a system clicks—when the math works, the water flows, and a landowner realizes that they have just weathered a three-month dry spell without drawing a single drop from the municipal supply or their well. This book is the distillation of those years, and it begins with the question that should come before any