Rainwater Harvesting For Drylands and Beyond

Rainwater is seen both as a useful resource and a waste product. On one hand it keeps the plants fresh, but on the other hand is can wash polluted road runoff into the rivers. This book is about how to find a balance through conservation, and a lot of hard work. It’s meant for arid lands, where everything is dry and you have cactuses, but when it rains in arid lands, the soil can be washed away. The rain will eat away the soil, flush it downhill, and your backyard can disappear in days. As for lost soil, it ends up downstream and silts up the waterways.

Lancaster begins with simple rock dams, easily built with no cement or tools, to slow the downhill flow of water. The book progresses to another problem with drainage in the USA, and that is the pavement. When huge swaths of land are paved, water doesn’t soak into the soil, but into storm drains, which drain into the waterways. Not only does this flush all the chemicals from autos into the rivers, but since the water doesn’t drain into the aquifer, it goes dry. You’ll end up having to pump water up, and that requires energy. Lancaster recommends starting the dams at the top of the hill, and building more as you move downward. As for road runoff, he gives step-by-step plans for “rain gardens” which soak up road runoff and allow the water to drain directly into the aquifers.

The author rails against culverts, arguing that huge pipes running under roads are “shotguns”  that create higher pressure and more erosion. I have to wonder what effect the LA River has, because it’s been culverted for decades. If the banks weren’t paved, would the vegetation absorb the pollution? If so, what about the Gowanus Canal in Brooklyn?

One basic tenet of this book, with regards to landscaping, is to go native. Lawns don’t exist in nature in the Southwest, and not only do they guzzle water (pumped from the aquifers) but when they dry out you get fires. Gold courses are notorious water wasters in Arizona, Texas, and New Mexico, leaving less water for drinking and firefighting. Lancaster stresses native trees, shrubs, and grasses that grow with limited water. Most important, he provides ways to do these things on your own, with no need for expensive landscaping, just a shovel and a strong back. No capital needed!