1. Begin with long and thoughtful observation.
Use all your senses to see where the water flows and how. What is working, what is not? Build on what works.
2. Start at the top (highpoint) of your watershed and work your way down.
Water
travels downhill, so collect water at your high points for more
immediate infiltration and easy gravity-fed distribution. Start at the
top where there is less volume and velocity of water.
3. Start small and simple.
Work
at the human scale so you can build and repair everything. Many small
strategies are far more effective than one big one when you are trying
to infiltrate water into the soil.
4. Slow, spread, and infiltrate the flow of water.
Rather
than having water run erosively off the land’s surface, encourage it to
stick around, “walk” around, and infiltrate into the soil. Slow it,
spread it, sink it.
5. Always plan an overflow route, and manage that overflow as a resource.
Always have an overflow route for the water in times of extra heavy rains, and where possible, use the overflow as a resource.
6. Maximize living and organic groundcover.
Create
a living sponge so the harvested water is used to create more
resources, while the soil’s ability to infiltrate and hold water
steadily improves.
7. Maximize beneficial relationships and efficiency by “stacking functions.”
Get
your water harvesting strategies to do more than hold water. Berms can
double as high-and-dry raised paths. Plantings can be placed to cool
buildings in summer. Vegetation can be selected to provide food.
8. Continually reassess your system: the “feedback loop.”
Observe
how your work affects the site, beginning again with the first
principle. Make any needed changes, using the principles to guide you.
These
principles are the core of successful water harvesting. They apply
equally to the conceptualization, design, and implementation of all
water-harvesting landscapes. You must integrate all principles, not
just your favorites, to realize a site’s full potential. Used together,
these principles greatly enhance success, dramatically reduce mistakes,
and enable you to adapt and integrate a range of strategies to meet
site needs. While the principles remain constant, the strategies you
use to achieve them will vary with each unique site.
Original Source Brad Lancaster Rainwater Harvesting for Drylands and Beyond