About the SFMGA

Monday, June 18, 2007

The 8 Principles of Water Harvesting

by Brad Lancaster

  1. Begin with long and thoughtful observation. See where the water flows and how. What is working, what is not? Build on what works.
  2. Start at the top 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.
  3. Start simple and small. 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 soil.
  4. Spread and infiltrate the flow of water. Rather than having water erosively run off the land's surface, encourage it to stick around, and infiltrate 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 inn times of extra heavy rains and, where possible use that 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. Vegetation can be selected to provide food.
  8. Continuously 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.

Brad Lancaster is the author of Rainwater Harvesting for Drylands, Rainsource Press, www.HarvestingRainwater.com