June 30, 2019

Rainwater Harvesting, Vol 1 by Brad Lancaster

Eight Principles of Rainwater Harvesting

  1. Begin with long and thoughtful observation: Notice what’s working and what’s not.
  2. Start at the top of your watershed and work your way down: Collect water at the top, and then let gravity drive your water distribution downhill to meet your needs.
  3. Start small and simple: Strategies are easier to implement and adjust when they are small. Small mistakes are easier to fix than big mistakes.
  4. Spread and infiltrate the flow of water: Slow it, spread it, sink it. Don’t let water erosively run off your land.
  5. Always plan an overflow route, and manage that overflow as a resource: Take advantage of heavy rains.
  6. Maximize living and organic groundcover: Create a living sponge.
  7. Maximize beneficial relationships and efficiency by “stacking functions”: Berms can double as raised walking paths. Plants can also cool buildings. Vegetation can also provide food for people, animals, or insects.
  8. Continually reassess your system since it’s a “feedback loop”

Notes

  • Good rainwater harvesting helps prevent mosquito breeding.
  • Replace paved parking and driveways with pavers to reduce runoff.
  • Native plants are a much better choice for water conservation.
  • Using bio-compatible soaps allows you to use greywater to water plants.
  • Consider waterless compost toilets.
  • Plant shade trees on the east and west sides of buildings.
  • Before you plant trees, you must plant water. (Implement rainwater harvesting earthworks.)
  • Get a detailed topographic map of your land to identify watersheds and ridge lines.
  • 1 inch of rain on 1,000 sqft of surface area can capture 600 gallons of water.
  • The highest quality source of water is direct rainwater capture. Use this for drinking.
  • Earthworks to learn: swales, berms, terraces, infiltration trenches, infiltration basin, imprinting, mulch, diversion swales, check dam, one rock dam, rock plunge pool
  • Cisterns will be covered in Vol 3.
  • Every foot of elevation provides 0.43 psi of water pressure.
  • Orient buildings east-west, with long walls facing south-north) to maximize winter heating and minimize summer heat.
  • Design roof overhangs and awnings to shade in the summer but not in the winter.
  • Always pair a raised path with a sunken basin to capture runoff and grow shelter and beauty for the path. Plant a tree in the basin.
  • Build a Zuni bowl to repair a headcut.
  • A wide gully is more stable than a deep gully. Stabilize with rock check dams and vegetation.
  • Stable floodplains are nature’s solution to flooding. Do not disturb.
  • Exposed roots are an indication of erosion. Find and repair.
  • Plant cottonwoods, sycamores, willows near water.
  • Waffle gardens are the opposite of raised beds, used for capturing rainwater.
  • In floodplain farming, grow more cold-hardy crops and use earthen walls to spread water.