How to dig a water catchment
- Water catchments need Clay Soil. Sandy soil will allow water to leak. (This is fine as a step in Groundwater recharge, but no good for a catchment.)
- Don't dig new water catchments without knowing about the soil underneath. Expanding existing water catchments may be a better idea.
- Find out where the clay layer finishes, and don't dig past it. If you do, or there is any leakage, use more clay to patch it.
- Where evaporation is high, water catchments should be deeper and narrower. Shallow and wide means more water lost to evaporation.
- Look at water quality as well as quantity. E.g. use a Sedimentation trap or Settling pool to allow Sedimentation, reducing solids (including soil and animal waste). An Infiltration well is a useful step in improving water quality.
- Manage the catchment. Look at inlets and the catchment area.