Fresh clean water is an important component to life. Americans take it for granted, though other parts of the world aren’t so lucky. The average U.S. household uses 100 to 160 gallons a day (versus 2 to 5 gallons for the rest of the world) with agriculture using the most. In my bioregion (Northeastern Ohio), I’m less than 50 miles away from the Great Lakes, one of the biggest freshwater bodies in the world. Because of this abundance, other parts of the country are eyeing this grand resource (like California, which is in the middle of a deep drought).
One of the tenets of permaculture is the conserving and storing of resources, including water. Household water has several categories , including fresh, grey, and black. Fresh is obviously used for drinking, cooking, and cleaning. Grey is water that was previously used for cleaning (think shower or kitchen) that can be repurposed (like flushing toilets or watering non-edible plants). Black water is fecal matter, though urine can be considered grey (though it’s yellow) as it’s used as crop fertilizer in some countries like China. Separating water use instead of putting it into one system like current conventional engineering is a big step towards having enough water for everyone in the future.
Permaculture design works to store and release water so it’s available when it’s needed. Soil building helps by adding water holding compost and biomatter. Drip irrigation puts crop water where it’s needed, right at the plant roots. Maintaining leaky old infrastructure (pipes, etc) reduces waste to a minimum. Reforestation of barren land keeps water from running off unprotected soils, saving both water and topsoil. Swales (water harvesting ditches on contour) slow water down, allowing it to seep into to ground instead of running quickly over sloped land. Keyline plowing (first perfected in Australia) uses deeply plowed groves on the contours of a agricultural field to accomplish the same goal as swales.