Slow it. Spread it. Sink it… is the recurring principle for water management on land. So down the slope of a hill, you can apply this using dams, swales, plants, aquaculture, rainwater harvesting, shallow wells, mulching, animals drinking water, greywater systems and the soil itself, which when healthy is excellent at water retention.
During class, we took a virtual tour of some real life examples of urban water management. For example, in Los Angeles there is a government policy where new builds have to have zero rainwater run off. BedZED in South London is another example, where the permeable street scape ensures water can drain into the natural water table or be shepherded into wildlife ditches. Green roofs also help sponge up rainfall while creating extra habitats for wildlife, and another insulating layer for the building.
Swales
A few days ago I didn’t really know what a swale was, now I’m in love with them. They are basically ditches that capture water. They are dug on contour so that water can evenly soak and spread into the soil without causing any erosion channels. Swales were talked about throughout the permaculture course as a key growing strategy, particularly in arid lands where water is particularly scarce. We also covered gabions, a type of wall which controls water flows to slow erosion patterns.
Swale profile by Reny Mia Slay, Introduction to Permaculture
Dirt! The Movie
In the evening, I watched the film Dirt. One of the things that moved me from the film was the plight of farmers in India. Under considerable stress, 200,000 farmers have committed suicide since 1997. One of the underlying causes is the rapid shift towards heavy pesticide use, coupled with rapid technological advances. With little guidance or support for dealing with these changes, farmers were poisoning their lands and becoming dependent on agri-chemicals that they were unable to afford.
Whilst cooking dinner that night, there was a partial eclipse of the moon. It was pretty special, although we didn’t fully realise that it was an eclipse until after it happened. With my new permaculture buddies, we chatted around the fire, feeling optimistic and excited about applying some of our new knowledge from the day.