Uploaded on Apr 26, 2009
Geoff Lawton on the use of swales (shallow ditches) for passive water harvesting for individual farms in hot and dry climates.
The genius is that it keeps water from evaporating, by storing it under ground, moving slowly through the soil, and keeping it available for extended periods of time.
As much of Third World agriculture is still rain fed, this is a low cost alternative to huge government dams that need a lot of maintenance and create risks in dam failure.
Where large irrigation dams disrupt people, the ecology, and cost millions to build, small on-farm water harvesting ditches like these can be put in place on any farm, whithout disrupting the area around it.