Description of Challenge
In the tropics, human activities have resulted in rivers and dams silting up while the levels of ground water are falling. Human activities such as deforestation and industrial agriculture have left the soils exposed to erosion and compaction and this has led to increased surface run off and reduced infiltration. More run off cause more erosion which in turn causes siltation of water sources such as dams and rivers. At the same this also leads to flooding and reduced recharge of ground water stoThe true source of water is not the dam nor the river but the rain (Mugove Walter Nyika)
Solution
The ‘S’ Principles: Looking at the rain as the main source of water, we need to harvest it at the source by slowing it down and stopping it from flowing using swales and mulch or ground cover. Swales are ditches on the ground that are dug truly on contour. Swales cause flowing water to spread slowly and thus more of it will get a chance to sink into the ground thereby recharging the ground water store. Over time the springs that may have disappeared in the past will spring back to life. The contours along which we dig the swales are determined using a simple instrument called an ‘A’ frame.
