Since the mid-1980s, the positive impacts of these simple, cost-efficient water harvesting techniques become clear, following their increasingly widespread adoption. Their use has allowed smallholders to reverse land degradation, improve soil fertility, sustainably increase crop production, achieve food security, and create more productive, diverse and resilient farming systems. At the same time, groundwater is recharged, improving access to drinking water for the entire year, and creating opportunities for irrigated vegetable gardening around wells.

The people of Ranawa faced an existential crisis in 1984, but today they are less poor, better fed, better clothed, and better housed. Every family in the village now has the cash to invest in at least one mobile phone, indicating that they are also better connected. Would this transformation have been possible without their efforts to restore the productive capacity of their village lands?

The combination of planting pits and contour stone bunds has helped to effectively restore degraded land in the village of Ranawa and in many more villages in the northern part of Burkina Faso’s Central Plateau. How scalable are these techniques? The construction of contour stone bunds obviously requires the presence of stones close to the farmland. The zaï planting pits function well in conditions of 400–800 mm rainfall. Rainfall below 400 mm would require much bigger pits to hold more water and rainfall greater than 800 mm risks drowning the crops in the pits. Zaï pits have also been used to restore degraded land that is flat and has a hard crust.

As the construction of contour stone bunds and the digging of planting pits require an important investment in labour, they are usually found in areas with high population densities (30+ persons per km²). In 1989, 13 farmers from Illela district (Tahoua Region) in Niger visited Yatenga region, and on their return, began to experiment with planting pits. Thereafter, planting pits were widely adopted in that part of Niger (see case study in this issue: Post-project impacts of restoring degraded land in Tahoua, Niger). Planting pits and contour stone bunds are simple water harvesting techniques that do not require massive investment, and have the potential for scaling to other dryland areas across
the Sahel and the Horn of Africa where the conditions mentioned above are met.