Rainwater harvesting generally involves three components:

• A catchment surface
• A delivery system
• A storage reservoir

Because of the height of the large 75,000L tanks, household roofs are not tall enough to serve as a catchment surface.  For each tank, a small shed is constructed with corrugated iron roofing.  These sheds also serve as shaded gathering areas and potentially as spaces that might be developed for communal trade projects such as food processing.

The delivery system is a basic gutter, which carries the water to a filter before it enters the tank.  The filtration system is a bucket layered with specific types of gravel and sand.  One of the benefits of this simple system is that it can be maintained and replaced as needed by the residents themselves, not relying on external expertise or complex parts.

The storage reservoir is a cement tank with a tap at the base for retrieving water.  There is an overflow pipe and an access hole at the top of the tank for cleaning out the reservoir at the end of each season.  The location of the tap ensures that a small amount of water always remains in the tank so that contaminated stream water does not enter the tank when cleaning.

When completed these rainwater harvesting tanks will supply the residents of Adexor and Adexor-Kpodzi with all of their drinking and food-related water.  Stream water will still be collected for bathing and laundry.  Providing education and developing a strong water management system with the residents will ensure that the stored water can last throughout the dry season.

Why rainwater harvesting?

Drilling wells around Adexor has not been successful due to extensive granite rock in the area. The limited groundwater that has been accessed is salty. A piping system proposed by the local Water and Sanitation Department proved to be very costly and presented many potential complications. Based on research and input from village residents, rainwater harvesting is the most feasible and sustainable solution for Adexor’s water needs.