Wire-cement tank
Rainwater harvesting can be an effective and low-cost alternative to groundwater usage. The water collected during the wet season can be stored in cylindrical storage tanks until it is needed in the dry season.
Bricks are used to make smaller tanks of 0.5-3 m3 and natural stones are used for tanks of 3 to 120 m3. The construction starts by laying 2 PVC tubes on the ground (for the outlet and drain). Then stones are placed in a circle and secured with steel wire. The inside and outside of the tank is then plastered with cement. No steel bars are needed since the wire functions as reinforcement. Leaks are repaired with cement.
Suitable conditions
Rainwater harvesting requires at least an annual rainfall of 100-200 mm. Depending on the size of the storage tank; the wire-cement tank has a capacity of 0.5 m3 - 120 m3.
| Advantages | Disadvantages/limitations |
|---|---|
| - Easy to construct and repair. - Less material needed than square or rectangular tanks. |
Construction, operations and maintenance
Material needed for a tank of 1 m3:
- 120 construction bricks
- Sand
- 50 kg cement
- 1 kg of steel wire.
Costs
Country experiences
In Nicaragua short "hands-on" training courses teach users how to make their own storage tank for irrigation.