|Carpentry for Vocational Schools - A Teachers Handbook|
Common watertanks are made of corrugated iron and available in sizes of 80 gallon (360 litres), 660 gallon (3000 litres) 1000 gallon (4500 litres) and 2000 gallon (9000 litres).
The size of the tank depends much on the size of the roof, the number of people using water and the space to put the tanks. If a very large roof is available, try to put as many tanks as possible to avoid a big loss of water. On small roofs, try to put large a tank, because it takes a long time to fill it up and you have to make sure the tank is filled in the wet season.
To achieve sufficient water pressure in the house, especially when installing a shower, an "overhead tank" has to be put on the roof of the house. Also in connection with a hot-water solar system, an overhead tank is needed. These tanks are usually 80 gallons and are connected by a pump to the ground tanks. There are electric pumps available, but because of non existing powersupply in rural areas, a manual hand pump is more appropriate.