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The application of Appropriate Technology

This section contains photographs that detail the construction of a gravity flow water system for 32 families. The system cost £130 per family and took 30 people 18 days to build. Before the system can be designed the area must be surveyed.

The system consists of:

  • A spring tank;
  • A main pipeline, including a pipe bridge;
  • A reservoir tank;
  • A distribution network that leads to a tap at each house.

For a gravity flow system to work properly the pipes must run full of water with no air locks. Gravity can then be used to move water, over hills and undulations, between the spring and the reservoir tank. This method works for as long as the spring tank is at the highest point in the system and that there is enough height difference, between the spring tank and the reservoir tank, to give a sufficient flow rate once friction losses have been taken into account. The distribution network also uses gravity to move water to the taps through thinner pipes.