Rainwater

The quality of rainwater as it falls is usually very good until it contacts the ground or a roof. It then varies according to the cleanliness of the catchment and storage systems. While rainwater may not always be reliable, it is a frequently ignored source of water for domestic use. There are two main types of rainwater catchments:

1. Roof catchments
2. Ground catchments

Roof Catchments

Roof catchments can be constructed for individual houses by using the current roof, adding gutters and building a tank equipped with a water filtering device. To learn how to build roof catchments, refer to the Rainwater Harvesting and Lifewater sites that list several resources.

The tank must be opened and cleaned from time to time. There is little maintenance required aside from this disinfection procedure and cleaning the gutters, pipes and filter to avoid clogging. Other types of roof catchments are used to recharge groundwater wells. The Directorate of Special Village Panchayats in India has additional resources.

If there is not enough water to last throughout the dry periods an additional tank may be required. Also if the maintenance is not performed on the system, there is a good possibility of contamination.

Ground Catchments

Catching rain in constructed or naturally occurring depressions in the land is a technique that has a long history in various countries including India, China and Sri Lanka for the purposes of irrigation, water conservation and providing drinking water. To learn more about a wide variety of rainwater harvesting techniques in India, Rainwater Harvesting has good resources available. UNEP has information on how populations in countries such as Jordan, Syria and Israel use artificial reservoirs to store surface runoff and rainwater.

For More Information 

CAWST offers a four-day course on Rainwater Harvesting that explores the following topics in greater detail.