Why use Roof Water Harvesting?

Roof water harvesting is useful because it helps households and communities make better use of the rainwater that is already available. Instead of relying only on a distant tap, standpipe or tanker, rainwater can be collected directly from the roof and stored close to where it is needed.

One of the biggest advantages of roof water harvesting is that roof run-off is often the cleanest rainwater available. When systems are well designed and maintained, this water can be used for many important household needs, and in some cases even for drinking and cooking.

Roof water harvesting can help to:

• Provide a more reliable water supply at home, especially during times when other water sources are interrupted or limited.
• Save time and effort, because water is stored on site and does not need to be carried long distances.
• Reduce pressure on communal or municipal water supplies, especially for non-drinking uses such as washing, cleaning and watering small gardens.
• Support small food gardens near the home when there is surplus water, especially during dry spells. Even a few extra buckets of water at the right time can help keep key crops alive.

Strengthen household and community resilience in dry periods and drought years by using multiple water sources more wisely.
Roof water harvesting therefore fits well within a Multiple Use Systems (MUS) approach, where different water sources are used for different purposes – for example, roof water for drinking and household use, and other sources for livestock or larger gardens.

Roof water harvesting makes better use of the rain that already falls on buildings.

• Roof water is often the cleanest rainwater available when systems are properly managed.
• Stored roof water can improve reliability of water supply at household level.

• Surplus roof water can help support small food gardens during dry periods.
• The practice reduces pressure on other water sources and strengthens resilience in times of scarcity.

Think about your own household or a nearby school or clinic:

• What water sources do people currently rely on there (for example, tap, borehole, standpipe, tanker)?
• What difference could it make if there was also a tank collecting water from the roof?