What is Roof Water Harvesting?

This topic introduces roof water harvesting as a simple way of catching and storing rainwater from roofs for household and garden use.

Roof water harvesting is the practice of catching and storing rainwater that falls on the roof of a building. Instead of allowing this water to run off and be lost, gutters, pipes, and storage containers are used to collect and keep it for later use.

In this course, roof water harvesting is treated as a Catch and Store rainwater practice at a small scale (Scale 1) – for example, at houses, schools, clinics, churches, or community buildings.

In a typical roof water harvesting system:

• The roof acts as the catchment surface.
• Gutters and downpipes collect the rainwater and guide it to a storage point.
• A tank, drum, or reservoir stores the water so that it can be used later.

The main purpose of roof water harvesting is to collect water from roofs for household use – especially drinking, cooking, washing, and cleaning – and, where there is surplus, to support small home gardens close to the house.

Roof water harvesting is usually:

• Low to medium technology – based on simple gutters, pipes and containers.
• Low to medium skill – once set up, households can operate and maintain it themselves.
• Medium cost – depending on roof size, tank type and materials used.
• Medium maintenance – mainly keeping the roof, gutters and tank clean and in good working order.

Key points:

• 🌧️ Roof water harvesting catches rainwater from roofs.
• 📦 It is a Catch and Store practice at small scale (Scale 1).
• 🏠➡️🛢️ It uses roofs, gutters, downpipes and tanks or containers.
• 🚰🥗 The main purpose is to collect water for household use; surplus can support small food gardens.
• ⚙️💸 It is a low to medium technology, medium cost practice that most households can learn to manage over time.

Think about a house, school or community building you know well.

• Does it have gutters or a tank?
• If not, what happens to the rainwater that falls on the roof when it rains?