Rain-Water Harvesting

There are several reasons why harvesting rainwater is a good idea!

• Firstly - By storing a water tank beneath your garden connected to your gutter or on your roof, you can store a large amount of water during the rainy season, ready for use during the dry summer season. This water can be used to water your lawn and flower beds and also replenish ponds and bird baths.
• Secondly - By storing and using rainwater to reduce the pressure on the National Water supply, which every year comes under more pressure due to climate change.
• Thirdly - Storing water in a rainwater harvester reduces the risk of flooding during the wet seasons.

Many EcoHouses are fitted with cisterns which collect rain water as it falls on the roof. This water can then be used as part of the general water supply for the Ecohouse.

This water is called grey water and can be used as the household’s main domestic water supply. 

If you wish to start using Grey Water to run your household appliances like washing machines, dishwashers, toilets and baths, you need first to have some idea of the amount of water needed. 

For a rough estimate per average load, 

• Sink 5 – 20 litres (depending on activity)
• Dishwater 10 -20 litres
• Washing Machine (front loading) 50 litres
• Shower 15- 30 litres (depending on flow speed and time)

Other considerations include Number of

• People in the household (normal occupancy)
• Other appliances and flow rates
• Average Temperature
• Amount of rainfall per day/month/year
• Rates of moisture evaporation
• Soil Type (for overspill)

For more info, EcoHouseAgents has a guide to 6 of the best Rainwater Harvesting systems.