Harvested rainwater can potentially be used as an alternative source of water for various domestic purposes such as supplying toilet cisterns, car washing, etc.
Rainwater harvesting systems are increasingly being incorporated into new developments. Insofar as existing developments are concerned, the provision of a storage tank and the cost of its installation are important considerations. The cost of installing a rainwater harvesting system will be influenced by the existing roof drainage arrangements and the level of storage required. The cost of retrofitting an average sized suburban semi-detached household with a rainwater harvesting system is estimated at between €4,000 and €6,000 and would also require signification modifications to internal plumbing systems in order to avoid cross contamination with the public water supply.
There are no plans at this time for the introduction of a scheme of grant aid for the installation in existing houses of domestic rainwater harvesting equipment.