How much water can be saved from xeriscaping?

It has been estimated that as much as 50-70% of treated house water goes to watering gardens and lawns. It has also been estimated that xeriscaping can cut that down to 10%. The figure can be further reduced, down to zero, with the use of grey and rain water. Grey water is recycled water from the house - except from the toilet. Rain water can be collected in rain barrels. A large portion of water that comes to our homes is used up for watering our plants. Today, when many places are experiencing water shortage, the need to plan a water wise garden has grown in importance.