CHANGING YOUR TOILET TO A HIGH EFFICIENCY (HE) TOILET
Toilet usage accounts for 30% of domestic water consumption in the United States. In commercial office environments, toilets contribute to 82% of water consumption. In most toilet improvements: restaurants, assembly venues, work places with 3 or more people per toilet, and homes with higher occupancy, will see the complete cost back in water savings in the first year. Other homes and uses will see different savings.
Calculating the expected savings in changing your toilet to a high efficiency (HE) toilet is easy to determine as long as you know the frequency of usage and the cost of water per unit. (See attached spreadsheet to calculate your own savings.)
By 2014, all toilets sold in California must be high efficiency (HE) toilets (1.28 gallons or less per flush). By 2017 this will be federal law. There are rebates available that range from $75-$200 per toilet, in some Bay Area cities and towns.