A rainwater cistern will help reduce your demand for utility supplied water used for irrigation purposes, particularly in seasons of unpredictable rainfall. An especially large cistern will also be useful in storing rainy season rainfall for use in no-rain seasons.
Calculation in Completed Actions is actual savings which is updated monthly.
Drain-water often takes with it significant amounts of heat. A heat recovery system uses warm drain water to warm pipes that are bringing in fresh, clean water on its way to your water heater - thereby reducing the energy the water heater needs to expend to do its job.
Some stoves do not make efficient use of energy; this is especially true of older models.
A leaky toilet can waste 20,000 gallons a year. Toilet leaks in many cases can be obvious (sounds coming from the toilet when it is not running), but in other cases can be harder to detect.
Just one faucet with a constant drip can leak up to 10,000 gallons a year.
Your pool will naturally lose some water to evaporation and splash-out. Your pool may also gain water from rainfall. Pools should be watertight, but sealants deteriorate and parts of your pool shift and crack. Pools can leak through any of these cracks or through dislodged fittings.
Water evaporates much more quickly during the hot part of the day.
Some ovens do not make efficient use of energy; this is especially true of older models.
Some water heaters lose much of the heat they consume. This is especially true of older and lower cost models, and important in homes with large numbers of people.
Although some manufacturers set water heater thermostats at 140° F, most households usually only need them set at 120° F. Setting the thermostat at a lower temperature threshold can save substantial amounts of energy.