A showerhead. Photo: Wikipedia

Israeli households waste nearly two gallons each a day letting the shower water run while it heats up. That’s nearly ten billion gallons of wasted water a year. In the United States it’s even worse–far worse: nearly one trillion gallons of water are wasted each year.

Now a group of students at Israel’s Ariel University have developed a new system, called “Has-Ham,” designed to reduce water waste by conserving fresh water and rerouting it back for domestic use. The system, which is installed in showers, collects the cold water that runs while people are waiting for it to get warmer.

As Israeli innovation blog Nocamels.com explains: “The system stores the water until hot water reaches the shower head and only then directs it for the consumer’s use. At the same time, the water is pumped out of the storage tank and is ready for re-use. The ‘Has-Ham’ utilizes temperature sensors which control the flow of water into the taps. In essence, the system recognizes the cold water running through the pipes and makes sure that instead of flowing out of the faucet, it is directed to the storage tanks to be re-used later.”

The students working on the project told Nocamels.com: “In Israel, like in many other countries, there’s a water shortage. This shortage is due to climate, population growth, a greater need [for water] and dwindling water sources. In light of these facts, we are obligated to conserve as much water as possible.” The students say that, as far as they know, there is no other system that stores fresh water for re-use.

The students add that “the goals we set for ourselves were that the water conservation system would not use too much electricity, that stored water would be used as fresh water and not ‘grey-water,’ that the system be user-friendly and that it recognize the proper water temperature before rerouting the water back to the user.”