How much water do you use when showering, or washing your hands, or washing the dishes? Not how much does the average person use, but how much to you use? That’s what the team over at Teague Labs set out to find with this water usage feedback system. The sensor used is a Koolance flow meter which is intended to measure coolant flow in PC liquid cooling systems. At $20, it makes a nice low-cost sensor which was paired with a WiFi enabled Arduino. In the image above they’re using an iPad as a screen so that you can see how much water you’re using (or wasting) as you wash your hands. This resulted in saving 1/2 gallon of water every time someone washed their hands.

The project code, schematic, and board files are all available for download. Along with the hardware build there’s some nice server-side software that gathers and graphs the data over time. We’ve seen a lot of power-meter hacks, but it’s nice to have the option to track water usage, even if this is tailored to just one tap at a time.