In an effort to make it easier for people to monitor their daily water use in the shower, a French design firm has invented a new kind of shower head that flashes different coloured LED lights to let you know how much you've used up.

Demonstrated at the recent CES conference in Las Vegas, the LED lights in the Hydrao Smart Shower change colour depending on the volume of water used. It'll glow green at the 10-litre mark, purple up to 50 litres, and then beyond 50 litres, it'll start flashing red, which looks annoying enough to make you want to finish up. 

Right now, the average American is using 75-80 litres (19-21 gallons) of water every single time they shower, and when you're spending an extra 10 minutes in there shaving or deep-conditoning your hair, that total is going to skyrocket. 

Add that to the fact that you're also using energy to heat all that water, and your daily shower starts to get really resource-heavy. But the Hydrao looks like a really cool way to help you keep tabs on what you're doing.

"The system works with a companion app, available for iOS and Android, to let users track water use over time, with further options to change the water consumption threshold and what colour the shower head flashes," James Temperton reports for Wired UK.

The developers at Start & Blue say the 1,000 people who have already been using the first generation Hydrao have seen an average reduction in water use of 25 percent, which is pretty awesome when you start adding up all those litres over the weeks and months. 

Another big plus with this technology is that it requires no battery or electricity to keep the LED lights on - they're run entirely by a built-in turbine system that's powered by the flow of water into the shower head.

The technology works with any conventional shower hose, and the second generation will go on sale for around $US99 in February or March. 

Meanwhile, the rival smart shower head we reported on back in August is still in the testing phase, but if successful, will offer a more expensive option that promises to use 70 percent less water each time you shower. The Nebia is now being tested by shower enthusiasts at Apple, Google, and Stanford University, having garnered high-profile investment money and $US3 million from Kickstarter.

Maybe 2016 will be the year we start being responsible with our showering habits.