People around the world are finding innovative ways to save water and energy to do their part in protecting the environment little by little.

Here, YouTube vloggers (video bloggers) Mike and Lauren recently took on a challenge from Quikrete to design the best project using one bag of concrete, with a prize of $2,500 going to the winner. Their creation is a toilet tank sink. Using concrete, Mike and Lauren molded a sink top to fix to the top of the toilet. They then routed the fill water through the sink faucet. The result is that the flush lever will run water through the faucet for users to wash their hands before the water is drained to the toilet tank for flushing the toilet.

They duo estimates the innovation saves a gallon of water per person per day, see how they managed the whole project in their video above.