Water is a natural resource that some of use humans take for granted. It seems that we can turn on a facet to find an unlimited supply. That’s not true in all parts of the world. In the US, toilets use 27% of household water requirements. That’s a lot of water to only be used once. The water filling the toilet after the flush is the same as that comes out of the sink. [gregory] thought it would make sense to combine toilet tank filling with hand washing as those two activities happen at the same time.

To accomplish this, a DIY sink and faucet were put in-line with the toilet tank fill supply. The first step was to make a new tank lid. [gregory] used particle board and admits it probably isn’t the best material, but it is what he had on hand. A hole was cut in the lid where a metal bowl is glued in. Holes were drilled in the bottom of the bowl so that water could drain down into the tank. The faucet is just standard copper tubing. The curve was bent by hand using a wire wrap method to keep it from kinking. The only remaining part was to connect the fill line (after the fill valve) to the faucet. Now, when the toilet is flushed, the faucet starts flowing.

Although [gregory’s] project may have increased the percentage of household water used by his toilet, it’s only due to the reduction of non-toilet related water usage. This water saving mod has inspired quite a few folks to make their own sink-toilet hybrid, check them out: