sometimes, people use the finished water instead of just putting it back into the river. they can use it to water golf courses or make fountains run. you may have seen non-potable water sings at these places this means the water is safe to water the plants or make the fountain run but it is not safe for you to drink. they can also send finished water straight to a water treatment plants to make drinking water. or they can send it deep into the ground to increase the groundwater supply.