On your water bill you see a thing that is referencing your sewer bill. But how do they figure that out? During the late fall to early spring SAWS takes what is called a winter average. This is taken by averaging your water usage during these moths So to control your water bill year round, all you have to do is reduce your water usage during those months. Typically lawns go dormant during this time so watering them is a waste and not watering is one easy area to save your water usage.