How do they refill water towers?
Water towers are kept full by a pump that is drawing water from a well. The tower stores enough water to keep up with the daily use of the area it supplies. Generally, in the morning they are nearly full and by the end of the day, may be less than half full or even near empty. The pump then runs all night to refill the tank. When the tank reaches capacity, the pump shuts off. My brother runs a small water company in Arizona, and this is the layman’s explanation he gave me.
The purpose of a water tower is to provide a steady pressure to a municipal water supply as well as store water. The pumps on the water supply operate at a level to supply the average of what the town uses in a day. During times of low water usage (when the pump is pumping faster than the water is being used), water flow up the pipe and into the water tower. At times of high water usage (at times when water is being uses faster than the pumps are working), it flows back down the same pipe and into the homes. So, the towers use the same pipes to fill and empty the towers. See http://www.howstuffworks.com/water.htm for more.
