Transmission mains are larger in size in order to supply all the water the town needs or demands. The transmission main runs from the treatment plant to the distribution system.

The distribution system consists of water pipes or water mains that supply or distribute water throughout a town. Public water supply distribution systems can have a few hundred feet to many hundreds of miles of water mains depending on the size of the public water supply system.

These water mains are buried below the frost line often under the roads we travel every day. The water mains in a public water supply distribution system vary in size depending on future needs and fire protection. If a new road is going to be built and has the potential to eventually have many homes or businesses on it, the water main will be a larger size to supply all the needs of the homes and businesses, but also must be able to supply enough water to effectively and efficiently fight a large fire. A short, dead-end road with only a couple homes on it and no chance of future development will have a water main of a smaller size because it will never have the water demand that the larger, more developed roads will have.

Within the public water supply system are main gate valves, service lines, fire hydrants, and storage tanks. Main gate valves are located on the water mains throughout a public water supply system to temporarily stop or shut off the flow of water to a road or section or area of a town, if needed, such as in case of an emergency like a water main break.

Customers’ service lines are much smaller, individual water lines that bring water from the water main to the customer’s home or business. Each customer has an individual valve to temporarily shut the water off to the home or business in case the homeowner needs to make repairs or maintenance to the building’s water system.

Fire hydrants are located throughout a public water supply system for the obvious reason of fighting fires, but also are used to flush the water supply system as part of a regular maintenance program to improve water quality of the drinking water inside the water mains.

Storage tanks are the large bluish-green tanks standing tall above the trees on a hill. The tanks are a back-up supply of water for the town to draw on in case of a large fire. As the water level inside the tank drops during a fire, the treatment plant will come on and begin producing more water to pump to the tanks and keep supplying water to both the town and the fire without ever completely running out of water. The tanks also provide pressure to the water system.


Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.