Water Mains
One of the most important requirements in any city is the construction and maintenance of an adequate water supply system. Water, which is collected in distant reservoirs, is carried into a city’s storage tanks through pipes and tunnels often hundreds of feet below the surface. To maintain a constant flow, both are situated, whenever possible, at a particular slope called a grade. If at any point enough of a grade cannot be achieved, the water must be pumped.
Because of the size and complexity of the pipe systems within a city, it is impossible to rely on gravity to move the water. To insure complete distribution throughout the city a constant pressure is maintained in the pipes by continuous pumping.
The largest water pipes under the street, called mains, are made of concrete, VC,PVC or cast iron. They carry water from centralized pumping stations into predetermined districts of the city. Smaller pipes, called submains, are connected to the mains and carry water down each street. The smallest pipes, called branch lines (or service lines), connect the submains to the plumbing systems within each building.
Once the location of a water pipe has been determined, the outline of the trench in which it will rest are marked on the street surface. The asphalt and concrete roadbed between the lines is then removed and the trench dug to the required depth. All water pipes are buried in the ground . This is a level about four feet below the surface . The trench is kept as narrow as possible so that a minimum amount of fill will be needed once the pipe is laid. The more fill used around the pipe, the more chance there is of excessive settlement. As a section of pipeline is completed, it is carefully tested. If all the connections are found to be watertight, gravel is carefully packed around the exposed portions of the pipe and the remainder of the trench filled with soil, All pipelines are laid out as straight as possible to reduce the increased friction that arises when water is forced through sudden curves.
Metal gates, called valves, are located inside the pipes, enabling a section to be shut off and repaired without closing the entire system. On top of each valve is a nut that is reached through a small opening in the street or sidewalk called a valve box. Each valve box is covered by a small square or round cast-iron lid, Valves are opened and closed by tuning the nut with a long-handled wrench called a gate key. Other valves, called air valves, which are located at high points along the pipeline, allow any trapped air to escape without releasing water.
Please Note: The water Division is not permitted to do any work on private property; therefore, the homeowner or a plumber must resolve any problem between the meter and the house.
