Town Talk: Exercising the water main valves

Each year the Water Department performs maintenance on various parts of the water distribution system. Every year we flush and exercise the fire hydrants in town. Several fire hydrants need repair each year due to damage from cars and/or trucks running off the street and hitting the hydrant. When we flush the hydrants, we flush lots of water into the street and it causes some dirty water problems for customers.

There is one part of the system that requires maintenance each year, but even though we might cause some minor traffic problems it is not obvious just what the Water Department people are doing. This is when our crews are out with two specialized pieces of equipment to exercise the valves that are on the water mains underground. Some of these valves are as deep as 15 feet underground. These gate valves, as we call them, are necessary to enable us to shut down small portions of a neighborhood’s water main to repair a broken water main without having to shut down the entire water main in a four block or larger area.

In order to ensure that these valves will operate correctly when we need them to operate, each valve must be operated. We use a machine that will apply hydraulic pressure to slowly close each valve and then open it again. This machine measures the torque needed to turn the valve as well as counts how many turns are necessary to completely open or close the valve. Generally, these valves are located in the streets and many are in intersections. There may be as many as four valves in an intersection.

So, if you see water department trucks and personnel in the street with some odd-looking equipment attached to a vertical rod projecting into the ground this spring, they are most likely exercising the water main valves.

As always, if you have any questions about what you see Water Department personnel doing, or if you have questions about water quality, please call the Water Department at (507) 359-8279.

Editor’s Note: The City of New Ulm presents a weekly column highlighting activities in different departments in the city government. Once a month the city will answer questions from readers. Questions on New Ulm city issues can be sent to comments@ci.new-ulm.mn.us.