What Is Involved in Replacing a Water Main?

On average, Denver Water crews install or replace about 70,000 feet of pipe a year. Replacements are done for various reasons including: to repair or avoid main breaks and pipe corrosion, to alleviate water quality problems, to increase available hydrant fire flow, and to improve overall area delivery.

In your neighborhood: Denver Water crew working on pipes.

Denver Water has an annual budget of about $4.5 million solely for these purposes. During the drought conditions in 2002 and 2003, improvement and replacement projects were delayed to save water; large amounts are used to sanitize new pipes.

The water distribution system contains 2,574 miles of water mains. Every improvement and replacement project is a little different, because of conditions at the project site. The information provided below is a typical work process, illustrating what you can expect if Denver Water is working in your neighborhood. When we are working in your neighborhood, you should receive a notice describing the project and providing contact information, in case you have questions. To inquire about a specific project, please contact the project foreman, who is identified on this notice.

The typical process to replace a pipe involves twelve steps. Once work begins, it may be delayed or interrupted because the crew replacing your main is responsible for emergency repairs of water-main breaks, should one occur elsewhere. If a crew is called away to repair a main break, they might be off the project site for a few days, a week, or longer.

  1. Give notice to customers.

    Tip from the Crews
    After a main repair, you may see reddish discoloration in the water caused by small amounts of iron compounds flushing out of the system. These iron compounds are not hazardous, and you can clear up the discoloration by running the cold water a few minutes. Sometimes, particles of iron can get into your aerators, causing a loss of water flow. If this happens, take off the aerator on a faucet. If you see hard particles in it, rinse them off and do any other aerators as well. Don't forget the shower head. You can avoid clogging issues by running the cold water in the bathtub or an outside spigot.

  2. Cut and rotor mill the pavement.
  3. Dig the trench.
  4. Install the replacement pipe.
  5. Sanitize and pressure test the new pipe.
  6. Test the water quality in the new pipe twice.
  7. Obtain Water Quality Lab approval for new service pipe.
  8. Disconnect service lines from original pipe and connect service lines to new pipe. *
  9. Cut off and abandon the old main in place.
  10. Cover trench and place temporary paving over the trench.
  11. Repair damage to private property caused by the project.
  12. Pave the work area as required by the City Right-of-Way office.**

Notes:

* Denver Water repairs leaks between the main in the street and the street-side shutoff valve to reduce water loss. Where an existing service line is found to include lead, and in some other cases, a new service line is installed from the new water main to the shutoff valve by the street. The service line from the street-side shutoff to a residence or business is owned the customer, and its repair and maintenance is the customer's responsibility, not Denver Water's.

** Permanent paving may be delayed due to weather or to combine projects into one large paving job.