North St. Vrain Pipeline Relocation

Press Enter to show all options, press Tab go to next option

Project Status Update

On Saturday, Oct. 19, the contractor will be working on the 24-inch pipeline at the south intersection of Apple Valley Road and U.S. Highway 36. Access to Antelope Road is available from the NORTH side of Apple Valley Road at US 36.

Week of October 14, 2019

The 24-inch pipeline has been installed and tested. The contractor is waiting for some fitting to complete the tie over to the existing line at the beginning and end of the project.

Apple Valley Road will be milled on Monday, Oct. 14, and Thursday, Oct. 17. Asphalt patching will begin on Tuesday, Oct. 15, and will be completed the week of October 21. Residents living within the construction zone will have access to their driveways. Flaggers will help owners access their properties.


In spring 2019, the City of Longmont and Town of Lyons began relocating their existing water lines from the North St. Vrain Creek corridor to Apple Valley Road. This relocation is expected to continue through fall/winter 2019.

Both pipelines are used to provide drinking water to Lyons and residents along Apple Valley Road.

The relocations will reduce the risk of damage and loss of water service from future natural disasters, including floods.

Longmont and Lyons are coordinating the water line relocations to minimize impacts to residents in Apple Valley.

Goals and Proposed Improvements

Lyons will relocate a 12-inch water line; Longmont will relocate a 24-inch water line.

The water lines will be relocated to provide greater protection from natural disasters and allow better access to the pipelines for future operations and maintenance. Currently, the existing pipelines are within the floodplain or floodway of the North St. Vrain Creek and run along or cross the creek. Pipeline access in most cases requires crossing private property.

The new pipeline locations will be installed within the Apple Valley Road right-of-way with the majority of the pipelines situated outside of the floodplain. The image shows the location of the Longmont water line. The Lyons water line will begin at Apple Valley Road and Antelope Road and end at Apple Valley Road and US 36.

Click on the map below to view a PDF of the relocation project.

North St Vrain Pipeline Relocation Map


The two water line projects are scheduled to begin construction in June 2019 and continue throughout most of 2019.

During construction, most activity will occur within a 500-foot construction zone that will be closed to all traffic except emergency vehicles. At the end of each work day, the road will reopen to two-way traffic.

Work hours will initially be from 8:00 am to 7:00pm within Boulder County jurisdiction and 7:00 am to 7:00 pm in the Town of Lyons jurisdiction. The City of Longmont and Town of Lyons will coordinate the two projects whenever possible to minimize the impact to residents.

View the letter mailed to residents about the North St. Vrain Pipeline construction (PDF).


Both pipelines were affected by the 2013 Flood and will receive federal funding for their relocations.


City of Longmont Project Manager: Larry Wyeno 

Town of Lyons Recovery Lead: Tracy Sanders

Questions or comments about this project may be submitted via or by contacting the PWNR Customer Service Center at 303-651-8416.

View Full Site