Work will also lead to a partial closure of nearby Walden Ponds

The City of Boulder will close Sawhill Ponds as early as Oct. 2, to begin a multi-year project to improve the city’s main sanitary sewer line. Boulder County will also close the west side of adjacent Walden Ponds Wildlife Habitat for this project. Both areas are located near Valmont Road and 75th Street.

The closures are intended to help expedite the project and protect wildlife from disturbances. The closures are currently scheduled through March 15, 2024, and may be extended depending on project progress. The new pipeline will be constructed primarily along existing trails, and heavy construction will only occur outside of the seasonal osprey closure window for Sawhill Ponds.

The city recognizes the impact this project will have on visitors who enjoy nature at Sawhill and Walden Ponds and encourages our community to visit other open space and parks locations. For updated trail information and current closures areas, download the Boulder Area Trails Map.

The Main Sewer Improvements project will enhance and rehabilitate the city’s main sanitary sewer line, located next to Sawhill and Walden Ponds. The project aims to:

  • Strengthen wastewater infrastructure by rehabilitating the existing sewer line.
  • Protect public health by increasing wastewater capacity.
  • Reduce flood vulnerability by moving wastewater flow out of the floodway.
  • Protect and conserve the environment by decreasing the risk of wastewater discharge.

As part of this project, the city will make accessibility improvements for visitors experiencing mobility challenges, along with trail enhancements as part of the site restoration. Impacted areas, including upland areas, wetlands and trees will be restored with native plant species in coordination with open space staff. Stormwater best management practices will be followed to protect adjacent creek areas.

For more information on the Main Sewer Improvements Project and impacts, please visit the city’s website.

Photo by: Ann G. Duncan

Sawhill Ponds closure and pipeline