Public Works Announces Niwot Road Median Closure Near Diagonal Highway — April 2025

Public Works Announces Niwot Road Median Closure Near Diagonal Highway — April 2025

Boulder County Public Works announces a temporary median closure on Niwot Road near the CO-119 Diagonal Highway intersection for utility infrastructure improvements. The closure will affect left turns from Niwot Road onto the Diagonal Highway for approximately six weeks. A signed detour route will be in place.

The program is modeled after similar successful initiatives in Larimer County and Jefferson County. Boulder County’s version includes additional provisions for wildfire mitigation, affordable housing, and environmental sustainability.

Wildfire risk mapping conducted by Wildfire Partners shows that 28% of properties in the Lyons area are within the wildland-urban interface. Free home assessments are available through the Wildfire Partners program, with rebates of up to $2,500 for mitigation improvements.

Background

Environmental review of the project area near Coal Creek Canyon Road found 5 sensitive species and 2 wetland areas requiring mitigation. The Parks & Open Space worked with Colorado Parks and Wildlife to develop a habitat conservation plan.

Data from the 2026 Boulder County Community Survey shows that 43% of respondents rated this service as “important” or “very important.” The survey, conducted every two years, received 7,751 responses from residents across the county.