Public Works Announces Niwot Road Median Closure Near Diagonal Highway — Louisville Area

Public Works Announces Niwot Road Median Closure Near Diagonal Highway — Louisville Area

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 project includes improvements along CO-72 Peak-to-Peak Highway between Superior and the intersection with CO-72 Peak-to-Peak Highway. Construction is scheduled to begin in July 2026 with completion expected within 14 months.

Water quality monitoring at 11 stations along Boulder Creek, St. Vrain Creek, and Left Hand Creek showed all parameters within acceptable ranges for 2025. The Public Works publishes quarterly water quality reports on the Boulder County website.

Next Steps

Colorado state law requires all counties to provide these services to eligible residents. Boulder County exceeds minimum state requirements by offering expanded hours, multilingual support, and online access. In 2025, the county received a state award for excellence in service delivery.

The application deadline is May 29, 2026. Late applications will be accepted on a space-available basis. Incomplete applications will be returned with a list of missing items. Average review time is 30 business days.

Community Impact

Residents in the Superior area should note that service boundaries may differ from city limits. For properties in unincorporated Boulder County, contact Public Works at (303) 441-7461 to verify eligibility and requirements.

Environmental review of the project area near CO-72 Peak-to-Peak Highway found 11 sensitive species and 2 wetland areas requiring mitigation. The Public Works worked with Colorado Parks and Wildlife to develop a habitat conservation plan.