Undergrounding Electrical Lines in Boulder

Undergrounding is the process of relocating overhead electric distribution lines below ground. This work typically occurs within the public right of way, such as streets or sidewalks, and is often coordinated with other public infrastructure projects, such as roadway reconstruction, multimodal improvements or utility upgrades.

Undergrounding can:

• Reduce wildfire ignition risk from overhead lines
• Improve service reliability during high winds and severe weather
• Protect critical infrastructure
• Reduce long-term maintenance needs
• Improve streetscape aesthetics and viewsheds

Undergrounding power lines is a proven way to improve reliability and reduce wildfire risk. However, undergrounding is not always feasible. In some areas, steep or rugged terrain, environmental constraints or limited space due to existing utilities like water and sewer lines make underground construction difficult, costly or disruptive.

Overhead powerlines can pose a wildfire risk during extreme weather conditions, particularly high winds. Undergrounding removes these lines from exposure to wind, falling branches, and other hazards that can cause damage or spark fires.

Undergrounding is not the only way to reduce wildfire risk. In Boulder, undergrounding is one part of a broader wildfire mitigation and grid modernization strategy that also includes:

• Using composite and steel poles instead of wood
• Installing insulated power lines
• Upgrading electrical equipment to be more fire-resistant and durable in extreme weather
• Advanced fault detection technology, which helps utilities quickly identify problems like downed or damaged power lines
• Increased vegetation management
• Drone inspections to identify and repair issues earlier

Learn more about Boulder’s wildfire mitigation efforts.

Boulder has a long history of undergrounding electric infrastructure, particularly in newer areas of the city and during major reconstruction projects thanks to local regulations. As a result, a majority of the city’s electric distribution system is already underground.

In recent years, undergrounding efforts have been accelerated and more intentionally aligned with wildfire mitigation, multimodal transportation projects and long-term planning for a more resilient energy system.

How the City’s Partnership with Xcel Makes Undergrounding Possible

Undergrounding projects in Boulder are made possible through the city’s franchise agreement with Xcel Energy.

Under this agreement:

• Xcel makes available the equivalent of 1% of the annual revenues it collects from the Boulder community for community-directed undergrounding projects in the public right of way.
• On average, this funding equals approximately $1.2 million per year.
• Projects are typically coordinated with other city capital improvements to reduce costs and disruption.

Settlement Funding

As part of a settlement agreement with the city, Xcel made an additional $11.5 million available. This amount represents the equivalent of 1% in franchise fee revenues for the roughly 10 years Boulder was out of franchise, meaning the city did not have a formal franchise agreement in place with the electric utility. During that time, Boulder did not receive the franchise fees typically paid to cities. This settlement funding helps account for that gap and supports city priorities related to the electric system.

Through 2024:

• $16.4 million has been available and allocated to undergrounding projects
• Funding has supported four major projects across the community

Beyond these projects, the city will continue to accrue 1% funds annually for future undergrounding efforts.

Recent Projects

North Broadway Undergrounding Project

$3.9 million | Completed 2022

This project converted about one mile of overhead lines to underground along North Broadway, from just south of Violet Avenue to U.S. Highway 36. It was completed alongside the city’s North Broadway Reconstruction Project.

Why this area was prioritized:

• Support future redevelopment
• Avoid cutting into newly reconstructed concrete roadways
• Improve reliability for customers and businesses along and west of North Broadway

19th Street Undergrounding Project

$2.3 million | Completed 2024

This project converted approximately 3,300 feet of overhead electric distribution lines to underground along 19th Street between Upland and Norwood avenues. It was coordinated with the 19th Street Multimodal Improvement Project.

Why this area was prioritized:

• Create space in the public right of way for a multimodal path
• Improve reliability for surrounding neighborhoods

East Arapahoe Undergrounding Project

$7.9 million | Completed in 2025

This project undergrounded approximately 0.8 miles of overhead distribution lines along East Arapahoe Road, from McArthur Drive to 56th Street. The work is coordinated with the East Arapahoe Multi-Use Path and Transit Stop Project.

Why this area was prioritized:

• Make space for a regional multi-use path
• Reduce impacts to adjacent properties
• Improve long-term reliability along a major corridor

Chautauqua Undergrounding Project

Cost TBD | In progress

This three-phase project began in 2024 and is being completed in partnership with the Chautauqua Association. It will underground some overhead distribution lines in Chautauqua and the adjacent open space.

This is one of the most complex undergrounding projects Xcel has undertaken in Boulder.

Why this area was prioritized:

• Reduce wildfire potential in a high-risk area
• Improve the sightlines in a nationally significant landscape

Looking Ahead

Undergrounding will continue to be one of several tools Boulder uses to improve community safety, reliability and resilience. Xcel Energy has several undergrounding projects in and around Boulder that will be constructed in the next few years as part of their Wildfire Mitigation Plan. This includes:

• North Boulder: Xcel will underground the line that runs along Highway 36 north of Boulder, starting at Jay Road
• South Boulder: Xcel will underground several sections of line that run through high vegetation areas around NCAR and CU South, as well as along Highway 93.
• 75^th Street: Xcel will underground the line that runs along 75^th Street between Lookout and the city’s Water Resource Recovery Facility, just south of Jay Road.

While not every overhead line can or should be undergrounded, the city and Xcel Energy will continue to:

• Prioritize projects that reduce wildfire risk
• Coordinate undergrounding with major capital projects
• Invest in advanced grid technologies and maintenance

Together, these efforts support a safer, more reliable energy system for Boulder as the community plans for a changing climate and an increasingly complex energy future.