Providing High Voltage Routing and Permitting Services to Strengthen Colorado’s Electric Grid

Challenge

Colorado’s Power Pathway is a large-scale, high voltage transmission project designed to strengthen Colorado’s grid and enable future renewable generation across the state. The project, led by Xcel Energy, consists of about 550 miles of new 345-kilovolt double-circuit line, four new electric substations, and upgrades at four existing substations. Xcel Energy—a client of Tetra Tech’s since 2008—faced a complex routing problem that required balancing system planning and cost drivers. It involved extensive environmental, cultural-resource, land-rights, and land‑use considerations across 12 counties.

The project triggered environmental clearance and field surveys and multiple permitting processes in different jurisdictions, creating potential operational delays and mitigation costs. It also generated strong local concern as several jurisdictions and communities opposed the project and public hearings were often contentious. The client needed sustained, meaningful stakeholder engagement and clear regulatory coordination to address community impacts and keep the project on schedule.

Solution

Tetra Tech’s energy experts delivered a data-driven, multi-disciplinary routing and siting program that narrowed 20-mile-wide study areas (totaling over 14,000 square miles) into focused, buildable corridors using a GIS-based suitability analysis combined with field verification. Three thousand miles of preliminary alignments were drawn from that suitability model, then refined by comparing alternative links within each focus area and eliminating options with greater environmental or land‑use impacts. Tetra Tech developed resource assessments to inform targeted pedestrian, windshield, and aerial field surveys—including ground and aerial raptor nest surveys and rolling biological/wetland investigations—so avoidance and mitigation measures could be identified early and incorporated into routing decisions.

On the permitting and outreach side, Tetra Tech combined local permitting know-how with strong public engagement to keep the project moving through 12 counties. Tetra Tech prepared 19 major land‑use permits, supported Xcel at 24 jurisdiction hearings (summarizing comments and answering concerns in real time when needed), and ran a large strategic communications and outreach campaign—a project website, mailings, email newsletters, social media ads, 47 public meetings, and media placements—to keep agencies and communities informed and help reduce schedule risk.