Loudoun releases draft plan for transmission corridors; officials stress limits of county authority

County planning staff and consultants on Tuesday presented a draft electrical infrastructure comprehensive plan amendment (CPAM) that would add a county map and policies to guide the siting, design and aesthetics of new high‑voltage transmission corridors.

The plan proposes that co‑location and upgrades to existing transmission corridors should be the county’s first choice and that undergrounding should be used selectively “to minimize impacts on residential communities and sensitive rural and historic areas,” Pat Giulio, Department of Planning and Zoning, told the Board of Supervisors. The draft also calls for early public engagement and corridor management practices that allow native plants and pollinators in rights‑of‑way.

Planners said the CPAM is intended to give utilities, the State Corporation Commission (SCC) and the regional transmission operator a visual and policy framework to reference when routing new lines. “The combination of both the policies and the map provide a detailed framework and a guide for electric officials, the SCC, and other decision makers,” Giulio said.

Why it matters: Loudoun has seen an extraordinary rise in electric demand tied to data centers, and supervisors pressed staff for clarity on whether the county can actually require or block undergrounding or route choices. Supervisors repeatedly asked staff to make clear to the public the limits of county authority under federal and state review processes — especially the role of PJM, FERC and the SCC.

Details of the draft: Consultant Paul Vernon of Kimley‑Horn walked the board through technical findings and elements staff says are already in the draft policy memo. Among the points presented: modern conductors and reconductoring can increase capacity within an existing right‑of‑way; undergrounding is far more expensive and is usually used in short, strategic segments; and co‑location with existing corridors, roads or rail can reduce new land acquisition and visual impacts. Vernon said, “This is not anti‑development work, this is pro economic development.”

Supervisors pushed for specifics on demand and infrastructure needs. One supervisor recited county projections staff presented earlier in the study: Loudoun’s electric demand from data centers could grow up to 150 percent to about 8.2 gigawatts by 2028, a number supervisors said will drive future transmission, substation and possibly 30–50 new substation proposals. Staff said planning for substations and specific new corridors is part of phase two of the county’s work and would include public input.

On undergrounding and legal limits: Planners repeatedly told the board the SCC and other state or federal designations can supersede local preferences. “When it comes to the NITC, they supersede the SCC,” staff said when asked about National Interest Electric Transmission Corridor designations, and noted that the SCC must still consider a county’s comprehensive plan when evaluating an application.

Next steps and schedule: Staff said policy refinement and public engagement will continue through the summer, with an in‑person town hall planned for July 23 at Douglas Community Center and public hearings planned for the fall. The project team also plans targeted meetings with utilities, referral agencies and stakeholder organizations and will publish an online comment form.

Board reaction: Supervisors welcomed the draft but asked staff to emphasize to residents that the county’s policy guidance can be limited by state and federal regulators. Several supervisors urged that the public engagement be framed as both education and comment, because many residents “believe we have more authority than we do.”

Bottom line: The CPAM sets a county preference for upgrades and co‑location over new corridors and for selective undergrounding in sensitive areas, but staff cautioned the board that the final outcome on any proposed transmission project will depend on regulatory proceedings outside the county’s sole control.