Beyond the Campus: The Power Lines Behind Virginia's Data Centers, and the Streams They Cross
In July 2022, Dominion Energy told data center companies that power for some new facilities in eastern Loudoun County would be delayed for years. The reason, as Data Center Frontier reported, was transmission: lines and substations hadn't kept pace with demand. By 2026, the fix was under construction or in front of regulators across the state, and every new corridor crosses streams and wetlands on its way to Data Center Alley.
The build-out in Loudoun County
Loudoun County tracks the projects inside its borders on its transmission lines page. As of September 2026, that list includes:
| Project | Voltage | Status, per Loudoun County |
|---|---|---|
| Mars to Wishing Star | 500/230 kV | SCC approved April 2023; under construction |
| Aspen to Golden | 500/230 kV | SCC approved February 2025; upheld by the Supreme Court of Virginia, February 2026 |
| Golden to Mars | 500 kV and 230 kV | SCC final order selected Route 3A |
| Morrisville to Wishing Star | 500 kV | Filed with the SCC, February 2026 |
| Line 514 Corridor Improvements | 500 kV and 230 kV | Filed with the SCC, May 2026 |
| Valley North | 765 kV | Not yet filed; Board of Supervisors voted to oppose it, September 2026 |
Several of these reuse existing corridors. Others need new right-of-way through farmland, forest and the stream valleys of the Potomac's tributaries.
The 765 kV backbone
The largest project statewide is Valley Link, a joint venture of Dominion Energy, FirstEnergy Transmission and Transource. Its Joshua Falls to Yeat line would run about 115 miles at 765 kV from Campbell County to Culpeper County and carry up to 6,600 megawatts toward Northern Virginia, according to the Virginia Mercury. PJM, the regional grid operator, first selected the project in February 2025, per the Piedmont Environmental Council. Valley Link planned to file its route with the SCC in fall 2026, with a ruling expected in fall 2027. Lines this size need a cleared corridor about 200 feet wide, 29 News reported.
Where streams and wetlands come in
A power line rarely fills much of a stream. Its impacts come from tower foundations, access roads, temporary crossings during construction, and the clearing itself. Spread across a corridor 100 miles long, small impacts add up, and they land in many watersheds at once.
Two permit programs apply.
The federal side
Electric utility lines in waters of the United States are usually authorized under Nationwide Permit 57, which the Corps reissued in January 2026. The permit limits the loss of waters to half an acre, and for linear projects the Corps generally applies that limit to each separate crossing. The 2026 version adds a note encouraging early coordination with the Coast Guard where lines cross navigable waters. Our post on the 2026 nationwide permits covers the rest.
The state side
Virginia's general permit for utility and public service company activities sets compensation ratios for permanent wetland impacts: 2:1 for forested wetlands, 1.5:1 for scrub-shrub and 1:1 for emergent. It also says that permanently converting a forested wetland to an emergent wetland counts as a permanent impact, mitigated at 1:1.
That last rule matters most for power lines. A right-of-way kept clear of trees for decades turns a wooded wetland into a meadow without placing any fill, and that change can still require credits. The state program also reaches wetlands that fall outside federal jurisdiction after the Supreme Court's Sackett decision, which we cover in our WOTUS post.
In September 2025, DEQ announced its tentative decision to certify most of the 2026 nationwide permits, including NWP 57. For covered work that generally means no separate state application, but one is still needed when the Corps finds the work is outside federal waters or not covered by a nationwide permit.
Planning mitigation for a corridor
- Delineate the whole corridor early, including forested wetlands that will be cleared but not filled.
- Count impacts by watershed. A long line can cross several HUC 8 watersheds, and each impact needs mitigation from a bank whose service area covers it.
- Get credit availability letters for each watershed before filing, so the Corps and DEQ see a complete plan.
- Expect to secure mitigation before work in the affected waters begins.
- Site substations and access roads to avoid wetlands wherever the route allows.
Credits in Data Center Alley
Potomac Mitigation Bank sponsors a stream and wetland bank and several nutrient banks in Loudoun County, where many of these lines converge, plus banks in Westmoreland County. New substations and access roads also add impervious surface that falls under Virginia's stormwater rules, where nutrient credits can cover what a site can't treat. Send us the corridor or project location and the impacts by watershed, and we'll confirm which of our banks can serve it. Request pricing or call (540) 251-1321.
