Digging deeper: How Nature-based Solutions are powering the future of transmission line projects

Transmission lines are the backbone of economic growth and require vast corridors that often intersect with sensitive environments. As of 2024, over 27,000 miles of high-voltage transmission lines are under development across the U.S. through 2030 (ACP, BNEF). Each mile carries the potential for environmental impact, but also opportunity.

How do we expand the energy grid without sacrificing the health of wetlands, forests, streams, and the habitats of endangered species? This is where Nature-based Solutions (NbS) come in.

What are Nature-based Solutions?

NbS go beyond simply offsetting environmental damage. Instead, they use ecological science to build resilience and restore balance to the environment. By planting native vegetation, rehabilitating streams, and protecting habitats, NbS projects not only meet regulatory goals but also leave ecosystems healthier than before.

These solutions harness the power of nature to address environmental, community, and economic challenges sustainably. For example, restoring wetlands can help reduce flooding, planting trees can improve air quality, and protecting coastal habitats can shield communities from storm impacts. This is achieved by emulating natural processes instead of relying on built infrastructure. NbS are gaining recognition as cost-effective, long-lasting strategies. At the same time, they promote community well-being and support the long-term health of ecosystems, creating benefits that extend far beyond the environment itself.

Case Studies

Supporting Dominion’s transmission network in Virginia, West Virginia, and North Carolina 

For developers and EPCs working long linear corridors, the hardest part of the schedule isn't usually any single approval; it's keeping federal, state, and local agencies aligned across hundreds of miles of changing jurisdictional conditions. RES has been doing exactly that work for Dominion since 2008, across more than 500 miles of linear utility lines and three states with very different regulatory environments.

The work spans the full pre-construction stack: wetland delineation, Threatened and Endangered species surveys, erosion control planning, Stormwater Pollution Prevention Plans, and the federal and state permitting that ties them together. Doing all of it under a single program,  rather than spinning up new teams and methodologies project by project, is what allows Dominion to maintain consistent documentation standards across jurisdictions and avoid the resubmittal cycles that typically slow multi-state corridor work.

Dominion Transmission Lines, West Virginia

The largest single project in the program was the 96-mile rebuild of the Mt. Storm to Doubs 551 transmission line. A corridor of that length crosses dozens of stream and wetland features, multiple USACE district boundaries, and several state regulatory frameworks. RES coordinated USACE-approved wetland delineations, Clean Water Act permitting, rare species surveys, erosion control, and stormwater authorizations as a single integrated workstream, and all approvals were secured in time to keep construction on schedule.

Across 17 years and three states, the program has maintained consistent documentation standards and avoided the resubmittal cycles that typically slow multi-state corridor work, a consistency that's hard to assemble project by project but compounds when it's built into a long-running program. For Dominion, that means transmission schedules that hold across changing jurisdictional conditions and approvals that arrive when construction needs them.

Sensitive corridors in the Delaware Water Gap

The Susquehanna–Roseland Electric Reliability Project, located in Pennsylvania and New Jersey, required upgrades through the Delaware Water Gap National Recreation Area. With sensitive species, cultural sites, and invasive plant concerns, oversight was intensive. RES ensured permit compliance while coordinating with the National Park Service (NPS). Our work provided the client with confidence that construction could move forward without delays or violations, while maintaining positive relationships with regulators and the public.

Stream realignment at Lauschtown Substation

Stream realignment, if carefully designed, can deliver a net ecological gain rather than just minimize loss. When PPL Electric Utilities needed to build a substation in Pennsylvania, a stream had to be relocated. Rather than simply rerouting water, RES designed a functioning stream and wetland system with higher ecological function than before. This approach turned a regulatory requirement into an opportunity: by creating a stream and wetland system with greater ecological function, PPL Electric Utilities not only met compliance needs but also reduced long-term risk, enhanced resilience against flooding, and strengthened community and stakeholder relations.

Supporting renewable energy integration

Transmission development is critical to renewable energy expansion, and projects are more successful when NbS are built into permitting and construction. The following are examples of how ecological planning can benefit both biodiversity and project performance.

Projects that create biodiversity by establishing pollinator-friendly habitats and restoring ecosystems can deliver measurable benefits. At Prairie Wolf Solar in Illinois and Mammoth Solar North in Indiana, RES designed Vegetation and Soil Management Plans (VSMPs) that stabilized soils, reduced panel shading, and created pollinator-friendly habitats. These measures improved biodiversity while lowering maintenance costs and ensuring long-term site resilience.

The Mammoth Solar North project uniquely incorporates livestock grazing for vegetation management. The site features a mixed herd of sheep, alpacas, donkeys, and livestock guardian dogs. Sheep help manage vegetation, while alpacas and donkeys manage vegetation and also serve as guardian animals, protecting against ground and aerial predators.

Mammoth Solar North, Indiana

At Bingham Solar in Michigan, RES partnered with National Grid Renewables to integrate Monarch butterfly conservation into a large-scale solar project, streamlining regulatory approval while restoring valuable habitat.

Monarch butterfly

At the Pioneer Trail, Green River, and Jordan Creek wind projects, RES implemented mitigation strategies to protect endangered Indiana bats (IBAT) and Northern long-eared bats (NLEB), generating hundreds of conservation credits and securing long-term federal permits. Similarly, the Headwaters and Meadow Lake wind projects benefited from a full-delivery approach that provided mitigation credits, habitat restoration, and long-term stewardship, ensuring compliance while supporting species recovery.

Habitat protection for at-risk species

The Indiana Statewide Bat Conservation Bank and the Pennsylvania Bat Conservation Bank illustrate how habitat banking can support bat populations by preserving and enhancing critical roosting and foraging areas. In addition to these large initiatives, region-specific mitigation banks allow for targeted conservation that addresses local ecological needs. These are RES-operated banks, and species mitigation credits are available for purchase by permittees.

Habitat restoration can streamline regulatory approvals, reduce permitting delays, and build public trust. The Heidelberg Materials Habitat Conservation Plan and Wet-Mesic Dolomite Prairie Transplant and Lockport Prairie and Prairie Bluff Ecosystem Restoration projects in Illinois focused on restoring ecosystems vital to endangered species, including the federally protected Hine’s emerald dragonfly (HED), as well as state-listed species such as the Blanding’s turtle and the Spotted turtle.

Hine’s emerald dragonfly

The risk of overlooking ecological planning

When transmission projects move forward without long-term ecological planning, the challenges can add up quickly. Regulatory approvals may stall or fail to materialize, pushing back construction schedules and driving up costs through redesigns or fines for noncompliance. Overlooking habitat protection can also invite litigation, reputational damage, and weaken trust with local communities.

From an ecological perspective, the stakes are just as high. Losing wetlands, forests, or habitat for endangered species can lead to tighter oversight in the future and make it harder to advance new projects. This puts bottom lines, timelines, and the ability to meet tomorrow’s energy needs on the line.

Building smarter and restoring naturally

Success in tomorrow’s energy landscape belongs to those who plan smarter, work with nature, and see every mile of transmission not just as infrastructure, but as an opportunity to power communities and restore the environment. With thoughtful planning, power generation can be advanced while protecting and preserving natural resources. Science-led solutions can create long-term ecological value that supports resilient infrastructure, regulatory certainty, and community trust.

Ready to connect your next transmission project with the power of restoration?

Contact RES to learn more about how we can help you with your transmission line projects.