Cedar Swamp Road runs north out of Jericho as Route 107. It passes through Brookville, Upper Brookville and Old Brookville before it bends toward Glen Head. In the state's paperwork, that 4.7-mile stretch now has a second name: part of Segment 4 of the Propel NY Energy project, a new 345-kilovolt underground transmission line that will be buried in the road.
On September 17, 2026, the New York State Public Service Commission adopted the project's Joint Proposal and granted a conditional Article VII certificate. Most coverage treated that as the moment the project was "approved." For a buyer weighing a house on or near Route 107, the approval answered where the line goes. It left open the question a buyer actually needs answered: in which years the trenching reaches this part of the road.
Two Lines, One Road
The Brookville area sits where two of the project's six segments meet. The Joint Proposal's project description sets out both routes, road by road.
| Segment 4: Ruland Road to Shore Road | Segment 5: Syosset to Shore Road | |
|---|---|---|
| Voltage | 345 kV | 138 kV |
| Total length | About 18 miles | About 10.9 miles |
| Starts at | A new Ruland Road substation in Melville | LIPA's existing Syosset substation |
| Local roads | Jericho Turnpike, Old Jericho Turnpike, Old Cedar Swamp Road, then 4.7 miles of Cedar Swamp Road | South Woods Road, Cold Spring Road, Muttontown Eastwood Road, Route 106, then 3.2 miles of Northern Boulevard |
| Villages crossed | Brookville, Upper Brookville, Old Brookville | Muttontown, Upper Brookville, Old Brookville |
The two routes join at Cedar Swamp Road. According to the project description, Segments 4 and 5 will both be installed in Cedar Swamp Road and Glen Head Road between Northern Boulevard and Glen Cove Avenue. From there they head to a new substation on Shore Road in Glenwood Landing. On that northern stretch, which runs through Old Brookville toward Glen Head, two separate cables are scheduled to go under the same pavement.
When crews reach any of these roads depends on how the state authorizes construction.
Why the Certificate Is Not a Construction Schedule
The certificate approves the project as a whole. Digging is authorized separately, one phase at a time, through filings called Environmental Management and Construction Plans, or EM&CPs. The Commission's September 17 order states that the Phase 1 and Phase 2 EM&CPs were still under review and needed Commission authorization before construction could begin. It also requires a Notice to Proceed and a pre-construction meeting at least 14 days before work starts.
Appendix C of the Joint Proposal sets out what each phase is expected to cover:
- Phase 1: vegetation clearing and station work at the new Barrett, Shore Road and Ruland Road substations and the transition station in New Rochelle.
- Phase 2: limited portions of Segment 6, the Shore Road to Sprain Brook crossing, including the landfall drilling sites in Nassau and Westchester.
- Later phases: the terrestrial cable segments, including Segment 4 and Segment 5, followed by the submarine portion under Long Island Sound.
So the two plans the Commission was reviewing this fall cover substations and the harbor landfall. Neither covers Cedar Swamp Road. The plan that sets out how crews will work on Route 107 through Brookville belongs to a later phase, which has to go through its own filing and review. Propel's construction schedule page still lists its detailed schedule as "coming soon." Its Town of Oyster Bay page describes phased construction from late 2026 through 2030.
At the state level, the project is largely settled. For a buyer, what matters is which part of a four-year construction window lands on the road in front of a particular house.
Approved, Then Challenged
The approval has also faced steady challenges since it was issued.
On October 2, the Department of Public Service issued the project's water-quality certification, which the federal Clean Water Act requires. On October 19 it withdrew it. Newsday reported that Jason Zehr, interim executive director of the department's Office of Renewable Energy Siting and Electric Transmission, wrote in a filing, "I hereby rescind the certification." The department later described the step as administrative, because the application "had not been filed on the public docket for the project."
According to the Long Island Herald, the withdrawal followed objections from the Village of Sea Cliff. The village's administrator, Bruce Kennedy, raised concerns about disturbance of the harbor bottom and shellfish habitat in Hempstead Harbor. Propel spokeswoman Marykate Guilfoyle told the Herald the rescission was "purely an administrative activity." She said Propel had resubmitted its application and would keep advancing permits in order to begin construction later this year.
Several parties have also asked the Commission to rehear its September 17 order:
- The Village of Sea Cliff, which filed on October 15
- The North Shore, Roslyn and Syosset school districts, in a joint petition that also asks for a stay of the order while it is considered
- Iroquois Gas Transmission System
- The Property Owners' Association of North Shore Acres, whose petition argues that key construction details have been "deferred to later Environmental Management and Construction Plan phases"
That last argument is the same timing gap a Brookville buyer faces, raised in a formal filing. Under the Commission's own process, the details that matter most for any one stretch of road are settled late.
What the Work Looks Like When It Arrives
The certificate conditions already describe what a street will be like once its phase is authorized, even though the dates are not set.
According to the project description, most of the land-based cable will go in through open-cut trenches with concrete-encased conduit. Trenchless methods are reserved for selected crossings. Splice vaults are generally spaced about 2,000 feet apart. On a 4.7-mile run of Cedar Swamp Road, that works out to roughly a dozen vault locations.
The Commission's order sets the ground rules for that work:
- Hours: Construction is generally limited to daytime. Nighttime work is allowed when necessary or in non-residential areas, with at least 24 hours' notice to affected municipalities, adjacent landowners and businesses, except in specified circumstances.
- Near schools: Within 300 feet of a school building, work is limited to four hours a day while school is in session.
- Access: Crews must keep pedestrian and vehicle use continuous except where safety requires otherwise, notify municipalities, schools and businesses of upcoming schedules, and restore residential access within 15 minutes of a good-faith request.
The 15-minute access rule matters most for houses whose only driveway opens onto Route 107. A trench across the apron is a real possibility for some stretch of the work, and this condition limits how long it can block the way in or out.
Reading the Timeline From a Closing Date
Propel says it still intends to begin construction later this year. In September, Long Island Business News reported that site work could begin in late 2026, with further construction expected in mid-2027 once remaining approvals are in place, and completion targeted for 2030. Put those dates next to the phase sequence and the early work goes to substations and the harbor landfall. The road segments come after.
Take a buyer who goes into contract on a Route 107 house this winter. That buyer is probably moving in before Cedar Swamp Road's construction plan has been filed, and living there through whichever stretch of 2027 to 2030 that plan sets. A buyer on a side street a few hundred yards away is in a different position. That household might deal with detours and nothing more. The difference between those two houses is real, but no listing shows it, and the plan that will define it has not been written.
For buyers comparing Brookville with Upper Brookville or Muttontown, the routes in the table above show which frontages are affected. Most homes in all three villages sit on roads the project never touches.
Quick Questions
Is Cedar Swamp Road the only Brookville-area road on the route? No. Before reaching Cedar Swamp Road, Segment 4 runs along Jericho Turnpike, Old Jericho Turnpike and Old Cedar Swamp Road in Jericho. Segment 5 joins Route 107 from Northern Boulevard.
Where can I follow the filings? Everything is filed under Case 24-T-0446 on the Public Service Commission's document system. Background on the September approval is in the Department of Public Service announcement.
Who answers questions about a specific address? Propel lists a toll-free project line, 1-800-347-9071, and an email address, [email protected], on its contact page.
This post is general information about a public regulatory process, not legal or financial advice. If the project could affect a purchase you're considering, confirm the details with your attorney.
When I value a house on Route 107, I look at the construction phase covering the road out front as well as the comps. If you're weighing a home along the Propel route and want to factor that window into your offer, Patricia Santella can help. Request Your Personalized Market Plan.