A Maine judge vacated a 1-mile lease of state public land to Central Maine Power (CMP) on Tuesday, threatening the entire 145-mile New England Clean Energy Connect (NECEC) transmission corridor through the western side of the state.

The Maine Superior Court ruled that state park land, along with other land owned by the state for conservation or recreation, cannot be “reduced” or its uses “substantially altered” unless the Maine legislature approves the changes with a two-thirds majority, according to the state constitution.

The judge also concluded that the Maine Bureau of Public Lands (BPL) did not provide notice to the legislature or the public of the lease contracts.

“Given the subject matter at issue here — constitutionally protected public lands — the need for transparency and public process is heightened,” the court wrote in its decision.

Environmental groups that oppose the transmission corridor argued in court that construction of the transmission line in the Upper Kennebec Region is destructive to the largest undeveloped forest east of the Mississippi River.

Many of the people involved in the opposition against the project work as river guides on the Moose and Upper Kennebec Rivers, which cross the rugged landscape threatened by different kinds of development over the last few years.

A large swath of trees will be cleared for the project, posing a barrier to wildlife crossings and affecting forestry operations in the area, Tom Saviello, a volunteer with the advocacy group No CMP Corridor, said in a phone interview with NetZero Insider.

The line would also cut between two ponds that hold 95% of the remaining native trout. Water runoff from the transmission construction could warm the water in the ponds, changing the ecosystem for the trout, Saviello said.

Thorn Dickinson, head of NECEC Transmission, issued a statement saying the company is “reviewing the Superior Court’s decision to determine our next steps on the matter.”

CMP currently holds the lease of public land but is transferring it to NECEC Transmission. Both companies are owned by Avangrid (NYSE: AGR).

The $1 billion NECEC project is intended largely for the benefit of Massachusetts residents, who are paying for the construction of the 1-mile, 300-ft wide corridor.

November Vote

The NECEC project faces an even greater risk in November, when Maine residents vote on whether to approve three new potential requirements for transmission line construction in the state that would effectively halt the hydroelectric energy transmission line.

The Maine legislature would have to approve the construction of any high-impact electric transmission lines under the potential requirements by a two-thirds majority, according to a report by independent research firm ClearView Energy Partners. Second, the legislature would have to approve any use of public lands for transmission lines and related facilities. The state would also entirely prohibit the construction of high-impact electric transmission lines in the Upper Kennebec Region.

The mandates would be retroactive to 2014, including the NECEC transmission line.

CMP can appeal the ruling that vacates the lease, but it is not likely a higher court would rule differently if the state constitution requires two-thirds approval from the legislature. 

The BPL could also issue a determination that the lease does not reduce or substantially alter the public land in question, but opponents could still challenge the lease and the determination, the report said. 

CMP will “have no choice but to negotiate the terms of this public lease in an open and transparent way,” Saviello said.