Rodney Porter wears a top hat indicating his stance on rejecting Central Maine Power's proposed hydropower transmission corridor, during an election night party, Tuesday, Nov. 2, 2021, in Farmington, Maine. Credit: Robert F. Bukaty / AP

The five-year battle over the $1 billion hydropower corridor through western Maine will reach a critical juncture Monday, when jurors will consider key questions about the project’s timeline.

Here are the key dates that got the project, formally known as the New England Clean Energy Connect, to this point.

Feb. 16, 2018: Avangrid and its subsidiary, Central Maine Power Co., won the bid from Massachusetts for their $950 million joint project with Hydro-Quebec to bring 1,200 megawatts of transmission capacity through a 145-mile transmission line from the Canadian border to Lewiston. CMP submitted applications for all state and federal permits in mid-2017.

May 3, 2019: A Maine Public Utilities Commission order granted a major permit for the project alongside a $250 million benefit package including rate relief for Mainers that clinched the support of Gov. Janet Mills. The ruling came 20 months after regulators began work on the case.

Jan. 8, 2020: Maine’s Land Use Planning Commission issued a certificate approving CMP’s New England Clean Energy Connect project.

May 11, 2020: The Maine Department of Environmental protection approved a permit for the project.

Sept. 16, 2020: Opponents of the project launched a second referendum bid to stop it. An earlier attempt at a referendum was ruled unconstitutional by the high court in August 2020.

Nov. 4, 2020: The Army Corps of Engineers granted a permit for the project.

Jan. 15, 2021: The U.S. Department  of Energy issued a final major permit for the NECEC project to allow construction into Quebec. Additional local permits by towns and cities may be required.

Feb. 9, 2021: The first pole of the project was hoisted near Moxie Pond in West Forks.

Feb. 22, 2021: The anti-corridor referendum received enough signatures to make the November ballot.

Nov. 2, 2021: Maine voters supported the anti-corridor referendum by a 60 percent margin.

Nov. 3, 2021: The corridor’s parent company filed a lawsuit challenging the constitutionality of a part of the referendum that would ban the project retroactively, something that was a main focus of the pro-corridor side’s campaign.

Nov. 19, 2021: Mills asked NECEC Transmission to stop construction until the Maine Business and Consumer Court ruled on its request to temporarily prevent enforcement of the referendum. NECEC had restarted work on the corridor the day after the referendum vote.

Nov. 23, 2021: The Maine Department of Environmental Protection suspended its project permit after a hearing the previous day, saying the referendum constituted a major change in circumstances.

Nov. 29, 2021: Maine’s Supreme Judicial Court ruled a lease covering about 1 acre of public land crucial to the project in rural Somerset County was granted lawfully by the Mills administration.

Dec. 16, 2021: The Maine Business and Consumer Court denied NECEC Transmission’s request to stop the anti-corridor law from taking effect.

Dec. 19, 2021: The new law created by the referendum took effect.

Dec. 22, 2021: NECEC Transmission asked for the case to be moved to the Maine Supreme Judicial Court, which it was on Dec. 28, 2021.

Aug. 30, 2022: Maine’s Supreme Judicial Court ruled that part of the referendum blocking the corridor project was unconstitutional and infringed on NECEC Transmission’s rights to build the project. The Law Court sent the case to the Business and Consumer Court to decide whether NECEC Transmission had built enough of the project in good faith to give it “vested rights” to continue.

April 10, 2023: Jury selection and opening arguments in the case are scheduled in the Business and Consumer Court in Portland. The project remains stopped pending the court’s decision.

Lori Valigra, senior reporter for economy and business, holds an M.S. in journalism from Boston University. She was a Knight journalism fellow at M.I.T. and has extensive international reporting experience...