Cutting for transmission lines for the New England Clean Energy Connect project off Enchanted Mountain Road near Jackman. Credit: Linda Coan O'Kresik / BDN

A Maine judge signaled Wednesday that he will rule this week on a request to let the builders of a $1 billion hydropower corridor resume construction before a new law goes into effect on Sunday that would stop the corridor.

District Court Judge Michael Duddy said he wished he had more time to review the request to halt enforcement of the anti-corridor referendum passed by voters in November, but he has only two business days to consider it before the new law goes into effect. However he rules, the case is likely headed to the Maine Supreme Judicial Court. The project was halted after a Maine regulator cited the referendum in suspending a key permit.

The corridor’s builders, NECEC Transmission LLC and Avangrid Networks Inc., filed a lawsuit requesting the injunction the day after Election Day, alleging the referendum was unconstitutional, violating legal principles that include vested property rights and separation of powers. Along with Central Maine Power Co., the two companies are subsidiaries of Avangrid Inc.

The plaintiffs told the judge during arguments on Wednesday that retroactively applying a law to the permitted project would harm investor trust in future projects. They want to prevent the Maine Public Utilities Commission and the Bureau of Public Lands from enforcing the new law, lawyer John Aromando told the court. The referendum bans high-voltage transmission projects in the upper Kennebec River region and requires more legislative approval for similar projects going forward.

At the heart of the arguments the judge must consider is a concept known as “vested rights,” in which NECEC and Avangrid would need to show they have been actively developing the project in good faith and thus should be allowed to proceed.

The companies have invested almost $450 million in the project so far, or about 43 percent of its total cost, Aromando said. They could finish tree-cutting by the end of the year if allowed to restart work, but they have only installed a small percentage of the poles, and the lines and converter station still need to be completed. He said that shows the companies have vested rights and proceeded with the project in good faith.

But a state attorney defending the law argued that CMP and its affiliates were not operating in good faith because the companies were aware of the referendum and knew there was a serious threat to the project but proceeded to build anyway.

Avangrid already was alerting its investors before construction started on the project earlier this year that the referendum was an issue, Assistant Attorney General Jonathan Bolton said. He also voiced concern about possibly interrupting state business by involving the Maine House and Senate in the preliminary injunction request.

The judge must now weigh when the corridor’s builders knew about the threat to the project and whether they acted in good faith as they kept building, or whether to allow the popular referendum to go into effect on Sunday.