Behind-the-scenes Metropolitan Council communications with local officials and others are fair game in a lawsuit claiming the agency prematurely locked in a route for the Southwest light-rail line, a federal magistrate ruled Monday.

The oral ruling was a victory for the Lakes and Parks Alliance (LPA), a group of opponents of the line's path through western Minneapolis who sued the Met Council in 2014. The regional planning agency sought to block the LPA's request for a wide range of communiqués, including Met Council correspondence with City Council members, local government employees and prospective contractors about the project.

"This is what we wanted, and we were pleased that the court granted it," said Lewis Remele, an attorney for the LPA. The ruling remains subject to appeal.

The proposed $1.77 billion Southwest light rail would travel from downtown Minneapolis to the western suburbs, hitting St. Louis Park, Hopkins, Minnetonka and Eden Prairie. It is expected to open in 2020.

The lawsuit centers on the controversial combination of Southwest light rail, freight traffic and recreational trail users in the Kenilworth corridor near the Chain of Lakes, the routing preferred by the Met Council. Squeezing the three modes together there requires building a series of new tunnels and bridges in the wooded area.

The plaintiffs claim the Met Council improperly limited itself to that alignment, rather than remaining open to other alternatives, before completing the full environmental review process. The council says it is following processes outlined in state and federal law and has not prematurely closed the door on future changes.

The final environmental review for the project, now in a draft stage, is due to be released this summer.

"We want to know what the discussions have been, what the negotiations have been and the process that led to this determination of the tunnel route," Remele told U.S. Magistrate Judge Steven Rau.

Remele said in an interview that the correspondence they are seeking could help show, for example, that the Met Council made what amounted to a binding promise to stop considering moving freight rail traffic from the Kenilworth corridor to St. Louis Park. Moving that freight traffic was a component of several alternative routes originally studied, including two that ran light rail through the Kenilworth corridor without tunnels.

St. Louis Park approved early Southwest plans in 2014 with the written understanding that freight relocation would no longer be studied, "except as required for any continuing environmental review."

"In that agreement, it seems to suggest the Met Council is promising St. Louis Park that that issue will never be revisited," Remele said. "And they try to waffle out of that now on the idea that the agreement isn't binding. But we suspect that we might find some e-mails that might say otherwise."

The Met Council filed for a protective order to shield it from providing the documents requested by LPA, saying it would be "unfair, inefficient and unnecessary." Attorneys for the agency argued that the suit should instead be based on records released after the final environmental review is complete.

"We believe [the administrative record] will clearly support that reasonable alternatives were analyzed," said attorney Charles Nauen, representing the Met Council.

"There's not even a final decision about the project," Nauen added, citing significant changes to the Southwest route this summer due to rising costs.

Much of Monday's discussion Monday related to an order this August from Judge John Tunheim, which declined early judgment in the case in the expectation it would become more appropriate once "the record is more adequately developed."

Rau said in his decision Monday that LPA is seeking the information Tunheim needed to make a judgment in the case. He gave Met Council 15 days to respond, following any appeal.

Southwest project spokeswoman Laura Baenen said Monday that they had not yet seen the order. "We will have to review and assess our options," Baenen wrote in an e-mail.

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