An appeals board has rescinded a permit for a $30 million expansion of a botanical garden in Maine months after work began.

The Bangor Daily News reports that the Boothbay Board of Appeals ruled Thursday in favor of property owners who border the Coastal Maine Botanical Gardens. They have argued the project will degrade the water quality of a nearby lake.

The board says the organization was classified as a museum, which is not allowed in the watershed.

The organization’s director of marketing, Kris Folsom, says they will return to court to “correct the Board of Appeals’ unfortunate error.”

The decision comes a week before the garden’s annual light show is set to start. They have cited the event’s crowds as a reason for the expansion.