KENNEBUNKPORT — After years of uncertainty over an effort to reconstruct a historic tidal grist mill that once stood in Kennebunkport, the Planning Board finally voted to approve the application by the Kennebunkport Conservation Trust in a 4-1 vote.

The grist mill stood on Mill Lane in Kennebunkport, a short distance from Dock Square, since the 18th century until it burned down in 1994. The Kennebunkport Conservation Trust acquired the one-and-a-half acres of land it once stood on, which included the Clement Clark Boathouse, which the trust had used to give tours to children at local schools about the early history of Kennebunkport.

In 2010, the trust began to consider reconstructing the mill, and applied for permits from state and federal agencies to rebuild within the shoreland zone. As a mill powered by the ebb and flow of the ocean and used for grinding grain, it would be the only tidal mill in North America, according to a tidal mill expert invited by the Conservation Trust. Originally, the trust brought a further-reaching proposal to the Planning Board, including additional buildings. However, these were stripped away, and the current proposal only includes building within the original 800 square feet.

A group of abutters opposed to the project argued that when the property was originally permitted by the town in 2011, it was used for storage, and that this therefore would not fall under what the ordinance considered a museum, among other concerns about the noise level and overall character of the neighborhood.

The Planning Board sought legal assistance from Town Attorney Amy Tchao at a meeting in July. Tchao wrote a letter indicating that the central issue the board needed to decide was whether the Clement Clark Boathouse was being used as a museum, as defined by Kennebunkport’s ordinance, after 2011. This would allow the Conservation Trust to construct the mill as an “accessory structure.”

Under Kennebunkport’s land use ordinance, a museum is defined as “a nonprofit institution operated principally for the purpose of preserving and exhibiting objects of historical, cultural, scientific or artistic interest and which may also engage in incidental retail sales of items related to its principal purpose.”

The lone dissenter on the Planning Board, John Hathaway, found that the Trust’s use of the property did not meet that definition.

“I think this is a very intriguing project; I’m sure it will be well done … but I don’t see how this constitutes a museum,” Hathaway said. “I think a year ago a statement was made that this was used as storage,” referring to the land trust’s previous application. He also disagreed with the assertion that the grist mill would not be a manufacturing or commercial use.

“If people were in their home knitting sweaters and inviting the public … it well could be a manufacturing use,” Hathaway said. “I’m saying theres a line … a fine line.”

Gregory W. Reid, the vice-chair of the Planning Board, disagreed with Hathaway, saying that the ordinance’s definition would apply.

“My problem is … I think the definition of a museum is so vague I don’t see how it allows to not say it is at this point.”

After two and a half hours of discussion about various conditions of the approval – that no amplified music will be allowed, nor will buses, or events outside of normal museum hours – a subdued Planning Board voted and adjourned.

John Bannon, an attorney who represents a group of abutters opposed to the project, asserted that the use of the structure does not dictate whether it is permitted in a July interview. He told the Journal Tribune that no decisions had been made by the abutters yet on how to proceed.