PORTLAND – Restrictions on houseboats in Portland Harbor could take effect later this month as local officials move to address an apparent increase in demand for houseboat moorings.

A regulation unanimously approved by the Board of Harbor Commissioners would bar houseboats and floating businesses from anchoring or mooring in open water. Instead, they would be restricted to established marinas and be required to have sewer, water and power connections.

With waterfront property at a premium and recreational boating on the rise, harbor officials say demand for houseboat moorings has increased. Last summer, one man wanted to lease several moorings for houseboats he planned to build and rent as vacation homes. Another wanted to relocate a houseboat from Portsmouth, N.H., which consisted of a three-story house on a 100-foot barge.

Portland is not alone in addressing the houseboat issue.

Boothbay Harbor and Harpswell have had houseboat restrictions for years. Harbor officials in Falmouth, Long Island, Freeport, Cumberland and Yarmouth are considering similar regulations.

The Portland Harbor proposal will be aired Monday before the Portland City Council and will take effect Dec. 29 unless councilors object. The South Portland City Council already reviewed the regulation and took no further action.

“Our primary concern was safety,” said Richard Ingalls, chairman of the Board of Harbor Commissioners.

Ingalls said safety concerns ranged from the seaworthiness of homemade houseboats to the potential danger of having houseboats moored in open waters. “Some people build a shack on a raft and call it a houseboat,” said Eric Pearce, harbor master for Portland and South Portland.

Commissioners also considered the high demand for harbor moorings, the environmental impact of houseboats and the aesthetics of having a colony of houseboats in the harbor.

“As a native Mainer, I would rather not see a coastline cluttered with a thousand houseboats,” said Charles Lane, Portland’s attorney to the harbor commission.

Last year, Curtis VanBrocklin of Portland applied for 20 moorings at Fort Gorges, near Little Diamond Island, because he wanted to start a houseboat rental business. VanBrocklin said his houseboat is safe and should be treated the same as any other boat. Pearce said no mooring field has ever been located at Fort Gorges because it’s considered a rocky, dangerous area to anchor boats.