Minimum lot size requirements for new parcels in Harrisonville should be doubled, say Mackinac Island Master Plan Committee members, who want to reducing density there to relieve the burden on the city’s wastewater treatment plant and increase lot sizes to accommodate septic systems.

New lots plotted in Harrisonville will have to be at least 10,000 square feet in size, committee members say, agreeing to recommend the change during a Tuesday, August 24 meeting. The change would not apply to current lots, which would be grandfathered under the city’s current regulations that set the minimum size for a lot at 5,000 square feet.

The proposed zoning change would apply to future plotted lots, subdivided lots, and spit lots, say committee members, and would be a move toward controlling future population density in that area.

The proposed zoning change will need approval from three more city committees on its way to adoption. The Ordinance Committee will review the recommendation and, if it is in agreement, the change will be sent to the Planning Commission, which will hold a public hearing before the City Council makes a final decision.

“Given state regulations as they apply to septic and its required space, we just have to state boldly that we are locked into this 10,000-foot size,” said Alderman Mike Hart, who chairs the committee.

City attorney Tom Evashevski pointed out that In a revised Master Plan, density will likely be curtailed so as not to overload the city’s water and sewer infrastructure, suggesting that the city has no plans to enlarge its treatment facilities in the future. Harrisonville, however, which is mostly on septic systems, has liberal density allowances.

The inconsistency was brought to light by consultant Connie Dimond of JJR in Ann Arbor, who was hired more than four years ago to work with the city to update the Master Plan. She pointed out that sewer systems typically will allow a higher density of people where as septic systems usually limit the density.

Harrisonville residents asked not to be included in the city’s sewerage system when it was first constructed, and, except for some employee housing which is attached to a private sewer main installed by Grand Hotel for its Woodville housing, most homes use septic systems. If the state requires Harrisonville homes to tap into the city sewer system, the sewer plant could not handle the additional capacity without a major expansion.

“By not reducing density where we have septic systems,” said Mr. Evashevski, “you might describe it as kind of a time bomb because I think a lot of us feel that, in time, the state is going to say, ‘no more septics, you have got to hook up.’ And it really is inconsistent with our overall plan to not reduce density in Harrisonville.”

Harrisonville has the potential to double in population under current zoning.

“If you did have sewer up there and we left the 5,000 square foot as minimum lot size, and that’s not a very big lot, then you could be looking, by our current zoning, at two dwelling units per lot,” said Dennis Dombroski, city zoning administrator. “So that would essentially, for all practical purposes, double Harrisonville.”

If the city continues to treat Harrisonville inconsistently, said Mr. Evashevski, then the Master Plan needs a statement that rationalizes the city’s stand and could have trouble defending zoning if the inconsistency continues.

“I don’t think there should be a rationale,” he said, “if we are striving for consistency. If, for whatever reason, we decide we are going to treat Harrisonville differently by not proposing reduced density, we had better have an explanation as to why.”

Mr. Hart said Harrisonville was allowed smaller lot sizes to allow homeowners to split their lots so their children would have a place to build homes. Higher density also allowed for the establishment of dormitories and other high-density employee housing units, an issue that raised strong protests from residents there.

“We all want to provide for our children,” said committee member Barb Fisher, “but then we have to think about other ways of going about that. So if this [lot size] is for the sake of residential, I think some residents have to learn to accept what they have and what the rules are. If we are doing this for the sake of employee housing, then stop it. We have enough up there and we don’t need any more.”

To be compatible with state law, said Mr. Hart, the city has to impose a minimum 10,000 square foot lot size.

“It rules out lot splitting above that,” he said. “It is just as simple as that.”

The committee did not establish its next meeting date.