Unofficial results show the incorporation proposal failed by a 60 percent to 40 percent margin Tuesday.
Its defeat means the area will continue to operate as a township under the county council.
The proposed city of 63,500 people would have included the communities of Millcreek, East Millcreek, Canyon Rim and Olympus Cove.
Opponents say incorporation would have meant higher taxes and an unnecessary layer of new government, and the vote shows that most people in the township are pleased with the services they receive from the county.
Supporters say incorporation was needed to better control planning and zoning matters, and to keep fees and taxes in check.
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