The process is defined by Ohio law. It is basically of opposite of an area being annexed. There are 3 sets of documents that need to be submitted to the county.
A surrey plat from the recorders office.
A list of the lots that will leave the city.
A petition of 51% of the land owners requesting to leave.
Once this is done, the city and the township will work out a formula to share property taxes to pay for any improvements in the area that is leaving the city. In our area, that would be the costs of upgrading the storm drains a few years back.
Who leaves and who stays is up to the people. Everyone east of Plainville Rd can leave, or only the people in odd numbered houses on Palmetto between Kenmore and Berwick can leave.
The issue to think about is the long term future. Is the city going to raise income taxes? Is the city going to implement an inheritance tax (Mariemont has one)? Will my property be more attractive to buyers if it’s in the city or township?
