Hartland Community Enrichment Organization

Hello everyone. I just bought a property that is in a flood zone and when I went to the town office to pay the back two year taxes on the property the town manager said that the most I could do with the property was to park a camper on it. Previous to the foreclosure the property had been run as a resturant. The owner died and the property went into foreclosure. I was then told the property had lost it's grandfather status and the property could not be used. Does the COE or town have to notify the property owner of the property losing it's grandfather status and can a town tax a property at the commercial rate for the back two years if they are calling it a vacant lot or unusable property? Thanks for any info.