Does a 69% increase in assessed value mean my property taxes will increase 69%?

No.

A revaluation does not, by itself, generate additional property tax revenue for the City or other taxing jurisdictions. The revaluation changes how the tax base is valued and how the tax levy is distributed among properties.

Your final property tax bill will depend on the tax levies established by the various taxing jurisdictions—including the City, School District, Fond du Lac County, Technical College, and State—and your property's share of the overall tax base.