Who should pay for new sewers or for fixing the streets? Cities usually pay part of the bill with general tax dollars (that is, everyone pays for it), and requires the nearby property owners to pay the rest through “special assessments”.
The maximum amount any property owner can be charged is based on a formula: First, what was the fair market value of that property before the work was done? That is, how much could that property have been sold for then? Second, what is the fair market value of that property now, with the new sewer or street? The amount that the property value went up is the maximum amount that property owner should pay in special assessments.
Cities never use this formula. They make up their own formulas, which means that some property owners may be billed more than is legal. When that happens, those property owners have the right to appeal their special assessments to court.