Once an optimal fund has been achieved then it is a recommended practice that government's establish a budget that will maintain the fund balance.
The GFOA states that the minimum fund balance should be "no less than two months of regular general fund operating revenues or regular general fund operating expenditures."
Strongly recommended that the county establish a minimum fund balance in the debt service funds of at least 6-13 months of expenditures.
GASB Statement requires a written adopted minimum fund balance policy if the county is maintaining a minimum fund balance.
Over-estimating revenues and under-estimating expenditures will jeopardize the financial condition of the local government.
If your county has gone through reappraisal confirm with the property assessor on the value of the penny and the certified tax rate. Also, confirm with the trustee on the percentage of prior year collections