Ad valorem tax.

Annually an ad valorem tax of not exceeding 11/2 mills may be levied upon all property in the county, which shall be levied and collected as other county taxes are levied and collected. The taxes shall be charged to the general fund, but such revenue may be appropriated by the county for the cost of constructing, operating, maintaining, expanding, enlarging, improving, or developing any project or projects herein specified, or for the payment of the costs of removing and relocating any structures, installations, or facilities which in the opinion of the board of county commissioners may be required for the safe and efficient operation of any such projects. Said tax may be levied, collected, and expended for any of the purposes herein specified notwithstanding the cost and expense thereof which may have been incurred in a previous year, and when so collected and used the tax shall be considered to be levied, collected and used for a county purpose.