Unless otherwise provided by ordinance, the City shall continue to use, for the purpose of ad valorem municipal taxation, the County system of assessment and tax collection, as such system is now in effect or may hereafter be amended and insofar as such provisions are not in conflict with this Charter.
   If the City Council fails to fix the rate and levy taxes on or before August 31st in any year, the rate for the next preceding fiscal year shall thereupon be automatically adopted and a tax at such rate shall be deemed to have been levied on all taxable property in the City for the current fiscal year.