If the event requires police department staffing due to road closures or site security, police department personnel will be required. The sponsor of the event shall be required to prepay the estimated costs of providing the officers prior to the issuance of the event permit. The personnel fees will be calculated by determining the number of police officers who will be required, the number of hours the officers will be on duty, and the city’s full cost of providing the officers on an hourly basis. If the actual cost to the city of providing the officers on the day of the event exceeds the sponsor’s deposit, the sponsor shall be billed for the difference.