The executive and administrative powers, authority and duties of the city, not otherwise provided for, shall be distributed among and assigned to five departments as follows:
1. Department of public affairs.
2. Department of finance.
3. Department of public works.
4. Department of public safety.
5. Department of supplies.
The department of public affairs shall be under the supervision of the mayor, subject to the provisions of this Charter, and each of the other departments shall be under the supervision of one of the other councilpersons, according and subject to the provisions of this Charter.