The executive and administrative powers, authorities and duties in such cities shall be distributed among departments as follows:
(1) Department of public affairs,
(2) department of accounts and finances,
(3) department of police, sanitation and public safety,
(4) department of fire protection and water supply,
(5) department of street cleaning and maintenance,
(6) department of public improvements, and
(7) department of parks and public property. The council shall determine the powers and duties to be exercised and performed by, and assign them to, the appropriate departments. It may prescribe the powers and duties of all officers and employees of the city, and may assign particular officers or employees to more than one of the departments. It may require any officer or employee to perform duties in two or more of the departments, and may make such other rules and regulations as may be necessary or proper for the efficient and economical management of the business affairs of the city.