The operational emergency management organization of the city shall consist of the officers and employees of the city so designated by the director in the emergency management plan, as well as all organized volunteer groups. The functions and duties of this organization shall be distributed among such officers and employees in accordance with the terms of the emergency management plan. Such plan shall set forth the form of the organization, establish and designate divisions and functions, assign tasks, duties and powers, and designate officers and employees to carry out the provisions of this chapter. Insofar as possible, the form of organization, titles and terminology shall conform to the recommendations of the state division of emergency management of the state of Texas and of the federal government. (1988 Code § 2-1-4)