§ 350. Department of public works. The head of the department of public works shall be the director of public works. In counties adopting the county manager form, the county director form and the county president form, the office of county superintendent of highways and of county engineer, if any, is abolished and the functions, powers and duties of the office shall devolve upon the department of public works. Nothing in this article contained shall be construed to impair the powers of the county superintendent of highways in counties adopting the county administrator form of government, and the county superintendent of highways of any such county shall continue to have and exercise the functions, powers and duties of his office as now or hereafter provided by law.