For the purpose of promoting health, safety, prosperity and general welfare, as well as for the purpose of securing coordinated plans for roads, airways, railways, public buildings, parks, playgrounds, civic centers, airports, commercial, industrial and residential developments, water supplies, sewers and sewage disposal, drainage and other improvements and utilities (excepting, however, privately owned public utilities engaged in furnishing light, heat, power, transportation or communication by telephone or by telegraph or otherwise, as to which the provisions of this chapter shall not apply) in that portion of Kent County which is not included within the corporate limits of any city or town, unless any territory within such corporate limits is included upon request made by the governing body of authority of any such city or town, and as well as for the purpose of preventing the unnecessary duplication of such improvements or utilities, a department known as the Regional Planning Commission of Kent County is created for the area to be known as the Regional Planning District of Kent County.