Delaware constitution
Article II
Section 25

The General Assembly may enact laws under which municipalities and the County of Sussex and the County of Kent and the County of New Castle may adopt zoning ordinances, laws or rules limiting and restricting to specified districts and regulating therein buildings and structures according to their construction and the nature and extent of their use, as well as the use to be made of land in such districts for other than agricultural purposes; and the exercise of such authority shall be deemed to be within the police power of the State.