A Development Permit is required for any manmade change to the regulated flood hazard area.  This includes alterations to the landscape (such as filling or excavating), erection of above grade structures that will obstruct flood flows (such as fences, pools), in addition to constructing new buildings, or adding additions to existing buildings.  Improvements to existing structures also require a permit.

The complexity and review time for a development permit will depend on the amount of work proposed, whether the work is in the flood fringe or the floodway, and whether a Hydraulic and Hydrological (H&H) study is required.