Improperly
designed grading and inadequate drainage may aggravate flood hazards
to buildings and cause runoff, soil erosion, and sedimentation in the
zones of lower flood risk, the Interflood Zone, and the Non-Regulated
Flood Plain. In
these locations, local agencies may regulate building elevations above
street or sewer levels.
In
the next higher risk zones, the Special Flood Hazard Areas and the Non-Velocity
Coastal Flood Areas, the elevation of the lowest floor and its structural
members above the Base Flood Elevation is required.
In
the zone of highest flood risk, the Coastal High Hazard Areas, additional
structural requirements will apply.