Areas subject to alluvial fan flooding have irregular flow paths that result in erosion of existing channels and the undermining of fill material. Those areas are identified on the flood insurance rate map (FIRM) as AO zones with velocities.
A. All structures must be securely anchored to minimize the impact of the flood and sediment damage.
B. All new construction and substantial improvements must be elevated on pilings, columns or armored fill so that the bottom lowest floor beam is elevated at or above the depth number.
C. Use of all fill materials must be armored to protect the material from the velocity of the flood flow.
D. All proposals for parcel map development and subdivision development must provide a mitigation plan that identifies the engineering methods used to:
1. Protect structures from erosion and scour caused by the velocity of the flood flow;
2. Capture or transport flood and sediment flow through the development to a safe point of disposition.
E. All mobile homes shall be prohibited within the identified hazard area except within existing mobile home parks. (Ord. 213A, 2010)