This standard provides guidelines for planning, designing, and constructing engineered buildings in flood-prone areas to mitigate flood damage. It details methods for determining flood loads like hydrostatic, hydrodynamic, and debris impact forces, and provides design strategies such as 'dry proofing' and 'wet proofing' and foundation considerations.
Provides guidelines for flood resistant construction practices for engineered buildings.
Quick Reference Values
Minimum freeboard above Design Flood Level (DFL)0.3 m
Factor of safety against buoyancy (uplift)1.1 (Dead Load / Buoyancy Force)
Unit weight of water (assumed)9.81 kN/m³
Design debris impact load from a log (450kg at 3m/s)4.5 kN (concentrated load)
Maximum flow velocity to consider dry flood proofing1.5 m/s
Key Formulas
Hydrodynamic Drag Force: Fd = 0.5 * Cd * ρ * V² * A
Hydrostatic Force (per unit width): Fh = 0.5 * γw * h²
Buoyancy Force: Fb = γw * Vd
Practical Notes
Accurately determining the Design Flood Level (DFL) is the most critical first step; all other design parameters depend on it.
Choose between 'wet proofing' (allowing water in and using durable materials below DFL) and 'dry proofing' (making the structure watertight). Dry proofing is only suitable for low flood depths and velocities.
Do not neglect foundation design for scour. Floodwaters can erode soil from around footings, leading to catastrophic failure even if the building itself resists water pressure.