Nonstructural Measures

Flood risk is a combination of two components; the chance (or probability) of a particular flood event and the impact (or consequence) that the flood would cause if it occurred.  Flood damage reduction measures can either reduce the chance of flooding or the impact of flooding.  Structural measures such as dams, levees, and floodwalls alter the characteristics of the flood and reduce the probability of flooding in the location of interest.  Nonstructural measures alter the impact or consequences of flooding and have little to no impact of the characteristics of flood.

Nonstructural Flood Proofing measures include:

The following initial assessment tool provides a quick reference for comparing the applicability of different flood damage reduction measures including structural and nonstructural measures:
Flood_Damage_Reduction_Measures_Matrix.pdf

 

A brief presentation of the different Nonstructural Measures is provided below.  Detailed discussion on each of these types of Nonstructural Measures can be found in the Publications and Guidance sections of this website. 

elevation Elevation involves raising the buildings in place so that the structure sees a reduction in frequency and/or depth of flooding during high-water events.  Elevation can be done on fill, foundation walls, piers, piles, posts or columns. Selection of proper elevation method depends on flood characteristics such as flood depth or velocity.
Relocation Relocation involves moving the structure to another location away from flood hazards.  Relocation is the most dependable method of protection and provides the benefit of use of the evacuated floodplain.
Buyout  Buyout/Acquisition involves  purchase and elimination of flood damageable structures, allowing for inhabitants to relocate to locations away from flood hazards. 
Dry Flood Proofing Dry Flood Proofing involves sealing building walls with waterproofing compounds, impermeable sheeting, or other materials to prevent the entry of floodwaters into damageable structures.  Dry flood proofing is applicable in areas of shallow, low velocity flooding.
Wet Flood Proofing Wet Flood Proofing measures allows floodwater to enter the structure, vulnerable items such as utilities appliances and furnaces are relocated or waterproofed to higher locations.  By allowing floodwater to enter the structure hydrostatic forces on the inside and outside of the structure can be equalized reducing the risk of structural damage.
Berms or Floodwalls Local Levees and/or Floodwalls are freestanding structures located away from the building that prevent the encroachment of floodwaters. 
Flood Warnings  Flood Warning Systems alert inhabitants in flood prone areas of impending high water.  Depending on the type of warning system and advance time inhabitants have the opportunity to evacuate damageable property and themselves from the flood prone area.
NFIP  Flood Insurance provides insurance to assist in recovery from a flood event