US Army Corps of Engineers

National Nonstructural Committee (NNC)

Nonstructural measures are permanent or contingent measures applied to a structure and/or its contents that prevent or provide resistance to damage from flooding.  Nonstructural measures differ from Structural measures in that they focus on reducing the consequences of flooding instead of focusing on reducing the probability of flooding.

Nonstructural measures include:

  • Elevation
  • Relocation
  • Buyout / Acquisition
  • Dry flood proofing
  • Wet flood proofing

Nonphysical Nonstructural measures include:

  • Flood Warning Systems
  • Flood Insurance
  • Floodplain Mapping
  • Flood Emergency Preparedness Plans
  • Land Use Regulation
  • Zoning
  • Evacuation Plans
  • Risk Communication

The National Nonstructural Committee was founded in 1985 to promote the use of nonstructural methods.

National Flood Barrier Testing & Certification Program NNC Flood Damage Reduction Matrix NNC Structure Attribute Table
National Flood Barrier
Testing & Certification Program
Flood Damage 
Reduction Matrix

Attribute Table 

National Nonstructural Committee (NNC)

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During the early 1970's, the Flood Plain Management Services (FPMS) Program, under it's Guides, Pamphlets, and Supporting Studies element, was pursuing several flood proofing initiatives. Larry Flanagan, Chief FPMS in LMVD, was involved in residential flood proofing systems and in testing flood proofing materials at the Waterways Experiment Station (WES); Sam Cowan, Chief FPMS at SAD, was involved in developing a flood proofing primer and in documenting the elevating of a residence located along Peachtree Creek in Atlanta, GA; Herm Lardieri, Chief FPMS in Pittsburgh District, was involved in developing standards of flood proofing in buildings and related codes and in drafting EP 1165-2-314 Flood-Proofing Regulations; and Bob Hall, Chief FPMS in Los Angeles District, was seeking flood proofing techniques that would prevent sheet-flow flooding of  structures in California. As flood proofing activities continued to increase, it became evident that some means of coordination was needed.

An Ad-hoc Committee on Residential Flood Proofing was formed in May of 1978. It was chaired by Larry Flanagan with Sam Cowan, Herm Lardieri, and Bob Hall as members and Bob Plott as OCE Coordinator. It was dedicated to residential flood proofing and its activities were loosely coordinated. Much of its work and its accomplishments involved completing the work initiated by its individual members and avoiding overlap. The ad-hoc committee met twice, once in 1978 and once in 1979. In 1980, Bob Hall left the FPMS Program and the committee. In 1984, Larry Flanagan left the committee and Dr. Carl Pace was brought on board as a technical advisor for the work he and Larry were doing on testing flood proofing materials at WES. The committee's last effort was to acquire the materials that were used by headquarters to publish Flood Proofing Systems & Techniques - Examples of flood proofed structures in the United States.

It became evident that a means of coordinating and providing direction to future flood proofing activities under the FPMS Program was necessary. Hence, charter members were appointed on 20 September 1985 and on 8-9 October 1985 the initial meeting  of the U.S. Army Corps of Engineers National Flood Proofing Committee (NFPC) was held at SAD to finalize a Committee charter and to elect Committee officers.

The NFPC charter was ratified at headquarters by the Chief, Flood Plain Management Services and Coastal Resources Branch and signed by the Chief, Planning Division, Directorate of Civil Works, Office of the Chief of Engineers on 12 December 1985. It subsequently was revised in 1990, 1994, and 2006 primarily to increase the number of its members from the initial five to seven and then to nine.  Currently, there are seven members.

The National Nonstructural Flood Proofing Committee is celebrating 30 years of service to the nation in flood risk management.

The NNC functions under the general direction of the Chief, Planning Community of Practice, Directorate of Civil Works, HQUSACE. The objectives of the NNC are to:

  • Promote the development and use of all nonstructural flood risk reduction measures
  • Risk expertise on all aspects of nonstructural flood risk reduction and associated opportunities
  • Disseminate nonstructural flood reduction information
  • Partner with Planning Centers of Expertise in all aspects of nonstructural flood risk reduction and associated opportunities
  • Provide leadership in all aspects of floodplain management

NNC Charter: The current NNC Charter can be downloaded HERE.


Chief, Water Resource Systems Division
Hydrologic Engineering Center

Planner, New York District

Planner, Fort Worth District

Water Resource Certified Planner, New Orleans District

FRM Economist, New Orleans District

Hydraulic Engineer, New York District

Nonstructural Flood Risk Management

Nonstructural flood risk management measures are proven methods and techniques for reducing flood risk and flood damages by adapting to the natural characteristics of flooding within the floodplain. In addition to being very effective for both short and long term flood risk and flood damage reduction, nonstructural measures can be very cost effective when compared to other flood risk management techniques.

Risk = f [(Probability of Flooding) x (Consequences)]

Probability of Flooding is the frequency of flooding or how often does flooding occur in a particular location.

Consequences are the potential life loss or damages associated with flooding. Structures (residential, commercial, critical, public, and industrial), land use (agricultural, urban, public), and infrastructure (highways, roads, rail, utilities) are the potentially damageable assets. Reduce the consequences of flooding and risk is reduced. Nonstructural measures are invaluable wherein the goal is to reduce flood damages without modifying the characteristics of the flood event.

Nonstructural flood risk management can be categorized as a set of physical or nonphysical measures utilized for mitigating loss of life as well as existing and future flood damages. The physical measures determined to be most commonly implemented are those which adapt to the natural characteristics of the floodplain without adversely affecting or changing those natural flood characteristics. Because of their adaptive characteristics to flood risk, wherein these measures support the National Flood Insurance Program as administered by FEMA and generally cause no adverse affects to the floodplain, flood stages, velocities, or the environment, these measures may also be referred to as Flood Risk Adaptive Measures (FRAM) and can be incorporated into existing or new structures to mitigate for potential future flood damages.

The following initial assessment tool provides a quick reference for comparing the applicability of different flood damage reduction measures including Structural and Nonstructural Measures.


3-D View of Nonstructural Flood Risk Reduction


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TitleDescriptionPublication DateSorted By Publication Date In Descending Order

Planning Bulletin 2019-03: Further Clarification of Existing Policy for USACE Participation in Nonstructural Flood Risk Management and Coastal Storm Risk Management Measures 

The purpose of this planning bulletin is to provide further clarification on policy with respect to evaluation of nonstructural measures. This bulleting supplements Planning Bulletin 2016-01, Clarification of Existing Policy for USACE Participation in Nonstructural Flood Risk Management and Coastal Storm Risk, which is still in effect.12/13/2018
Planning Ahead Quarterly NewsletterA publication spotlighting Corps planners who help decision-makers identify water resources problems, conceive solutions to them and compare the importance of the inevitable conflicting values inherent in any solution.1/1/2018

National Nonstructural Committee

A factsheet about nonstructural flood proofing including definitions, techniques and authorities. 12/21/2016

FEMA P-312, Homeowner's Guide to Retrofitting (3rd Ed.)

Guide for homeowners who want to protect their homes from flooding regardless of experience with flood protection methods or building construction techniques.6/30/2014
FEMA P-936, Floodproofing Non-Residential BuildingsThe primary focus of the guidance document is on dry floodproofing technologies for non-residential buildings, but it also includes an overview of other techniques including wet floodproofing and the use of levees and floodwalls. The publication provides information about regulatory requirements, design considerations, and descriptions of floodproofing methods and equipment.7/31/2013
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Nonstructural Measures

The different Nonstructural Measures are described provided below. A detailed discussion on each of these types of Nonstructural Measures can be found among our Publications.
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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 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/Acquisition involves purchase and elimination of flood damageable structures, allowing for inhabitants to relocate to locations away from flood hazards.

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 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.

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.

Flood Insurance provides insurance to assist in recovery from a flood event

Floodplain Mapping is a nonphysical nonstructural measure identifies flood risk, whether in the form of a map which portrays flood boundaries, or as an inundation map illustrating the depth of flooding, this measure is a significant tool when addressing flood risk.

Flood Emergency Preparedness Plans Local officials are encouraged to develop and maintain a flood emergency preparedness plan (FEPP) that identifies hazards, risks and vulnerabilities, and encourages the development of local mitigation. The FEPP should include the community’s response to flooding, location of evacuation centers, evacuation routes, and flood recovery processes.

Land Use Regulations are effective tools in reducing flood risk and flood damage. The principles of these tools are based in the National Flood Insurance Program (NFIP) which requires minimum standards of floodplain regulation. 

Zoning is also beneficial in reducing flood risk. A community may determine that certain areas are too hazardous for human habitation and restrict development from occurring. Other areas may be determined to be risk free. This is a long-term investment tool for alleviating flood risk.

Evacuation Plans require detailed hydrologic analyses for determining the rate of rise of floodwaters for various rainfall or snowmelt events. When used in conjunction with flood warning systems, this measure can provide significant loss of life avoidance and flood damage reduction benefits. Evacuation planning should consider vertical evacuation as well as the traditional horizontal evacuation. This measures should only be implemented when there is signification response and action time available for floodplain occupants to evacuate. Rally points as well as evacuation routes should be thoughtfully planned and communicated to the public.

Risk Communication  develops and uses educational tools such as presentations, workshops, hand-outs, and pamphlets to communicated flood risk and flood risk reduction measures to government entities and floodplain occupants in an effort to reduce the consequences associated with flooding.

Contact the NNC

Lea Adams, P.E.
Chief, Water Resources Division
Hydrologic Engineering Center (HEC)
U.S. Army Corps of Engineers

609 2nd St
Davis, CA 95616

p: (530) 302-3729
f: (530) 756-8250