Flood Risk Management

Hazards, Performance and Condition, Benefits/Consequence Flood risk management (FRM) is one of USACE Civil Work’s three core missions, alongside support for commercial navigation and restoration of aquatic ecosystems. USACE’s FRM activities seek to reduce the threat to life and property from riverine and coastal storm flooding through the development and communication of advanced knowledge, technology, and solutions.

What is flood risk? Flood risk is a combination of the likelihood of a natural or man-made flood hazard happening and the consequences or impact if it occurred. Flood risk is dependent on a source of flooding (such as a river), a route for the flood water to take, and damages caused by the flood (such as damage to homes and businesses).  Managing flood risk starts with understanding the chance that certain hazards could occur and then identifying the corresponding magnitude of the potential outcome. If any flood risk management structures exist, such as a dam or levee, the performance of those structures also needs to be considered when determining flood risk. Although FRM structures provide some level of protection, they do not eliminate flood risks. Flooding can still occur in surrounding communities and watersheds even with flood risk management measures (structural and non-structural in place.

Understanding Flood Risks

Flooding in Hamburg, IA

Flooding in Hamburg, Iowa. 2019

FRM looks at the risks associated with potential flooding and is informed by previous storms or flood events. In addition to considering the past, FRM looks to the future through modeling and forecasting possible storms –examining the likelihood, severity, and magnitude of storms and flooding.  Assessing riverine and coastal storm flood risk helps communities better understand the loss of life and property that would result from different potential flooding situations.

USACE FRM Framework includes the following four components:

  • AWARENESS of potential risks associated with flooding events – Collaborate with communities to better understand their past experiences and concerns for future flooding.
  • ANALYSIS of flood risk – Conduct studies and investigations to better understand flood risks, such as where, when, and at what magnitude the flooding may occur and to identify the potential impacts to community safety and property.
  • ADDRESS flood risk – Work with community leaders to determine what risk-reducing actions are feasible and cost-effective. This could range from construction of structural, nonstructural, or nature-based projects to planning activities, such as developing evacuation plans.
  • ADJUST approach to operating and maintaining FRM structures – Monitor and re-evaluate operation of FRM structures due to changed conditions, as needed; renourish beaches, shorelines, and streambanks; or rehabilitate FRM structures to continue providing the intended protection from flood risk.

Working in the Nation's Interest

By the numbers USACE has planned, designed and constructedUSACE has helped mitigate flood impacts on riverine and coastal communities for nearly 100 years. Riverine and coastal storm flooding cannot be stopped, but actions can be taken to reduce communities’ vulnerability when facing flood risks.

Congress authorizes USACE—the primary federal agency charged with water resources development— to plan, construct, operate, and maintain hundreds of riverine and coastal storm FRM projects. Each USACE project is unique, addressing the community’s specific needs.





Flood Risk Management Benefits for 2011-2020 In fiscal year 2020, benefits provided by USACE riverine FRM projects was estimated at $257.9 billion; the 10-year average for FRM benefits for fiscal year 2011-2020 was estimated to be $161.8 billion annually. National economic benefits are estimated by calculating the annual flood damages that USACE FRM projects prevent. These estimates are based on the weather conditions for a given year, and, as flooding varies from year to year, some years may demonstrate greater benefits than others.  USACE is currently developing similar information for coastal storm FRM projects.





Supporting Community Resiliency

USACE planning, technical assistance, and research programs provide community partners with planning services, management approaches, models, tools, and engineering advances to help reduce the threat to life and property damages from riverine and coastal flooding. USACE delivers innovative and environmentally sustainable solutions to the Nation’s flood risk challenges, contributing to local communities’ resiliency across the U.S.

In an era of increasingly frequent and powerful storms, the FRM mission is more important than ever. Riverine and coastal flooding impact millions of people both directly (e.g., bodily harm, property damage) and indirectly (e.g., supply chain interruptions).

USACE’s FRM activities extend beyond riverine and coastal storm risk management projects and infrastructure. Through research and development, technology transfer, and stakeholder engagement, USACE supports the implementation of nonstructural and natural and nature-based FRM solutions to help communities in improving their resiliency.

Collaborating with Partners

USACE joined congressional representatives and federal, state and local partner agencies, for a ceremonial groundbreaking at Folsom Lake, California, where USACE will construct the Folsom Dam Raise project to help further reduce flood risk in the Greater Sacramento region. (January 2020)

USACE joined congressional representatives and federal, state and local partner agencies, for a ceremonial groundbreaking at Folsom Lake, California, where USACE will construct the Folsom Dam Raise project to help further reduce flood risk in the Greater Sacramento region. (January 2020)

USACE FRM activities are rooted in partnering with local, state, tribal, and federal agencies, as well as the private sector and other stakeholders. USACE works with partners to design, construct, operate, and maintain projects that manage flood risk across the nation.

FRM is a shared responsibility. There is no single public or private agency or organization that can manage flood risk on its own. Collaborating with multiple interests in a particular community helps facilitate shared riverine and coastal flood risk by broadening understanding and emphasizing shared governance and coordinated actions.