Brief Flood Mitigation

Introduction

Floods are the deadliest, costliest and most common form of natural disaster in the United States and in the world. They are caused by hurricanes, heavy rainfall, overflowing rivers, broken dams, overfilled urban drainage basins, tsunamis, water channels with steep sides, and ice- or snow-melt. Floods are difficult to predict, which means states must be prepared to respond at all times.

Forms of Flood Mitigation

Flood mitigation approaches fall into two categories—structural and nonstructural. Structural forms of mitigation mitigate harm by reconstructing landscapes. They include floodwalls/seawalls, floodgates, levees, and evacuation routes.  Nonstructural measures reduce damage by removing people and property out of risk areas. They include elevated structures, property buyouts, permanent relocation, zoning, subdivision, and building codes. Structural solutions have lost popularity over time as old dams and floodgates have failed.

FEMA released a report in 2017 called "Innovative Drought and Flood Mitigation Projects" that evaluates four disaster mitigation approaches highlighted by an EPA-commissioned report: "Aquifer Storage and Recovery, Floodwater Diversion and Storage, Floodplain and Stream Restoration, and Low Impact Development (LID)/Green Infrastructure (GI)." The report assesses each approach based on cost, efficacy, feasibility and fulfillment of Hazard Mitigation Assistance (HMA) requirements.

The report finds that all four options are consistent with HMA’s requirements and guidelines and will effectively mitigate the impact of climate disasters, including floods. Aquifers are primarily used to mitigate the impact of droughts, so the following descriptions focus on the other three recommendations. 

• Floodwater Diversion and Storage - Diverting floodwaters into wetlands, floodplains, canals, pipes, reservoirs, or other conduits helps mitigate flooding by allowing for a controlled release of water outside of residential or metropolitan areas.  At least 16 states have enacted legislation since 2010 establishing intent, programs, or funds to build floodwater diversion or storage systems.
• Floodplain and Stream Restoration – Floodplains and streams not only mitigate the risk of floods but can also mitigate bank erosion and benefit local ecosystems. Floodplains store stormwater runoff, reducing the number of floods and their severity.  10 states have passed legislation to restore streams or floodplains to mitigate flood damage since 2010. 13 bills have failed in the United States Congress concerning floodplain restoration since 2010. Five more are pending.
• Low Impact Development (LID)/Green Infrastructure (GI) – LIDs and GIs mitigate the risk of floods by storing water. They tend to mimic natural hydrology and include innovations such as green roofs and permeable pavement. Most states have implemented some form of LID or GI. 

State Action

At least 19 states and Puerto Rico enacted legislation in 2019 related to flood mitigation.

Federal Mitigation Legislation

Spring 2019 Disaster Aid Package

In June, Congress passed a long-awaited $19 billion supplemental disaster aid package for states most affected by 2017, 2018 and 2019 disasters. Disaster mitigation sections included:

• $1 billion in Flood Control and Coastal Emergencies account for expenses to prepare for flood, hurricane, and other natural disasters, as well as support certain emergency response operations.
• Nearly $800 million to the Army Corps of Engineers to investigate and build high-priority flood and storm damage reduction projects.
• $2.4 billion in Community Development Block Grant funds, in part requiring any remaining funds to be used for mitigation activities.
• $50 million to the National Oceanic Atmospheric Administration to improve forecasting.
• $50 million for Title IX funds for public-private partnership to support coastal resiliency.

Fall 2018 Disaster Recovery Reform Act

Congress passed HR 302, the Disaster Recovery Reform Act (DRRA) in October 2018. Considered the most comprehensive disaster reform legislation since Hurricane Katrina, the new law covers the full spectrum of disaster phases but specifically increases the federal investment in predisaster mitigation.

DRRA establishes the Building Resilient Infrastructure and Communities program, which will commit certain funding from the Disaster Relief Fund to predisaster mitigation efforts. It allocates 6% of the combined obligations estimated following a major disaster—unemployment assistance, assistance to low-income migrant and seasonal farmworkers and crisis counseling assistance and training—to mitigation assistance (Section 1234). That 6% is made available the following year on a competitive basis for states that have experienced a major disaster in the last seven years to use for mitigation projects. Mitigation funding is also provided for wildfire prevention (Section 1204).

Important for states, Section 1239 of the law also directs the FEMA administrator to revise and update the factors considered when evaluating a governor’s request for a major disaster declaration, including the way FEMA estimates the cost of major disaster assistance based in part on the capacity of a jurisdiction to respond to disasters.  

NCSL drafted and advocated for language in the final law that specifically requires consultation with state and local governments:

“In determining the capacity of a jurisdiction to respond to disasters, and prior to the issuance of such a rule, the Administrator shall engage in meaningful consultation with relevant representatives of State, regional, local, and Indian tribal government stakeholders.”

The inclusion of this language ensures that FEMA considers this important perspective before making changes to the way disaster assistance is calculated, based on such capacity. This language reflects NCSL’s current Homeland Security and Emergency Management policy, which in part promotes consultation as well as mitigation-focused policy. NCSL issued a letter to the full Senate in July of 2018 highlighting certain components of the legislation and advocating for its passage.