CS22B - Concurrent Session 22B: Our Levees are Failing Us

Abstract Description: Many levees are providing an illusion of protection and failing to meet the needs of those who are supposed to be protected by them. This presentation by the Ohio Department of Natural Resources (ODNR) will take a realistic look at the state of levees in Ohio and discuss opportunities for change.

A levee is often defined as "a human-made barrier with the primary purpose of reducing the frequency of flooding to a portion of the floodplain". Just as one expects that the bridges they cross every day will remain standing, it is reasonable for the public to assume that a levee will protect their homes, businesses, and communities from flooding. However, the levels of protection believed to be provided and the ability of these levees to perform are often not meeting expectations.

For example, FEMA accreditation indicates that protection is offered through the 1% annual chance flood event. Accreditation removes the regulatory floodplain for the protected area, in turn eliminating requirements for flood risk reduction and mitigation measures for development. Does this enabling of non-resilient development in areas which were previously considered floodplain create unknown risks?

In 2024 alone, ODNR identified two internal drainage failures of two separate accredited levee systems which resulted in the inundation of flood-protected structures. In one case, the levee itself likely exacerbated the flooding that occurred.

In this presentation, the circumstances of these Ohio levee failures and lessons learned will be presented to provide a foundation for exploring the topic of levee safety as it currently stands at all levels of government. Finally, a comparison will be made of the current state of levee safety to its potential future with the ongoing efforts at the Federal, State, and local levels. This will include how ODNR is utilizing materials such as the National Levee Safety Guidelines to plan for how levee safety could operate in Ohio in the future.