The Levee Safety Program has recently completed the first summary report of the flood risks and benefits associated with levee systems included within The U.S. Army Corps of Engineers (USACE) portfolio of levees. Utilizing the best available information gathered from risk assessments, this report provides valuable information that allows for improved management and investments at a portfolio level, including policy and technical guidance, training, and research and methods development. In addition, this report establishes a baseline that allows for future analysis of portfolio trends in inventory and risks…risks that impact your customers, your loan portfolio, your branches, and your staff.
USACE portfolio levees represent an unknown portion of the total levees in the United States. In the National Levee Database there are roughly an equal number of miles of levees that are outside of the USACE Levee Portfolio as are ones within it.
OVERVIEW OF THE USACE PORTFOLIO: The USACE levee portfolio includes about 2,220 levee systems totaling approximately 14,150 miles in length. Over 1,200 levee sponsors operate and maintain 2,000 of these levee systems, spanning roughly 70% of the length of the entire portfolio, pointing out that effective risk management is unlikely without comprehensive approaches of sponsors, communities, and USACE. To complicate matters further, fifteen percent of levees include multiple segments, which usually mean multiple operations and maintenance authorities. Since performance of the levee is only as good as its “weakest link,” understanding and engagement of all parties within a single system is critical.
Much of What We Value is Behind USACE Levees
Breakdown of USACE portfolio levees by entity responsible for operations and maintenance and the percentage of miles of the total portfolio.
Risk assessment results to date, LSAC is an acronym that stands for Levee Safety Action Classification. These classifications have five categories (very low risk to very high risk).
SOME KEY RISK DRIVERS: The graphic below shows the top levee performance drivers.
Percentage of levee systems with each levee performance risk driver. One system may have multiple drivers.
COST ESTIMATES TO REDUCE RISK: Initial cost estimates, which are agnostic as to who pays, range from $6.5 billion to $38 billion, with an expected cost of $21 billion. One observation from this data is that a relatively modest cost ($300 million) of improving evacuation effectiveness across all levees is a smart investment. Costs are significantly lower than infrastructure improvements and directly reduce risk to loss of life by getting people out of harm’s way.
Communities behind nearly one quarter of the levees have no evacuation plan.
Reprinted and adapted from the FEMA News article of the same name by Brad Arcement, P.E. & Noah D. Vroman, P.E.
If you would like to learn more about the risks we are assuming as a nation, as well as at the state level with our levees, the full report is available Here, and the Executive Summary is available Here.