Amid relentless storms and rising water levels after five years of drought conditions, the levee along the San Joaquin River just south of Manteca, California, became damaged in late February 2017. About 500 residents in the rural area were told to immediately evacuate. There was no time for flood damage preparation. Luckily, crews were able to fix the levee before it experienced a catastrophic failure.
The United States has thousands of miles of levees and, while they’re designed to reduce the risk of flooding, the American Society of Civil Engineers states that they do not offer full protection against the disaster.
The Purpose of Levees
A levee is a manmade structure, generally an earthen embankment, to control, contain or divert the flow of water and reduce flood risks. Engineers build the structures parallel to waterways, and may add floodwalls to levee crowns to increase their height without increasing the embankment’s base. Levees may also have closure and drainage devices that are constructed and operated according to sound engineering practices.
The first levees in the U.S. were built about 150 years ago by farmers with land in floodplains to protect their crops. Today, levees protect a variety of settings as developments have replaced many farmlands. The U.S. Army Corps of Engineers sets the standards regarding levee building and maintenance best practices. The USACE builds and maintains about 15 percent of the levees in the country. The remaining 85 percent of levees in the USACE Levee Safety Program are locally owned and maintained.
To ensure the effectiveness and safety of levees, responsible owners hire trained inspectors to examine the structures regularly. Inspectors look for signs of trouble, such as erosion, unwanted vegetation, unstable slopes, improper excavations and structures, floodwall or riprap damage, settlement, and seepage. The USACPE states that citizens have the right to report levee-related concerns to local government officials and levee owners.
Understanding Your Flood Risk
There is always a possibility that flood waters will exceed a levee’s capacity, regardless of how well it was built. Flooding can also occur if waters overtop a levee or if the structure fails. The Federal Emergency Management Agency recommends understanding your flood risks if you live or own a business near a levee so you can take appropriate preventive steps.
Taking action to reduce your risk of flooding includes:
- Being aware of the levees in your area
- Knowing your flood risk by visiting FEMA’s Flood Hazard Mapping site
- Implementing the flood damage preparation steps outlined in your disaster preparedness plan, such as keeping important files on upper levels of a building to reduce flood damage to documents
- Including recovery and business continuity steps in a disaster preparedness plan
- Purchasing sufficient flood insurance to reduce costs related to rebuilding, restoring your property and document recovery
As you learn more about the impact of levees in your area keep in mind:
- The USACE operates and maintains levees in the federal levee system
- FEMA identifies and maps flood-related risks
- Local governments, communities and private levee owners are responsible for maintaining their own levees
- Citizens are responsible for understanding flood-related risks and taking steps to prepare their homes and businesses
Flooding is the most common natural disaster in the U.S. The risks associated with levees change over time because the weather varies annually and conditions within watersheds are not constant. Unless you own a levee, there is little that you can do to prevent a breech. However, you can take steps to prepare and protect your home and business. Speak to a specialist at Polygon today to learn more about preventing flood damage to documents in your business and about our disaster recovery support services.