From the Document: "Earthen infrastructure in the U.S. comprises around 85,000 earthen dams, also known as embankment dams or earth filled dams, and most of the 100,000 miles of levees. Many earthen dams and levees face considerable risk from both natural and man-made hazards. Rehabilitation of these aging infrastructures relies mainly on the same materials used decades ago to build and reinforce the structures. Failure of any of these structures could result in major negative impacts on the U.S. economy and threaten the health and safety of surrounding communities."
Cybersecurity and Infrastructure Security Agency: https://www.cisa.gov/