An external peer review panel commissioned by the Corps of Engineers has validated the Corps’ high-risk classification for Herbert Hoover Dike in south Florida.
Herbert Hoover Dike is one of six dams the Corps identified as having a high risk of failure during a screening of 202 dams in 2005, 2006, and 2007. (HNN 5/2/07) Independent external peer review panels were commissioned to review Corps findings and recommendations for all six dams.
Reviews of four of the dams, including Herbert Hoover, 270-MW Wolf Creek in Kentucky, 135-MW Center Hill in Tennessee (HNN 9/10/07), and Isabella Dam in California, have been completed. (HNN 11/21/07)
Herbert Hoover Dike is an earthen embankment system on the perimeter of Lake Okeechobee. Components of the system have been constructed intermittently since the early 1900s. The system encircles almost all of the lake, which has a surface area of about 730 square miles. It consists of about 140 miles of earthen embankment with 57 water control structures.
The external panel’s Herbert Hoover Dike Consensus Report, released Nov. 2, found the Corps’ Class I designation ï¿½Urgent and Compellingï¿½ is appropriate for the project. It cited piping at several locations and studies that conclude part of the dike would fail with sustained lake elevations above 21.5 feet, calculated as a once in 100-year occurrence.
It also said seepage volume and distress indicators in certain reaches at reservoir levels above 17 feet are cause for concern, as failure is considered very likely when operating at, or above, those levels for significant time.
The external panel said it supports the general design principles of a proposed $856 million rehabilitation program that would be completed in 2030. The program would feature a partial cutoff wall through the dike to prevent piping, the movement of material carried by seepage.
The Corps is responsible for lake management and the dikes in the system; the South Florida Water Management District owns and operates other structures in the system.