About the Dam Safety Modification Study

In 2016, the U.S. Army Corps of Engineers completed an evaluation known as the Herbert Hoover Dike Dam Safety Modification Study (HHD DSMS) to  address problems and develop alternatives for rehabilitation of the dike. 

The DSMS was the most comprehensive study ever conducted on the dike.  It reviewed the geology and geometry of the dike in multiple locations.  The study examined impacts from a full range of structural and non-structural alternatives which could be implemented to reduce risk. 

The results of the study provided the final roadmap toward the ultimate goal of reducing the failure risk at the Herbert Hoover Dike.


As the Dam Safety Modification Study has progressed, the Corps completed analysis on consequences that would result from a breach in the dike with a lake level at elevation 25 feet (NAVD).

Based on this analysis, the Corps identified seven common inundation zones designed to illustrate areas that could be impacted.  Failure of the dike at any location along the lakeside of a common inundation zone would flood the impacted area with at least one foot of water.


Corps approves dam safety modification report for Herbert Hoover Dike - August 31, 2016

The U.S. Army Corps of Engineers has finalized a key report that authorizes additional rehabilitation work on the Herbert Hoover Dike that surrounds Lake Okeechobee in south Florida. The Corps’ Jacksonville District received notification on Aug. 30 that the dam safety modification report for the dike has been approved, marking the culmination of a four-year effort to conduct a risk assessment of the 143-mile earthen structure and develop alternatives for its rehabilitation.

The report, known as Herbert Hoover Dike (HHD) Dam Safety Modification Study Environmental Impact Statement focuses on a tentatively selected plan to extend embankment repairs over 28 miles on the south and west sides of the structure. 

The approved repairs include installing 24 miles of seepage barrier, commonly known as a partial cutoff wall from Moore Haven to Lake Harbor (this is in addition to installing 6.8 miles of seepage barrier between Lake Harbor and Belle Glade approved in a 2015 report).  The Corps also plans to install four miles of cutoff wall near Lakeport.  In addition, engineers recommended armoring the embankment around the State Route 78 bridge near the Harney Pond Canal and installing floodwall near water control structures on the Harney Pond and Indian Prairie Canals.

Jacksonville District engineers anticipate rehabilitation work on the dike will continue until the mid 2020s, around 2025.  The current cost of additional construction features is estimated at $900 million.



Poster from Public Meeting
Jan. 2016


Presentation from Public Meetings
(Jan. 2016)
Herbert Hoover Dike Rehabilitation Project Presentation