2014 promises to be busy year for dike rehabilitation

Published Feb. 4, 2014
Culvert 11 before removal in March 2012

Culvert 11 before removal in March 2012

The lights at the movie theatre dim…the screen lights up with a preview of coming attractions…the deep, booming voice of an announcer fills the air…

“Coming soon, the biggest, most comprehensive report on the risks associated with Herbert Hoover Dike. Don’t miss it when it hits the streets in the spring of 2014.”

Okay, it’s unlikely that announcement will make the big screen, but Jacksonville District is putting the finishing touches on a risk assessment report for the 143-mile dike that surrounds Lake Okeechobee.  The report is expected to be the source of much conversation in light of huge water releases last summer from the lake due, in part, to the poor condition of the dike.

“This is the most comprehensive analysis that’s ever been done on the risk associated with Herbert Hoover Dike,” said Tim Willadsen, project manager for rehabilitation at the dike. “This report identifies the challenge, which helps drive discussions on the remaining solutions needed to reduce the risk at the dike.”

2014 is shaping up to be a very busy year for rehabilitation at the dike.  Jacksonville District continues to press on with construction projects, and will move closer toward completing a study that will provide options on the remaining measures needed to reduce the risk of dike failure.

The completed risk assessment will be used to develop and formulate solutions through a process known as a Dam Safety Modification Study (DSMS). The goal of the DSMS is to identify and prioritize the remaining measures necessary to finish rehabilitation. It is anticipated that the final Dam Safety Modification Report (DSMR) will be ready in 2015. 

Rehabilitation work has been ongoing since 2007. However, previous risk analyses weren’t as comprehensive as the current effort.

“When we started work, the intent was to fix Reach 1, and then move on to Reaches 2 and 3 on the south side of the lake,” said Willadsen. “Now, we want to make investments in dike repairs that will lower the risk across the entire system, not just one portion of the system.”

One measure that’s already known is addressing the 32 federally owned water control structures, commonly known as “culverts.” These structures currently pose the greatest risk of dike failure.

“The culverts were identified as the greatest risk to failure due to loss of material into and around them,” said Willadsen. “Replacing these structures is the current priority.”

Culvert replacement construction began in 2012. By the end of 2013, contracts had been awarded to replace 16 of the 32 culverts needing attention. Culvert 11, located south of Port Mayaca on the east side of the dike, is furthest along in its replacement. 

“These structures aren’t like driveway culverts,” said Willadsen. “To replace a culvert, we have to install a cofferdam to hold back the lake while crews do their work, remove the old culvert, and pour the concrete to install the new culvert.  It sounds simple, but it’s a very complex and time-consuming process.”

Jacksonville District anticipates awarding additional contracts to replace culverts later this year.  Those opportunities will be advertised on the FedBizOpps website (www.fbo.gov) when solicitation packages are ready.

While culvert construction presses ahead, Jacksonville District continues to work through the DSMS process.  Staff from nearly every district organization as well as other Corps offices across the nation have been developing and reviewing options for the next phase of dike rehabilitation.

“We started off with a lot of ideas,” said Willadsen. “Now we’re narrowing the large number of ideas into a suite of alternatives that we believe are worthy of further investigation.”

Willadsen says the district would like to present a tentatively selected plan this summer, so environmental reviews can begin.  Public participation will be a key part of the process. 

“For various reasons, there’s a lot of interest in what is going on with the dike and the rehabilitation,” said Willadsen. “Our goal is to ensure we are reducing the risk of dike failure by making appropriate investments on behalf of the nation’s taxpayers. Rehabilitation of the dike is necessary to protect lives and property in the adjacent communities.