Study: Jacksonville Would Be Nation's Most Expensive City To Protect With Seawalls

Jun 20, 2019

Yet more research shows Florida – and especially Jacksonville – has an expensive road ahead in dealing with rising seas.

Local coastal engineer Erik Olsen said seawalls along the St. Johns River will likely need to be raised and drainage improved.
Credit Ryan Ketterman / For Visit Jacksonville

A new study by the Center for Climate Integrity shows Jacksonville tops the list of the most expensive cities to protect with seawalls.

According to the study, Jacksonville would need about $3.5 billion to construct 632 miles of seawalls to protect itself from rising seas by 2040.   Jacksonville has more square miles to contend with than any other city in the continental U.S. because of its consolidated government with Duval County.

Top 10 List Of Cities Facing The Most Expensive Seawall Costs:

1.) Jacksonville - $3,460,516,000

2.) New York - $1,973,735,000  

3.) Virginia Beach - $1,716,510,000          

4.) Marathon, Fla. - $1,506,927,000         

5.) Fire Island, N.Y. -  $1,449,948,000      

6.) Galveston, Texas - $1,057,849,000    

7.) Charleston, S. C. - $1,031,923,000     

8.) Bolivar Peninsula, Texas - $966,919,000          

9.) Tampa - $938,350,000            

10.) Barnstable Town, Mass. - $889,226,000 

The study only looked at seawalls when combating sea level rise. If other costs such as tougher building standards and buyouts were added, the estimates would be significantly higher.

Development is continuing along Jacksonville Beach. In the distance a crane can be seen in this photo. A new Margaritaville resort in the 700 block of 1 Street North is being built.
Credit Bill Bortzfield / WJCT News

The Center for Climate Integrity asserts that the cost for protecting Jacksonville breaks down to $3,990 per person.

Florida faces the greatest cost in the nation, should it decide to erect the estimated amount of seawalls needed: $75.9 billion for 9,243 miles of seawalls. To put that into perspective, the entire state budget for Florida was $85 billion in 2018, according to the Center for Climate Integrity.

“Florida is by far the most heavily impacted state, with costs reaching nearly $76 billion statewide, 23 counties facing at least $1 billion in seawall expenses alone (and often far greater price tags according to local estimates), and 24 communities where building just this rudimentary level of coastal protection will cost more than $100,000 per person,” the study’s authors wrote.

However, a local coastal engineer calls the report “pretty sensationalistic.”  

Erik Olsen is a principal engineer at Olsen Associates, Inc and a member of Jacksonville’s Adaptation Action Area Working Group, which is exploring policies to protect Jacksonville from an assumed 2-feet rise in sea level by 2060.

He said the purpose of the study is to be an eye opener. Olsen also points out that in Jacksonville’s case, seawalls are only a partial solution, and one that would be primarily for areas along the St. Johns River.

In regards to coastal area, Olsen said, “You're not talking about the implementation of seawalls. Pragmatically, you're talking about dunes and increasing the elevations of your beach restoration projects.”

Higher seawalls will likely be part of the solution, though, along the riverbank at Friendship Park on the Southbank, for example.

“I have measured the elevation of the seawalls around downtown just to get an idea as to how they vary. You’d have to raise it, probably, about two feet,” he said.

But seawalls only address a part of the issue. “You can raise the elevation of the seawall, but it doesn’t really, necessarily, affect the drainage,” he said.

He points out that areas like parts of San Marco and Riverside can’t drain fast enough into the St. Johns when big storms hit.

The Center for Climate Integrity claims the costs outlined reflect the bare minimum coastal defenses that communities need to build to “hold back rising seas and prevent chronic flooding and inundation over the next 20 years.”

Olsen’s Jacksonville group hasn’t made any specific recommendations yet. “We’re only at the stage where we are identifying the area that we should be flagging as endangered,” he said.

But Olsen does stress the need for lawmakers to elevate sea level rise on the priority list.

“When will elected officials begin to acknowledge that this is a phenomenon — just like schools, just like redevelopment —  that this is a phenomenon that the city of Jacksonville needs to address?” he said.

The report can be downloaded here and the data sets are available here.

On the topic of sea level rise and how the First Coast is adapting, WJCT News will soon launch a website called ADAPT. You can sign up to be notified about the launch here.

Bill Bortzfield can be reached at bbortzfield@wjct.org, 904-358-6349 or on Twitter at @BortzInJax.