If your seawall fails, you may not be able to rebuild it if it falls. As your building has aged, think about how many times you have paid large sums of money to keep it in good repair. Whether it was paint, a new roof, or seal coating for your paved areas, when one of these items reached it’s expected life, you replaced it. What caused you to take action? You can see them. Those things that are out of sight usually are out of mind until they bring themselves to your attention due to a failure, such as a roof leak. Now, consider how often you actually take notice of your seawall, if you have one, like never?
If you live on a waterway you probably have a sea wall. When was the last time you took a good look at it’s condition. Have you ever paid a professional to give you an evaluation of its life expectancy? Do you have a reserve set aside for the purpose of replacing it if it fails? Do you even have a line item in your budget for it’s yearly maintenance? A sea wall certainly qualifies for “the out of sight out of mind” syndrome. The only problem is, a roof can leak and the drip will annoy you to take action. When a sea wall leaks, cracks, or has interior structural corrosion failure it does not tell you, you may never see it, and as it ages it does so slowly and quietly without disturbing anyone.
seawall tie backs and dead men
Sea walls are usually not insurable items, as are roofs, building paint, or stairways. If sea walls fail, you can’t look to your insurance company to recover losses. All losses for sea walls are paid out of pocket by homeowners directly. This fact became very evident to those property owners who suffered sea wall failures during Hurricane Elena, back in the mid 80’s. I’ve seen claims paid for paint stripped off a building due to high winds, which had sand in them, creating a sand blast effect. The windstorm policy paid on the remaining life of the paint job, which the association used to offset their re-painting costs. Even if sea walls were a covered loss item, since their regular maintenance is so often ignored, insurance companies would most likely not pay a loss claim unless the association could prove they had a maintenance plan in place and was acting on that plan. Failure to perform proper maintenance would void any claim paid. Setting aside a sea wall reserve could be one of the most important reserve items you can fund.
No one expects a sea wall to look good, so it is never painted or sealed to protect it. In fact, some abuse it by drilling holes into it for boat cleats, davits, or railings without thinking that they could be severely shortening it’s life. A sea wall is thought of as a tough, ugly, necessary thing that is never appreciated for fulfilling its purpose and is only hated when it fails to perform (no, this definition does not also apply to anyone you know).
So What’s Happening?
What’s happening is that the regulatory agencies that control the permits necessary for sea wall installations and repairs are taking a much more aggressive stand against installing them in new developments. They have studied how they have had an adverse effect on the environment and how the evidence has showed that previous designs are not adequate to protect against the flood forces a hurricane can create. Their existence has taken away breeding
grounds for marine life, and storms have revealed that they need to be much stronger and of a different design to properly protect buildings. In some areas of Florida, there is a movement on to remove them from barrier islands altogether.
I spoke with Mark Petersen, Environmental Specialist II, State of Florida Department of Environmental Protection, South West District, Submerged Lands and Environmental Resources Program. Mr. Petersen warned property owners to be aware of the current policy on sea wall replacement. Currently the state has a prohibition on vertical sea walls on state submerged lands. New sea walls are very difficult to get approved. With regard to existing sea walls, he stressed that property owners need to pay close attention to maintenance to make sure theirs does not fail. “Once failed, with water behind it, on the bay or the gulf, they can no longer get authorization to re build that seawall. ”
rebuild seawall – framing
We contacted the Tampa office of the United States Army Core of Engineers. They had no comment regarding policies on sea walls and their replacement. According to their office, if an owner requests a permit to rebuild, they require that owner to complete an application which contains questions that their office will use to determine which permit would apply to their given situation and location, and whether one would be permitted or denied. Generally speaking, if the State of Florida DEP would allow a replacement and that work would require a permit, then their office would also.
When I started my research for this article, I was shocked to learn that the coastal islands face a huge issue. Most homeowners haven’t any idea what they are facing in the near future, or even now. When you couple the fact that sea walls on the bay or gulf that fail now may not gain approval to be rebuilt with the possibility of little or no reserve fund and little or no hope of a claim against your insurance policy, it causes great concern. It should cause a call to action to inspect your sea wall and to maintain it to make sure your sea wall is not a candidate for failure. There are a lot of sea walls in Florida’s coastline, beaches, and bays. If a large hurricane hits, taking out the seawalls, with so many buildings being built so close to them, the land behind them, and the buildings built on top of that land could collapse and fall into the water also.
seawall maintenance weep holes
I tried to imagine a hurricane traveling North along the coast and punishing the West coast barrier islands with winds, waves, floods, and rains placing hydraulic pressures on these 30 year old sea walls as never before. Then I tried to imagine if the sea walls failed, and the ground behind them gave way to the sea and waterways, and the house foundations failed, and the buildings fell into these waters. The picture wasn’t pretty. You draw your own.
Now that you may be feeling the pangs of regret for not having paid attention to your sea wall over the last thirty years, it may help for you to understand the various parts of a sea wall and how they form a system, how your sea wall ages, what factors cause the most stress, and what you can do now to save it. There are ways to strengthen it and change its design to better meet the new recommendations of the state.
What Can You Do?
Common sense would tell you to have your sea wall inspected by an engineer licensed and trained in marine structures, or at the least a marine contractor with an appropriate license for repairs. During this inspection a number of items are checked including (see “the sea wall system” below for terms and definitions) , the vertical panels should be inspected for horizontal cracks at the average water line and elsewhere. The cap should be checked for horizontal cracks and spalled concrete, much like you would inspect a condominium concrete floor to see if it requires restoration. The tie backs should be excavated to inspect them at various levels and depths. The dead men should be checked to make sure no movement has occurred and that the connection to the tie backs is secure. Tests should be conducted to determine the levels of salt present in the concrete at various depths, especially at the interior reinforcing steel bar depths. And the weep holes should be checked to make sure they are still venting.
rusting seawall cap
If the resulting report indicates that the structure can be saved, and is not to a point of disrepair, then the engineer will make recommendations on what should be done. As long as repairs are completed, he also can give you a life expectancy in years for its replacement. Your association can use this information to establish a reserve fund for this purpose. He then can create a set of specifications on what repairs should be done, what materials to be used, and at what urgency the repairs should be addressed. The association can use those repair specifications to obtain bids from qualified marine contractors to do the work, and provide a budget for future repairs and maintenance.
Even though you may have engaged a contractor to do your repairs, keep in mind there are several factors that enter into when the repair work can start. There is a line known as the “Coastal Construction Line”. It appears only on maps and was created years ago to determine where construction can take place with regard to proximity to the shoreline. You must determine where your existing sea wall is located with respect to this line. If your sea wall is in part or in total on the water side of the line, it may take months to get a permit, or you may not be allowed a permit at all. If the sea wall is landward of the line, the permitting process takes much less time. This can be determined ahead of time by your engineer, and most certainly will be discovered during the request for permitting process.
Know Your Sea Wall System
If you could cut away a cross section of a typical sea wall system built more than fifteen years ago, you would see basically the same picture sea wall after sea wall. The main components are named as follows.
seawall revetment
Vertical wall panels. These prefabricated panels are set in place and jetted into the sand (sea bottom) so they are plum and true and their tops meet at the same height. The idea is to jet them into the sea bottom to a depth of at least one half their total height. A ten foot panel should be in the ground at least five feet, with five feet above the sand.
The cap. The cap is the square or rectangular section that sits on top of the vertical panels and runs horizontally along the entire length of the sea wall. It has reinforcing steel bars which run horizontally within the concrete the entire length of the cap. It is connected and tied into the vertical panels with reinforcing steel bars. This cap is usually formed and poured in place with concrete.
Tie backs. The tie backs are steel bars which are connected into the reinforcing bars of the cap, and run backward away from the cap connecting into the dead men.
Tie Back Anchors or ” Dead Men”. The tie back anchors are formed and poured in place, concrete square or rectangular blocks of concrete and reinforcing steel bars. They have straight sides and corners to develop a coefficient of friction so they do not “slide” toward the sea wall. Their forces hold back the sea wall cap and vertical panels through the tie back.
Back fill. The key to holding the dead men in place is proper backfilling to make sure there are no voids or pot holes beneath the surface. If there are voids, in years the dead men may slide forward, causing the cap to protrude outward, indicating a weakened condition to the system. The system’s weakest link could cause a domino effect, a breach, which could cause the rest of the system to go when it does.
Weep holes. In the case of severe water pressure behind the sea wall, most systems have holes in the vertical panels for water to escape into the sea. These holes alleviate some of the hydraulic pressure which builds up when it rains or when flooding sea water tries to return to the sea behind the panels as the ground becomes saturated.
Now and Then
One of the problems with the design used thirty years ago, was that now there is not as much sand and sea bottom on the water side of the vertical panels as there once was. When istalled thirty years ago, these vertical panels were ten feet in height, and they did have five feet of sand to hold their “toe’s (the bottom of the vertical panel) in place. There were no homes built landward and many seawalls even had beaches on the water side. Through the pressures of tidal current, wave actions, and boat prop washing, and development sand has eroded from the base of seawall vertical panels, a process known as “scouring”. If enough of this sand is removed the wall can become suspect to fail due to the toe “kicking out”. Without any back pressure to hold the toe of the wall in place, the wall can move outward, weakening the wall or causing total failure.
Boat “prop washing” is a major problem. When the first sea walls were installed there were no homes, no docks, no pilings, no boats. Dredging for docks was permitted then. Since dredging has not been permitted for many years (seeing sand removal as a sea wall problem) some property owners defeat this prohibition by backing their boats into their docks and running their propellers hard to remove the sand from the sea bottom. Over a period of time they remove as much sand as they need to make sure their boat has enough draft at extreme low tide.
seawall tie backs and dead men
This weakened sea wall panel condition becomes a particular concern when you consider what happens during a hurricane. A combination of factors collide and accumulate creating a great force against the sea wall. Tidal forces become extreme, wave action increases, and rain falls heavily on the land adjacent to the wall. The ground becomes saturated creating a huge hydraulic pressure against the wall. Add to that condition a severe low tide and a scoured boat basin, and you have the condition that causes sea wall vertical panels to kick out. Front docking boats may be a bit more inconvenient, but it may extend the life of your sea wall and help protect your homes and buildings. Discouraging boat prop washing is one thing an association can do to help and can adopt rules prohibiting it altogether. Another is in adding Rip Rap.
Rip Rap, Is Not A Tune You Sing
“Rip Rap” is usually large rock, boulders, or some environmentally approved material put in place to secure up marine structures. We spoke with Dave Walker, Pinellas County Environmental Program Manager, Department of Environmental Management, Waterway Navigation. His department overseas all permits which are necessary for rip rap placement, as well as all sea wall repairs and installations. Mr. Walker and the department are in favor of and encourage rip rap placement . They feel that in addition to proper repairs and maintenance, adding rip rap can strengthen the existing wall system to a degree which vastly improves its chances of surviving a hurricane.
condo revetment seawall
Other than the structural enhancement rip rap offers, the environmental factors it brings are many. Using Rip Rap not only secures the wall in place, but it also creates habitat for young marine life. Remember, before there was a seawall, there was a shore probably dotted with mangroves and rock which served as a breeding ground for marine life. When the seawalls were installed the breeding grounds were removed, and this served as a part of the overall fishing decline problems within the Tampa Bay area and other Florida coastal communities that began decades ago.
According to Mr. Walker, there are requirements for the materials to be used for rip rap. It must be clean used concrete or natural rock, with no exposed rebar. It cannot contain any paint, tars, asphalt or toxic materials. For example people like to use old roof tiles that are painted. These are not allowed unless they are scoured clean of paint. There is a size requirement. Each item must be no less than 12 inches and no greater then 36 inches in diameter. There is judgement involved in each case however. Mr. Walker pointed out that items that have been approved in the past on certain occasions are: broken up sidewalks, driveways, and concrete block if not painted. If there is reinforcing steel inside the concrete, it must be cut off flush with the concrete surface. No protruding re-bar is allowed. Not only does protruding re-bar create a safety hazard, but it creates a minor marine hazard to fish and wildlife. With regard to slope, the rock or material must create a slope of 2 to 1. For example, for every two feet of rock laid in place the height of the slope should be one foot . This sloped rock does create a concern for docking boats, and lends even more favor to docking boats front end in since the front end of a boat creates less draft and is also sloped.
When speaking with Mark Petersen, he explained that if cost is a factor, many times the department will allow a base of concrete or other materials covered with a topping of more esthetically pleasing natural rock. Their office encourages rip rap revetment. Mr. Petersen explained that with a vertical seawall, wave energy is taken abruptly and full force with the vertical panel. Also, scouring occurs from direct wave action, which is the removal of sand at the vertical panel toe. With rip rap revetment (“revetment” meaning to repel), wave energy is reduced on both counts and the life of the wall is extended.
Getting The Salt Out
Concrete is concrete is concrete, say the workers restoring concrete on coastal buildings. It doesn’t matter so much what it is a part of, balcony, pool deck, or sea wall. What matters is where it is, on a coast line or in the middle of the state. The concrete vertical panels, cap, tie backs, and dead men suffer the same 
deterioration due to chloride (salt) absorption and penetration as a upper level balcony or patio slab or a common walkway. The seawall has reinforcing steel rods and they can and do rust (corrode) and loose their strength if enough salt has penetrated its interior. An inspection may require chloride (salt) testing to determine the amount present at various depths. If necessary, an approved migratory chloride reduction solution should applied, as well as a penetrating concrete sealer after the repairs are completed, such as the Aquron system. Care should be taken to use only environmentally approved products since application of these products is most often over the sea water, which is very fragile and sensitive to petroleum and solvent based products. Also, cathodic systems may be applied also to halt the effects of electrolysis that may be occurring. Your wall may require additional testing and repairs based on its design, condition, and testing results.
Should You Rush To Action?
There are stories about sea wall companies using scare tactics to get property owners to do repairs before they are necessary. There is a rumor that basically says there is a law which requires property owners to replace their sea wall within 90 days after losing it during a storm. I asked Mark Petersen whether there was any truth to this rumor. He explained, ” Not according to our rules, (but he is not speaking for the county or for the core of engineers.) But as for the state, there is no time frame. However, the laws are written so that a permit is required for situations that are not exempt. Exempt situations include sea walls on artificial water bodies, residential canals, and for repair or replacement of existing sea walls within one foot waterward of present location. It is also very important that the subject sea wall must be functional, meaning lacking an exchange of water behind the seawall. There is also a third category, construction of a seawall between two existing seawalls. With the exempt areas, if a sea wall is removed or has failed, they need to replace it “Expeditiously”, or as quickly as possible. With a hurricane, they do take that into consideration. During the March 1993 no name storm, they allowed up to a year for people to replace their sea walls. But each case is a judgement call, and up to the program manager, using good reason to follow the intent of the law. Anything that is not exempt requires a permit, an Environmental Resource Permit.”
As to pressure sales tactics from aggressive sea wall contractors on owners to re build quickly, Mr. Petersen responded, “If a contractor is saying that there is a time frame to pressure an owner into action, then he is not correct. An owner should contact the state or county offices for accurate information regarding re-building your seawall in case of a failure.”
seawall collapse old florida
Regarding state permits required for rip rap installations, a “Noticed general permit” is required, with a $100 application fee. For rip rap placed at the base of sea walls, adjacent neighbors can go in together on this where one permit can cover many neighbors. The permitting process takes approximately 30 days. They issue the permit under the state law. The county also has a permit for “shoreline stabilization”. He cautioned that the core of engineers also has a permit that may be required, as well as the local county and/or city. No one authority has more strength than another, they are equal in importance for obtaining a permit. In some cases a city permit is permitted in lieu of a county permit.
Many have stated that if the “Big One” ever does have a direct hit on Tampa Bay, that it isn’t the flooding that worries them, if they can get people evacuated. It is when the water leaves that can erode enough sand to create another John’s Pass. In 1929 John’s Pass was created after a hurricane left us. One wonders what will become of those narrow beach areas, or areas where tidal currents are already severe. Water chooses the course of least resistance. Make your sea wall strong so your property is not the weakest link in the chain. We strongly suggest you have your sea wall inspected annually, add an operating line item, and a reserve line item, and also adopt a proper maintenance program for your sea wall.
