What kind of flood defense barrier is best for you?

March, 2018

Flood Defense Group takes great pride in having the largest selection of flood defense barriers in North America for a reason.  There is no single solution that is best for every situation.

It has been our experience that most companies who market flood defense barriers will regularly claim that their solution is the best when perhaps it is not.  These are some of the considerations we take into account when suggesting a barrier that is the best fit for your situation.

Height/Depth of anticipated flood waters

This is typically our first question.  What is the depth of the flood water you are trying to protect against?  Flood Defense Group has barriers that range in size from just over 19” tall to stackable barriers that can easily achieve over 20’ in height.  We do not believe in providing a barrier to protect against 10’ of flood water when you only experience 1’ of historical flooding.  That would be a waste of your hard-earned dollars.

Picture: NOAQ Boxwall, easily deployed

See it in action at www.flooddefensegroup.com/noaq-boxwall-now-in-stock.html

Our NOAQ Boxwall is 19.68” tall which is adequate to protect against the vast majority of flood events we see but we also understand that many locations see flooding at a greater depth than that.  In Houston, Texas during hurricane Harvey, there were large areas that saw between 10’-20’ of floodwater and more.  In these cases, we would supply a stackable barrier.

Sometimes, projected flood depths change at the last minute.  If you deployed a 2’ barrier and flood predictions change to over 3’ of incoming flood water, you might be in trouble.  To this end, we have barriers that can be built, and then built higher as flood predictions change.  Examples of this include our Louisiana Floodwall, Defencell, and Muscle Wall flood barriers.  These barriers provide options to create an immediate flood defense barrier which can be expanded on as the flood situation develops.

Pictures:  Defencell reinforced berm construction sequence

What are you building on?

Just about any flood barrier on the market can be built on concrete, asphalt, or grass.  However, sometimes it is necessary to build flood barriers through loose sand, mud, or on uneven terrain.  Perhaps you have obstacles like gas pipes, electrical lines, or obstructions within the path of your desired floodwall.  What can be done?

Soil filled barriers are our preferred method for many of these situations.  Both the Defencell and Louisiana Floodwall products are soil filled and have no bottom.  Therefore, you get great ‘sealing’ to the ground because as the units are filled, the soil/sand fill material is coming in direct contact with the soil it is being built upon.  This minimizes the ability of water to seep under your wall.  These two products can be thought of as earthen building blocks which perform well in difficult areas.

The Louisiana Floodwall is the least expensive barrier on the market when achieving height and can easily be modified to ‘plumb’ pipes through a wall or made to be thicker, thinner, or otherwise modified for a variety of different reasons or applications.  It is also easily repaired should it get damaged.  If we are trying to hold back (or redirect) really high water, violent water, big storm surges, or even debris flows, this would be our ‘go-to’ product.  It can be made as thick as needed and stacked extremely high giving you a wall of whatever mass/weight necessary to deal with big problems.  This is the reason the USACE use this design for most of their flood defense operations when it comes to temporary flood barriers.

Pictures: Louisiana Floodwall being joined, filled, and stacked

Do you need a long-term solution?

Defencell is a soil filled barrier made from a heavy duty, non-woven geotextile that is expected to live upwards of 100 years when buried.  In addition to being a stand alone flood defense barrier, it is a fantastic tool for flood defense landscaping!  Bury it!  This product can be the core of an earthen berm so if water overtops the berm and cascades down the ‘dry side,’ it will not be able to erode the berm to the point of breaching which is a common cause of levee failures.  This product can be used to create low berms or high berms or stabilize riverbanks, canal banks, sand dunes, and a variety of applications limited to your imagination.  Remember, it might be less expensive to create some long-term flood defense landscape features which can tie together with temporary flood defense barriers.

Pictures:  Defencell coastal restoration sequence and a reinforced and revegetated coastal berm.

Reusable vs Not Reusable

Our soil filled barriers are generally not reusable.  They do cost less than most reusable barriers on the market and have their places within the flood fighting arena.

We understand that a homeowner being faced with a constant threat of flooding may not want to change the landscape of their property or mess with large piles of soil and heavy machinery used in installing soil filled barriers.  They want an easy solution they can deploy as required.  Our reusable barriers consist of the Muscle Wall, NOAQ Boxwall, and NOAQ Tubewall products in addition flood panels which are attached to your structure directly.

Picture:  NOAQ Tubewall deployed examples without water and being overtopped

When it comes to the residential market, the NOAQ Boxwall is the clear favorite.  It is lightweight, easily assembled by a single person, and stacks away in your garage (or the back of a truck) for future deployments.  It is 19.68” tall.  Additionally, it will instantly redirect flowing water that is already in place.  This is a huge advantage!

However, if you want something bigger, we have the Muscle Wall which we believe to be one of the most robust, reusable barriers on the market.  The water fill gives it weight that makes it nearly impossible to move which leaves it standing strong against high and violent water.  This product has extension pieces which allow you to create additional height after building it as required and simple to dismantle.  Pull the plug, the water drains out, and reclaim your barriers for storage until the next flood.

Pictures:  Muscle Wall being carried, filled with water, and lined with a plastic liner

How much notice do you have before floodwaters arrive?

If you have minimal notice until floodwaters are present, the NOAQ Boxwall is the winner on speed of installation followed by the NOAQ Tubewall which is quickly filled using air.  The Muscle Wall can be deployed within a matter of minutes if immediately available but takes some time in filling it with water.

Price

We have a pricelist which details pricing all our different barriers that are then broken down to cost per linear foot.  You will find options that are among the least expensive options on the market and reusable options which are slightly more expensive but built to last and be deployed repeatedly.

"Seepage" and the use of plastic liners

Seepage can be described as the passage of water to the dry side of the barrier.  During a flood event, water can be coming from the sky, gutter downspouts, and even through the ground under your barrier.  (this is especially true in Florida) Plastic liners, while not always necessary, are an extremely inexpensive addition to any flood barrier which helps mitigate against seepage and is a necessary part of the Muscle Wall system.

In cases where the ground is really soft, uneven, or prone to under seepage, it can commonly be mitigated against with the use of a plastic liner.  If you take a 10' (or 20’) wide section of plastic (by 100' long), you start on the 'dry side' and wrap it up and over your flood barrier which, in the case of a 2’ flood wall for example, would leave you about 6' of extra plastic.  You stretch this out into the direction of the incoming floodwater and weigh the leading edge down.  (weigh down using something heavy like a steel pipe, a chain, angle iron, or sand bags.  'Turf Stakes' which look like large staples used in grass also are an inexpensive solution for added security in attaching plastic sheeting to the ground which may be a good idea during a hurricane.  As the incoming floodwaters rise and sit on top of the plastic, the weight of the water pushes the plastic to the ground creating a water resistant seal to the ground 6' before it even gets to your flood barrier.  This is an easy and inexpensive way to compensate for poor ground conditions.

The Muscle Wall and Boxwall products both have firm flat surfaces on the bottom of these barriers.  Sometimes, when building on a sidewalk for example, the concrete may be uneven from growing tree roots, frost heaves, or curbs.  These areas would naturally create a path for water to pass through.  The use of a plastic liner quickly compensates for these types of voids naturally found within the urban landscape.  If you are ever making home made flood defense barriers, get lots of plastic!  It helps, it works, and it is inexpensive.

Picture:  Lined Muscle Wall

The last line of defense

Pictures:  Sump pump examples with homemade water capture depressions/holes

If you have water that may sit around your house for a number of days, the water is still working it’s way in!!  It isn’t stopping and will begin to seep up from through the ground or any other avenue of approach it can find.

This is why we are huge proponents of sump pumps; the last line of defense.  We always suggest installing your flood barrier far enough away from your house such that you can walk the entire perimeter during a flood fight to inspect what is happening and easily identify any problem areas.  This also allows a space for you to identify any water that has come in and pump it away.  If you have an identified low spot, that is where you place the pump.  I would even create a prepared hole/box below ground level for pump placement.  It doesn’t have to be fancy but rather give a good place for the water to pool and aid your pump in not ‘running dry’ because the water which may be present isn’t deep enough to suck out.

If you must evacuate the area, water activated sump pumps are inexpensive and worth the investment.  These require power and if you anticipate power to go out, a small generator may also be a good idea.

Conclusion

There is no ‘one size fits all’ when it comes to flood defense barriers and the variety of challenges you may encounter.  We believe there are solutions to most all problems you may encounter.  If you can ever use our opinion whether it be about our barriers, competitive barriers, or even home-made solutions, give us a call.  We are here to help and enjoy taking the time to do so even if you aren’t a customer.  We always enjoy the conversation!

© 2017 Flood Defense Group LLC. All Rights Reserved

ManShak Marketing & Design