When an industrial site, workshop or technical facility is exposed to flood risk, the first question to ask is not necessarily whether to install a flood barrier or a removable flood barrier.
A professional site may be exposed through a door, gate, loading bay, yard, several access points or a much longer perimeter. Before choosing a technical solution, it is therefore essential to understand how water is likely to reach the building, how high it may rise, which installations must be protected as a priority and under what conditions the teams will be able to respond.
The choice between a removable flood barrier and a larger flood barrier comes afterwards, based on this analysis.
For 2 L’Eau Protection, flood protection is therefore part of a comprehensive approach: assessment of the design flood scenario, site visit, analysis of water pathways, assessment of the building and its operation, followed by the definition of the most appropriate equipment.
The design flood scenario: the starting point for the assessment
Before deciding where to install protection, the first step is to define the scenario against which the site must be protected.
The design flood scenario is the reference scenario selected to size the flood protection strategy.
Several parameters must be assessed:
- the potential water level
- the rate at which the water may rise
- the possible duration of the event
- the available warning time
- surface runoff or overflow phenomena
- data from previous events or available hydraulic studies.
This information helps determine how much time teams will have to respond and when the protection systems will need to be deployed.
The protection height cannot therefore be chosen arbitrarily. It must correspond to a realistic scenario while also remaining compatible with the characteristics of the building and the structures to which the protection will be attached.
Assessing water pathways across the entire site
Once the design flood scenario has been defined, it is necessary to understand how water may move across the site. Reviewing topographical survey plans and carrying out a site visit makes it possible to assess the topography, low points, threshold levels, doors, gates, loading bays, technical access points, networks and runoff areas.
It is also important to anticipate possible bypass routes. Protecting one door may be insufficient if the water can simply continue along a façade and enter through another opening a few metres away. Flood protection must therefore be considered across the site as a whole rather than as a series of independent products.
2 L’Eau Protection's projects illustrate the wide variety of configurations encountered. Projects involving the flood protection of the Arkema plant and the protection of the Vandoren plant demonstrate the importance of adapting the strategy to the specific characteristics of each industrial environment.
Identifying what needs to be protected as a priority
Not all areas of an industrial site have the same level of criticality. A room containing electrical panels, IT equipment or control systems may be far more sensitive than a circulation area or secondary storage space.
The assessment must therefore take into account the consequences of water entering different parts of the site. Electrical equipment, production facilities, stock, goods, premises required for business continuity and access routes essential for employees or emergency services must all be identified.
This prioritisation also avoids automatically seeking to protect the entire site. In some configurations, it may be far more relevant to secure a limited number of strategic areas where flooding would have major consequences.
Checking whether the building can withstand water pressure
The water level does not only determine the height of the barrier. As the water level rises, the pressure exerted on the protection equipment and on the building itself increases significantly.
It is therefore not enough for a barrier to be watertight. The forces must also be transferred to supports that are capable of withstanding them.
An operator may, for example, wish to install protection capable of retaining two metres of water. However, if the walls, façade or foundations of the building are not designed to withstand the corresponding pressure, the solution cannot be implemented as initially envisaged.
Several alternatives may then need to be considered: reducing the protection height, reinforcing the structure, moving the line of defence or installing a barrier away from the building so that the forces are transferred differently.
This structural aspect is essential in industrial and technical environments, where the flood protection system must form part of a coherent overall construction solution.
Considering operational constraints before choosing the solution
The system must then be assessed against the actual operating conditions of the site. A factory or workshop has daily flows involving employees, forklifts, vehicles, HGVs, maintenance operations and deliveries. Some access points must remain available until the last possible moment, particularly for emergency services or evacuation. Deployment time is therefore also a decisive factor.
A technically effective solution that cannot be installed within the available timeframe does not provide genuinely operational protection. It is therefore necessary to know how many people can be mobilised, where the equipment is stored, how much it weighs, how long installation takes and what handling resources are required.
A barrier several hundred metres long may, for example, be hydraulically relevant but unrealistic if the site only has a small number of operators and limited warning time.
Degraded operating conditions must also be anticipated: night-time deployment, heavy rain, reduced staffing levels or a power failure.
The technical choice must therefore take into account both the flood risk and the organisation's actual operational capabilities.
When should a removable flood barrier be used?
Only after this assessment should the selection of equipment begin.
A removable flood barrier is generally a suitable solution when the risk is concentrated around one or more clearly identified openings. It can, for example, protect a service door, workshop entrance, electrical room, sectional door or access point to a technical facility.
In its removable form, the barrier allows the opening to remain completely clear under normal operating conditions. The components are installed only when an alert is issued.
This solution is particularly suitable when teams can respond quickly and the walls, threshold and supporting structures are capable of correctly withstanding the forces exerted by the water.
The flood protection work carried out at a John Deere site is an example of several entrances being protected within an industrial environment. Here, the removable barrier addresses a localised issue by preventing water from passing through openings identified as vulnerable.
When should a flood barrier be used?
A flood barrier becomes particularly relevant when protection needs to be considered on a larger scale.
It can protect a wide opening, secure several access points at the same time, close off a substantial perimeter or create a line of defence upstream of the building. In the latter case, the objective is no longer to close each individual door but to prevent water from reaching an entire area.
This strategy may be appropriate for an industrial platform with several buildings or where there are too many openings to protect individually.
Longer systems such as Floodwall flood barriers can be used in this type of configuration.
2 L’Eau Protection also works on particularly sensitive facilities, including projects involving the flood protection of nuclear power plants.
A flood barrier is not automatically more effective or more appropriate than a removable barrier. It simply addresses a different scale of protection.
Combining flood barriers and removable barriers when required
In many projects, there is little value in simply opposing flood barriers and removable flood barriers. The two systems can be entirely complementary.
A barrier can create a first line of defence to prevent water from reaching part of the site, while removable barriers secure particularly sensitive openings. A watertight door can also complement the system where certain access points require permanent protection.
This combined approach makes it possible to adapt protection to the movement of water, the criticality of equipment and operational constraints. It also ensures that resources are concentrated where they are genuinely needed.
Sizing the protection height and length
Once the protection principle has been defined, each item of equipment must be accurately sized. The height depends on the design flood scenario and the selected safety margin. The length depends on the openings and the perimeter to be protected.
These two parameters directly influence the forces exerted on the system, the number of components required and the installation constraints. An opening less than one metre wide and a fifteen-metre industrial entrance clearly cannot be addressed in the same way.
The example of the Profroid plant protected against flood risk illustrates the importance of accurate sizing. FM Approved flood barriers were installed as part of a scenario involving up to 900 mm of water.
Reliability of flood protection systems for professional sites
When protection is intended to safeguard an industrial operation, strategic equipment or sensitive infrastructure, reliability naturally becomes an important consideration.
For relevant projects, 2 L’Eau Protection offers equipment that meets the requirements of the FM Approved certification.
This recognition can provide a useful reference point for operators, insurers, engineering firms and specifiers involved in flood-risk prevention.
However, it does not mean that every solution offered by 2 L’Eau Protection is FM Approved, nor does certification remove the need for a detailed site assessment.
Even tested equipment must be correctly sized, installed on a suitable structure and incorporated into a coherent operational procedure.
Business continuity at the heart of flood protection
For a company, the consequences of flooding extend far beyond physical damage.
A production line that is out of service, a damaged electrical panel, unavailable IT equipment or an inaccessible technical room can cause disruption lasting several days or even longer.
The flood protection strategy must therefore incorporate business continuity.
This issue is also essential for technical infrastructure and sites providing important services.
2 L’Eau Protection has therefore worked on projects involving flood protection for CPCU and the protection of Orange facilities against flooding from the Seine.
The objective may therefore be less about making the entire site completely watertight and more about preventing the shutdown of equipment and areas that are essential for maintaining or resuming operations.
From site assessment to installation: support from 2 L’Eau Protection
Protecting an industrial site against flooding is not simply a matter of selecting equipment from a catalogue.
2 L’Eau Protection supports companies, industrial site operators, technical facility managers and those responsible for sensitive buildings from the initial assessment through to commissioning of the protection systems.
The process begins with a site visit and an assessment of the characteristics of the design flood scenario.
The teams then analyse potential water pathways, vulnerable points, the assets to be protected, structural constraints and the organisation of the site.
Based on this information, different recommendations can be considered: removable flood barriers, larger barriers, perimeter protection systems, watertight doors or a combination of several solutions.
2 L’Eau Protection can also work as part of a wider project involving engineering firms, civil engineering contractors, installers, insurers and other technical stakeholders.
The objective is to provide a technically appropriate solution that is also genuinely practical to deploy on site.
Testing the systems and preparing the teams
Installing the equipment is not the final stage.
A protection system must also be capable of being deployed correctly on the day it is needed.
Operators must know where the components are stored, who is responsible for deployment, the order in which the systems must be installed and how to check that they have been fitted correctly.
Regular exercises make it possible to test the procedure under realistic conditions.
They may reveal that equipment is stored too far from where it is needed, that a component is difficult to handle, that installation takes longer than expected or that certain access points have changed since the system was designed.
Feedback can then be used to adjust procedures and, where necessary, the equipment itself.
2 L’Eau Protection also provides equipment and spare-parts follow-up to help keep the systems operational over time.
Building a flood protection strategy that can actually be deployed
There is no universal solution for protecting a professional building against flooding.
The process must begin by defining the design flood scenario, assessing the water pathways and identifying the equipment or areas that must be protected as a priority.
The ability of the building to withstand the forces involved, operational constraints, warning time and the human resources genuinely available must then be assessed.
A removable flood barrier may be an appropriate solution for an individual opening. A flood barrier may be more suitable where a large width, several access points or an entire area need to be protected.
On more complex sites, a combination of both solutions may be preferable.
The protection must therefore be correctly sized from a technical perspective while also remaining genuinely deployable during an emergency and compatible with business continuity requirements.
2 L’Eau Protection's teams support operators and decision-makers throughout this process, from site assessment through to installation, testing and feedback.
Contact 2 L’Eau Protection to assess the flood protection requirements of your site.
Frequently asked questions about flood barriers and removable flood barriers
What is the difference between a flood barrier and a removable flood barrier?
Both systems are designed to limit water ingress, but they generally operate at different scales. A removable flood barrier is particularly suitable for an identified opening, while a larger flood barrier can protect a wide opening, several access points or an entire area. The choice should nevertheless result from the site assessment rather than from this distinction alone.
What is the first step before installing flood protection?
The first step is to define the design flood scenario and assess the site: expected water level, rate of water rise, warning time, low points, vulnerable openings and equipment requiring protection. This information can then be used to determine the most appropriate solutions.
How should the height of a flood barrier be selected?
The height must be determined according to the selected flood scenario and the characteristics of the site. It must also be compatible with the ability of the walls, supports or foundations to withstand the forces exerted by the water.
Can a flood barrier protect an entire industrial site?
Yes. Some systems can protect substantial perimeters or create a line of defence upstream of several buildings. Their suitability nevertheless depends on the movement of water, the site's topography, the available personnel and the time available for deployment.
Can a flood barrier be combined with several removable barriers?
Yes. This combination may even be the most appropriate solution on certain sites. A larger barrier can protect a substantial area while removable barriers secure particularly critical openings.
Why is the number of available operators important?
A protection system may be technically suitable but impossible to install quickly enough. The number of operators, the weight of the components, their storage location and the available warning time must therefore be taken into account from the design stage.
Why should exercises be carried out after installation?
Exercises make it possible to measure the actual deployment time, train the teams and identify potential difficulties before a real emergency occurs: a missing component, equipment that is difficult to access, a poorly understood procedure or an organisation that needs to be improved.
Is an FM Approved solution automatically suitable for every site?
No. Certification provides a performance reference for the equipment concerned, but it does not replace flood-risk assessment or correct sizing. The solution must always be adapted to the site's configuration, design flood scenario and operational constraints.