The limits of current flooding diagnostics: how to better protect your property in 2025

Why standard property diagnostics do not detect all flood risks

Since 2003, French legislation has required property owners to provide their buyers and tenants with a diagnosis detailing the natural and technological risks to which their properties are exposed. This Information for Buyers and Tenants (IAL) is a crucial element in decision-making during a property purchase or commercial lease.

According to the article R. 125-24 of the Environmental Code, every owner must indicate whether their property is located in an area affected by one or more natural risk prevention plans (PPRN), specify the status of this PPRN (prescribed, anticipated, approved, or under revision), and detail specific natural risks.

The limits of the Géorisques platform in the face of new climate realities

To carry out this diagnosis, owners are directed to the Géorisques platform (www.errial.georisques.gouv.fr), developed by the Ministry of Ecological Transition and the BRGM. By simply entering an address, the user receives a report on potential technological and natural risks.

However, this approach has a major flaw: it only takes into account areas officially classified as flood-prone, primarily related to river floods and groundwater rises.

In reality, the situation on the ground is very different. Statistics show that:
•    Nearly 10 million jobs in France are located in flood-prone areas
•    92% of the municipalities in Île-de-France have been subject to at least one natural disaster order for flooding between 1982 and 2021
•    88% of these floods were due to runoff phenomena rather than traditional floods

Rainwater runoff: the invisible risk ignored by standard diagnostics

The majority of current floods are caused by intense and sudden precipitation that generates significant runoff, quickly saturating drainage systems. These phenomena often affect areas that are not classified as flood-prone in the PPRN.

This gap creates a dangerous situation where businesses and individuals believe they are protected against flood risks, while they remain vulnerable to these new types of increasingly frequent climatic events.

The financial impacts of an incomplete diagnosis

The increase in natural disasters related to climate change already has a direct financial impact on all French people. The Cat-Nat fund, which we all indirectly finance, will see its surcharge increase from 12% to 20% on January 1, 2025.

An incorrect assessment of risks leads to:
•    Costly material damages for businesses and individuals
•    Significant operating losses
•    Impacts on employment (partial unemployment)
•    Excessive use of the Cat-Nat scheme
•    A general loss of purchasing power

When the official diagnosis fails to prevent a disaster

Let’s take the concrete example of a restaurant for which the Géorisques diagnosis indicated no flood risk. Following a violent storm, the establishment found itself under 80 cm of water, causing significant damages that the owner had not anticipated.
This case perfectly illustrates the problem: the standard diagnosis was technically compliant with regulations but completely inadequate in the face of new climate realities.

The Climate Performance Diagnosis: an innovative approach to anticipate real risks

To address these challenges, the Climate Performance Diagnosis (DPC) developed by Tardigrade AI offers a comprehensive assessment of the climate vulnerability of a property.

This innovative solution stands out by:
•    Analyzing exposure to a dozen climate hazards, including rain floods
•    Using a digital twin of the terrain incorporating surrounding constructions, soil types, and slopes
•    Making projections based on IPCC models to anticipate future risks up to 2050
•    Precisely geolocating potential water heights

In the case of the previously mentioned restaurant, the DPC would have identified a rain flood risk with a 2% probability of experiencing a water height of 80 cm in the next 20 years.

How to reduce rain flood risks

With precise information on actual risks, property owners and businesses can implement effective preventive measures:
•    Raise sensitive equipment and machines
•    Avoid storing important products or documents in exposed areas
•    Install removable protection devices (flood barriers)
•    Pre-position drainage pumps
•    In some cases, reconsider the location of a new installation

Conclusion: Anticipate to better protect your assets

The climate is changing, and our risk assessment methods must evolve accordingly. A static diagnosis based solely on PPRN is no longer capable of effectively anticipating current and future climate risks.
As a property owner or business leader, you cannot prevent the rain from falling, but you can now rely on tools like the DPC Tardigrade AI to preserve your assets, your work tool, and the employment of your employees.

FAQ: Flood Diagnostics and Protecting Your Property

What is a flood caused by rainwater runoff?

A flood caused by rainwater runoff occurs when intense and sudden precipitation cannot be absorbed by the soil or drained by drainage systems. Water then flows over the surface, potentially causing flooding even in areas that are not near waterways.

What is the difference between flood and runoff flooding?

A flood is related to the overflowing of a watercourse (river, stream) that leaves its bed. Runoff flooding is caused by intense precipitation generating surface runoff, regardless of the proximity of a watercourse.

Why are runoff floods becoming more frequent?

Climate change is leading to an increase in episodes of extreme and sudden precipitation. At the same time, growing urbanization and soil sealing reduce natural absorption capacity, worsening the runoff phenomenon.

Is the flood diagnosis mandatory when selling a property?

Yes, since 2003, Information for Buyers and Tenants (IAL) is mandatory and must state whether the property is located in an area affected by a Natural Risk Prevention Plan (PPRN).

What exactly does a standard IAL diagnosis contain?

The standard IAL diagnosis indicates whether your property is located in an area covered by a PPRN, specifies the status of this plan (prescribed, approved, etc.), and details the officially identified natural risks, such as river floods or groundwater rises.

Why can the Géorisques diagnosis be insufficient?

The Géorisques diagnosis is based solely on areas officially classified as flood-prone in the PPRN, which generally do not take into account rainwater runoff flooding. However, these represent 88% of claims in Île-de-France.

What is the Climate Performance Diagnosis (DPC) by Tardigrade AI?

The DPC is an innovative solution that evaluates the complete climate vulnerability of a property by analyzing exposure to a dozen climate hazards, including rain floods. It uses digital twins of the terrain and projections based on IPCC models.

How does the DPC differ from the standard Géorisques diagnosis?

Unlike the Géorisques diagnosis, which is limited to officially flood-prone areas, the DPC analyzes the relief, soil types, surrounding constructions, and future climate projections to identify all types of flood risks, including runoff flooding.

How to know if my property is particularly vulnerable to rainwater runoff flooding?

Certain signs may alert you: your property is located at the bottom of a slope, in a natural basin, or in a highly urbanized area with few green spaces. A Climate Performance Diagnosis will provide you with an accurate assessment of this vulnerability.

How to access the Climate Performance Diagnosis?

You can obtain a DPC for your property by directly contacting Tardigrade AI or by visiting their website. The diagnosis can be carried out for any type of property, residential or commercial.

Do you want to obtain a diagnosis for your business? Contact us today.