Draguignan: Clay Soil, Subsidence and Cracks – Official Data

The official clay classification (GéoRisques/BRGM)

The GéoRisques platform (BRGM) classifies Draguignan at high exposure to clay shrink-swell (RGA), with some sectors at medium exposure. This is the benchmark level used by insurers and notaires to assess the risk on a plot.

This classification completes the decree history above: the hazard rating says what can happen, the decrees say what has already happened. A house rated “high exposure” that has come through one or more dry summers carries a risk of damage that is all the better documented.

What the official clay mapping says

The GéoRisques platform (BRGM) classifies Draguignan at high exposure to clay shrink-swell (RGA), with some sectors at medium exposure. This is the benchmark level used by insurers and notaires to assess the risk on a plot.

This classification completes the decree history above: the hazard rating says what can happen, the decrees say what has already happened. A house rated “high exposure” that has come through one or more dry summers carries a risk of damage that is all the better documented.

Draguignan: ground conditions that demand local knowledge

Draguignan, with its 40,826 inhabitants, is a case we often come across on the ground: the commune stretches from the first foothills of the Préalpes de Grasse to the plain of the Argens, and this gently sloping topography shapes the nature of the soils considerably. You find Keuper marls and clays there that are particularly sensitive to the shrink-swell phenomenon, especially in the neighbourhoods built on the former agricultural terraces around the historic centre and towards Les Collettes. The built fabric is highly heterogeneous: Provençal villas from the 60s-70s on shallow foundations, more recent estate houses developed in the 90s-2000s on the outskirts, often built quickly with no in-depth soil survey. Vegetation also plays a significant role: the many pines and olive trees planted in rows near homes pump water from the soil at depth, intensifying the drying-out of the clay during summer drought, a frequent occurrence in the Var. The result: we regularly record differential settlement on this type of plot, with stair-step cracks on façade corners, particularly marked after dry summers followed by the intense rain episodes typical of the Var climate. Individual houses with a garage extension or an added conservatory are the most exposed, because these light structures respond differently from the main building to ground movement.

Drought in the rear-view mirror: 35 years of measured rainfall

The area’s weather archives cover 35 complete years (1991-2025). The driest ever recorded: 2007, with 393 mm over the year, against a local average of 759 mm. 2022 ranks as the 9th driest year out of 35 (594 mm against an average of 759 mm); 2023 follows in 14th place (676 mm).

This ranking gives the true measure of the recent sequence: when the years 2020-2023 sit high up the list of dry years, the clay has had no time to rehydrate between episodes – the textbook scenario for delayed cracking. The reverse is just as instructive: a very wet year following an exceptional drought triggers abrupt swelling of the ground.

Draguignan: 24 Cat Nat prefectoral decrees since 1982, in chronological order

Each line = an event recognised by an interministerial decree published in the Journal officiel (GASPAR database):

• 🔴 05/1989 → 12/1992 – Drought – clay shrink-swell (RGA) (prefectoral decree of 05/01/1994)
• 🔴 01/1998 → 12/1998 – Drought – clay shrink-swell (RGA) (prefectoral decree of 27/12/2000)
• 🔴 01/2002 → 06/2002 – Drought – clay shrink-swell (RGA) (prefectoral decree of 25/08/2004)
• 🔴 01/2004 → 03/2004 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔴 07/2004 → 09/2004 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔴 01/2007 → 03/2007 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔴 01/2016 → 12/2016 – Drought – clay shrink-swell (RGA) (prefectoral decree of 25/07/2017)
• 🔴 07/2017 → 09/2017 – Drought – clay shrink-swell (RGA) (prefectoral decree of 18/09/2018)
• 🔴 07/2019 → 09/2019 – Drought – clay shrink-swell (RGA) (prefectoral decree of 29/04/2020)
• 🔴 01/2022 → 09/2022 – Drought – clay shrink-swell (RGA) (prefectoral decree of 03/04/2023)
• 🔴 04/2023 → 06/2023 – Drought – clay shrink-swell (RGA) (prefectoral decree of 18/06/2024)

Expert reading: 11 droughts and 13 floods. Clusters (several decrees close together) flag up crisis periods – the summer of 2022-2023 is the best recent example. An owner whose damage dates from a covered period has a solid Cat Nat file; outside a covered period, the way forward is an action against the seller.

The complete chronology of the 24 natural disasters recognised in Draguignan

Each line = an event recognised by an interministerial decree published in the Journal officiel (GASPAR database):

• 🔵 08/1984 → 08/1984 – Floods (prefectoral decree of 05/12/1984)
• 🔴 05/1989 → 12/1992 – Drought – clay shrink-swell (RGA) (prefectoral decree of 05/01/1994)
• 🔵 10/1990 – Floods (prefectoral decree of 28/03/1991)
• 🔵 09/1992 → 09/1992 – Floods (prefectoral decree of 23/06/1993)
• 🔵 01/1994 → 01/1994 – Floods (prefectoral decree of 27/05/1994)
• 🔵 11/1994 → 11/1994 – Floods (prefectoral decree of 03/03/1995)
• 🔵 01/1996 → 01/1996 – Floods (prefectoral decree of 02/02/1996)
• 🔴 01/1998 → 12/1998 – Drought – clay shrink-swell (RGA) (prefectoral decree of 27/12/2000)
• 🔵 11/2000 – Floods (prefectoral decree of 29/05/2001)
• 🔴 01/2002 → 06/2002 – Drought – clay shrink-swell (RGA) (prefectoral decree of 25/08/2004)
• 🔴 01/2004 → 03/2004 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔴 07/2004 → 09/2004 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔴 01/2007 → 03/2007 – Drought – clay shrink-swell (RGA) (prefectoral decree of 07/08/2008)
• 🔵 06/2010 → 06/2010 – Floods (prefectoral decree of 21/06/2010)
• 🔵 11/2011 → 11/2011 – Floods (prefectoral decree of 18/11/2011)
• 🔴 01/2016 → 12/2016 – Drought – clay shrink-swell (RGA) (prefectoral decree of 25/07/2017)
• 🔴 07/2017 → 09/2017 – Drought – clay shrink-swell (RGA) (prefectoral decree of 18/09/2018)
• 🔵 01/2018 – Floods (prefectoral decree of 26/03/2018)
• 🔵 10/2018 – Floods (prefectoral decree of 26/02/2019)
• 🔴 07/2019 → 09/2019 – Drought – clay shrink-swell (RGA) (prefectoral decree of 29/04/2020)
• 🔵 11/2019 → 11/2019 – Floods (prefectoral decree of 28/11/2019)
• 🔵 10/2021 → 10/2021 – Floods (prefectoral decree of 15/10/2021)
• 🔴 01/2022 → 09/2022 – Drought – clay shrink-swell (RGA) (prefectoral decree of 03/04/2023)
• 🔴 04/2023 → 06/2023 – Drought – clay shrink-swell (RGA) (prefectoral decree of 18/06/2024)

Expert reading: 11 droughts and 13 floods. Clusters (several decrees close together) flag up crisis periods – the summer of 2022-2023 is the best recent example. An owner whose damage dates from a covered period has a solid Cat Nat file; outside a covered period, the way forward is an action against the seller.

Damp, water ingress and rising damp in Draguignan

Damp in a wall can have four causes – rising damp, water ingress, condensation or a leak – and the treatments are completely different depending on the origin.

You have spotted damp at home in Draguignan and may be tempted to rush into resin injections or a mechanical ventilation system. My message: not so fast. Without a diagnosis of the exact origin, you risk paying for a pointless treatment that will solve nothing.

The 4 causes and how to recognise them

• Rising damp: stains rising from the ground, often limited to the first metre of wall, efflorescent salts, blistering renders.
• Water ingress: rain-related halos, appearing near a crack, a roof or a defective gutter, worse after a storm.
• Condensation: misted windows, mould in cold corners, poorly ventilated rooms (bathroom, kitchen), frequent in poorly insulated homes.
• Leak: a localised stain near a pipe, an upstairs bathroom, a persistent smell, a climbing water bill.

The trap of the diagnosis sold by the treatment contractor

In Draguignan as elsewhere, some damp-treatment companies offer a “free quote” – but the firm selling the injection has every interest in diagnosing… rising damp. That diagnosis is not independent: it exists to sell a service, not to identify the true cause. Frequent outcome: thousands of euros of injections installed on a wall that was in fact suffering from a simple leak or a ventilation defect, with the damp returning a few months later.

Before commissioning works, have an independent diagnosis drawn up by an expert who has nothing to sell you at the end of the report. Contact us for a damp diagnosis in Draguignan, and read the damp guide for 06, 83 and 13 to understand in detail the four causes and their appropriate treatments.

Draguignan: drought, clay and cracks – what the official figures reveal

Your house is cracking in Draguignan and you are wondering whether it is the drought? The commune totals 11 drought prefectoral decrees (full list below) and 13 flood decrees, i.e. 24 natural disaster declarations (Cat Nat) – one of the heaviest records in the Var. On the weather side, the trend matches: two dry years back to back (2020, 2022), then 2024 climbs back to 1,021 mm (+30%) – exactly the cycle that puts foundations under strain in the Dragon City, in the heart of the Haut-Var.

Cassini Expertise, an independent building firm, handles cracks and drought-related damage in Draguignan and throughout the Var. This page brings together the official data specific to the commune: compare it with what you observe at home, and know when to act.

Does my cracked house in Draguignan match a recognised drought decree?

The GASPAR database (decrees published in the Journal officiel since 1982) records 24 natural disaster declarations (Cat Nat) for the commune:

• 11 drought prefectoral decrees (differential ground movement linked to clay shrink-swell (RGA))
  • event of 01/05/1989 (prefectoral decree of 05/01/1994)
  • event of 01/01/1998 (prefectoral decree of 27/12/2000)
  • event of 01/01/2002 (prefectoral decree of 25/08/2004)
  • event of 01/01/2004 (prefectoral decree of 07/08/2008)
  • event of 01/07/2004 (prefectoral decree of 07/08/2008)
  • event of 01/01/2007 (prefectoral decree of 07/08/2008)
  • event of 01/01/2016 (prefectoral decree of 25/07/2017)
  • event of 01/07/2017 (prefectoral decree of 18/09/2018)
  • event of 01/07/2019 (prefectoral decree of 29/04/2020)
  • event of 01/01/2022 (prefectoral decree of 03/04/2023)
  • event of 01/04/2023 (prefectoral decree of 18/06/2024)
• 13 flood prefectoral decrees and storm

Why check these dates? If your cracks appeared during a period covered by a decree, you can claim natural disaster declaration (Cat Nat) compensation – provided you declared the loss to your insurer within 30 days of publication of the decree. If that deadline has passed, or the decree does not match, the judicial route against the seller remains, for hidden defect (vice caché) or fraud (dol). In both cases, keep your dated photos and your invoices: they provide the proof.

Am I in an at-risk clay zone in Draguignan?

The GéoRisques platform (BRGM) classifies Draguignan at high exposure to clay shrink-swell (RGA), with some sectors at medium exposure. This is the level your insurer and your notaire already consult to assess your plot – you can check it yourself on georisques.gouv.fr with your address.

This classification completes the decree history above: the hazard rating says what can happen, the decrees say what has already happened. If your house is in a high-exposure area and has come through one or more dry summers, take cracks seriously from the first signs.

Why does my house move after the rain, and not only in summer

Annual rainfall recorded on the Draguignan weather grid (Open-Meteo data):

• 2019: 1,073 mm · 2020: 654 mm · 2021: 711 mm · 2022: 594 mm · 2023: 676 mm · 2024: 1,021 mm
• Average over the period: 788 mm/year, driest year: 2022 (594 mm)
• Two years in marked deficit (2020, 2022): 654 mm then 594 mm
• Then 2024 bounces back strongly, at 1,021 mm (+30%)

Shrink-swell plays out in two acts: first the drought dries out the clay at depth (shrinkage, first cracks), then the return of the rain rehydrates the ground at a stroke (swelling, differential movement). If your house has shallow foundations – the case for the majority of villas built between 1970 and 2000 – expect the damage to emerge 12 to 24 months after the dry spell, not during it.

Are my cracks linked to drought or just normal cracking?

Watch above all for:

• A stair-step crack, passing through the wall, wider than 2 mm
• A crack that evolves: fit a tell-tale (a band of plaster or a glued strip of glass) and compare after a few months
• Associated damage: doors and windows sticking, tiles splitting diagonally, render bulging
• Clay ground, a tree close to the house, a drain in poor condition

With 11 drought prefectoral decrees on the commune’s tally, if you build up several of these signals, have a survey carried out before any repair – and before any buying or selling decision. Repairing render without treating the cause is money wasted.

How to know whether the ground has really moved under my house

The piezometric station for the area (ADES/Hubeau network, regular measurements) tells the story of the drought better than any speech. Average summer aquifer level, in metres NGF:

• summer 2021: 156.69 m
• summer 2022: 154.15 m
• summer 2023: 155.91 m
• summer 2024: 165.69 m
• summer 2025: 166.13 m

The trend speaks for itself: the water table fell by nearly 2.54 m between summer 2021 and summer 2022, then climbed back above its initial level (166.13 m in the latest summer on record). This back-and-forth sums up shrink-swell: the clay ground contracts when the water table falls, then swells again when it rises. Your foundations do not follow these movements at the same pace – hence cracks that appear with a 12 to 24-month lag after dry summers. If your damage dates from around 2023-2024, the 2021-2022 episode is probably the cause.

Buying or selling a cracked house in Draguignan: what to do?

Between the recent drought decrees and the volume of transactions, quite a few properties are changing hands with damage kept quiet. If you are the buyer and discover cracks after the sale, you have two possible routes:

• Hidden defect (article 1641 of the Code civil): serious cracks, invisible at the viewing, predating the sale → price reduction or cancellation of the sale, action to be brought within 2 years of discovery
• Fraud (dol) (article 1137): the seller knew and concealed the damage → cancellation and damages, action within 5 years; the commune’s GASPAR decree then helps underpin the file

To bring either action, appoint a property-law solicitor (avocat) – and arm yourself with an expert report that dates the damage.

What does an expert do during a drought/clay visit in Draguignan?

• Technical visit: survey and classification of your cracks, crack-width measurements, functional damage
• Context analysis: clay zone, the commune’s natural disaster declaration (Cat Nat) history (11 drought decrees), local drought episodes
• Costing of works: underpinning, injections, drains – with several scenarios depending on your budget
• A written report, directly usable by your insurer or your solicitor

For an on-site visit: building expert in Draguignan.

Independent firm, with no ties to any building contractor. Request a visit in Draguignan – see also our complete RGA and Cat Nat guide for 06, 83 and 13.

Soil surveys on clay ground: what the regulations say

The requirement for a prior geotechnical survey has applied since 1 October 2020 (ELAN law, art. 68); the new exposure map of 1 July 2026 widens its scope. This obligation, stemming from ELAN law no. 2018-1021, article 68 (decree no. 2019-495 of 22 May 2019), applies particularly to Draguignan (high exposure in the BRGM classification).

• What it changes for building: the soil survey is no longer an option – the ELAN law makes it compulsory in an exposed zone for every sale of building land and every construction contract. Adapted foundations, ground treatment, drainage arrangements: the specifications flow directly from the survey.
• What it changes when buying a recent property: ask whether the survey was carried out and which specifications were applied. A house built without following the geotechnical recommendations on clay soil is a medium-term cracking risk.
• What it changes when selling: the absence of a survey on a property built before the obligation is not a defect in itself – but if damage appears, a seller who knew about it and concealed it exposes themselves to an action for fraud (dol).
• The link with the data above: Draguignan combines high exposure with a well-documented history of drought decrees. Building or buying here without checking the nature of the ground means building on a known and measured risk.

Cassini Expertise handles these files: compliance checks between geotechnical specifications and execution, damage surveys on clay ground, counter-expertise. Request a consultation.

Soil surveys on clay ground: what the regulations say

The requirement for a prior geotechnical survey has applied since 1 October 2020 (ELAN law, art. 68); the new exposure map of 1 July 2026 widens its scope. This obligation, stemming from ELAN law no. 2018-1021, article 68 (decree no. 2019-495 of 22 May 2019), applies particularly to Draguignan (high exposure in the BRGM classification).

• What it changes for building: the soil survey is no longer an option – the ELAN law makes it compulsory in an exposed zone for every sale of building land and every construction contract. Adapted foundations, ground treatment, drainage arrangements: the specifications flow directly from the survey.
• What it changes when buying a recent property: ask whether the survey was carried out and which specifications were applied. A house built without following the geotechnical recommendations on clay soil is a medium-term cracking risk.
• What it changes when selling: the absence of a survey on a property built before the obligation is not a defect in itself – but if damage appears, a seller who knew about it and concealed it exposes themselves to an action for fraud (dol).
• The link with the data above: Draguignan combines high exposure with a well-documented history of drought decrees. Building or buying here without checking the nature of the ground means building on a known and measured risk.

Frequently asked questions

Is Draguignan in an at-risk clay zone?

Yes. The Alpes-Maritimes and the Var are very broadly covered by the clay shrink-swell (RGA) hazard (BRGM mapping, free to view on georisques.gouv.fr with your address). In Draguignan, the 11 drought decrees recorded in GASPAR confirm this is not a theoretical risk: it has already happened, several times over.

Can a cracked house in Draguignan be covered under the natural disaster scheme?

Only if your damage falls within a period covered by a decree (the latest recognised drought periods: 1994, 2000, 2004, 2008, 2017, 2018, 2020, 2023, 2024) and if you declared the loss within 30 days of publication of the decree. Failing that, the action against the seller remains – and there, precisely dating the damage through a survey becomes decisive in winning your case.

Can the data on this page be checked?

Yes: the decrees come from the GASPAR database (Journal officiel, open data sets, 2025 update), the rainfall from Open-Meteo weather archives for the Draguignan grid. Cassini Expertise does not adjust these figures – you can cross-check them yourself before calling us.

Drought right now (as at 04/10/2026)

In the commune: recent rain (3 days ago). Rainfall over the last 30 days: 19 mm, against roughly 54 mm expected at this time of year – a 65% deficit.

A sustained deficit over this window, especially in the growing season, often precedes by a few weeks the drop in the water table shown above: it is the first signal owners can track themselves, before any cracks appear.

Where do the rains stand? (as at 05/10/2026)

In the commune: recent rain (4 days ago). Rainfall over the last 30 days: 19 mm, against roughly 56 mm expected at this time of year – a 66% deficit.

A sustained deficit over this window, especially in the growing season, often precedes by a few weeks the drop in the water table shown above: it is the first signal owners can track themselves, before any cracks appear.

Drought right now (as at 12/10/2026)

In the commune: recent rain (4 days ago). Rainfall over the last 30 days: 67 mm, against roughly 64 mm expected at this time of year – a 5% surplus.

A sustained deficit over this window, especially in the growing season, often precedes by a few weeks the drop in the water table shown above: it is the first signal owners can track themselves, before any cracks appear.

Where do the rains stand today? (as at 19/10/2026)

In the commune: recent rain (1 day ago). Rainfall over the last 30 days: 78 mm, against roughly 73 mm expected at this time of year – a 7% surplus.

A sustained deficit over this window, especially in the growing season, often precedes by a few weeks the drop in the water table shown above: it is the first signal owners can track themselves, before any cracks appear.

Aquifer memory: 26 years of measurements, a well-documented context

The reference piezometric station for the area (002LDFT) has been monitoring the aquifer since 2000 – 26 years of records. As at 02/10/2026, the average level over the last thirty days is 141.35 m NGF (French ordnance datum). Across the whole record, the aquifer has spent only 7.2% of its time below this level: a very low level, rarely reached in the station’s history.

• Last equivalent episode: 04/01/2024 – 2.7 years ago
• Frequency: 26 similar episodes recorded since 2000, i.e. an annual return on average – in hydrologists’ language, a rare event
• Historic minimum: 141.1 m NGF, reached on 01/10/2000

This long memory changes how the risk is read: a low level is not just a weather episode, it is an event whose frequency is known. For a house on clay, it is this frequency that tells you the probability of fresh settlement – and therefore how urgent the precautions are.

Find out more: Article 1641 of the Civil Code and the hidden defects warranty (garantie des vices cachés), explained.

Survey carried out by Frédéric Faucouneau, independent building expert – Antibes, Alpes-Maritimes (06), Var (83), Bouches-du-Rhône (13). Find out more

📅 Last updated 06/11/2026 - Cassini Expertise, independent building expert – departments 06, 83 and 13.