Quarries and subsoil of Paris’s 15th arrondissement
High risk Paris 75015
The 15th arrondissement, Paris’s most populous, is crossed by the Grand Réseau Sud along its eastern edge (Vaugirard, Convention, Cambronne, Balard). Lutetian coarse limestone quarries are present there, though less dense than in the 14th. The Grenelle and Javel areas are less exposed. Before underpinning works or a purchase, a subsoil check remains recommended, particularly in the eastern part of the arrondissement.
What public data say about the 15th
| Underground network | Grand Réseau Sud (GRS) |
|---|---|
| Mined rock | Lutetian coarse limestone |
| Undermined area | Part of the ~508 ha of the Grand Réseau Sud (eastern edge). |
| Galleries | Included in the GRS’s ~200 km of galleries. |
| Selected risk level | High |
| Confidence in the classification | high |
| Nature of the ground | Limestone plateau (GRS, east) + alluvial deposits of Javel/Grenelle (west) |
| Foundation issue | Ground varies by location: load-bearing limestone to the east, soft alluvium near the Seine to the west. G1 followed by G2 geotechnical studies are recommended, with attention to the depth of competent ground near the banks. |
Sensitive sectors of the 15th
- Vaugirard, Convention, Cambronne, Balard areas
- Eastern part of the arrondissement most exposed; Grenelle and Javel less affected
Ground, fill and clay shrink-swell
The 15th arrondissement is crossed by the limestone Grand Réseau Sud to the east (see quarries section), while the Javel and Grenelle areas, on the edge of the Seine to the west, sit on modern alluvium. Plastic clay was historically extracted at Vaugirard.
Ground varies by location: load-bearing limestone to the east, soft alluvium near the Seine to the west. G1 followed by G2 geotechnical studies are recommended, with attention to the depth of competent ground near the banks.
Unlike almost all French municipalities, inner Paris has no official mapping of the clay shrink-swell hazard (RGA). The BRGM explains this explicitly: the Paris subsoil is largely made up of reworked and artificial materials (backfill, infilled former quarries), which does not correspond to the standard methodology for this mapping — centred on detached houses, which are in the minority in Paris. This does not mean that there is no risk of differential settlement, but that no official area-by-area study exists for the capital: a ground investigation remains the only reliable way to assess a specific plot before purchase or construction.
Your steps to take in the 15th before a purchase or works
A subsurface check is recommended before purchase or works, especially in the eastern part. Consultation with the IGC (Paris quarry inspectorate), a geotechnical study and an Errial statutory risk statement (ERP).
- IGC (Paris quarry inspectorate) information sheet — the authoritative source on the condition of the parcel’s subsoil: €10, issued within 8 days, via the City of Paris online service.
- Statutory risk statement (ERP) — mandatory for sale and letting, generated from Errial; note, it does not return cavity data in Paris.
- geotechnical survey — G1 mission before purchasing a building plot, G2 AVP before a construction or underpinning project.
- Referral to the IGC (Paris quarry inspectorate) for planning — prefectoral orders require it to be consulted for any planning permission in a quarry-risk area.
Frequently asked questions
Are there underground quarries beneath Paris’s 15th arrondissement?
Yes. The 15th arrondissement is recorded in the public data of the IGC (Paris quarry inspectorate) as an area affected by the « Grand Réseau Sud (GRS) » network, in a rock type of Lutetian coarse limestone. The risk level selected is « High », with high confidence in the classification of the area. Western edge of the Grand Réseau Sud, Vaugirard / Convention / Balard area.
How can I find out whether my specific address in the 15th is in an undermined area?
Quarry zoning must be read at plot level rather than arrondissement level. There are two options: the official information sheet from the IGC (Paris quarry inspectorate), at €10 and issued within 8 days, which is the legally binding source; and Sous-sol Paris’s instant pre-assessment, at €15, which matches your address against public data and immediately provides you with a readable report, including the steps to take. This pre-assessment is for information only and does not replace the IGC information sheet, the statutory risk statement (ERP), or a geotechnical study.
Why do the 15th’s cavity data not appear on Géorisques?
Because for départements 75, 78, 91, 92, 93, 94 and 95, cavity data are not published on the Géorisques portal: they can be consulted with the IGC (Paris quarry inspectorate) for Paris and the inner suburbs, or with the relevant interdepartmental service. This is why a standard statutory risk statement (ERP) remains silent on Paris quarries and gypsum.
Is quarry risk in the 15th covered by insurance?
Disorders linked to former quarries do not fall under the « natural disaster » scheme. In the event of collapse, infill works, estimated at 40 000 to 200 000 €, remain the responsibility of the owners. This is what makes checking before purchase essential.
Other arrondissements
- Subsoil of the 14th arrondissement
- Subsoil of the 16th arrondissement
- Subsurface of the 13th arrondissement
- Subsurface of the 17th arrondissement
- Subsurface of the 5th arrondissement
- Subsoil of the 6th arrondissement
- Subsoil of the 7th arrondissement
- Subsoil of the 12th arrondissement
- See the 20 arrondissements
Sources
- City of Paris — Everything you need to know about the subsurfaces
- Institut Paris Région — Underground risk study (quarries)
- Wikipedia — Paris, Geology section
- APUR — Profile of the 12th arrondissement
- BRGM — Why is there no map of the clay shrink-swell hazard for Paris?
- Géorisques — Clay shrink-swell, 2026 version (data)
- Géorisques — Underground cavities (data)
- City of Paris — the IGC (Paris quarry inspectorate) location
- City of Paris — Known areas of former quarries (IGC)
Page updated on 11 September 2026.