Undermined ground and landslides in Ostrava
Old mine galleries and landslides cannot be seen, but they can damage a building. Which Ostrava neighbourhoods stand on stable ground, where there is undermined ground or a slope deformation, and what follows from it.
What we map
The Czech Geological Survey keeps two registers that concern the ground under a building: undermined areas, where mining took place in the past, and slope deformations, meaning landslides and other slope movements, active or stabilised. For each address we check whether it lies in either, and for a neighbourhood we count the share of addresses outside both, on stable ground.
Why Ostrava is undermined
Hard coal was mined under a large part of Ostrava for two centuries. Mining in the city ended in the 1990s, but the old galleries and shafts stayed underground, which is why the undermined area is large mainly in the centre and in the older neighbourhoods around the former mines. Buildings on undermined ground are common today and mostly without trouble; for older buildings and for building a new house, though, it helps to know what lies beneath.
Neighbourhoods with the most stable ground
Ostrava neighbourhoods on stable ground
- 100 % of addresses on stable ground Dubina Ostrava-Jih
- 100 % of addresses on stable ground Krásné Pole Krásné Pole
- 100 % of addresses on stable ground Výškovice Ostrava-Jih
- 100 % of addresses on stable ground Polanka nad Odrou Polanka nad Odrou
- 100 % of addresses on stable ground Stará Bělá Stará Bělá
- 99 % of addresses on stable ground Poruba Poruba
- 92 % of addresses on stable ground Hrabová Hrabová
- 90 % of addresses on stable ground Bělský Les Ostrava-Jih
- 74 % of addresses on stable ground Radvanice Radvanice a Bartovice
- 65 % of addresses on stable ground Zábřeh Ostrava-Jih
Where undermining or landslides are most common
Most addresses on undermined ground or a landslide
- 0 % of addresses on stable ground Vítkovice Vítkovice
- 0 % of addresses on stable ground Slezská Ostrava Slezská Ostrava
- 0 % of addresses on stable ground Muglinov Slezská Ostrava
- 0 % of addresses on stable ground Moravská Ostrava Moravská Ostrava a Přívoz
- 0 % of addresses on stable ground Mariánské Hory Mariánské Hory a Hulváky
The maps are drawn for the surroundings, not for a single plot. A neighbourhood or address on undermined ground does not mean the building is at risk: what matters is how deep and when the mining was, and how the building is built. Every neighbourhood shows the detailed figure in its housing section.
What to ask before buying
- The building office: which restrictions apply to the plot, whether it is on undermined ground or a slope deformation, and what the office would require for an extension or a new building.
- The building’s condition: cracks in the walls, sloping floors, doors and windows that stick. They can have many causes, but on undermined ground or a slope, take a closer look.
- Insurance: ask whether the insurer covers damage from undermining and landslides, and on what terms.
- A new house: on undermined ground and on a slope, count on an engineering-geological survey and, depending on it, stronger foundations.
Frequently asked questions
Which Ostrava neighbourhoods have the most stable ground?
The ranking on this page orders neighbourhoods by the share of addresses outside undermined areas and slope deformations, from the Czech Geological Survey’s maps. At the top are those where all or nearly all addresses stand on stable ground.
What does undermined ground mean?
A place under which mining took place in the past, leaving old galleries, pits or shafts. The surface above them can collapse or slowly settle, which is why the building office asks for an expert report for building on undermined ground.
Can I buy a house on undermined ground or on a landslide?
Yes, many buildings stand on undermined ground and on stabilised slope deformations without trouble. Before you buy, though, ask the building office which restrictions apply to the plot, and in an older house look for cracks in the walls and floors.
