Geological description
Area corresponding to rivers, lakes, reservoirs, lagoons, permanent marshes or submerged coastal strips. The point consulted lies on a body of water identified cartographically by the IGME in its geological map. There is no developable substrate accessible in this location.
Foundation ?
It is not possible to found on a body of water. If the plot borders a body of water, the geotechnical study must focus on the bank materials (generally alluvial or deltaic) and consider the risk of flooding and undermining.
Excavatability ?
Not applicable.
Settlements ?
Not applicable.
Water table ?
The point is submerged or permanently saturated.
Seismic risk ?
Areas covered by masses of water do not present any direct seismic hazard for foundations. However, tsunamis generated by submarine earthquakes can affect coastal structures. In reservoirs, earthquakes can cause internal waves (seiches) and dam failure if the impoundment basin overlies liquefiable soils.
Construction advantages
- No constructive advantage. The point is located over water.
Site limitations
- It is not possible to build on a body of water.
- Plots close to bodies of water usually have soft alluvial soils with a very high groundwater table.
- Flooding and scouring risks in riverside plots.
Where this soil is found
Alerts
Hazard- If the queried point appears as a water body but the plot is in dry land, this may be due to the scale of the geological map (1:50,000). It is recommended to consult a nearby point on dry land in order to obtain the classification of the actual substrate.
- Adjacent plots with water bodies have specific risks: a very shallow water table, soft alluvial soils, risk of flooding and undermining of riverbank edges.