Piezometric Level

Level reached by the water at a point and at a given moment of time in a tube reaching down to the body. It can be transferred onto a piezometric map. Some unused boreholes are used to measure this level. These are called piezometers. This measurement of the body’s level should not be likened to a measurement of water reserves, and the technical characteristics of the installation, the geographical sector, the geological context, and pluviometry should be taken into account when interpreting it.

This level corresponds to the body’s pressure, and is generally given in metres NGF in France.
When this level exceeds ground level, the body is called an artesian body: the water is then spurting up.

The piezometric maps established using all the measured data, give a graphical representation of the surface of groundwater bodies, and enable their progression over time to be monitored and to identify their runoff direction.