The hydrogeological map displays the distribution of groundwater, bedding conditions, dynamics, and specific characteristics of its composition.

To carry out hydrogeological mapping, monitoring wells must first be installed at specified intervals. Samples taken from these wells are delivered to a LATAK-accredited laboratory to determine the aggressiveness of the groundwater.

During the drilling process, the groundwater level is measured from the ground surface in each borehole. Since the ground surface is tied to absolute elevations, the groundwater levels can also be referenced to those absolute elevations.

Determining the groundwater level elevation is necessary to identify the direction of flow and hydraulic gradient of unconfined groundwater. By knowing the soil’s filtration capacity (m/day) and the thickness of specific soil layers (such as sand or clay), and considering construction climatology standards, it is possible to calculate groundwater inflow and drainage capacity—for example, into a construction pit. This enables builders to estimate the pumping capacity required for dewatering.

Likewise, in order to obtain accurate information for hydrogeological mapping, groundwater level fluctuations must be monitored throughout the entire year. This is important because the depth of foundation construction is determined based on the thickness of ground frost.

In the hydrogeological map, using appropriate software, contour lines (isolines) are used to depict the groundwater level relief.