The field measurements carried out included Topographic Surveying, where a total of 542 characteristic points were recorded for the construction site. The field measurements took place using such a methodology as to conform to standards of Presidential Decree 696/1974 for land surveys with accuracy 1:500 , so as to comply with the regulations set forth by Greek legislation. All raw data during the field measurements on 21st and 22nd of December 2023 were recorded using the suitable equipment (Total Station)

After the completion of the field measurements, took place the process of raw data in the office by using suitable software. The resulted set of points is exported in CAD environment and more specifically in Autodesk’s AutoCAD Civil 3D 2022.

Volume measurement was completed using Autodesk AutoCAD Civil 3D 2022. In the software were created surfaces for every stock inventory material (for water depositions and mud depositions) which were made up of triangles by connecting the points that make up the surface data with triangles that form a triangulated irregular network. The elevation of any point in the surface is defined by interpolating the elevations of the vertices of the triangles that the point lies in. It should be noted that TIN surfaces are most useful for mapping highly variable surfaces.

The volumes’ estimation of stock inventories were made by using two methods for reasons of ensuring accuracy:

• By using the composite method, there is created a new surface based on the triangulation of points from a base surface (bottom of the lake) and the respective comparison surface (upper surface of the lake). Volumes are calculated from the newly created surface, and
• Sectional method computes the volume between the base surface (bottom of the lake) and the respective comparison surface (upper surface of the lake) by using data from sections.