• 456 haarea size
  • 1.946aerial photos
  • 5 cm/pxaerial photos resolution


The Sava river corridor between Krško and Brežice

Project Name

Control of the construction of the accumulation pool of HPP Brežice with a small drone


HESS d.o.o., Infra d.o.o.


2016 - 2017

Construction of the accumulation pool is carried out in connection with the construction of HPP Brežice. The artificial lake will stretch over 16 kilometres, from the power plant in the direction of Krško. It will include approximately 20 million cubic meters of water, which is comparable to the volume of water in Lake Bled, and its surface will cover 300 hectares.

The investor, HESS (Hydroelectric power stations on the lower Sava), and a public company Infra from Krško, which is responsible for infrastructure work in the construction of hydroelectric power stations on the lower Sava, want to follow and monitor the progress of this demanding construction project. With continuous aerial photography of the massive construction site in Brežice, Geavis allows them real-time control of volumes of mass movements, i.e. excavations and fills, during the construction.

In each aerial photography cycle, we at Geavis process stereopairs of aerial photos and make a point cloud to obtain 3D raster and metric model of the construction site surface. From aerial photographs and digital surface model we then prepare high resolution planar orthophoto plan that HESS and Infra use for the supervision of the construction.

The vicinity of Cerklje ob Krki military airport and Krško Nuclear Power Plant contribute to the complexity of Geavis` operational procedures. The construction of the reservoir is located in the area of controlled airspace of the airport. Flying is prohibited within the radius of 1km from the Nuclear Power Plant. After a thorough review of the equipment and operational procedures, the Civil Aviation Agency of the RS approved Geavis flying, i.e. outside working hours of the military airport and outside the prohibited area over the reactor. At Geavies, we hope that with the amendment of the Aviation Act in June 2016, which will govern the area of unmanned aircrafts, we will gain the legal basis for the authorization of flying also over the area of the Nuclear Power Plant.