Case history


Service for the riverbed discharge measurement


The Autonomous Region of Aosta Valley has requested the execution of flow measurements in order to develop and/or update the rating curves of some water courses in the territory and to integrate its hydrological database.

The 3-year assignment was entrusted to CAE which carried out the riverbed discharge measurement service in the region, confirming its professionalism in field surveys and environmental analysis.



The discharge measurements, both planned and on request, were carried out within the territory of the Aosta Valley Region limited to the watershed area of the Dora Baltea River and its tributaries in the different flow conditions (low, moderate and high level) with current-meter and salt dilution methods.

In the Aosta Valley region, it is certainly complex to perform the discharge measurement and to create the related rating curves. In winter, due to the combined effect of snow and hydroelectric use, the hydraulic heads in the riverbed are particularly low.

However, during the moderate and high level phases, due to the melting snow, the water speeds involved can be significant. The same as the presence of solid and material movements which must always be considered, given the torrential regime of the river sections to be analysed.



The 70 annual surveys were carried out on the 24 sites for a duration of 3 years. The most interesting characteristics of the instrumentation available to each CAE technician team were the hydraulic reels, propeller sets with different diameters, kits for suspended measurements with different weights, the indispensable ADCP sensors on floating supports and chemical probes for measuring electrical conductivity.

The instrumentation is then completed with the use of scanning total stations to read the free surface of water in cases it is difficult to read the staff gauge.

Among the qualities especially appreciated by the clients, we can mention the solid company organization that allowed CAE to employ the operators with certified experience, who were equipped with the complete and adequate instrumentation to perform the service.

With this contract, once again CAE proved to be a valid partner for the public administration authorities by guaranteeing the supply of reliable services and important technical know-how.