This instrumentation approach carried by VNF meets several objectives:

• Continue VNF's voluntary commitment to the EMS (Environmental Management System) approach through the ISO 14001 certification of part of its waterways as part of the optimization of water resource management;
• Meet the obligation to respect instream flow downstream of any withdrawal structure (Article L. 214-18 of the Environment Code);
• Determine as precisely as possible the volumes of catches and discharges within the framework of the abstraction fee to be paid to the Rhine Meuse Water Agency.

The installation of the water level and flow velocity measuring equipment was entrusted to the Messinian agency of SADE, which provided the following services:

• The construction of civil engineering works housing the equipment or the modification of existing works (modifications of spillways, addition of a weir on an existing structure...) ;
• The supply and installation, commissioning and metrological validation of the measuring instruments necessary for the collection of information, their local processing and backup and the transmission devices to the remote management site (TOPKAPI supervision software).

On the various equipped sites, the level measurements are carried out by radar sensors PARATRONIC CR420 and immersed sensors PARATRONIC SNA. The speed measurement is carried out by ultrasonic sensors NIVUS NOS and Nivuflow, or by gauging (M. Hauter, Gestion Hydro).

On each site, the sensors are connected to PARATRONIC LNS low power acquisition units. The data transmission to the TOPKAPI supervisor is done either by ADSL or GPRS/3G.