It explains the objectives in detail and shows how this equipment fits into a general program aimed at preserving the quality of the natural inheritance (urban streams and warterways) as well assuring the perenniality of the man-made heritage (main outfalls and sanitaion works).

The structure adopted for the monitoring-network is based on measuring points of the flow and quality of effluents in transit in the network, or discharged by the main storm spillways, linked to recording rain gauges and a teletransmission system.

The technologies used for the main collectors are analyzed (water-level measurements by pressure-sensors or ultrasonics, water-flow speed measurements by doppler effect or transit time), and their implementation in main sewers is shown.