By akademiotoelektronik, 08/04/2023

Drones earn their place in water management in France

They monitor pipes, sewers, dykes and rivers: drones, whether they fly, float or roll, have earned their place in water management in France, replacing humans in certain tasks dangerous.

Alban Chesneau, helmet on his head, lifts a manhole cover with a pickaxe. The In-R manager grabs the drone by its protective cage and drops the machine into the conduit.

All lights on, the drone sinks, the walls of the manhole returning the high-pitched sound of the four small engines. The technician now relies on his camera to navigate the sewerage network in Orléans, in central France.

"With a single opening, we will be able to inspect between 150 and 200 meters depending on the nature and the cleanliness", explains the pilot based in Saint-Herblain (west).

The obstacles can be numerous and the piloting difficult in a confined environment: cobwebs, roots, water level... The inspection can be limited to around fifty meters per descent.

"But the number of batteries on the site, we will be able to make an inspection panel which rotates between 750 meters to one kilometer per day", adds the man with the remote control. "Without having to descend from a human in the network."

Not far from there, Jean-François Bramard, founder of the Cambulle company in Bouc-Bel-Air (south), is also preparing to lower his device, a rover.

"We need an agile machine, with quite special properties that allow it to move in places where there are stones, bottles, roots, a multitude of objects. The objective, it is to be able to carry out recognition images to consider work", he explains, checking that the wheels are articulated in all directions.

For the French giant Suez, which manages part of the Orléans sanitation network, small remote-controlled vehicles are a real asset.

"These techniques are fully operational. This year, we carried out 3 kilometers of inspection in Orléans, on structuring networks that it was essential to inspect. (...) In concrete terms, this makes it possible to know the state heritage under the cities", welcomes Alexandre Ventura, head of innovation, diagnostics and robotics at Suez.

- Risks avoided -

"These are hours of work underground (...) and risk-taking avoided", he says with satisfaction.

These benefits are not limited to sewers. Drones are used in almost every sector of water management, such as dike monitoring.

"During an inspection, qualified people examine on foot. By using a drone with a camera, we have access to interesting points of view that people on foot do not have access to", says Jordan Perrin, engineer at France Digues, the association of dike managers.

The addition of a thermal sensor can also make it possible to locate leaks. A lidar (laser telemetry) also makes it possible to obtain a fine topography of the area.

"Before it was a helicopter-borne device. It costs much less now", appreciates the engineer. "And we can now also use aquatic drones for all bathymetry."

This is the radius of ADCPro. The floating devices of the company based in Breuil-en-Vexin (Paris region) thus monitor rivers, lakes, ports and bodies of water. She works for regional environmental departments, water agencies, laboratories and even Suez and Veolia.

Its monohulls or trimarans, which can carry up to 25 kilos of instruments, are used in multiple missions: "mapping the seabed", gauging to obtain "instantaneous flow", sampling, details its president Danny Engel.

The small orange boats also measure various parameters (chlorophyll, ammonium, nitrates, pH, conductivity, temperature, turbidity, etc.) in places that are difficult to access for a crew. “The hydrojet engines (water propulsion, editor’s note) make it possible to evolve in algae or port areas without being worried by the ropes”, appreciates the manager.

Again, with an obvious payoff. "The interest is also not to have anyone on the water, because there is a risk of drowning", he continues. "Normally, it takes three on a boat: a pilot, a technician and a supervisor. Trained people and sometimes for a long time. We only need one pilot. And losing a drone is acceptable, losing a man is not ."