At the helm of the boat fitted with a cutter blade that morning, Richard. Bob screwed on his head and polarized glasses on his nose, he scans the bottom of the water to constantly adjust the cutting height of the algae. In front of him, sits majestically the castle of Maintenon (Eure-et-Loir). “There are worse working conditions,” smiles Florent Louisot, river technician for Chartres Métropole. “It’s not always easy, Richard says, it’s sometimes 40° with the sun reflecting off the aluminum hull”.
Concentrated on the cut, the pilot is also focused on any obstacles that the 2.40 m wide blade could hit. “The boat weighs four tonnes, you have to be careful with the rocks, but we have also already found shopping carts, bicycles, mopeds at the bottom of the water”, lists the river technician. “To cut well, you have to go as deep as possible. It goes up to one and a half to two meters” points out Jean-François Plaze, elected delegate to the Green Plan at the River for Chartres metropolis.
Exotic algae from goldfish bowls
The shallow-draft boat allows you to sail below decks even if the crew has to lower their heads. “It passes five centimeters from the top of the seat,” smiles Richard. For two days, the two operators have been going back and forth in the moat of the Château de Maintenon. “It’s like for a mower, we proceed by section, we take visual cues on the pillars of the aqueduct in one direction, and on the castle on the way back” explains the helmsman. The action of the mower boat limits the proliferation of algae. Growth facilitated by stagnant water, particularly sunny. “Five days of work are needed here”, to eliminate bur-reed and elodea, the majority aquatic plants in the water features of the Château de Maintenon, notes Forent Louisot. “We have been observing exotic herbs from the aquarium industry for several years. People have the awkwardness of swinging their goldfish in the water with the algae in question,” laments the elected official.
The cut seaweed rises to the surface and then drifts to a floating dam located downstream where it is recovered before being composted. “One to three skips of seaweed come out of the river bed each year,” observes the vice-president.
Cleaning the river improves the circulation of water. “The higher the speed of water flow, the less the vegetation develops, remarks Florent Louisot. If we didn’t come, the stream would be completely covered. It would heat up and lose oxygen, and that would promote fish mortality.” After Chartres and Maintenon, weeding will be carried out for four weeks at the end of August, in the municipalities of Jouy (Eure-et-Loir) and Saint-Prest (Eure-et-Loir).
#Chartres #mow #river #promote #flow #water
