Race Against Time: City of Reims Battles Invasive Milfoil Plant Proliferation in Léo Lagrange Park Pond

This Monday, May 13, an impressive carousel lives in the pond in the Léo Lagrange park, in Reims. Two large water machines scrape the bottom of the body of water, looking for a very difficult plant: Heterophyllum Milfoil. Coming from the United States, this plant put down in the body of water at the end of 2022. If, originally, it produces oxygen, the proliferation has been a cause for concern, as Manuel Marx, space technician, remembers Greens City: “We made up 15 m³ last year.. Milfoil can grow up to thirty centimeters a week according to the operator Voies navigables de France (VNF). It is so a race against time which is coming.

To cope with this impressive proliferation, the City of Reims has a a three-step attack plan. The first is to pluck the plants while they are “removing as many roots as possible”specifies the technician. “It is a gentle way for biodiversity. The ducks are in the middle of their breeding season so they haven’t nested yet, the fish are pretty much the same. We can already see them in the places where the milfoil has been removed. They are already breathing better! “ This stage could last several more days.

“We can’t get rid of milfoil”

Then, bio-treatment is distributed in the water: “microorganisms and coccolithic chalk”who needs “remove Milfoil from nutrition” thus improving the amount of oxygen in the water. Another treatment, blue color, should prevent the photosynthesis of the plant. So you should not be surprised if the pond has a turquoise blue color. For their part, the aquatic plants are dried “for two or three days”before going to compost.

A protocol set to last: “We can’t get rid of milfoil, we can only reduce the proliferation.” Operating cost: “45 000 euros”.

The aquatic plants are dried “for two or three days” before being composted, explained Manuel Marx. © Radio France –
Clementine Prouteau