But for this, the Metropolis of Lyon had to begin the “largest decontamination and renaturation project on the banks of the Rhône” (says the water agency cited by Pierre Athanaze) never achieved.
And, as is often the case, Pierre Athanaze, environmental vice-president at the Métropole de Lyon, discovered along the way how the operations to be carried out were more important than expected.
“Small stream, big construction site”he admits.
A phreatic stream, the Rize emerges in the Miribel-Jonage park and begins its short journey in the town of Décines. Then she enters Vaulx-en-Velin to be buried (buried) over 800 meters along the industrial zone which bears her name.
The piping of the watercourse dates back to the 1960s with the creation of this industrial zone. Further on, the Rize emerges, along avenue Grandclément de Vaulx, to end up flowing into the Jonage canal and disappearing there. This means that the Rize flows into the Rhône and dumps all the pollution accumulated during its course, particularly when it flows alongside the companies located there.
For Pierre Athanaze, the first sentence of the “Save the Rize” operation consisted of touring all the industrialists participating “sometimes without even knowing it, by sending untreated water into the river water outlets by connection error” to the pollution of the watercourse.
The final count (far from the 10 or 20 initially estimated) gives 151 companies which, in very varying proportions from each other, participate in the pollution of the Rize. All these companies were visited, and all will be helped by the technical services of the Metropolis to bring their polluting discharge into compliance, which they have until 2025 to comply with.
Then – in 2026 – it will be time to act on the Rize itself, and launch the renaturation operation of this mythical watercourse (an underground river which flows into the Rhône after meandering under Villeurbanne and Lyon) and completely real. To do this, the Lyon Metropolis will redesign a watercourse a few meters from the current one (which is not the historic bed of the river) and clean up the thousands of cubic meters of polluted sediments found there.
The final route, give or take a few meters, has not yet been drawn: soil surveys still need to be done so as not to pass over a pocket of gravel and risk losing all the water. But the first shovel is coming soon: “I can tell you that when this project has been successfully completed I will be the happiest vice-president”concludes Pierre Athanaze, smiling.
@lemediapol
