Praz-sur-Arly is to join the French-mountain-village-with-a-lake club, with plans to complete the build by late 2022 and open for swimming in Summer 2023.
From the photo above it appears to be located on the other side of the river to the Les Belles games area, with a footbridge to connect it.
Work started clearing the land in Nov 2021 (photos here).
All the other amazing lakes in the area can be found here.