Lac d‘Aiguebelette

We spent the nights of the 29,30,31 of August at camping Sorgey Lac d‘Aiguebelette. We'd visited this area some years back when returning from Sardinia. It's reported to be the warmest lake in France  and with a water temp of 26c it must be! The site was in great location with a designated beach area. Public beaches are not evident as you have to pay to use lakeside swimming areas. Although it was a great site I was left feeling a bit suspicious when they added a further 10% on the bill (acsi rate 15e per night) for taxes but didn't give us a receipt.