For a riverside site I suggest the Dordogne - there are all sorts of sites along the river bank ranging from simple municipal sites up to commercial five star places, and you don’t say what you want to pay.
For lakes you can look at the Massif Central area south west of Clermont Ferrand - that area is peppered with lakes and almost every lake has campsites - being higher up it will be cooler there than the Dordogne, but wetter too. Once again the campsites cover a wide price range. So your choice.
Big sites, good for teens, or smaller sites for parents? There are lots of sites, (of both types) along the Dordogne river. Have a look at Soleil Plage, or the site next door La Bouysse - both have great river access. However, even there it can get very hot in mid-summer. Or look at Les Alicourts at Pierrefitte, just south of Orleans, which has a small lake, plenty of other lakes all around, and is in the middle of a forest for lots of different dog walks.
Love these ideas! Thank you.
Lac d’orient is a fab lake but I wasn’t keen on the campsite in peak summer a few years ago.
Le Massif Central seems good.
Milau (love this area too - stayed at an RCN site nearby and it was gorgeous) and the Dordogne are too far south for our dog.
We have now booked somewhere in the vendee by lac de jaunay and the beach - Le Pin Parasol.
Merci à tous!
Bonnes vacances!