bande de bord à quai

17:50 Jan 8, 2020 

I can't see the property address on your link, only the street name. But the houses front right onto the water, separated from it by a narrow quay or towpath.
http://www.airbnb.com/s/Les-Marinas-d'Aigues-Mortes--Aigues~...
I'm not sure what I'd say for "bassin d'agrément". It's a kind of canal or lagoon for pleasure boats.

17:17 Jan 8, 2020 

Thanks very much for your help so far. Here is a link to the address of the property: https://adresse-francaise.com/street.php?i=300030850 The property is a villa at 'Les Marinas de Saint Louis'

17:11 Jan 8, 2020 

Yes, I think "quai" may mean the very edge, and the "bande de bord" could be the area immediately behind it, which we would call the quay. But it would be useful to have pictures confirming this.

16:58 Jan 8, 2020 

bande de bord à quai (interface entre le quai et les terre-pleins) (http://mediatheque.supdeco.sn:81/mediatheque/doc_num.php?exp...

16:42 Jan 8, 2020 

And do please note this is no 'ornamental pond'!! It connects to the canal and has a mooring!
'agrément' in terms of property often translates well as 'recreational' or "leisure' , and this is one case where 'basin' (cf. 'canal basin') might not be out of place.
As for your term, I believe it simply means that one part of the (natural) bank is built up as a kind of 'quayside', which would be consistent with the other clues.

16:34 Jan 8, 2020 

I think it's just a roundabout way of saying quay. You could presumably check this by Googling for pictures of the property.