Perhaps the fountains are close to The Americas Plaza, a shopping centre. This is approx.half way between Las Americas and Loc Christionos,

Regards,

Billyboy.

As billyboy says there are fountains at Americas Plaza.But what is this area, is it Las Americas or Los Cristianos?Its debatable.Some say one some say the other,myself included.I have a place at Tenerife Royal Gardens,and tell people I have a place in Los Cristianos.
There are some fountains in Los Cristianos, I seem to remember.Although I cant be sure if I have ever seen them working,at the top of the street that leads down to the port.But this area is not normally walked by a lot of tourists.

There is a fountain in Los Cristianos at the end of Avenida Suecia opposite the roundabout at the top of San Telmo and the road up from the ferry port in the harbour

im sure the ones there talking about are the ones under Harry's cocktail bar in the Safari centre - next to Med Palace Hotel. Near where the "balloon" Used to be
click on this link it may help you locate where it is by sight rather than directions
http://www.tenerife.com/en/harrys_fotos2.asp

If so, those fountains are in the Las Americas resort according to the Arona District council.