nandi with a water flow is also seen at a place(forgot the name, but not thakkolam) near TN - Andhra Border.
Locals claim that the nandhi water flow never has vatththified... may be summer la andha water dhadiman kammiyaa irukkum and monsoon la dhadiyaa irukkum.. aana water ninnadhu illainnu solraanga....
local aalunga ellaam anda nadhi fountain la vara thanniya dhaan use panraanga for all purpose including household and agriculture
nandhi vaayilirundhu fountain maadhiri vandhu oru kulathil vizhughiradhu... then andha kulam rombi vaaikkaal vazhiyaa paayudhu.....
it shows how the drainage systems were effectively used by ancestors... idhey maadhiri niraiya underground drainage syria la and turkey la kandu pidichindu irukkaanga...
because of our ignorance and non maintenance niraiya drainage silt deposit la clog aairukku..