the pond which both mention is the current Muchalinda pond. I've attached an except of one of the websites which mention that the current location is inaccurate.
A Japala Nuga Tree was situated in the eastern section of Maha Bodhi across the river Neranjana. Presently the place is marked on the east point of entry to Maha Bodhi. Mucalinda cetiya is situated about two miles from the Neranjana river’s upper bank. Even now this village is called Muchalinda. The present Muchalinda pond had been built when the Maha Bodhi Vihara was built. The earlier site is now only a mound of earth. The present statue with the hooded cobra sheltering the Buddha and amidst the pond had been built by Burmese.
Taken from: http://www.infolanka.com/org/srilanka/religion/14.htm
PS. I will be away in Sri Lanka for the next two weeks so I will not be able to respond to this thread til I'm back