Reading this sentence makes me feel relieved somehow XD
A mély víznél nincsenek, mert most éppen a forgalmas utcán játszanak.
I think "there are not any" would also qualify?
Yes, and also the similar 'there aren't any'. Nevertheless, 'there are no' is the most elegant choice, in my opinion.
yes, though I am not sure if only the most elegant solution should be accepted in the source language :D
As to the English translation, I agree with ion1122.
As a native English speaker, I have to admit that the English translation offered here seems a little unnatural. I wouldn't use 'AT the deep water' on its own. The use of 'at' leaves me wanting more detail: 'at the deep water what?'
The English "by" is awkward sounding in English. In flows much better.
But the Hungarian sentence doesn't necessarily mean they're in the water.
jsiehler is correct. You cannot assume they are 'in' the water.
I'd say "near" as a better translation - even if it isn't exactly what the Hungarian says. But "by" is better than "at".
In American English the natural translation of this would be "There aren't any children by the deep water." "There aren't any" should be accepted as a translation of nincsenek.