"Здесь нет воды."
Translation:There is no water here.
"Isn't" is a contraction of "is not" and "there is not water here" isn't a correct sentence.
It may be ungrammatical, but we do say "there isn't" like that not infrequently in English. I'd say it should be accepted. I'm not even sure it is ungrammatical.
I don't think it's ungrammatical per se. E.g. "there isn't any water here" is perfectly grammatical. "Not" negates the verb (is) while "no" negates the noun (water). English allows one to chose between these two ways of expressing the same idea, it's just that one choice may be less common than the other.
Compare this with "I haven't got/don't have a car" vs. "I have no car".
I wrote 'here is no water'. Would this be grammatically correct in English (and should I report it), or is this an unnatural shape and - while understandable - not preferred in day-to-day speech/writing?
It's unnatural and not preferred in day-to-day speech/writing. At least where I live.
Considering you're from the island, I'll accept that as a valid reason. Thanks, Tigs!
She stresses the ы in воды when saying the whole sentence, but when i clock on the word alone, she stresses the о. Which is it?
"Воды" (stress on the last syllable) is genitive of "вода". In Russian, any indication of the amount: стакан (a glass of), много (a lot of), мало (а little) and even нет (no) requires genitive. So, "a glass of water"="стакан воды", which should not be too surprising since English "of" is fairly reliable indicator of geitive in Russian.