But the lessons are about learning Russian, not about appeasing English speakers.
'Where here water' is what the Russian sentence says. If there is no 'natural' English translation, a correct one should do. 'Where is there water here' isn't wrong and no one has to ask this in English. If you are complaining about the English you are missing the point.
there is a similar sentence here in duolingo: https://forum.duolingo.com/comment/11530319/%D0%93%D0%B4%D0%B5-%D0%B7%D0%B4%D0%B5%D1%81%D1%8C-%D1%8F%D0%B1%D0%BB%D0%BE%D0%BA%D0%BE
Anyway, I would ask: "Where is the water from here (= this place) ?"
I think it would clear up a lot of confusion if Duo would accept rough translations that carry the same idea. If I were in this situation, I would say, "Where can I get some water?" not "Where is the water here?" or "Where is there water here?" If you have to explain what a sentence means, you've defeated the point of having a sentence by not communicating clearly in the first place.
This makes no sense in English. You could ask if there is water here or simply ask where there is water. But if there is water here, you would know it so why ask "where". Clearly this does not mean what you think it means, in English. If you are asking about a general area, for example in this building, you would ask "where is there water?". But as you are phrasing it, here is immediately here. For example you are sitting at a table. Why would you ask if there is water on the table? Whether there is water on the table or not, why do you ask where it is? Where and here are incompatible in meaning. In English, "here" means within reach, within an arm's distance, less than a meter. If you mean "here" to be a wider area, you must say so, either explicitly (Where is there water in this area?) or with a hand gesture or within the context of having previously been talking about a big area. In this case, издесь means nearby, not here.
Where is there water here is a so bad translation I doubt anybody would use it ever in real life. I mean three location adverb in the same question??? Like why the "where is the water here" not the correct translation, when it has two location just like the russian sentence?
I still don't understand why anyone would ask this sentence unless they were being snide/sarcastic. If you are sitting at a table in a restaurant and there is no water on it, I suppose you could ask this question rather than say "Hey idiot waiter, bring us some water!". But asking literally is impossible in English, either there is water here of there isn't. If there is water here you already know it is here because it is within arm's reach and you can see it. That is the meaning of "here" in English. Otherwise the water is there, not here. You could of course say "near here" or nearby or around here or in this general vicinity or in this building or in this village. But you cannot say here unless you are blind.
It's another language, so that means they may say things differently but are used to conveying the same idea. Such as saying "car red" in spanish. You're gonna have to understand at that some point there will be a disconnect to your language, hence "translation". Russian people are used to asking where the water is (say a water fountain) in this manner, just because it doesn't add up in english is irrelevant, you need to feel the different ways they construct sentences in order to become fluent rather than jamming the jigsaw pieces in a way that makes sense to your mother tongue.
You are correct if we are translating English (or any other language) to Russian. But if we are translating Russian to English then proper English syntax and grammar should be accepted. If a translation makes no sense in English, then translations that do make sense should be accepted. If 10 people report a better translation, the algorithm should start accepting it.
The basic problem we have here is although эдесь is a valid translation for "here", the inverse is not true. эдесь does not mean here. It simply does not, this translation is simply wrong. эдесь means nearby and nearby is not here. Unfortunately too many people butcher the English language. We who are learning Russian are expected to be respectful of the Russian language. It is a beautiful language. But so is English.
"Where here is the water" should be accepted. As a native English speaker that makes sense to me as meaning the same thing. Imagine if you were being interrogated and told the police you had water somewhere nearby, I would imagine them asking "Where here is the water" while pointing where they think it is