Was that the right thing to do? Putin did take it over, but shutting out the water only hurted the Ukrainian and Russian civilians living there. Russia had to import water to ensure the Ukrainian and Russians living there could drink.
We don't have any direct power to stop Putin from doing what he wants, except through total war. So we punish other people who also don't have any direct power to stop him to save face - Crimeans, ordinary Russians, etc.
If Russia wasn't able to make the expensive investment to supply water and people die of dehydration what would be the headline? "National Hero Zelensky Denied Water to Ukrainians and Russians As Revenge For Putin's Actions"