All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It isn`t permissible to dispose of the water endowed for drinking against the purpose for which it was endowed ;therefore, not abiding by that purpose is an act of transgression. Moreover, it isn`t permissible to use the water endowed for drinking to achieve ritual purity or to use the water endowed for ritual purity to wash utensils and the like.
Legal scholars were strict in this regard because drinking water is vital to people. Not only that, but they have also banned moving it from the place where it was originally endowed, even if it was to be used for drinking." It isn`t permissible to use the water endowed for drinking for a purpose other than drinking or even to move it somewhere else to be used for drinking."{E`anat At-Talibeen, P. 1/69}.
Ibn Hajar(May Allah have mercy on him) was once asked about the water endowed at mosques for purposes of ritual purity: Is it permissible for a person to move that water to their house to use it for ritual purity although people, at the mosque, are in need for it, and is it permissible or not if people weren`t in need for it? He replied, "One who has donated water or has endowed items, to a certain mosque, to be used to achieve ritual purity isn`t allowed to move that water or those items to another place to be used for that same purpose.
This is because it isn`t permissible to move drinking water endowed to the mosque somewhere else."{Al-Fatawa Al-Fiqhia Al-Kobra, P.3/266}. And Allah knows best.