To leave someone helpless in a difficult situation
He abandoned his wife and five children and left them high and dry.
(leave somebody/something) high and drya) if someone is left high and dry, they are left without any help or without the things that they needb) if a boat, area etc is left high and dry, it is left on land because the water that surrounded it has gone down The once-thriving port of Rye was left high and dry as sea levels retreated.
Cambridge Advanced Learner's Dictionary - 4th Edition
leave sb high and dry informal
to do something that is not at all convenient for someone and put them in a very difficult situation:
They pulled out of the deal at the last minute leaving us high and dry.
© Cambridge University Press 2013
leave someone high and dry
to leave someone in a difficult situation which they are unable to do anything about
Schools with better reputations will be flooded with applications while poorer schools will be left high and dry.