dig a well when thirsty do anything too late; do a thing at the last minute;lack of forethought; take measures only when in urgency; start acting too late ? ～，悔之何及！ (許仲琳《封神演義》三十五) It is too late to regret not to have dug a well until you are thirsty.
臨渴掘井lin ke jue jing
not to dig a well until one is thirsty—start acting too late
臨渴掘井
start to dig a well only when one feels thirsty—make no preparation until the last moment;start acting too late
臨渴掘井lín kě jué jǐnɡ
臨：到。到口渴時才去挖井。比喻事到臨頭才去想辦法，不早做準(zhǔn)備。not make timely preparations, take action at the eleventh hour