a person who regularly walks by the river cannot avoid getting their shoes wet (proverb); (fig.) it comes with the territory (e.g. a person with the power to grant favors will inevitably succumb to temptation and take a bribe)
trad. 常在河邊走，哪有不濕鞋
Also written 常在河邊走，哪有不濕鞋【cháng zài hé biān zǒu , nǎ yǒu bù shī xié】