The water that bears the boat is the same that swallows it up.

解释 ( paraphrase )
水喻百姓，舟喻皇帝。水既能承载船只，也可是使船只倾覆。比喻民心向背决定生死存亡。
这条谚语告诉我们：要深得民心，就要爱惜百姓。

This proverbs indicates that people can adhere a dominator and also can overthrow his domination. It shows the great power of people.

水：这里指百姓。
      Civilians.

舟：这里指皇帝。
      Emperor。

造句 ( example )
为政的人要爱惜百姓，所谓水能载舟，亦能覆舟，人民群众才是创造历史的主角。