waterworks的原义就是自来水厂，turn on the waterworks它的意思是“哇哇大哭、哭鼻子、眼泪汪汪、发起眼泪攻势”，尤其指以一种不真诚的方式哭，为了博取同情或引人关注。

【例句】
When my daughter wants something from her father she has only to turn on the waterworks and he gives it to her.
当我女儿向她父亲要东西时，她只要一哭鼻子，他就给她了。

The little girl turned on the waterworks after being criticized by her parents.
被爸爸妈妈批评后，这个小女孩发起了眼泪攻势。