The rain water drips from the eaves.

雨水从屋檐滴下。

《新英汉大辞典》

Now, when the rain fell, water ran down the sides of the dunes, carrying clay and silt particles with it.

如今降雨的时候，雨水会带着黏土和泥沙颗粒从沙丘两边往下流。

youdao

The rain seeps underground and the water may reappear later as springs.

雨水渗透到地下，可能以泉水的形式重新出现。

youdao

The rain harvesting systems mean that a family member no longer has to walk long distances to get water.

VOA: special.2009.07.27

Now this is a rain gauge, and it's sitting on a roof of a building, and when the water falls into this gauge, it sends a signal to the logic unit of the computer, which immediately notifies the memory bank of the computer to seek out its instructions for a rainy day.

这是一个雨量测量器，安装在一个楼房的,屋顶上，当水流入到这个测量器，它就给计算机的逻辑部件发送一个信号，计算机立即通知内存条,为下雨天找出相应的指令。

哈佛公开课 - 计算机科学课程节选

These collect rainwater. But the device is designed to collect water even when there is no rain.

VOA: special.2010.07.13

The rain water reached two feet on the main streets.

BBC: Eyewitness: Philippines floods

Last year, a complaint to the Buildings Department about rain water seeping into the building triggered an inspection that eventually led to the demolition order.

WSJ: Time Runs Out for Historic Harlem Row House

The new building will reuse rain water to flush the toilets and a solar electric generating system will be installed on the roof.

BBC: Artist impression of the new building