因为water是不可数名词，不可数名词一般看做单数，所以前面的be动词应该用is。只有像可数名词复数用are剩下的全部用is。
相关介绍
Water is forced through the pipes at high pressure.
水在高压下流过水管。
I tried to get a shot of him in the water.
我试着给他拍一张在水中的照片。
The scientists are taking water samples from the river.
科学家正从河中采水样。
Fishing is good at high water.
高水位有利于钓鱼。
All plants need light and water.
一切植物都需要阳光和水。
