Correct

库容

/ kù róng / 
Strokes

Example

As a Noun

storage capacity (of a reservoir, warehouse, etc)

1
Zhège
这个
shuǐkù
水库
kùróng
库容
yāo
约
wéi
为
3  000wàn
3,000万
lìfāngmǐ
立方米
  
。

The reservoir has a storage capacity of about 30 million cubic metres.