drainage
/ˈdreɪnɪdʒ/noun
mass noun
1- the action or process of draining something排水; 排泄; 放水：
the pot must have holes in the base for good drainage
花盆的底部必须有洞以保证良好的排水性
the drainage of wetlands.
湿地排水。
1.1
- the means of removing surplus water or liquid waste; a system of drains排水系统; 排水装置; 下水道。