drainage tunnel meaning in Chinese

排水洞
排水廓道
疏干隧洞

Proposed works for drainage tunnel in tsuen wan
荃湾雨水排放隧道的拟建工程
Drainage improvement in northern hong kong island - hong kong west drainage tunnel
港岛北部雨水排放系统改善计划港岛西雨水排放隧道
Application of grouting deep mixing piles to soft foundation treatment of city drainage tunnel engineering
浆喷深层搅拌桩在城市排水渠工程软基处理的应用