4 sentences

1. 这座城市的排水系统需要改进。

   zhè zuò chéng​shì de pái​shuǐ xì​tǒng xū​yào gǎi​jìn.

   The city's drainage system needs improvement.

   Source: Dong Chinese Dictionary

2. 这些地下的管子是用来排水的。

   zhè​xiē dì​xià de guǎn​zi shì yòng​lái pái​shuǐ de.

   These underground pipes are used for drainage.

   Source: Dong Chinese Dictionary

3. 施工人员正在装置新的排水管道。

   shī​gōng rén​yuán zhèng​zài zhuāng​zhì xīn de pái​shuǐ guǎn​dào.

   The construction workers are installing new drainage pipes.

   Source: Dong Chinese Dictionary

4. 这条公路下方修筑了多个排水涵。

   zhè tiáo gōng​lù xià​fāng xiū​zhù le duō gè pái​shuǐ hán.

   Several drainage culverts were built under this highway.

   Source: Dong Chinese Dictionary