Check the water meter
From China Digital Space
抄水表 (chāo shuǐbiǎo): check the water meter
Instead of shouting commands outside someone‘s home, the police can simply pretend to be from the water utility and coerce the person to open his/her door. Other times, the police may politely invite someone to drink tea.
This may also appear as 查水表 (chá shuǐbiǎo), which has the same meaning.