In The Sinking City 2, there is a special sluice gate in the basement of the church area, secured by a combination lock. To open or close the sluice gate, you need to unlock it. The code for the lock is 1672, with the hint located nearby: the password is the year the large clock was built, which is 1672.
How to Open the Church Sluice Gate Combination Lock in The Sinking City 2