en_tn/2ki/20/20.md

pool

A small area of still water for storage

conduit

A tunnel for carrying the water

are they not written in the book of the events of the kings of Judah?

This question is used to remind the reader that these things are recorded. See how this phrase is translated in 2 Kings 8:23. AT: "they are written in the book of the history of the kings of Judah." (See: rc://en/ta/man/translate/figs-rquestion)