General Information:

Isaiah continues to describe a time in the future when an army will attack the people of Jerusalem. (See: rc://en/ta/man/translate/figs-pastforfuture)

You counted the houses

Here "counted" means they inspected the houses to find material to help them rebuild the city wall.

"You made a storage place"

It is unclear what two walls Isaiah meant. The main point is that they built the reservoir within the city walls.

This refers to Yahweh.