The “brook” intended is probably not the Kidron, but the natural water-course of the Gihon, which ran down the Tyropoeon valley (compare the 1 Kings 1:3 note).
Related Commentaries of 2 Chronicles 32:4
2 Chronicles 32:4
4 So there was gathered much people together, who stopped all the fountains, and the brook that ranb through the midst of the land, saying, Why should the kings of Assyria come, and find much water?