Its construction may have been a creative solution to climate crisis , about 2,800 years ago, according to the researchers. The research, published Monday in the prestigious scientific journal PNAS, will be presented at the upcoming “City of David Studies” conference in early September.

The massive wall uncovered in excavations of the Siloam Pool in the City of David National Park, was built around 805–795 BCE – during the reigns of Kings Joash or Amaziah of Judah.

The discovery of the dam was made by the excavation directors Dr. Nahshon Szanton, Itamar Berko, and Dr. Filip Vukosavović on behalf of the Israel Antiquities Authority.

“This is the largest dam ever discovered in Israel and the earliest one ever found in Jerusalem. Its dimensions are remarkable: about 12 meters high, over 8 meters wide, and the uncovered length reaches 21 meters – continuing beyond the limits of the current excavation," the directors stated. "The dam was designed to collect waters from the Gihon Spring as well as floodwaters flowing down the main valley of ancient Jerusalem (the historical Tyropoeon Valley) to the Kidron Stream, providing a dual solution for both water shortages and flash floods.” “Thanks to highly precise scientific dating, this is the first time it is possible to point with certainty to a structure that formed the basis for the construction of the Siloam Pool, which until now we knew only from the Bible and historical sources,” adds Itamar Berko.

Video - Israel Antiquities Authority