Scholars had long agreed about how the Jerusalemites drew water from the Gihon Spring. According to the traditional understanding—now under attack—an elaborate underground system of tunnels was dug (perhaps by the 10th or 9th century B.C.E.) to give residents of the city access to the Gihon Spring, downslope from the city. As shown in the top drawing, the entrance to the system, according to the old theory, lay inside the city walls. This entry chamber opened onto a steep, stepped tunnel, which led down to a gently inclined, but sharply curved tunnel (the elbow-shaped bend in this tunnel can be seen most clearly in the plan on p. 31) that led to the top of Warren’s Shaft. From here, buckets could be lowered down the shaft to draw water that collected 40 feet below in a lower tunnel leading from the Gihon Spring.

But there are several flaws in the old theory: New excavations reveal that the system was not carved all at once. Further, Warren’s Shaft was not part of the system as originally carved—and was never intended to be. Instead, the curved tunnel completely bypassed Warren’s Shaft and continued through a cave that led to the newly discovered pool.

The Warren’s Shaft System, as it appears today, was carved in two stages. In the Middle Bronze Age II (18th to 17th century B.C.E.), the original system (shown in the lower drawing) was carved only in the soft Meleke limestone, which forms the top layer of bedrock throughout the City of David. Only centuries later (perhaps in the eighth century B.C.E.) was the horizontal tunnel deepened, perhaps to create a different route to the spring, by cutting into the lower layer of hard Mizzi Ahmar dolomite (as shown in the top drawing). Warren’s Shaft was accidentally reached at this point, and the top of the shaft was widened; but the shaft was not the goal of the diggers. The shaft has too many protrusions for a bucket to be easily lowered down it, and the water that gathers at the bottom is too shallow to be captured efficiently in a bucket.

These later tunnelers continued to deepen the tunnel even beyond the entrance to Warren’s Shaft—further evidence that this was not their goal. Their work stops short a few feet east of the shaft entrance; perhaps they quit when Hezekiah’s Tunnel, which brought water into the city, was cut in preparation for the Assyrian siege of 701 B.C.E.