These drawings show the Warren’s Shaft system as viewed in section, as though we could look at a vertical cutaway of the hill, and in plan, as if seen from above. The construction of the system required blockage of the outlet to the Kidron Valley (originally a natural drain for the Gihon Spring) and the engineering of the lower tunnel to bring the water into the “water chamber” at the foot of Warren’s Shaft. This allowed Warren’s Shaft to function as a well. Even during a siege, people within the city (note the position of the Jebusite and Israelite city walls) could walk down the steep upper tunnel, then through the more moderately sloped tunnel to the top of Warren’s Shaft, from which they could lower a bucket to raise water from the water chamber, 37 feet below.

Anomalies in the system have long mystified scholars, however. What is the dead-end shaft? Why does Warren’s Shaft extend below the level of the lower tunnel? Why does the upper tunnel—seen clearly in the plan—follow a hairpin course? What purpose did the blocked exit tunnel, jutting off the main tunnel above Warren’s Shaft, serve? Geologist Dan Gill proposes that the prior existence of a karst system (a natural occurrence of eroded shafts and conduits) explains these and other mysteries of the Warren’s Shaft system and Hezekiah’s tunnel.