The Megiddo Water Systems.
1. Spring
2. Spring chamber
3. Pre-10th century B.C. stairs to spring chamber
4. 9th century B.C. blocking wall at entrance to chamber
5. 9th century B.C. tunnel
6. 9th century B.C. stepped shaft
7. 9th century B.C. inset offset wall
8. Solomonic (10th century B.C.) gallery
9. Solomonic (10th century B.C.) covered stairway
Megiddo—The first of three water systems at this site was constructed before the 10th century B.C. It was very simple. It consisted of a stairway (3) at the base of the tell descending to the spring chamber (2) which was filled by a spring (1). To obtain water, one had to go outside the city walls.

King Solomon constructed the second water system in the 10th century B.C. as part of his large fortified city. He cut a gallery (8) through the casemate city wall extending from inside the city to the outside. (Here the casemate is covered by the later inset-offset wall (7).) Camouflaged with a dirt and wood roof, the gallery led to a set of stairs (9) which were also covered. These stairs joined the earlier set of stairs (3) which in turn connected with the spring at the base of the tell.

The latest water system at Megiddo was constructed by King Ahab in the 9th century B.C. A shaft (6) 115 feet deep was sunk inside the city. At the bottom of the shaft, a 200-foot long tunnel (5) led to the spring chamber (2) at the base of the hill. To prevent entrance into Ahab’s water system from outside the city walls, the earlier hillside entrance to the spring chamber was blocked by a wall (4).