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How Water Tunnels Worked, Dan P. Cole, BAR 6:02, Mar-Apr 1980.

Jerusalem, Megiddo, Hazor, Gezer and Gibeon all had systems to bring water safely within their city walls during time of siege—Cole offers new suggestions on how this technology developed.

Megiddo water tunnel“A city set on a hill cannot be hidden,” said Matthew (5-14). Neither can it easily be supplied with water.

Cities were built on hilltops because of the obvious defensive advantages. These advantages were somewhat offset by the disadvantage that the city’s springs or wells were normally at the base of the hill, outside the city walls. As the size of urban populations grew and the height of the cities themselves grew through successive rebuildings—creating higher and higher “tells”—the water supply moved progressively farther away.

In peacetime, this distance was merely an inconvenience for women and slaves; in time of war, it could be a fatal weakness. Under siege the city could be deprived of its water supply. No city can last for long without water.

Because almost no rain falls from March until October Palestinian cities were particularly vulnerable to prolonged sieges. Cisterns and other rain collectors inside the city walls were not replenished for six months or more.

Some ancient Departments of Defense solved the problem of bringing fresh water inside the city walls by means of massive engineering projects involving tunnels and shafts hewn through bedrock beneath their cities.a

Over the past century archaeologists have uncovered a dozen examples of such ambitious projects at various cities in ancient Israel. Now, a sufficient number of these engineering operations have been revealed to enable us to begin to reconstruct the development of hydraulic technology in ancient Palestine.

Probably the most famous of these water systems are the two cut into the Ophel Hill of Jerusalem (the so-called City of David). The earlier system is “Warren’s Shaft” (named for Charles Warren, who discovered it in 1867); it is also referred to as the “Jebusite Shaft” on the common assumption that it dates to the pre-10th century B.C. Jebusite city.b This system consisted of four elements. 1. A tunnel which was cut to direct water from the plentiful Gihon Spring (in the Kidron Valley east of the city hill), into a chamber deep within the hill. 2. A stepped tunnel which was cut downward from the street level behind the city’s defense wall and which led to 3. an almost horizontal tunnel ramp running out under the city wall to a point directly above the water chamber where 4. a shaft connected the end of this upper tunnel to the water chamber. A jar could then be lowered down the shaft by a rope and filled from the spring-fed chamber below.c

Later—in the 8th century B.C.—King Hezekiah replaced this earlier water system with a 1750-foot tunnel under the city which was cut by two crews starting at either end. This underground tunnel was graded or slanted so that it carried the water from the Gihon Spring, located outside the walls, to a pool inside the city. (See “How the Blind See the Holy Land,” BAR 05-03, “Queries & Comments,” BAR 05-06, and Hershel Shanks, The City of David (Biblical Archaeology Society, 1975).)

Next to Jerusalem, the best-known Israelite water system is the shaft and tunnel at Megiddo,1 which writer James Michener incorporated into his fictional “Tel Makor” in his novel The Source.

The famous Megiddo water system involved two elements- First, a large vertical shaft with steps cut down around its sides was sunk through the debris layers of earlier periods into the bedrock, going down 115 feet to the level of an already-known nearby spring. Second, a horizontal tunnel, 200 feet long, was dug, running from the bottom of the shaft out under the city wall to connect with the spring. As at Jerusalem, this tunnel was cut by two teams of pick men working toward each other, one from the bottom of the shaft and the other from the spring.

Dating an ancient water system which is cut into bedrock is no easy task. The pottery and other objects found in it can only suggest when it went out of use, not when it was originally constructed. The most reliable indication of the date of construction comes from the stratigraphy at the entrance to the system inside the city. It is a safe assumption that a shaft was cut after the latest stratum of the tell through which it cuts. This is not helpful, however, for dating a later system where ancient erosion has destroyed the uppermost strata.

The University of Chicago team which excavated Megiddo in the late 1920’s dated its water system to the 12th century B.C. because the latest stratum clearly cut by the shaft dated to that time. Unfortunately, several later occupation levels had eroded from around the top of the shaft, as we now know from other areas of the mound; the shaft should have been connected stratigraphically with the so-called “Solomonic stables” which the excavators uncovered immediately to the east of the shaft and with the inset-offsetd city wall which they traced around the mound from the Solomonic gateway on the north. Had Chicago’s excavators correctly connected the water shaft to the “Solomonic stables” and to the inset-offset wall, they would have dated the water shaft not to the 12th century B.C., but to the Solomonic period (10th century B.C.). This dating however, would also have been wrong, because the “Solomonic stables” and the inset-offset wall with which it was associated proved not to be Solomonic at all, but in fact dated to the 9th century B.C. In the late 1950’s Yigael Yadin became suspicious of the Megiddo excavators’ date for the inset-offset city wall and the buildings (including the “Solomonic stables”) related to it. Digging at Hazor, Yadin had found that the 10th century Solomonic gateway (strikingly similar to Megiddo’s) had been connected to a casemate walle over which a solid inset-offset wall had been laid in a 9th century rebuilding of the city (presumably by King Ahab).2 Yadin reasoned that if at Hazor a Solomonic gateway was connected to a casemate wall over which a solid inset-offset wall was built a century later, the same thing was probably true at Megiddo.

Yadin re-investigated the Megiddo walls in the 1960’s and clearly demonstrated that the inset-offset wall (and the so-called “Solomonic stables”) belonged to a rebuilding of the city after Solomon. Yadin uncovered at Megiddo, as he had at Hazor, beneath the inset-offset wall, a casemate wall from King Solomon’s time (10th century B.C.) which connected to the Solomonic gate in its initial phase.3

The Megiddo water system was not, however, the only water system in evidence at the site- the Chicago excavators found earlier, less technically developed water systems at Megiddo. One, just north of the 9th century B.C. water shaft is known as the “gallery”—a narrow passage leading from inside the city, through the earlier Solomonic casemate city wall. This gallery was directly above an old entrance to the same spring which the later shaft and tunnel system served. Steps descended from the end of the gallery, down the slope to this old spring entrance. A wood and earth roofing originally concealed the steps leading down the slope to the spring entrance.4

At the base of the slope, this covered stairway had connected with an even earlier set of steps. These steps descended into the face of the hillside to a water chamber cut out of bedrock around the spring.

Thus we can now reconstruct three stages of the water system at Megiddo- 1. Sometime in the Late Bronze or Early Iron Age—surely before the 10th century B.C. gallery—steps were cut into the base of the slope down to a natural spring; the area of the spring was enlarged by a chamber cut out of the bedrock. 2. When Solomon fortified the city in the 10th century, a narrow passageway or gallery led from inside the city, through the Solomonic casemate wall to a point above the spring; from there stairs, which were probably covered, led down the slope and connected the gallery to the old spring chamber entrance. 3. In the 9th century B.C., King Ahab replaced this system with the huge vertical shaft inside the city and the horizontal tunnel system leading from the shaft to the spring.
After King Ahab’s shaft and tunnel were cut, the old stepped entrance to the spring could be blocked up to prevent access from the outside. In fact, the excavators found this entrance blocked by a wall of huge stones.f

The steps of this outside entrance are now unblocked, so the modern visitor to Megiddo can enter the water system from inside the city, climbing down the 9th century shaft and follow the tunnel to the spring and then exit by way of the much earlier steps leading out to the base of the hill.

As we have seen, Yadin used what he had learned on his Hazor excavations to redate at Megiddo the inset-offset wall, the “stables” and therefore the water system with which it was associated, all to the 9th century B.C. Conversely, when Yadin returned to Hazor for renewed excavations in 1968, he was able to use the Megiddo water system to help him find a similar water system at Hazor.5

Yadin reasoned that Israelite Hazor should have had a comparable water system to Megiddo’s because of Hazor’s strategic military position controlling major highways and because of its strong fortifications in the 10th and 9th centuries B.C. Having already exposed a palace within the walls at the western end of the mound and having found the Iron Age city gate on the east, Yadin deduced that the only available place for a water shaft (and the most likely place based on the mound’s present topography) was midway along the south side of the tell.

A shallow depression in the mound at this point confirmed this reasoning. The depression was comparatively close to a wadi below, where water still flows today. In addition, earlier soundings in the depression had revealed no structures, only a deep fill. In short, it seemed the perfect place for an Iron Age water shaft.

Removing the tons of debris which had gradually filled the shaft after the 8th century B.C. destruction of Israelite Hazor was a mammoth operation and something of an act of faith on Yadin’s part. But his hunch was right. The water shaft was there. In the upper portion it was similar to the water shaft at Megiddo. As at Megiddo, it proved to have been dug after Solomon’s time, since the ramp leading down to the shaft and the retaining walls around it cut through buildings containing 10th century pottery. Moreover, these buildings were clearly associated with the 10th century casemate wall along the south slope of the mound. So the water shaft must have been dug after the 10th century.

More than 95 feet below the surface, Yadin finally reached the bottom of the shaft. Next he expected to find a tunnel branching off from the shaft to the south, in the direction of the water source outside the city, as was the case at Megiddo. This time his expectation proved wrong. Instead, he found a stepped tunnel leading down to the west, going 80 feet farther into the heart of the bedrock beneath the tell. There, indeed, Yadin found water—as had Ahab’s engineers 2800 years before- the natural water table over 130 feet below the city street!

Ahab’s engineers at Hazor apparently knew in advance that if they dug deep enough into the hill they would strike water; there is no evidence of false starts or fumbling on the part of Ahab’s diggers.

The Hazor shaft and stepped tunnel system was completely secure from an enemy because it was all inside the walls. It was thus a considerable improvement over the water system at Megiddo (and at Jerusalem, for that matter).

A military man himself, Yadin was immediately aware of the strategic importance of this ancient technological advance. He realized that as soon as hydraulic engineers at one city discovered the water table beneath their city, this type of water system would be copied and used elsewhere if conditions permitted. (It is unlikely that the discovery was made at Hazor because the Hazor engineers seemed to know ahead of time just what they were doing). This realization led Yadin to reexamine the date which had been assigned to still another water tunnel, one that R. A. S. Macalister had discovered at the beginning of this century at Gezer.

Macalister excavated at Gezer from 1902 to 1909. There he found a step-lined shaft which led into a tunnel, also stepped, which sloped downward into the heart of the hill until it ended in a long chamber at the water table level.6 All this was inside the city wall. Macalister dated the tunnel to his “Second Semitic” period—which we now call the Middle Bronze Age—about 1650 B.C. Macalister’s dating was based principally on some Mycenaean sherds from his “Third Semitic” period (the Late Bronze Age, 1550 B.C.–1200 B.C.), which he had found in the debris from the tunnel. He thought the tunnel must have pre-dated the pot sherds debris found in the tunnel. He was, however, wrong. We now realize that in the erosion that occurs after the breakdown of the retaining walls around the top of a shaft, sherds from almost any period can and often do make their way into the shaft cavity.

Yadin’s excavation of the Hazor shaft suggested to him that Gezer’s tunnel really belonged to a later period. He argued that the Gezer shaft and stepped tunnel, like the Hazor shaft and stepped tunnel, reflected the engineer’s knowledge that the water table could be reached inside the city. Since this technology, once discovered, was likely to be copied at various sites, Yadin expected that the Gezer tunnel should be dated close to the period of the Hazor water system, which he had clearly dated to the 9th century B.C.7

William Dever, who directed renewed excavations at Gezer from 1965 to 1971, maintained, however, that the Gezer water system probably dated to the Late Bronze Age.8 He thought the Middle Bronze city gateway too close to the shaft head to date the construction that early. On the other hand, Dever pointed out, Iron Age walls appear on Macalister’s plans above the area of the shaft, suggesting the water system had gone out of use before that time.g Therefore he thought the Late Bronze Age the most likely candidate for the Gezer water system.

Because Macalister had cut through all the building layers around the head of the water shaft at Gezer, there is no way to obtain new stratigraphic evidence to determine the last stratum through which the shaft was originally cut. This, unfortunately, is the only way to confidently date the system.

But whether the Gezer water system dates from the Late Bronze Age, as Dever argues, or from the Iron II Age, as Yadin argues, Yadin’s basic thesis still remains viable. Perhaps the stairs-to-water-table concept was known as early as the Late Bronze Age at such a major Canaanite city as Gezer. The Late Bronze II Age was a period of active trade among eastern Mediterranean cultures. Fine Mycenaean pottery from this period has been found in Palestine and Egypt and large Canaanite storage jars have turned up in Greece. Ideas as well as merchandise travel the same trade routes. We know that in this period Mycenae, Athens, and other cities in Greece had water stairs inside their walls which cut directly to the water table rather than out to springs. Thus, the Canaanites could well have learned from the Mycenaeans this technique of digging down to the water table inside the city walls.

The Gezer water system could have been dug at Canaanite Gezer in the Late Bronze II Age; it could then have been abandoned and choked with rubble at the end of the Bronze Age and have remained that way through the 12th–11th century B.C. Philistine occupation. Perhaps the top of the water shaft was still visible during later periods, but Israelite engineers of the 10th or 9th century B.C. would not have known about the water table concept on which this underground water system was based. In short, Israelite engineers may have had to rediscover this knowledge. Yadin may therefore still be correct in stating that once the stairs-to-water table concept was discovered (or rediscovered) by the Israelites in Iron II, this idea was likely to be quickly copied in other Israelite cities of the period. Thus, other Israelite water systems of this type probably should be dated to about the same time as Hazor’s 9th century B.C. system.

Naturally, it would be interesting to know where the Hazor engineers got their stairs-to-water-table concept. In other words, where was this type of water system first used by the Israelites?
A re-study of the complicated water systems and associated excavations at Gibeon (modern el-Jib) suggests to me that it was at Gibeon that Israelite engineers discovered—or re-discovered—the possibility of locating a source of fresh water inside the city, safe from enemy control during a siege.
The discovery of a huge pool-like shaft at Gibeon in 1956 came as a complete surprise, both to the excavators (led by James B. Pritchard of the University of Pennsylvania), and to the local villagers. It had been completely sealed from view under tons of fill and debris for over two and one-half millennia.9

When Pritchard and his colleagues began excavating the site, they were already inclined to identify it as ancient Gibeon, as Edward Robinson had proposed in 183810 based on his explorations of the area and the similarity of the modern name (el-Jib) to Gibeon. This identification was confirmed dramatically during the first season of Pritchard’s excavation with the discovery of storage jar handles inscribed with the name of Gibeon.11

Pritchard naturally knew about the famous “Pool of Gibeon” which is referred to in 2 Samuel 2-13–17. For a period after King Saul’s death (c. 1000 B.C.) David reigned over Judah while Saul’s son Ishbosheth ruled over Israel. David’s army led by Joab, and Ishbosheth’s army led by Abner met at the Pool of Gibeon. Each side appointed 12 young champions who faced each other on either side of the Pool of Gibeon. They were evenly matched, however, and in the bloodbath that ensued all 24 were killed—deciding nothing.

Despite this famous Biblical reference to the Pool of Gibeon, the discovery of the great shaft surprised Pritchard because another plausible candidate for the Pool of Gibeon had already been suggested.

Robinson had noticed on the northeast slope of the hill a large rectangular reservoir (37 × 60 feet across and 8 feet deep) which caught the overflow from a nearby spring. It seemed to him likely that this was the “Pool of Gibeon” mentioned in the Bible. Most scholars who accepted Robinson’s identification of the site as Gibeon also accepted his suggestion about the location of the pool. When Pritchard later excavated part of the reservoir, however, he found that none of the pottery sealed beneath the plaster lining pre-dated the Roman period, so the reservoir could not have been a “pool” from King David’s time.

Pritchard spent his first days at el-Jib investigating a long-known stepped tunnel which went from the spring at the base of the mound upward into the side of the hill. (This was the same spring which fed the as-yet unexcavated reservoir from the Roman period).

Pritchard had no reason, therefore, to suspect that the site would yield a second water system. The spot where he decided to begin digging on the summit of el-Jib, in fact, was dictated by his desire to uncover the upper end of the stepped tunnel which led from the spring. He found the upper entrance exactly where he expected it, directly inside a massive fortification wall.

He did not, however, expect that less than ten feet beyond the entrance to the stepped tunnel he would encounter the top of another water system, one so ambitious that it would take the rest of that first summer and all of the next to clear. The upper portion alone spanned some 37 feet in diameter and extended 35 feet down. To construct it required the cutting and hauling away of approximately 1100 cubic feet (almost 3,000 tons!) of limestone bedrock. This second water system is now almost universally identified as the Biblical “Pool of Gibeon”.

When fully cleared, the “Pool” revealed two distinct segments. The upper portion consisted of a 35-foot-deep cylindrical shaft with almost vertical sides and a relatively flat floor. One descended into the shaft by 40 steps which spiraled down around its side. All but the top three of these steps are cut from the living rock and are approximately five feet wide. They are well cut and not very worn. A low balustrade effect is created by a rim about 20 inches wide and averaging a foot or so high which was left on the inside edge of the steps. Pritchard suggests that this balustrade might represent the level of the initial workmen’s steps cut during the original quarrying out of the shaft.12

But the stairs do not end at the floor of the shaft. The steps continue downward for another 45 feet through a narrow, slanted tunnel which spirals down as if following the outline of the broad shaft above. This slanted, stepped tunnel reaches the water table within the hill at step 79, 80 feet below street level. There, a kidney-shaped water chamber had been hollowed out, about 22 feet long and 11 feet wide. (In addition, two small vertical shafts extend down from the floor of the pool shaft to the stepped tunnel, at its mid-point and near its termination. Presumably these had the function of providing light on the tunnel steps.)

This shaft/stepped-tunnel system leading to the water table inside the city should not be confused with the other water system at Gibeon. That water system consists of three elements- (1) a 146-foot-long stepped tunnel13 from inside the city down to a water chamber outside the city walls; (2) the cave-like water chamber with an entrance from outside the hill slope (similar to the earliest system at Megiddo); during times of siege, the entrance to the water chamber could be blocked; (3) a horizontal zigzag tunnel, 110 feet long, following the natural fissures in the bedrock leading to the spring—the source. By following the natural fissures in the rock, the flow from the source to the water chamber would be greatly increased. The source of the spring lies almost directly under the city wall.

Just before the stepped tunnel ends inside the city, it takes a sharp right-angle turn. This brings the entrance of the tunnel and its top steps parallel to and flush with the inside of the city wall. If the stepped tunnel had not taken this right-angle turn, it would have extended into the huge pool-shaft, barely 10 feet away.

Pritchard reasoned that the seemingly inconvenient 90-degree turn at the top of the stepped tunnel was probably necessary to avoid the rim of the pool-shaft. The pool-shaft, Pritchard concluded, must therefore have pre-dated the stepped tunnel system which he dated to the 10th century B.C.
Pritchard’s dating of the stepped tunnel was based on the following evidence- just outside the city walls, the stepped tunnel appears to have been deliberately opened to the ground slope surface during the cutting, perhaps to make it easier to steer the picking teams. (After completion, the exposed portion of the stepped tunnel was covered with huge slabs and concealed from sight.) The city wall at this point shows two phases. The inner wall is dated, by the latest pottery beneath it, to the Iron I Age (12th–11th centuries B.C.); the outer wall appears to be a strengthening of the fortifications in the 10th century- Since the stepped tunnel to the spring was cut through the bedrock beneath both walls (apparently in order not to undermine them), Pritchard concluded that the stepped-tunnel-to-spring system was built after the second of those walls, but probably not by much—i.e., late in the 10th century.

But if the Gibeonites already had a completely secure stairway down to the water table inside the city (the pool-shaft system), why would they later have built a more vulnerable stepped tunnel leading under and outside the city wall? Pritchard answered that perhaps the water flow in the pool-shaft system was not sufficient to meet the city’s needs. Such circumstances might have required the cutting of the second stepped tunnel directly to the spring outside the city wall, after which the pool-shaft and its stepped tunnel continued in use only as a supplementary system.

Pritchard recognized that the huge pool-shaft and its lower stepped tunnel represent two distinct phases of construction, but he argued that they are part of a single construction project. He believed that the engineers’ intention from the beginning was to cut a broad stairwell to the water table, but that a change in political or economic conditions (a new king? an increase in labor costs?) caused the Gibeonites to alter their plan and to complete the project along less ambitious lines, i.e., by the narrower stepped tunnel instead of by extending the broad and vertical pool-shaft. The threat of an enemy attack could have had the same effect, impelling the Gibeonites to change design in order to speed up the pace of their descent to a secure water source.

Whatever the reasons for the differences between the upper pool-shaft and its lower stepped tunnel, Pritchard was convinced that the two phases of the project were executed relatively closely in time because the steps in the pool-shaft show no more wear than the steps in the stepped tunnel below.

I should like to propose another solution to the Gibeon puzzle. Perhaps the pool-shaft and its continuation, the stepped tunnel that goes to the water table, were two distinct projects separated by a century or more. I suggest that the pool-shaft was originally dug only as a cistern for the collection of rain water—that in David and Abner’s time it was indeed a “pool” and nothing more than a pool.14

Following this suggestion further, the other stepped tunnel, leading to the spring outside the walls, was built after the pool-shaft in order to supplement the water supply by making the fresh water of the spring accessible inside the city (that is, through the stepped tunnel to the spring).

When, as part of that second project, the Gibeonites cut the horizontal feeder tunnel back into the hill from the spring to increase the flow of water, they certainly must have realized that they had reached a point almost underneath the earlier cistern shaft, which we have been calling the pool-shaft. Note the proximity of the inner end of the feeder tunnel to the area of the pool-shaft. The engineers might have thought that they were closer than, in fact, they were. Because of its zigzag course, the horizontal feeder tunnel extended some 16 feet less in actual distance than its 110-foot length.

The Gibeonites might have decided to cut a stairway tunnel down from the base of their earlier cistern (the pool-shaft) with the intention of reaching the level of the horizontal feeder tunnel and then cutting out horizontally to connect with it. The water chamber at the base of the pool/stepped-tunnel system does, in fact, extend in the direction of the feeder tunnel. Before reaching that goal, however, the Gibeonites hit the water table! They thus discovered a fresh water supply wholly secure inside the city walls. This project—and the discovery it led to—should be dated after the 10th century stepped-tunnel-to-spring system. An early 9th century date would be quite plausible.

The news of this remarkable discovery would have quickly spread. It could easily have become the model for Hazor, whose engineers opted for this system instead of the Megiddo shaft and tunnel system which led to a spring outside the city wall. This could explain why the Hazor system reflects such confidence in the result. After the Gibeon experience, the Hazor engineers would have known precisely what they were doing. (If Yadin’s dating of the Gezer water system is correct, Gibeon could have served also as the model for Gezer where the engineers also proceeded to their goal with confidence.)

My theory about the Gibeon water system assumes that the pool-shaft was first built as a cistern. Pritchard considered this possibility but rejected it because the fissured bedrock would probably not have retained water for long without plaster, and he found no trace of plaster in the pool shaft. But the Gibeon engineers may not have known this when they dug it. Perhaps they hoped that the bedrock would be as impermeable as it is in some other places in the region. Or perhaps the Gibeonites inhibited percolation out of the pool by periodically applying a clay mortar lining, all traces of which would have been washed away over time.15

Pritchard also argued that the pool-shaft and its lower stepped tunnel could not have been separate projects because of the balustrade left on the steps. The balustrade alongside the pool-shaft steps seems to continue as a rim around the top of the stepped tunnel cavity. According to Pritchard, “The balustrade left in the live rock at the point where the steps go below the floor of the pool indicates that the circular stairway into the [stepped] tunnel was a part of the plan of construction when the floor of the pool was leveled off. The floor on the east side is carefully smoothed, while on the south and southwest provision was obviously left for the descent of the stairway into the [stepped] tunnel.”16

But this same evidence might be used to argue the opposite interpretation. Why plan for a balustrade around the top of the tunnel steps? The water carriers on the steps would hardly need it at that point. If it was to protect persons standing on the pool floor from falling into the stepped tunnel, why wasn’t a similar rim left around the two holes in the pool-shaft which provide light to the stepped tunnel below? Why finish off the bottom of the pool-shaft at all if the intention had been to tunnel deeper?

Perhaps the balustrade at the bottom of the pool-shaft represents the lowest level of the earlier cistern steps, which had terminated in a platform slightly above the cistern floor to allow water carriers to fill their jars without stepping into the water when the water was at its lowest levels. Pritchard found a shallow, almost square basin hollowed out of the pool-shaft floor alongside the bottom segment of the balustrade. This might have been an installation to facilitate filling jugs when the water level was low. Perhaps when the stepped tunnel project was initiated below the pool-shaft, the earlier pool stairs were sufficiently worn to lead the pickmen to re-cut them, creating the balustrade effect in the process as an afterthought. The stepped tunnel which extended the line of the steps down through the earlier platform was made narrow enough to leave the outer edge of the platform as an incidental rim—not necessary, but also not in the way.17

One cannot say for certain that the stepped tunnel beneath the pool-shaft provides the specific “missing link” which prepared the way for the Hazor shaft-to-water-table system. But it is clear that the Hazor project presupposes an awareness of the subterranean water table deep beneath the Israelite city. The Gibeon water system, on the other hand, does not demand such prior knowledge. The groping of the diggers who accidentally found the water table under the city is apparent. Gibeon it seems, then, is the most likely model for the Hazor engineers who, with sure and steady picks, dug directly through bedrock beneath the city streets to the water table level, 146 feet below.

The water tunnels of ancient Israel—whether in Jerusalem, Megiddo, Gezer, Gibeon or Hazor—are records through which modern day tourists may wander. They are unique archaeological remains—testimony to the engineering prowess of the ancient inhabitants of Israel.

a. For the sake of clarity, the term “tunnel” will be reserved for horizontal cuttings, “shaft” for vertical ones, and “stepped tunnel” for angling ones.

b. There are reasons to question this early a dating, but they need not concern us here.

c. This shaft and tunnel system has been described and illustrated in “Digging in the City of David,” BAR 05-04.

d. An “inset-offset” wall is one which has periodic zigzag vertical cutbacks along its face. This device gave defenders a line of fire against attackers at the base of their wall; it became popular in Israel in the 9th century B.C.

e. A casemate wall consists of two parallel walls connected by periodic cross walls. The effect is to create a line of narrow rectangular rooms, but the main purpose probably was to provide a wall system with sufficient space on the top for defenders to maneuver easily. We know that this wall style was most characteristic of Israel in the 10th century B.C.

f. Sometime after the 9th century B.C. shaft/tunnel system was cut, the tunnel was deepened and graded so that the water then flowed from the spring to the base of the shaft inside the city. This saved steps for the water carriers who no longer had to walk through the tunnel, but the arrangement apparently proved unsatisfactory. Perhaps the water became fouled at the shaft end since it had no place to flow off. So the tunnel floor was again recut and regraded so the spring water no longer flowed to the base of the shaft.

g. I am not convinced by Dever’s argument against a 9th century date. One of the Iron Age walls which on Macalister’s plan appears above the shaft looks as if it could have been a retaining wall around the top of the shaft steps.

1. For fullest description see Robert Scott Lamon, The Megiddo Water System (Chicago. 1935).

2. Yigael Yadin, Hazor- the Rediscovery of a Great Citadel of the Bible (New York, 1975), pp 168, 187–193.

3. Yadin, Hazor, pp. 207–220.

4. A stairway of similar concept was excavated by James G. Pritchard at Tell es-Sa’idiyeh in the Jordan Valley in 1964; see Biblical Archaeologist XXVIII-1 (Feb., 1965), 12–14.

5. Yadin, Hazor, pp. 233–247.

6. R. A. S. Macalister, The Excavation of Gezer (London, 1912), II, 256–265; III, Plate LII.

7. Biblical Archaeologist XXXII, 3 (September, 1969), 70.

8. Ibid., 71–78.

9. For the fullest description of the Pool and its discovery, see James B. Pritchard’s Gibeon, Where the Sun Stood Still (Princeton, 1962), pp. 64–74.

10. Edward Robinson, Biblical Researches in Palestine (London, 2nd ed. 1860), Vol. I, pp. 454–456.

11. Pritchard, Gibeon pp. 45–52.

12. James B. Pritchard, The Water System of Gibeon (Philadelphia, 1961), p. 8. See this volume for the most complete technical description of both the Pool and the stepped tunnel to the spring at el-Jib.

13. The same general concept (stepped tunnel through bedrock to already-known spring source) is exhibited in modified form in “Warren’s Shaft” at Jerusalem. An even closer analogy may be the tunnel at Khirbet Bel ‘ameh (ancient Ibleam) near Jenin, but it has not been fully exposed or dated (see G. Schumacher in Palestine Exploration Quarterly, 1910, 107–112, Pl. 2).

14. If the pool had been used originally as a cistern, we should not necessarily find traces today at the top of the shaft of the channels which led water into the reservoir. When it was converted to its later use the channel endings would have been dismantled to prevent water from flowing into the cavity.

15. Alternately, the upper shaft may have been a grain silo. A silo of similar shape, complete with spiraling steps, is preserved at Iron Age Megiddo The installation at Megiddo, however, only entailed cutting through earlier earthen debris layers and then lining the silo walls with small stones. It seems unnecessarily ambitious of the Gibeonites to have hewn through solid bedrock merely for grain storage.

16. Pritchard, The Water System of Gibeon, p. 10.

17. A secondary cutting of the upper stairs would explain why they appear less worn than those of the stepped tunnel to the spring in spite of the fact that the pool appears to predate the stepped tunnel and yet to have been still in use right up until the city’s destruction at the end of the Iron Age. There is a further reason to suggest that the upper shaft may have been originally a reservoir. The Hebrew word identifying the early 10th century installation at Gibeon in 2 Samuel 2 and translated “pool” (berekah) seems to be used elsewhere in the Bible for places where water is collected- basins into which water flows, natural pools in which rain water collects and so forth, for instance Isaiah 22-9, 11; Ecclesiastes 7-5. I find no place where the meaning is clearly a source of water or a place from which water flows. One verse is particularly striking. In Nahum 2-8 the prophet writes, “Nineveh is like a pool (berekah) whose waters run away.” The implication, of course, is that the waters should not run away from a berekah- they should be held by it.

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