During December 2007 and January 2008, a trial excavation was conducted in a section of the Lower Aqueduct to Jerusalem in the Har Homa neighborhood of Jerusalem (Permit No. A-5333; map ref. 219904/626603), prior to paving a road. The excavation, undertaken on behalf of the Israel Antiquities Authority and underwritten by the Ministry of Construction and Housing, was directed by I. Zilberbod, with the assistance of R. Abu-Halaf and Y. Ohayon (administration), A. Hajian and M. Kunin (surveying and drafting), T. Sagiv (field photography), the Sky View Company (aerial photography) and I. Berin (plans).
Two segments of the Lower Aqueduct to Jerusalem were excavated (Area B1—length c. 25 m; Area B2—length c. 26 m; Fig. 1). Other unexcavated segments of the aqueduct (Area C—the western segment) were evident east and west of the excavation. An opening of a burial cave (Area A; Fig. 2) was exposed c. 450 m west of the excavation; it was not excavated. The beginning of the aqueduct is at the Solomon’s Pools, 765 m above sea level; it runs for a distance of c. 21 km to the Temple Mount, situated at an elevation of 735 m above sea level (A. Mazar 1989. A Survey of the Aqueducts Leading to Jerusalem. In D. Amit, Y. Hirschfeld and J. Patrich, eds.. The Aqueducts of Ancient Palestine. Jerusalem, pp. 174–175 [Hebrew]). The aqueduct was used from the Early Roman period (the Hasmonean era) until the Late Ottoman period.
Areas B1 and B2, located between the Bet Lehem and Sur Bahir spurs, are next to the road. The elevation of this aqueduct segment is 742 m above sea level. Five construction phases were exposed in both segments of the aqueduct (Area B1—Figs. 3–5; Area B2—Figs. 6, 7). The aqueduct in Area B2 was severed by the paving of a road and all the five phases are clearly evident in the section (Fig. 8).
Phase I. The earliest aqueduct was probably built in the Early Roman period (overall width c. 1.8 m). The walls of the aqueduct (W4, W5; see Fig. 8) were built of small stones bonded with light gray cement. The channel (L131; width c. 0.6 m, depth c. 0.5 m) was coated with at least two layers of plaster.
Phase II. The aqueduct was made wider in the Byzantine period (overall width 2 m). A wider wall (W3) was built on top of W5 of Phase 1 and a new channel (L130) of similar dimensions was built on Channel 131 of the previous phase. The channel was coated with pink plaster mixed with ground potsherds, which is characteristic of the Byzantine period.
Phase III. A repair (L129) that consisted of a gray plaster coating in the channel was discerned in the section of the aqueduct in Area B2. Comparing the construction phases in other segments of the aqueduct indicates that this phase should probably be dated to the Mamluk period.
Phase IV. The walls of the aqueduct (W1, W2; height 1.5 m) were raised in the Ottoman period. A terracotta pipe (L108, L111; diam. 0.25 m) composed of sections (length c. 0.3 m) was installed inside the channel.
Phase V. A later channel (L116; width 0.45 m, depth 0.15 m), plastered and covered with stone slabs (L114; max. size of the stones 0.50 × 0.65 m), was built above the pipe ascribed to Phase 4. Round openings (max. diam. 0.1 m; Fig. 9) were installed in the stone slabs, at intervals of 1 m, to prevent excess pressure in the water flow.