During July 2009, a salvage excavation was conducted at Horbat Yamma in Yavne’el (Permit No. A-5704; map ref. 247891/735290), in the wake of damage to antiquities caused by digging foundations of a house. The excavation, on behalf of the Israel Antiquities Authority, was directed by E. Amos (field photography and drawing), with the assistance of Y. Ya‘aqoby (administration), R. Mishayev (surveying), M. Hartal (guidance) and laborers from Tiberias.
A square (30 sq m) was opened toward the top of the mountain between Horbat Yamma in the east and ‘En Yavne’el in the upper Nahal Harzit stream channel (Fig. 1). Horbat Yamma had been surveyed in the past (License Nos. S-63/2008, S-71/2008, S-150/2009) and architectural remains that dated to the Early Bronze Age, and the Roman, Byzantine and Early Islamic periods were found.
The western half of a large reservoir was exposed (Fig. 2); its eastern side was destroyed by earthmoving work. The western wall (W3; width 0.85 m, preserved height 1.1 m) was exposed for a distance of 7 m, but its northern end did not survive. The wall, built of different size, coarsely dressed basalt blocks, was severed in its center by the foundation trench of a modern pipe (Fig. 3). The southern wall (W10; width 0.85 m), preserved a single course high and exposed for a length of 8.5 m (see L11; Figs. 2, 4), was also built of various size, coarsely dressed basalt blocks. The inside of the eastern wall (W12) was exposed in the northeastern balk (L12); most of the wall did not survive (see Fig. 2). The reservoir, between the insides of Walls 3 and 12, was 8 m long (Fig. 5). Assuming it was square, its area was probably 64 sq m; its volume cannot be calculated because the height of its walls is unknown.
The reservoir was built inside a deep hollow of brown field soil (Fig. 6). The bottom of the hollow was filled with small and large basalt stones, set in a thick layer of white plaster mixed with small gray inclusions (L13). The walls of the reservoir and its floor were coated with a thin layer of white plaster, to which a layer of pinkish brown hydraulic plaster, containing small gray and white inclusions (L7), was applied. Potsherds were embedded in the plaster while it was still soft, including large body fragments of mostly jars; afterward, its surface was made smooth (Fig. 7). The panels were plastered diagonally (Fig. 8) and the corners of the reservoir were made thicker with an angle that protruded inward (Fig. 9).
The reservoir was filled with basalt building stones (see Fig. 6), some of which still bore remains of white plaster, as well as fragments of pinkish brown plaster, embedded with potsherds, which apparently fell from the collapsed walls of the reservoir.
The potsherds found inside the plaster on the floor, on the walls and in the fill within the pool included bowls (Fig. 10:1), jars (Fig. 10:2–5), a holemouth jar (Fig. 10:6) and parts of pipes (Fig. 10:7, 8) that dated to the end of the Byzantine and the Early Islamic periods (sixth–seventh centuries CE).
The reservoir is situated between the Yavne’el Spring in Nahal Harzit and Horbat Yamma and a connection probably existed between the three sites. It is unclear whether the reservoir was used to store irrigation or drinking water. Presumably, clean water flowed from the spring, was stored in the reservoir and conveyed into the settlement by means of the difference in elevation.