“…In all water systems in the City of David, in Jerusalem (Reich and Shukron, 2004;Shiloh, 1992;Gill, 1991;Frumkin et al, 2003;Frumkin and Shimron, 2006) and in Megiddo (Lamon, 1935), the engineering mission was to connect the cities with outside springs via shafts and tunnels; hydrogeological considerations were hardly involved. In Gibeon (Pritchard, 1961), the tunnel dug at the bottom of the ''pool'' was unequivocally directed to reach a spring, not the groundwater, which was encountered a few meters from the spring (Cole, 1980). In Gezer -where dating is controversial (Macalister, 1912;Yadin, 1969;Dever, 1969) -the tunnel reached groundwater collected in a natural cave, which might has a connection outside the mound (Reich and Shukron, 2003) (Fig.…”