Excavation works currently being carried out in the fields at Mgarr ix-Xini are trying to establish the origins of the troughs in the valley and in the surrounding fields.
The works, which have been ongoing since 2005, have been visited by Gozo Minister Giovanna Debono.
The ministry said in a statement that the fields were probably used to cultivate vines for wine production. The excavations are also providing more information on the site, its use and nature and the period in which it was used.
Indications are that the system dates back to 600 BC.
The works form part of a project by the Regional Park Committee of the Mgarr ix-Xini valley set up between the Xewkija and Sannat councils. The excavations are being carried out in collaboration with the university's faculty of archaeology and the Cultural Heritage Superintendence.
Once the works are concluded, the aim is that the site would be promoted as a natural attraction.