Reservoirs dating back to 1534 were uncovered during excavation work for a social accommodation housing project in Cospicua, the government said.
The government said there are indications that the remains are of historic value. The Superintendence for Cultural Heritage was notified about the find.
The reservoirs are situated next to the area allocated for the project, and work can therefore continue, the government said. The idea is to preserve the reservoirs and incorporate them in the project.