Remains of an original aqueduct built during the Knights’ period have been found during works for a public garden strip in Mriehel. The project unearthed a section of the Wignacourt aqueduct, just before it joined the above-ground arches on Mdina Road, right opposite Farsons brewery - what a find!
From photos posted online, it seems as though archaeological monitoring is taking place following the discovery, and the historic stone slabs, called kaptelli were exposed carefully.

Brian Restall via Malta Water Association / Facebook
The Wignacourt aqueduct
The 17th-century structure was built by the Order of Saint John to carry water from springs in Dingli and Rabat to the newly-built capital city of Valletta. The water system included a series of underground pipes and over-arched viadcuts, which remained in use until the 20th century! Most of the arches still stand today, and can be seen as your drive through Attard, Balzan, Birkirkara, Fleur-de-Lys and Santa Venera.