WSC regularly inspects a number of perched aquifer spring sources related to the Wignacourt Aqueduct under our custody. This week we visited the underground water gallery of Wied il-Bużbież on the way to Baħrija, which is the longest of these underground tunnel branches.
These galleries were cut in 1864, and remain a true testament to our ancestors’ ingenuity and an impressive part of our industrial and colonial heritage. These water galleries where cut just below the Upper Coralline and tapped perched alluvial aquifers in the Rabat-Dingli plateau.
The galleries lie on average around 22metres below the surface and run for circa 2.3km, with around 150 shafts dug at regular intervals along the route to enable removal of spoil and ventilation. Guided by complex building calculations and determined mining skills, these galleries conduct water along underground tunnels to the Fiddien valley to join the Wignacourt supply to Valletta.
By 1911, all these spring sources and galleries where piped in order to diminish the risk of surface water pollution.
Despite the lack of rain, the volume of water remain copious till today. Until the mid-50s, this branch of the aqueduct remained an important source for potable supply in Malta, and provided an average of around 330,000 litres daily (1942-43, excluding May to August).