In 2015 the WSC produced 31.2 million cubic metres (cu/mt) of potable water in Malta & Gozo. Approximately 13.4 million (43%) cu/mt. were produced from various groundwater sources, the main one being Ta’ Kandja Pumping Station which is a series of underground galleries some 8km in length, 100m below ground.

Ta’ Kandja Galleries

Just over 13 million cubic metres per year are produced from underground sources, the main source being the underground galleries at Ta’ Kandja. These galleries are 97 metres below ground and radiate like the spokes of a wheel for thousands of metres. There are also 12 other pumping stations and 134 boreholes from where water is extracted.

Ta’ Kandja Underground Galleries are situated in the limits of  Siggiewi. This was the last pumping station built and was completed in 1963. It consists of a network of 6.2km of galleries out of a network of 42 km of such galleries which are beneath the Maltese island.

Reverse Osmosis

Groundwater production, however, is not enough to meet demand which means that the Corporation has to convert seawater into high-purity drinking water in its three RO plants at Pembroke, Cirkewwa and Ghar Lapsi and blend it with groundwater.  The long term deterioration in the quality of groundwater required the introduction of desalinated water to achieve the required quality (potability) levels which has forced the WSC to increase RO water production. This allows it to reduce groundwater production as a percentage of overall water production.

In 2015 just under 18 million cubic (58%) meters of water was produced by RO plants. cu/mt.

Storage & Control

This blend is stored in the 24 reservoirs in Malta, Gozo and Comino which have a total capacity of 400,000 cubic metres. All the production, transfer and storage of water is controlled and monitored in real time by remote sensing from the Control Room based at Luqa. Reservoir levels, flow rates and pressures are kept at optimal operating parameters at all times.


The water distribution system is a vast and complex network of over 2136 km of pipes, pumps, reservoirs, automated and manual valves and other components that bring safe, good-quality drinking water to your tap.

This network leads to approximately 142,000 water service connections to homes, businesses, industries, hotels, schools, etc., serving over 420,000 persons throughout the Maltese Islands.


The quality and safety of the water we produce is constantly checked by the laboratory which is fully accredited by both the National Accreditation Body of the Malta Standards Authority and the United Kingdom Accreditation Services (UKAS). Every year over 5100 samples are collected upon which approximately 54,500 physical, chemical and bacteriological tests are carried out.

Leakage Reduction

An extremely important part of our work is aimed at reducing system demand i.e. the amount of water entering the distribution system from our reservoirs and reverse osmosis plants. Over the past few years an aggressive leakage control programme using state-of-the-art equipment, refined work practices and policies. This has allowed the Corporation to reduce total water produced over previous years. 2015 was closed off at an average Infrastructural Leakage Index (ILI) value of 1.91, compared to 1.94 attained in 2014. This translates to an average value of 395 cubic metres per hour of leakage, compared with an average of 407 cubic metres per hour of leakage registered during 2014, which was a record year.

Just for comparison, leakage in 1995 was 4000 cubic metre per hour with a corresponding ILI of 20.

The WSC is looked upon as a “Best Practice” example of leakage control by other water companies.