History

Formed in the late 19th century, the Guernsey Water Company operated as the island’s only water supplier and distributor. By 1920, the company was providing water to 1,850 domestic customers, consuming an average of 550 megalitres (ML) of untreated water each year. The primary water sources at that time were seven wells in the St Martins and Forest areas.

In 1920 it was agreed that the States should take over the growing responsibility for the island's water supply, and the States Water Board was formed. It was an inauspicious start as the following year had the lowest rainfall ever recorded, putting the island's water supplies under great strain.

During the next 15 years, the Board constructed the island’s first WTW's at Kings Mills (above right) and St Saviours, which utilised gravity filters and chlorination equipment. Pumping stations were built to make use of water flowing through the island's valleys.

By 1930, consumption had more than doubled to 1,100ML every year and it was clear that increased storage capacity would be required. Initially, disused quarries in the north of the island were purchased to help maintain supplies, but it was clear that demand was only going to increase further.

In 1936, the Board proposed the construction of an impounding reservoir in St Saviour's valley which would create a 1,090ML reservoir (right). The project was agreed and work began in 1938. Work on the dam was halted during World War II, but commenced again in 1946 following the island's liberation from the German forces. The dam was sealed in January 1947, and by April, the reservoir was full to overflowing.

Over the following years, more pumping stations were built, disused quarries purchased and a new WTW constructed at Juas to meet the continuing increase in demand. By 1958 more than 3,400ML of water was being supplied each year. At this time, a revolutionary desalination plant, the first in the British Isles, was constructed to augment the island’s supply during the dry summers (left). The plant was reasonably successful and without it supply restrictions would have been likely in 1964 and 1965. However, the plant proved to be uneconomical to maintain and was decommissioned shortly after 1970.

Demand was up to 5,000ML a year by the hot summer of 1970, so the Board agreed to purchase Longue Hougue Quarry. This extremely deep reservoir can store 1,400ML of water, more than a third greater than the St Saviour's Reservoir, and is a major component of the island's water storage capacity.

The Review of the Machinery of Government in May 2004 resulted in the amalgamation of the States Water Board with States Works, Guernsey Technical Services, Harbours and Airports into the Public Services Department (PSD). The former States Water Board was renamed Guernsey Water, a business unit of PSD.

PSD is responsible for the delivery of key services and the provision of essential island infrastructure which facilitates the movement of people and goods on, to, through and off the island by the provision, management and maintenance of Harbours, roads and the Airports. It also secures the supply of fresh water and removal of foul water.

The Minister is elected from within the States of Deliberation and, together with a Deputy Minister and three other States representatives, takes responsibility for the Department. One non-States member can also be appointed as a non-voting Board member if required. Each business unit is encouraged to act commercially, and to generate revenue by its own means, rather than taking from the States’ general revenue account.