£130 million water investment to improve resilience
Guernsey Water plans to invest nearly £130 million between now and 2037 to renew and improve critical infrastructure and better protect the island against future water shortages.
Most of this - £72 million - is to be spent on maintaining the existing drinking water and wastewater infrastructure, parts of which are up to 100 years old. This will include replacing or upgrading essential water collection and treatment systems, water mains and storage tanks, sewers and manholes, pumping stations and the wastewater centre at Belle Greve.
A further £20 million is earmarked for a new reservoir at Les Vardes Quarry, which is expected to be available for conversion works to start from around 2035. Around half of this investment will install pipes to enable Les Vardes to connect into the network between the island’s reservoirs. This will start well before 2035 as it will take several years to complete. The reservoir will increase local storage capacity by a third and make the island more resilient to droughts, which are expected to be more frequent and severe as summers become hotter and dryer. It will also help meet forecast additional demand due to increasing population.
The utility also plans to upgrade its three water treatment works at a total estimated cost of around £20 million, to ensure continued compliance with drinking water quality standards. This is also needed to increase resilience to drought by enabling water collection from several local streams not currently captured due to the presence of pesticides and other chemicals such as PFAS.
The investment plan will be funded through a combination of charges and borrowing, to spread the cost between current and future water customers. This will mean above RPI increases for 2026, with metered customers set to see bills rise on average by around £4 a month, and unmetered customers by £6 a month.
The utility is also targeting efficiency savings to offset the level of future increases, with cost reductions of £355,000 included in its 2026 Budget.
Guernsey Water managing director Steve Langlois said it had to invest both to maintain the current ageing infrastructure and to improve resilience given changing rainfall patterns.
The ten warmest years on record in the UK have all occurred since 2000, with several areas seeing hosepipe bans in 2025. Although the island escaped water restrictions, storage levels in local reservoirs dropped well below average this summer. In Guernsey, rainfall between January and September was 13% less than average for the last 10 years, and 15% below the 30-year average.
“The issues we face are identical to what water companies across Europe are having to deal with, just without the economies of scale. We must prepare for a greatly increased risk of severe drought in future, which for an island poses additional risks. That means ensuring we have more capacity and greater resilience,” he said.
“At the same time, we cannot neglect the infrastructure we are already using today. It has been built up over the last 100 years and much of it requires renewal. We must invest adequately in this to ensure it remains stable and continues to meet the island’s needs. Failure to do so simply stores up problems for the future, which would be more costly for customers in the long run.
“Islanders can be reassured that as we are States-owned, we do not have to pay dividends to shareholders, unlike England. Every penny we collect in charges goes directly towards providing essential services and investment in critical local infrastructure.”