This page shows the water levels in our two biggest reservoirs – Arlington and Ardingly. We update this page every week.
How we fill our reservoirs
We usually fill our reservoirs in winter, ready for when people use more water in the summer. We use water from the River Cuckmere to fill Arlington Reservoir, and water from the River Ouse to fill Ardingly Reservoir.
Our reservoirs are really important in the summer. They give us millions of extra litres of water every day to meet the higher demand.
Ardingly and Arlington can store up to 8,300 million litres of water. They supply 8% of all the drinking water we provide to our customers.
We also get millions of litres of water every day from underground sources called boreholes and aquifers.
What to expect
Our reservoirs might look a bit low at the end of summer, but this is completely normal. We refill them between October and April when there’s more rain and higher river flows.
Ardingly Reservoir is currently about 99.1% full, and Arlington Reservoir is about 96.4% full (as of Sunday 13 April 2025).
Why saving water is important
It’s important to save water all year round. This helps us make sure everyone has enough water, especially in the summer when people use more.
Here are our top tips for saving water:
• Use a water butt to collect rainwater in your garden.
• Fix any leaky toilets.
• Re-use water wherever possible.
Further advice can be found here.
Our current reservoir levels (as of Sunday 13 April 2025)
Arlington Reservoir directly feeds our nearby treatment works, so water levels naturally decrease and increase as we draw water from the reservoir, before refilling it from the River Cuckmere when conditions allow.
