On 10 October 2025, we applied for a Drought Order from the Secretary of State on the River Ouse.
We have applied for this order because we have experienced extremely low rainfall this year, resulting in the water level at Ardingly Reservoir approaching critically low level.
The reservoir, which supplies 228,000 customers in Sussex, is currently at 27.6 per cent full. The impact on customers and communities of Ardingly Reservoir going empty cannot be underestimated as it could limit the amount of water we can supply.
Drought Order documents
You can also view the Drought Order application information at the following locations:
Ardingly Activity Centre, Ardingly Reservoir
College Road
Ardingly, Haywards Heath
West Sussex
RH17 6SQ
South East Water
Rocfort Road
Snodland
Kent
ME6 5AH
What is a Drought Order?
A Drought Order is similar to a Drought Permit in that it allows changes to be made to abstraction licences when there has been an exceptional shortage of rain. Both water companies and the Environment Agency (in England) can apply to the Secretary of State for a Drought Order to manage water resources for water supply and environmental benefit.
On a normal day, we must leave 20 million litres of water in the Lower Ouse below where we extract and treat water at Barcombe. If granted, the Drought Order would allow us to reduce the amount of water we leave in the River Ouse below Barcombe to 15 million litres a day, and if necessary, 10 million litres a day.
How will this help?
While it’s a reduction, it will have a number of benefits:
- Preserving water resources for longer
- Enabling the water within the reservoir to replenish faster before next
summer - Ensure a baseline flow continues to be released into the upper
reaches of the river, benefitting the whole river system.
We have worked closely with Defra, the Environment Agency and Natural England on this Drought Order application, which retains the measures already in place within our Drought Permit, which was granted by the Environment Agency on 22 September 2025.
Will this affect me?
The Drought Order does not directly affect customers, however, to conserve as much water as possible we are making changes to the Temporary Use Ban (hosepipe ban) that is currently in place, which will affect customers in Sussex.
On Friday 10 October we announced that we are removing all exemptions from the ban for our customers in Sussex, except for the ones that are for health and safety purposes.
These exemptions include:
- Watering new lawns at domestic premises
- Watering trees, whips, saplings and hedges planted before the ban
and within the last three years - Watering food crops at domestic premises or private allotments
If you live in Sussex and we previously wrote to you to say you were exempt from the hosepipe restrictions, this will end and you will no longer be able to use your hosepipe.
If you were not exempt but activities you were doing were covered by an exemption, this will now also end.
There are some circumstances where a hosepipe is needed for health and safety purposes. Only these will be allowed.
We understand you may have some questions about this, and how this might affect you due to additional needs. You can read more about the updated restrictions below.
The decline of Ardingly Reservoir
You can see the decline of Ardingly Reservoir since March 2025 here, but since mid-June the reservoir has been dropping steadily and is currently at 27.6 per cent full.
Although we experienced high rainfall at the beginning of September, average rainfall between March 2025 and August 2025 in that area of Sussex has been around 63 per cent. That’s the ninth driest it’s been in the last 150 years.
Below is a graph to show the rainfall in the River Ouse area compared to the long term average from May 2024 to September 2025.
As of today, to fill Ardingly Reservoir will mean we need at least 80 per cent of average rainfall from now until the end of the year. Forecasts currently suggest this level of rain will not be coming any time soon.
As you may know, Ardingly Reservoir provides a release of water, called the compensation release, into the Shell Brook (the stream which flows into the River Ouse) to compensate for the dam that was built to store water in the reservoir. Under our Drought Permit, which has already been granted, we have decreased the compensation release from four million litres a day, to one million litres a day, closer to the flow that would be there naturally at this time of the year.
As well as the compensation release, we also release enough water from Ardingly Reservoir for customer supplies, which we abstract at our water treatment works further down the river, to then treat for drinking water. After we abstract this water we must make sure there is 20 million litres left in the Lower Ouse part of the river, below where our treatment works are. If granted, the Drought Order would allow us to reduce the amount of water we leave to 15 million litres a day, and if necessary, 10 million litres a day.