Ardingly Reservoir

Following the driest spring in England since 1893 and hottest summer on record, parts of Sussex are now in drought. The lack of rainfall is putting pressure on both the environment and on drinking water supplies. Recent rainfall is helping, but so far enough hasn’t fallen it isn’t enough to reverse the current conditions and we need more than 80 per cent of average rainfall until February 2026.

Ardingly Reservoir supplies drinking water to around 228,000 customers in the Haywards Heath area. The reservoir is currently at 36 per cent full. We’ve been granted a Drought Permit that allows us to reduce the amount we release from the reservoir into the Shell Brook (the stream) and refill it earlier from the Upper Ouse, if river flows are high enough.

We’ve also applied for a Drought Order to further help conserve water. We’re also looking at alternative measures to provide more immediate support in replenishing Ardingly Reservoir. Crucial to this is working with Southern Water to allow the use of Weir Wood Reservoir to help refill Ardingly Reservoir.

Owned by Southern Water, Weir Wood Reservoir is not currently being used as the company is in the process of rebuilding the water treatment works to future-proof water resilience in the South East.

This means Weir Wood Reservoir is full, so this pipeline will allow us to pump water from Weir Wood to our Ardingly Reservoir. This will not impact Southern Water’s customers, but it will help replenish Ardingly, which is currently very low.

We are considering several options for this pipeline, along with potentially a new, temporary water treatment works at Weir Wood to treat the water before it’s pumped to Ardingly to prevent any transfer of invasive non-native species between the two areas.

We are currently developing and assessing route options. Details of the start date and programme, along with any roadworks needed, will be published here once confirmed.

This webpage will be updated as planning progresses.

We have been considering the environmental constraints of this project during the design work we’ve been carrying out over the last couple of months to make sure the selected route will have as little environmental impact as possible.

Once the proposed route has been confirmed, we’ll undertake further survey and investigation works to inform our environmental mitigation strategy. Where we are able to, we'll seek to enhance the environment where possible, while aligning with the project goals.