Havant Thicket reservoir delay impacts sustainability of Horsham Local Plan

Letter published in the West Sussex County Times 8 October 2026

Dear Sir,

Impact of reservoir delay on Local Plan

Southern Water and Portsmouth Water’s Havant Thicket Reservoir and integrated Hampshire Water Transfer and Water Recycling Project are essential upgrades intended to secure long-term water supplies across south Hampshire and parts of West Sussex, including the Sussex North Water Resource Zone.

Originally scheduled to be operational by 2029, the project has been delayed by five years and is now expected to be completed in 2034.

Unforeseen geological issues, and project expansion have more than doubled costs, from £339 million in 2022 to £822.9 million at November 2021 prices; at least £1 billion when adjusted for inflation. (Information obtained from national news media).

Whether additional funding will be forthcoming is dependent on the outcome of a three-week public consultation opened by Ofwat September 2026.

However, even with additional funding, the scheme’s technical and geological complexities make full completion and operation in 2034 uncertain.

How this delay and the resultant shortfall in Southern Water’s capacity to supply water could or would impact on Horsham District, its communities and the sustainability of the Local Plan ought to be considered at the in-progress examination of the District’s Local Plan by the examining inspector, Inspector Bore.

It would be beneficial if Ryan Lownds, Southern Water’s Strategic Planning Lead (Hampshire, West Sussex & Isle of Wight) were to attend and participate in the examination.

Could Horsham MP John Milne therefore liaise with the examining Inspector and Lawrence Gosden, Chief Executive of Southern Water, to facilitate Mr Lownds’ participation?

Yours faithfully,

Dr R F Smith

Trustee CPRE Sussex