The contracts cover 11 treatment sites – seven wastewater and four clean water facilities – aimed at boosting resilience, capacity and environmental performance across the region.

The largest, worth nearly £24m, comes under the priority water treatment works growth programme. This covers works at Billingshurst, Dymchurch, Goddards Green, Ham Hill, Northfleet, Sidlesham and Stockbridge. The programme will deliver capacity upgrades to meet rising demand and population growth.

A second £5m package under the nitrate removal programme covers Madehurst, Patching, Mossy Bottom and Patcham Water Supply Works, developing solutions to reduce nitrate levels and ensure drinking water compliance.

Both ECI contracts will run under the NEC4 Engineering and Construction Contract, with Kier working closely with Southern Water to refine design, improve constructability and guarantee programme certainty ahead of full construction.

Kier said sustainability and local value creation will be built into both projects through low-carbon design, waste reduction, and supply chain engagement, alongside new apprenticeships and training opportunities.

Andy Beech, framework director at Kier, said the awards reflect the trust Southern Water places in Kier to deliver projects in both clean and wastewater sectors, adding that the firm would bring extensive technical expertise and a collaborative approach to generate long-term value.

The wins strengthen Kier Natural Resources, Nuclear & Networks’ position as a major partner in the UK water sector, following recent AMP8 renewals with Yorkshire Water, Wessex Water, United Utilities, Anglian Water and Severn Trent.