Southern Water has appointed CMDP+, a joint venture between Costain and MWH Treatment, to shape and deliver its next strategic asset upgrade programme.

The award is for an initial seven-year term worth at least £500 million to Costain, with an option to extend by up to five years.

CMDP+ has successfully secured a place on two Lots of the new Strategic Delivery Partner framework, and the joint venture continues the long-standing relationship between Costain, MWH Treatment and Southern Water. The framework will deliver upgrades to water and wastewater assets, including treatment sites, pumping stations and reservoirs, during Asset Management Period 8 (AMP8) and beyond. Southern Water expects that its AMP8 programme, which runs from 2025 to 2030, will be the largest it has ever undertaken.

Costain has worked successfully with Southern Water through every asset management investment period since 2000 (AMP3). Earlier this year, the joint venture was awarded £65m of additional work for Southern Water’s current AMP7 investment programme.


Alex Vaughan, CEO, Costain, commented: "This AMP8 announcement builds on our growing positions with the leading water companies as they prepare for a nationally important period of record investment.

"This framework marks three decades of delivering industry leading essential solutions for Southern Water. Through our successful joint venture with MWH Treatment, we will upgrade water and wastewater services for Southern Water and its customers, safeguarding the environment, and securing water supplies across the region; as well as creating new jobs and added social value."

Paul Bresnan, Chief Executive, MWH Treatment, commented: "I am delighted that MWH Treatment is continuing our long-standing relationship with Southern Water, alongside our joint venture partner, Costain.

"We will see the need for continued innovation, along with more sustainable solutions that provide great value for customers with increased resilience against the impacts of climate change and population growth.

"Together with Costain we look forward to working with Southern Water to meet these challenges, collaboratively delivering the AMP8 investment into both water and wastewater services across the entire region.

"This significant award is particularly pleasing as many of our staff are Southern Water customers and will get the opportunity to make a difference in the area they reside."