Costain, the UK-based infrastructure solutions company, has been awarded a contract by Thames Water to aid in the design of a new reservoir in Oxfordshire. This project, known as the South East Strategic Reservoir Option (SESRO), aims to bolster water supply resilience for 15 million people across London, the Thames Valley, and regions served by Affinity Water and Southern Water.
The proposed SESRO reservoir, with a capacity of 150 million cubic metres, will not only secure water supplies but also enhance local biodiversity by creating new habitats and providing leisure and recreational facilities.
Costain's role involves conducting clay compaction trials to assess ground conditions at the designated site. These trials will involve constructing three test embankments on Thames Water-owned land, each 50 metres long, 20 metres wide, and up to 3 metres high. Geologists will then analyze the performance of Kimmeridge clay under various compaction scenarios, influencing the reservoir's final embankment design and construction methodology.
Costain has also provided constructability advice to inform Thames Water’s design proposals for the new reservoir. This includes recommendations on significant project elements such as embankment structures, tunnelling, and the integration of a rail siding from the nearby Great Western Mainline. Costain will also ensure safety, health, environment, and quality (SHEQ) standards are met, while serving as a logistical hub for all ground and environmental investigations, including archaeological assessments.
Clay compaction trials are set to commence this summer, with an expected duration of six to twelve months, contingent on weather conditions. Upon completion, all land used for the trials will be restored to its original state.
