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Resilient Geotechnics: water management strategies for construction

Event organised by The British Geotechnical Association

18 April 2023

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To mitigate flooding in the city of Rochdale, the UK Environment Agency is constructing large attenuation lagoons in the region of Littleborough. The construction of these lagoons required construction of a storm culvert beneath the Network Rail Calder Valley Railway Line, and required a 4-day rail blockade during which the track was removed, ground excavated, culvert installed and the railway line reinstated. 

A robust and resilient groundwater control system was required to ensure that the hydraulic head in underlying alluvium (clay, sand, gravel) was maintained below excavation formation level in advance of, and during, the 4-day blockade. The design had to consider the highly permeable geology, the conditions of the EA abstraction licence and discharge permit, whilst ensuring that any settlement of the railway line & embankment was within acceptable limits to Network Rail.


The British Geotechnical Association

The British Geotechnical Association

The BGA is the principal association for geotechnical engineers in the United Kingdom and organises a number of high profile events each year.


Dr Stephen Thomas

Dr Stephen Thomas

OGI Groundwater Specialists Ltd

founder director

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Dr Stephen Thomas

Stephen Thomas is the Founder and Director of OGI Groundwater Specialists Ltd.

Starting his civil engineering career in 1976, he has completed over 300 geotechnical, water and groundwater projects over 36 years working in the construction, water, and environmental industries. Supported by 10 years of university education in Swansea, Durham, and Oxford, Stephen delights in developing innovative solutions to overcome major engineering challenges.

After three years working in the United States, then six years at Oxford University, Stephen founded OGI in 1989 to provide specialist services in the field of groundwater engineering and management. 

His projects have been delivered predominantly in the UK to the infrastructure industry, but he has also worked on many international projects, including his favourite of working for the Native American Navajo Tribe in New Mexico, defending their holy River Jemez from over-abstraction of groundwater by industry.