The Challenges of Maintaining a Bateman Embankment Dam

Overview

This is a joint meeting of the British Dam Society (BDS) and the British Geotechnical Association (BGA).

Bateman reservoirs, designed by and named after English civil engineer John Frederick Bateman, were constructed in the 1850s and soon after. The unnamed reservoir that was the subject of the Fleming Award presentation is the largest of a chain of reservoirs east of Manchester.

The project reservoir experienced a significant amount of movement on first filling 150 years ago. Following concerns about recent changes in the rates of settlement in the dam, United Utilities determined that work to maintain and stabilise the reservoir was necessary.

The project involved extensive ground investigations (GI) and monitoring to determine the geotechnical parameters of the embankment, the foundations and the clay core. A ground model that was developed using the GI data showed that a high plasticity clay in the foundation layer was initiating a deep-seated slip.

The team sought a second opinion from Stantec, who came up with a similar understanding of the mechanisms behind the slip.

This led the team to consider several engineering solutions. These included a structural shear resistance and retaining approach with piles that would go through the clay horizon and socket into the rock at the base of the embankment. Another approach was to modify and improve the soft clay properties by jet grouting.

The team opted for the piling solution. This involved installing a 65m length of piles, which would anchor into the dam and avoid the central clay core – the water retaining element.

2025 Fleming Award winner
The British Geotechnical Association (BGA) awarded the 2025 Fleming Award to United Utilities, Stantec, and Keller for their work on maintaining a Bateman embankment dam.