Sheet Piling (UK) Ltd

Ridgegate Reservoir Refurbishment

Ridgegate Reservoir Refurbishment

Ridgegate is an impounding reservoir, one in a series of such reservoirs along the Bollin Brook, a tributary of the River Mersey. Built in the late 19th century and now owned by United Utlilities, several upgrades to the reservoir embankment have been proposed to extend the operational life of this important source of water.

Working on behalf of Costain, a new, permanent steel sheet pile cut off wall would be installed into both the western embankment and the southern embankment. These cut off walls were designed meet the Probable Maximum Flood (PMF) and Stillwater Level (SWL) plus wave height, resisting their horizontal loads for the next 100 years.

Phase one of the project will see the crest of the western embankment raised and levelled with the new sheet piles installed and made watertight with clutch sealant, to maintain watertightness to a hydrostatic pressure of 1 bar.

Owing to the restricted access of the site, the team at SPUK determined that a small excavator mounted MOVAX piling rig would be the best option to install the steel sheet piles. The GU16 section steel sheet piles were cut to length (3m) off site and delivered, ready to be installed as single piles.

A remote controlled tracked leveller with a 6.0Te payload capacity was used to transport the cut piles from the off-loading point, over a weak bridge, across the crest of the dam, to the MOVAX piling rig. Shuttling the piles in this way increased the efficiency of the installation programme and contributed to a successful, on-time delivery.

Once both phases of the refurbishment works are complete, the drinking water supply for the town of Macclesfield and the surrounding area will soon be secure for the next 100 years, thanks to the permanent sheet pile upgrade at Ridgegate Reservoir.