Civil engineering firm Land & Water has completed works as part of the largest restoration project that has ever taken place at World Heritage Site, Blenheim Palace.
The firm has dredged 300,000m3 from Queen Pool after 70% of the lake became less than 30cm deep when it should be around two metres. The area is a Site of Special Scientific Interest, which is often relied on for food by a variety of wildlife and so the works undertaken ensured the depth of the lake was increased whilst the eco-system was improved for the local flora and fauna. The dredged material has been relocated to Great Park where a landform has been constructed and trees have been planted to offset the carbon emissions generated.
The firm commissioned several pieces of equipment. It has often used long-reach excavators, however the team at this project instead commissioned three semi-long-reach machines and oversized dredging buckets to provide higher production in the shallower water. The project used a GPS dig system to give accurate dig control on the excavator and monitor the working position and progress. All Land & Water machines are operated on bio-oil, says the firm – important for the the environmental safety of the lake.
Charlie Oakes, Project Manager at Land & Water said the dredge had been “one of the most ambitious projects undertaken at the site over the last 300 years and one of the largest ever inland dredging contracts completed in the UK.”
“Despite some of the delays caused by the winter weather and archaeological findings of a Saxon mill, we are extremely pleased with how the dredge has gone and to have played our part in such a historic project.
He said they had used methods “designed to minimise the impact on the Estate as well as the environment and will help ensure that Queen Pool is future proofed to support the rich biodiversity that surrounds the lake as well as mitigating the risk of environmental damage.”
Kelly Whitton, Head of Built Heritage at Blenheim Palace said, “Without these essential works, which form part of our goal to spend over £40m on restoration within 10 years, the Queen Pool would have completely disappeared within 5 years, and we would have lost a critical element of the World Heritage Site, and our SSSI status.”
Over the next year Land & Water says it will be monitoring the landform in order to establish when it will be reinstated.