As part of a £40 million restoration goal, Blenheim Palace has announced the completion of its largest ever restoration project and one of the largest ever inland dredging projects in the UK. With the help of Land & Water, a leading wet civil engineering firm, the team has dredged 300,000 m3 (which equates to 500,000 tonnes) of silt from the Queen Pool.
The famous manmade lake, built by Capability Brown in 1763, had become less than 30 cm deep which is nearly two metres less than it should be. This indicated that if the project had not taken place, Blenheim Palace was at risk of the lake completely drying up within five years. Since work began 18 months ago, the team from Land & Water dredged enough silt to fill Wembley Stadium.
The silt is now being used to form a 16 hectare grass mound on the estate.
The team faced some challenges during the dredge. Not only was it battling with nature, it also came across old roads and infrastructure dating back 1066, which meant the site had to be shifted 50 metres whilst archaeologists investigated the findings, which has been determined to be an old Saxon Mill.
The dredge was strategically designed to minimise the impact on the environment and the estate as a whole. Land & Water commissioned several pieces of equipment to enable higher production in the shallower water. All the Land & Water machines operate on bio-oil which ensured the environmental safety of the lake.
Kelly Whitton, head of built heritage, explained: ‘By dredging the lake and returning the profile back to the Capability Brown design, we have saved England’s ‘finest view’ for the generations to come. Without these essential works, the Queen Pool would have completely disappeared, and we would have lost a critical element of the World Heritage Site and our SSSI status.’
The lake is a Site of Special Scientific Interest, which is relied on by a variety of wildlife for food. The work that has taken place has now ensured the lake is back to its original depth and has boosted the eco system for the resident wildlife. Blenheim Palace worked alongside ecologists to ensure their fish and nesting birds remained undisturbed throughout the process.
Charlie Oakes, project manager at Land & Water, said: ‘The dredge at Blenheim Palace is 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.’
Now completed, the lake has been restored to its original state, just in time for Capability Brown’s birthday (30 August). After the huge efforts of all involved, the Queen Pool is now futureproofed to support the abundance of biodiversity that surround the lake as well as alleviating the risk of environmental damage.
Pictures courtesy: Pete Seaward.