Did you know that the moat at Oxburgh Hall in Norfolk helps to keep the building standing? Last year a project was started to restore the water levels in the moat, which protects the foundations of the Hall and has helped to keep it standing for more than 500 years.
(photo credit: National Trust Images/Robert Morris)
Our building surveyor, Paul Coleman, explains…
During 2013 staff noticed that the water levels in the moat were noticeably dropping. The reason – the River Gadder, which flows through the Estate and feeds the moat, had started to develop some leaks in its man-made engineering structures (a sluice and weir).
These structures in the river help to manage the water levels in the moat, and in turn keep the foundations of the Hall wet, preventing the drying out and shrinkage of the ground below them. This would pose a risk of damage from subsidence, so urgent work began to carry out repairs to the river’s banks, brick weir and sluice. We also removed 750 cu m of silt from the river bed, as the river and its low lying river banks form a natural habitat for lots of fauna and flora.
We now have a river full of water, flowing into the moat and maintaining higher water levels than we’ve ever had before. The work will also have improved the water quality, which will encourage a greater diversity of species, allowing them to continue and flourish.
The works took place on a stretch of river that flows through My Lady’s Wood on the Estate. What’s great is that the work has also enabled us to partly restore this area of woodland. It now looks more like its original 19th century design, including the opening of more breath-taking views back towards the Hall. The improvements have also provided a water-way for otters to visit Oxburgh and we still have an active water vole population, so keep your eyes peeled the next time you visit.