The presence of unstable ground can have a profound effect on the planning and development of an area such as Ripon in Yorkshire. The city now has a planning zonation (MB PDF) to take account of the gypsum subsidence problems.
In the main subsidence-prone area, new developments require substantial site investigation, including geophysics to minimise the extent of intrusive investigation, to avoid the worst areas. They also need reinforced foundation designs to prevent their sudden failure and collapse. The Ripon bypass, which runs through the area, has a special plastic reinforcing net within its embankments, while the new Ure Bridge is designed to withstand the sudden loss of one upright support.
Whilst in Ripon the planning process has adapted to the subsidence problem, insurance is addressed at the national scale. There is a need for comprehensive subsidence insurance cover for the people of the area. Currently, most insurers cover the property, not the land or any liability laid against it. The risk to any individual building is relatively small, but the lack of insurance cover for these problems is devastating to those affected. In some states of the USA, subsidence insurance is compulsory, but in the UK it is largely unavailable.
If you would like to discover more then please contact the sinkholes team.