London’s clay ground, which constitutes about 80% of the city, is struggling to recover from prolonged drought conditions. Despite recent rainfall, experts warn that the clay has lost significant moisture, leading to shrinkage and cracking. This situation poses risks of subsidence, potentially damaging homes and buildings, particularly those constructed between the post-war period and the 1980s.
Geotechnical engineer Rob Higginson explains that a single rainstorm won’t suffice; sustained rainfall over an extended period is essential for the ground to regain its moisture. The topsoil may absorb some water, but much will run off before penetrating the clay layer below. This means that even as grass begins to green, the underlying clay will remain compromised for some time.
The implications for homeowners are serious, as subsidence can lead to costly repairs and decreased property values. The hosepipe ban currently in place for Thames Water and Affinity Water customers highlights the ongoing water scarcity issues in the region, exacerbated by record-breaking dry weather.
As London faces these challenges, residents may need to rethink their water usage and gardening practices. Understanding the slow recovery process of the clay beneath their feet could help them prepare for potential impacts on their properties and the environment.
Source: BBC News
