Flooding
Most of us think about rivers or streams bursting their banks after prolonged and heavy rainfall when they think of flooding. While “fluvial” flooding is certainly a risk for those of us living close to a waterway, as is coastal flooding for those with property situated close to the sea, other types of flooding also present risks to homes.
Pluvial flooding occurs when an extreme volume of surface water overwhelms urban drainage infrastructure to the extent that it cannot be carried away quickly enough and ends up in our homes. It is this type of flooding that, given sprawling urbanisation, failure to invest in a commensurate level of drainage infrastructure, and climate change, means UK homes are at greatest risk from this type of flooding.
Groundwater flooding takes place when the water table rises. Again, prolonged and heavy rainfall over an extended period of time tends to be implicated and flooding can happen, although even then water still might not emerge for some time after the rainfall event. In recent years, the water table has started to rise again due to a trend towards warmer, wetter winters. In addition, the gradual decline in heavy industry since the 1980s, when higher water volumes were taken from the land – “water abstraction” – to service the country’s industrial needs, has contributed to that rise. Properties situated on low lying strata – where the water table lies closer to the ground’s surface – are vulnerable. But groundwater flooding can also manifest itself on hillsides and its appearance is difficult to predict. It is most common in the south of the country where chalk strata are a more widespread natural feature of the landscape.
Groundwater flooding can emerge inside basements, or in the absence thereof, through airbricks, unsealed openings and even the internal flooring itself.
Thus, the most vulnerable parts of a building will tend to be the floors, along with the lower walls – particularly above the Damp Proof Course (DPC), if one is present.
There are several potential remedies that can be implemented to defend a home against groundwater flooding. This can range from reducing water levels and/or creating a means of diverting it away from a building, to raising the building – or, specifically, its ground floor level – above the water’s zone of influence.
If you think your home might be vulnerable to or is suffering damage as a result of groundwater flooding, contact us today to arrange an appointment for an investigative survey as the first step towards restoring dryness and watertightness to your home.