If your property search or local authority has identified your property or land as being susceptible to groundwater flooding then we can provide technical support on groundwater flooding risk. The data and assumptions used to generate these property search reports is often highly simplified and generalised over large areas. This means that many properties are frequently interpreted as susceptible to groundwater flooding when there is no risk.
Groundwater can also cause basements to flood in existing properties. This can happen where waterproofing measures have failed, or where groundwater levels are rising. If water is present in your basement or cellar it may be due to the entry of groundwater. Groundwater levels have been slowly rising for many years in cities like Birmingham and London, because less water is being pumped from wells and boreholes than earlier in the 20th century.
If you are buying, selling or developing a property our risk assessments can provide the information that you and your local authority, insurer, mortgage company or solicitor require in order to support decisions. If your existing basement or cellar is flooding, then we can help to determine the cause of the flooding and propose solutions.
Hydrogeologists at Hydrogeo can undertake a detailed study by producing a Groundwater Flooding Risk Assessment, providing a clear conclusion of the level of flooding risk at your property.
What is groundwater flooding?
Groundwater flooding is caused when the water table rises up from rocks or soils to above ground level, causing flooding to occur at the surface. This tends to occur after season-long periods of high rainfall. The rainfall infiltrates into the ground causing the water table to rise in response above normal levels. Groundwater flooding is likely to occur in subsurface structures such as basements and cellars, or in low lying areas where groundwater is close to surface.
Groundwater flooding is also known as clearwater flooding because unlike surface water flooding from rivers and streams, the water is often crystal clear due to the lack of silt. Also unlike surface water flooding, it can be difficult to protect a property from groundwater as flood defences such as embankments cannot prevent water rising from beneath the ground. The flood can last for long periods of time as groundwater slowly falls, and may contribute to surface water flooding. There may also be no clear indication that a property is susceptible to groundwater flooding – properties can be susceptible even if they are far away from any rivers or streams.
What is covered in a Groundwater Flooding Risk Assessment?
At Hydrogeo, our Groundwater Flooding Risk Assessments assess the following factors:
- Groundwater levels, both beneath the site and locally
- Groundwater features, such as springs, bournes and wetlands
- Geological and hydrogeological mapping
- Borehole logs and groundwater supplies
- Topography
- Historical mapping
- Historical groundwater data and incidents of flooding
- Available groundwater digital datasets
We assess all available data to allow a professional judgement of the risk to be made.
Why should I choose Hydrogeo?
Hydrogeo have undertaken Groundwater Flooding Risk Assessments for a wide range of clients and sites. At Hydrogeo we are a team of qualified geologists, hydrogeologists and contaminated land specialists with over 40 years of experience in geology and groundwater. All of our staff are either Fellows of the Geological Society or Chartered Geologists.
The findings of our reports are presented clearly and concisely. We can recommend whether further action is required, detailing next steps such as layout rearrangement, installation of drainage or changes in design such as the tanking of basements. Alternatively, a site may be found to have a negligible risk of groundwater flooding and require no further protection.
Contact us today
As every site is different, please contact us to discuss your project and requirements. If you would like to speak to someone at Hydrogeo about your requirements please call 07877 251644 or email chris@hydrogeo.co.uk. Alternatively, you may use the contact form at the top of this page.
Information and Guidance
Case study of groundwater flooding at a primary school
Government guidance groundwater flood protection – GOV.UK
Information on Groundwater Flooding – British Geological Survey
Groundwater Flooding FAQ – UK Groundwater Forum
