Groundwater Flooding – risk assessment, monitoring and solutions

Many infrastructure projects have the potential to affect the risk of groundwater flooding.  ESI’s in depth experience of the types of groundwater systems that give rise to such flood risks can be invaluable in terms of understanding the risk factors and the potential solutions.

 

Understanding the risks

Groundwater flooding is related to the emergence of groundwater at surface or within excavations or subterranean structures when groundwater levels rise.

 

The groundwater is commonly derived from superficial aquifers in response to adjacent river and surface water flood events or from deeper bedrock in relation to increased recharge.

 

Management of groundwater discharge along spring lines or during excavation is also relevant. In some cases increased recharge, from a soakaway system for example, or disruption of a small aquifer due to construction, may lead to a rise in groundwater levels which could impact adjacent infrastructure.

 

ESI provides a tiered approach to Groundwater Flood Risk Assessment ensuring the best value option is available for all sites:

  • Flood and Groundwater Flood Risk Assessment (FRA) Reports – our sister company GeoSmart Information offer a suite of reports providing clear and pragmatic advice regarding the nature and potential significance of flood hazards which may be present – visit their website.
  • Detailed Interpretative Assessment – a technical report using data from the Environment Agency, British Geological Society and a detailed conceptual model. Consideration of site layout.
  • Bespoke Assessment – ideal to support large developments, sites with complex geology and history of flooding. Includes greater modelling studies and advanced mitigation options.
  • Regional Groundwater Flood Risk Mapping – to understand business and property risks for specific regions, commercial groups, transport routes, or large infrastructure projects.

 

Groundwater forms one component of flood risk and ESI’s experience in other forms of flooding means that these can also be assessed.

 

In complex situations, a site visit and more advanced modelling work are offered to allow for a more definitive statement on flood risk at the site.

 

Site Investigation for larger or complex sites

If required site investigations that include drilling and subsurface testing can be provided to collect specific hydrogeological information.

 

Visits can be combined with other aspects of work, such as contaminated land and geotechnical assessment, to provide cost savings.

 

Design and implementation of groundwater control measures is undertaken to protect infrastructure, either during construction, or longer term.

Please contact us for more information on our Groundwater Flooding service.