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Understanding Groundwater Flood Risk

We’ve compiled guidance, useful Data, Downloads and Videos. We also organise Continuous Professional Development training events.

What is Groundwater?

Groundwater is any water found beneath the surface that fills pores or cracks in the underlying soil and rocks. It contributes 30 percent of the public supply water in England. In volume terms, that is over six thousand million litres per day, which is enough to fill 2500 Olympic-sized swimming pools every day, or run a dishwasher 400 million times*

Groundwater levels are higher in winter and reach a peak in the spring. During periods of prolonged high rainfall, the level of groundwater rises to the surface, beyond its normal range, which causes flooding.

*BGS data 2019

What is Groundwater flooding?

Groundwater flooding can be highly disruptive, lasting several months, and can cause extensive long term damage to property. This can include:

  • New springs developing and sudden water movement
  • Basement flooding
  • Overloaded sewers
  • Economic disruption and cost up to 30 days after surface flooding
  • Agricultural losses

Find out more about how GeoSmart can assist in relation to Groundwater at your Site.

How does Groundwater impact on Development Sites?

You may have purchased a site with a view to develop it, or you are an architect with a client who needs to appraise the site for master planning submission or to meet conditions.

In both instances, you need to know the drainage characteristics and whether groundwater could have an impact on the surface water flood management and may need a sustainable drainage approach, as determined by the Local Planning Authority. If the site has an industrial past, there may be contaminants in the soil which could be spread by groundwater, which will also need to be considered.

Our contaminated land assessments, Flood Risk Assessment Reports and Drainage Reports will guide you to make the right decision s to meet planning requirements.

How do I know I am at risk?

Groundwater is most commonly found in low-lying areas underlain by aquifers, such as Chalk or sandstone, or localised sands or river gravels in valley bottoms.

It is especially common in southern and eastern England, as well as parts of the Cotswolds, East Yorkshire and Eastern Pennines.

Alerts are now in place for residents who sign up to text alerts with the Environment Agency in affected areas.

GeoSmart provides the Flood Forecasting Centre with alerts on the future risk of groundwater flooding
Groundwater Flood Forecasting

What is at risk from groundwater flooding?

The two infographics below clearly demonstrate the number of properties and critical infrastructure that are at risk from groundwater flooding.

How does groundwater cause sewer flooding?

Groundwater can have a significant impact on critical wastewater networks. High levels of groundwater can access the sewer network through cracks in pipes or access chambers. This can mix to affect the local water table and be a significant risk to communities and businesses.

GeoSmart works with a number of water companies to provide alerts to them so they can manage their assets to protect communities.

Groundwater Sewer Infiltration Flood Forecasting

See what our customers have to say...

"During the conveyancing process for my current house purchase, I was extremely concerned to find the general search results revealed the house was at 'moderate risk of groundwater flooding'. I was unable to get any further information from anyone until I contacted GeoSmart. The staff I spoke to were friendly, helpful, efficient and extremely knowledgeable. The information provided was very site specific and focused. The staff member who talked me through the information and maps provided was very knowledgeable, answered all my questions and allowed me plenty of time to discuss issues. Thanks to GeoSmart for their great service."
Linda Barton
"We were impressed by the speedy, well-informed service and personal contact that we received. The report was thorough and comprehensive. We will certainly use GeoSmart's services in the future"
Gregory Gray
Gregory Gray Associates
"I would like to say that dealing with GeoSmart was a seamless experience from beginning to end - thank you for that"
Martin Lloyd
Martin Lloyd Associates
"Everyone involved from initial approach to receipt of report was knowledgeable, efficient and focused"
Robert McCall
OeMO Ltd
"Great service! Extremely fast and the report was very detailed and well received by the planners. Many thanks GeoSmart, we will definitely use your services again"
Nigel Slack
Michael Eyres Partnership LLP
"The service was great, fast and efficient. Everyone we talked to was very helpful and the details were well received by the planners"
Ben Thorns
Solid Digital Marketing Ltd
"The service for a Phase 1 Contaminated Land Study was excellent, fast and efficient! GeoSmart were willing to assist despite the extremely tight timescale to work with. We will definitely consider using your services again"
Craig Roberts
Hunter Page
"Efficient and friendly service, GeoSmart provided a clear and concise report within the timescales advised. Great service and I would have no problem recommending"
Geraint Harris
Vitec Consult
"We are very pleased with the service provided by GeoSmart. Their reports have been used to assist with numerous planning applications and have always been delivered to budget and on-time, much to our clients’ appreciation. We look forward to working with GeoSmart on future projects"
Alan Gunne-Jones
Planning & Development Associates
"The service provided was efficient and friendly. From the first phone call to GeoSmart they provided a clear, professional approach to my request within the timescales advised. Great service and I would have no problem recommending"
John Childs
Private Developer
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