Prospective Purchase Due Diligence

How to minimise flood risk when investing in property

Understanding the flood risk of a property is the first step to managing that risk and being prepared for what the future holds.

Around 5.2 million homes in England, or one in six properties, are at risk from flooding.

Being flooded is a horrible, traumatic experience. Filthy brown water devastates the ground floor of your home, contaminating everything in its path and creating huge upheaval, expense and stress.

Despite this, a YouGov Survey for Know Your Flood Risk found that 67% of residents and homeowners do not know their flood risk.

Depending upon the due-diligence reporting that you obtain for a property, a risk from flooding may be identified. This is no reason to cause instant alarm, it is simply an indication that further understanding is required to define any risk that may exist.

Predictive modelling of various sources of flooding is now widely available. During the early 2000s flood modelling was only available to the public for river and sea flooding.

In 2010, reservoir breach modelling was then released by the Environment Agency. Although this has a lesser statistical probability of occurring, it is still prudent to understand, as was nearly witnessed at Whaley Bridge during July 2019.

Since 2016, the Environment Agency now also includes surface water mapping within its national mapping dataset. There are also other flood mapping sources that can be obtained through private agencies, including the risks that may come from groundwater or canal breaching.

Importantly, it should be noted flood modelling maps are limited by their resolution, and often enough, cannot be relied upon at a property specific level. These are after all undertaken on a national scale.

Understanding the limitations of these maps should be undertaken through seeking professional flood risk advice. The adviser’s role is to translate what the flood mapping is showing to what would likely happen on the ground, at property level.

For instance, flood modelling may not take into account that a property is elevated above the surrounding ground, therefore providing existing resistance to flooding.

Furthermore, surface water modelling only takes limited local drainage networks into account within its modelling, meaning that the actual drainage measures for a property may in fact further reduce the perceived risk.

History has a nasty habit of repeating itself, therefore any evidence of previous flooding at the property or local area should also be sought and correctly understood, including the source, direction, duration and extent.

The property in question may benefit from a recently completed or earmarked flood defence scheme, which would reduce future risk. Your main objective should be to ensure that you have the appropriate knowledge at hand to have confidence that the property in question does not become a future flooding statistic.

The increased coverage within the news of climate change can no longer be ignored either. You should have confidence that the property is future proof in the sense that flood risk would not worsen at that location over time.

The property may be eligible for the Flood Re scheme, designed to make insurance affordable for domestic properties deemed at significant risk of flooding.

It is however worth noting that this scheme is only designed to run for 25 years from 2016, before transitioning into a free market in flood insurance, reflecting the flood risk to a property. It anticipates that homeowners in high flood risk properties will put in place mitigation measures over the 25 years.

When purchasing a property in a flood risk area, we recommend having a Flood Risk Technical Note to assess the long term flood risks. This may involve undertaking a Topographical survey to enable flood depths to be accurately predicted.

Please see below a snapshot of some of the services we offer:

Flood Risk Assessment

Flood Risk Technical Note Inline with:

• CIRIA Code of practice for property flood resilience – Edition 1 (C790F)
• The latest Law Society Practice Note on Flood Risk

A site walkover may be conducted to better to obtain the following information:

• Understand the mechanisms that may potentially cause flooding, the potential points of water entry, and the geography/topography of the property
• Note the type of construction of the property
• Note all external features which may exacerbate flooding
• Note the drainage connectivity at the property where accessible

The report will look to identify predicted flood levels/depths at the property, including an allowance for climate change where modelled.

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After 4 floods in 16 years, the Water-Gate Barrier was used in November and December 2012. The relief when it prevented what would have been a 5th and 6th flood was enormous. The best part is the piece of mind that follows.

Pam, Nottingham Resident

I would not hesitate to recommend Flood Protection Solutions, a very professional and detailed service.

Neil, Hebden Bridge Resident

The service that was provided was very good, communications were excellent, and they dealt with our issues in a very responsive and professional manner.

Trevor Palmer, Sellafield Ltd