What is a Flood Survey?

A Flood Survey is a site visit and accompanying flood risk assessment which makes an evaluation of the flood risk at a property or site, along with how that risk can be managed. A Flood Survey should consider 3 main areas; the construction type, the flood risk, and the occupier requirements.  The survey should include a review of the buildings and the surrounding areas, along with understanding the usage of the property, coupled with a report detailing the best ways to manage the flood risk, should it pose a threat to the property. The Flood Survey should be conducted by a suitably qualified and insured professional.

Assessing the Flood Risk:

In order to accurately assess the flood risk, the characteristics of a site must be comprehensively understood by a suitably qualified and insured surveyor, including the construction, drainage, and risk. Alongside this it is vital that the client goals, lifestyle and budgetary constraints are also understood, such that any recommendations can be tailored not just to the property, but also the inhabitants. 

It is recommended that the source-pathway-receptor flood surveying process is followed, to ensure all relevant areas are considered. Sources are the weather events or conditions that result in flooding, pathways are the routes between the source of the flood, and the receptor, and the receptors are the people, and built environments that can be impacted.

The following aspects should be considered as part of the Flood Survey:

• Location & Risk: The geographical setting must be assessed. This includes reviewing the relative ground levels across the site and with neighbouring areas. Watercourses and water bodies at the site or nearby must be identified, and the characteristics of these features recorded. The survey may also consider if neighbouring properties and land may affect the flood risk to the site.
  • The flood survey can also used as an opportunity to obtain anecdotal evidence of historic flooding at the site. First-hand accounts are often more reliable than information that can typically be derived from flood maps or flood risk reports.
• Construction: The scale, nature, and construction of the built infrastructure at a site need to be assessed. The assessment should seek to understand where floodwater may enter a property, and which areas may be more vulnerable, such as the locations of high-value items (white goods) or critical supplies such as electricity or gas.
• Drainage: The nature of the existing drainage is important. Are there separate systems for surface water and foul water? What feeds into these systems and where do they drain to? What is the condition of the drainage systems and are there any misconnections? And most importantly, whether the existing drainage system may pose a risk to the site.
• Site or Property Users and Occupiers: Understanding the users of a site helps to classify the likely vulnerability to flooding. The assessment should seek to understand who occupies a site, when it is occupied, and which areas are most critical to the occupiers.

• The flood survey should also be used as an opportunity to identify areas of uncertainty where further investigation may be necessary to comprehensively assess the flood risk at the site, such as a CCTV Drainage Survey in an effort to map the drainage layout, and determine if/where any Non-Return Valves may be needed.

All of these elements need to be understood to assess how flooding may affect a site; the potential flood extents, and potential flood impacts. Only once this information is collated can detailed and reliable flood mitigation options be determined.

What Regulations underpin Flood Surveys?

The Association of British Insurers state that Flood Surveys should be undertaken by qualified surveyors, or Civil Engineers. In the past there have not been any overarching regulations regarding Flood Surveys, and sadly neither term ‘surveyor’ nor ‘engineer’ is a protected title, which has, in some instances led to poor or incomplete assessments being conducted, and made it difficult for clients to determine why there is a broad price range in Flood Surveys, and what the benefits of a qualified specialist are.

In 2020, CIRIA introduced a voluntary Code of Practice (C790). This code of practice (CoP) is concerned with Property Flood Resilience measures that can be introduced to buildings at risk from flooding. It includes six standards that specify the recommended process, with Stages 1 & 2 covering the risk assessment and property survey.

The Code of Practice was a much-needed step forwards in terms of regulation.

Flood Surveys should be signed off by Chartered Water & Environment Managers from CIWEM. These professionals can use the post-nominals MCIWEM C.WEM. To learn more about CIWEM, you may wish to read our blog: What is CIWEM?

Why look for MCIWEM C.WEM Status?

At FPS Environmental, our team is led by Chartered Professionals, with all flood surveys approved and signed off by MCIWEM C.WEM consultants. Chartership with CIWEM demonstrates consultants are leaders in the water and environment profession.

The Chartered Water and Environmental Manager qualification (MCIWEM C.WEM) is the ultimate demonstration of skill and technical excellence in the field of water and environmental management. It is bespoke for those who have chosen a career path in the environment and water sector and it recognises the specialist skills attained. This provides the assurances sought by employers, clients, peers and the public of that the highest of professional standards with be provided.

What are the benefits of appointing a Flood Surveyor?

A Flood Survey can offer a number of advantages, including:

• Identifying the degree of flood risk for a specific area or piece of property can be done with the aid of a flood survey. Decisions concerning flood insurance, building design, and disaster preparedness can be made using this knowledge. It is also important to note that flood maps are not designed to be used to identify if an individual property will flood. They do not take into account all drainage connections, and will not account for if a property floor level is elevated above the surrounding ground level. Therefore, an experienced Flood Risk Consultant is needed to translate what the flood mapping is showing to what would likely happen on the ground, at property level. It may be that the risk to the property is lower than that depicted on a map, and by appointing a Flood Risk Consultant, the risk can be better determined.

• Finding flood mitigation options: A flood survey can assist in discovering feasible flood risk reduction options, such as the construction of flood barriers, the improvement of drainage systems, or the relocation of susceptible infrastructure. The survey will also assist in ensuring any measures are suitable and effective, along with providing cost effective mitigation plans.

• Regulation compliance: In some places, it may be necessary to conduct a flood survey in order to meet insurance needs or other requirements relating to the danger of flooding. Certain recommendations may also require a suitable Environmental Permit from the Environment Agency, or planning permission from a local council. The surveyor should be able to advise here.

• Peace of mind: Property owners and occupants can feel more at ease knowing that they have a greater grasp of the potential flood risk and any necessary actions that can be taken to mitigate that risk thanks to a flood survey. If you are considering buying a property or site, a Homebuyers Flood Risk Report can be conducted to ensure you are in an informed position prior to purchase.

• All things considered, a flood survey can be a useful tool for anyone who wants to better comprehend and control the danger of flooding.

How can FPS help you?

A Property Flood Resilience Survey or Due Diligence report can be completed to assess the risk to a property or site, determine existing flood resistance or flood resilience, and detailing what additional measures could be implemented to minimise the risk.

Should you require a Flood Survey to better understand the flood risk at your property, please get in touch to see how we can help.