Friday, 29 August 2014

Dataset Focus: Site Sensitivity Data

Spot the source. Trace the path. Discover the receptor.

Today we focus on our archive of site sensitivity data, which has been built to give you all the information you need to assess and mitigate the risk of contamination to your site

We also provide an overview of the volumes of data we hold relating to sensitive land use. 

Click here to access the further information.

Wednesday, 27 August 2014

Promap features of the week - Article 4

This week we deal with basic tips for customisation of your maps.

·         How to avoid accidentally dragging shapes out of position
·         How to undo incorrect points when in the process of adding a site outline
·         How to re-open an outline once completed to alter it

How to avoid accidentally dragging shapes out of position

When roaming around on your map screen (primarily when using the left click and drag option) there is the chance that you may accidentally drag a shape out of position. To avoid this happening you can choose either of the following two options:

  • Hold down the ALT key whilst roaming on your map. This will act as a temporary lock key and will hold everything in position.
  • Right click on your shape when you have it selected and select the lock option from the drop down menu (shown in the image above).

How to undo incorrect points when in the process of adding a site outline
  • If you make a mistake whilst in the process of applying a site outline using the shape tool in Promap you can undo it using the “backspace” key on your keyboard.
How to re-open an outline once completed to alter it

If you have made a mistake on your outline, rather than delete it and start again just follow the steps below:

·         Turn off shape tool
·         Left click away from your shape
·         Left click back on your shape to select it
·         Press return/enter on the keyboard    

This will undo the final click that completed your shape, undoing it and then allowing you to use the “backspace” key to rectify the shape.

Free Masterclass webinar: These features and more will be demonstrated during the next free webinar on 19 September 2014. To register, click here

If you found this Masterclass useful, keep an eye out for our next Masterclass blog which is due to be sent on the 3rd September 2014 . For more detailed advice on Promap why not book one of our training courses (which are all now FREE) or visit our training website by clicking here to find other useful tips and training aids.

If there are any other topics you would like to see included in the Masterclass blogs or if you have any other questions please call us on 0844 844 9965 or email us at

Friday, 22 August 2014

Dataset Focus: Historical Maps

From 1843 to 1999: Get the full picture

Welcome to the first in a series of  'Dataset Focus' articles.  Today, we focus on our digital archive of historical maps, which happens to be the UK's largest and is designed to give you the most in-depth view of how your site has transformed over time.

We also provide some background to our Russian Maps, which were initially created by the USSR during the Cold War, and cover 103 UK towns and cities from 1950 to 1997.

Click here to access the further information.

Tuesday, 19 August 2014

Darwin’s Theory of….Virtual Reality

Have you ever found yourself wondering where technology will take us next? At Landmark we’ve been asking ourselves that very question about augmented multimedia, often referred to as Virtual Reality, and wanted to share a few things with you.

We’ve seen two main styles of technology which we think are relevant to our customers and we’ve classed them as “assistive” and “immersive”. The assistive style presents you with something in addition to your view of the world but does not necessary fully integrate with it. The immersive style will either replace or fully integrate with your experience of the world around you. Let’s take a quick look at some examples.

Our Google Glass device is a good example of assistive VR. The unit provides a small projected image directly in front of your eye which appears as the equivalent of a 25 inch screen about 8 feet away. It responds to movements of the head and has a touch sensitive panel to one side for more direct manual controls. There is nothing between your eyes and the world except a small panel of information so it feels a very natural experience. As it accepts voice commands and has voice recognition, this makes it particularly useful in situations when speaking will allow you to do more activities in parallel.
With immersive VR, we’ll look at two ends of the cost spectrum. For the more premium user, we have the Oculus Rift. This device is fully immersive (YouTube videos of user reactions will show you some of the down sides of this!). Slightly different projections of the same image are directed at each eye, giving the effect of 3D reality. Couple this with a good pair of headphones and it is incredibly effective for simulations in controlled conditions. Oculus VR started via Kickstarter, the crowd funding site, and Facebook purchased the company for $2 billion earlier this year so we eagerly await how the technology will be exploited.

On a lower budget, we have Google Cardboard. This is a fantastic, low tech, reuse of everyday hardware to create a virtual reality experience – and it started life as a hobby project at Google. It is a cardboard headset in which you place your mobile phone. The “Cardboard” phone app then replicates the experience of more expensive headsets by displaying the two slightly different images on each half of your phone screen. Using the phone’s camera and spatial awareness, this creates a very passable version of the technology. All for around £15.
Finally, something between the two. Layar is an app which has been around for some time and creates layers of information on top of reality. It uses the spatial awareness of your mobile device to plot useful information on the image seen by your mobile device’s camera. It’s not immersive, but does allow your view of the world to be augmented with useful information. This technology is frequently used with printed media (newspapers / magazines) to add augmented reality to two dimensional media.

In summary, and unsurprisingly, we think that each flavour of virtual reality technology has potential uses and pitfalls. We will track the progress of this technology as we continually look for new and innovative ways to empower our customers, and provide the most effective access to our products and data.

Darwin Lee
Head of Development
Landmark Information Group

Monday, 18 August 2014

Football Grounds Through The Years

With the start of the Premier League Football season, it got us thinking about what our data could find out related to well-known existing or former football grounds.  Just an initial search on a handful of grounds has uncovered some interesting features, which we would like to share with you.

Our data team initially looked into the following grounds:
  • Manchester City Football Club – Hyde Road ground
  • Arsenal Football Club – Highbury ground
  • Port Vale Football Club – Athletic ground
  • Swansea City AFC – Vetch Field ground
  • Wembley Stadium
Manchester City’s Hyde Road:
Looking through historic maps shows a clear connection between industry and football pitches or sporting grounds. It shows that, at its roots, football was always a pastime for the masses and not the billion pound industry that it has today become.  Much of the grounds started off life on a piece of waste ground, and in the case of Manchester City’s Hyde Road ground in West Gorton, Manchester, industry reclaimed the site once the team relocated to its Maine Road ground in 1923.

1893 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1908 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1922 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
In its early days, the ground had only basic facilities, with the first stand being built in 1888.   Changing facilities were then added in 1896 – records show that until then, players had to change in a nearby public house!

By 1920, the club had outgrown the venue and a decision was made to seek an alternative venue. The club moved to the 80,000-capacity Maine Road in 1923, and Hyde Road was demolished shortly afterwards, where it was reclaimed by industry and the land was adapted into transportation depots.

Arsenal’s Highbury ground:
In 1913, Arsenal’s ground in Highbury, north London, was built on open or recreational space that belonged to the local college.  Located in the heart of a built-up residential area, Highbury has been developed to fit within a concentrated population (unlike some of the football grounds in the north that have been formed around industrial locations or sites).

Over the years, a huge amount of development has taken place in Highbury.  With residential space at a premium, when Arsenal relocated to its brand new Emirates Stadium in 2006, the ground was redeveloped into residential flats, which incorporates two of the stands, due to their Listed status.

The location of Arsenal’s stadium in Highbury in 1871 shows a fair amount of ‘open’ space:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
This 1896 map shows the extent of development that had taken place in the area over a 25 year period:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432 
The football ground makes its first appearance on this 1915 map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
In 1936 we can see that even more development has taken place at the stadium:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Fast forward to today, and we can see that the majority of the Highbury stadium has been converted into residential flats. Known as ‘Highbury Square’, the Clock End and North Bank stands have been demolished, while parts of the East and West Stands have remained and have been incorporated into the new housing development due to being Listed structures.
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Port Vale’s Athletic ground
Port Vale’s Athletic Ground was located in Cobridge, Stoke-on-Trent – an area that was known for its coal mining, clay pits and brick works.  This map from 1890 shows the location of the site in relation to the many collieries. Originally built in 1886, it was home to Port Vale for 27 years, before they left to instead play at the Old Recreation Ground in Hanley, Stoke-on-Trent.  

1890 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432

The Athletic ground remained as a sports venue for many years, with it becoming the local Greyhound Racing Track during the 1960s and 1970s. The ground was then redeveloped in the 1980s and today is the site of a residential care home.

1955 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Swansea City’s Vetch Field:
Opened in 1912, the Vetch Field was a multi-purpose stadium in Swansea, Wales, which was home to Swansea City until 2005. According to historic reports, the site was originally owned by the Swansea Gaslight Company, however surplus to requirements, the gas company handed the ground over to the football club to use. Interestingly, it has been noted that the playing surface was made of compacted coal cinder and so players were required to wear knee pads for the first season of football.

Located in a built-up residential area, Vetch Park was also home to “The Royal Arsenal” with barracks also located on site, showing the diverse use of the surrounding land.

Today, the ground is no longer in action, but has instead been transformed into an “urban utopia” of green space and allotments.   Our data shows that over 7,800 ‘points of interest’ that detail gardening, landscaping and tree surgery services are within the vicinity of Vetch Park, while the Local Plan data identifies over 2,100 land allocations for allotments (both existing and proposed).   Over 1,800 community projects and networks are also located in the area, showing how the benefit of former grounds is providing to the local residents.

1879 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1899 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1919 Map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Historic elements 1971, Modern Mastermap 2014:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Historic elements 1949, Modern Mastermap 2014:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Wembley Stadium
One of our earliest map images (1864) depicts the very green open space of Wembley Park, before work commenced on the development of ‘Watkin’s Tower’ in 1891.  Watkin's Tower was constructed in iron and was an ambitious project to create a visitor attraction in Wembley Park. According to records, the "Great Tower of London" was designed to surpass the height of the Eiffel Tower in Paris, however it was never completed and was in fact demolished in 1904, however it has been captured in time on the 1896 OS map.

By 1914 the Park has developed into a golf course, which matches with what is known as the ‘English Golf boom’; a shift in social attitudes and the development of the English Middle-class.  The figures of the resulting boom are impressive. In 1850 England boasted only one golf club; however by 1914 over 1,200 courses were used by over 200,000 keen golfers.

Our next detailed map is dated 1935, over a decade after the Empire Stadium was built in 1923. What’s interesting to note is the rapid development in the area; the green spaces of Wembley Park were quickly developed in less than 20 years.

The catalyst for this was the British Empire Exhibition, which was a trade/industry expo designed to promote the Empire. Most of what we now know as Wembley was intended to be temporary, although the changes to the area were permanent.  The park was never re-claimed and the area is still used for industrial storage and retail.

The Polygon shows today’s location of Wembley Stadium on a 1864 map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1896 map, which includes Watkin’s Tower / Wembley Tower:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432=
A 1914 map:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
1935 map showing the new Empire Stadium:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432
Wembley in the 1950s:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 10002243 
Wembley Stadium today:
Ordnance Survey © Crown copyright and/or Database Right. All rights reserved. Licence 100022432

Friday, 15 August 2014

Industry First: Landmark introduces Ordnance Survey’s Building Height Attribute data and 3D data bundle

Launched as part of a new 3D Data Bundle, which combines OS MasterMap detail mapping, OS Terrain 5 height data with the OS Building Height Attribute information, it provides a full 3D representation of both the natural and built topography of a site.   The 3D Data Bundle is ideal for developers, planners, surveyors and architects that want to review accurate site data as part of the survey and due-diligence process.   The model is also suitable for printing to 3D printers.

Carole Ankers, Product Development Director, said: “We are excited to introduce the 3D Height data bundle to the market, which incorporates OS Building Height Attribute data. Based on new and existing Ordnance Survey datasets, this provides models and data to help visualise the landscape and topography of a site for a range of applications, including line of sight planning, right to light, fly-through sequences, planning applications and to support overall development projects. It can also be used for urban planning and signal propagation analysis.”
The new 3D Data Bundle removes the need to source and combine individual datasets in order to produce 3D models.  Users can quickly access a visualisation via PDF or DWG, and the data can be easily incorporated into existing CAD or GIS applications for further detailed analysis.  

Concludes Carole Ankers: “Using our data expertise, we have devised a bundle that will help save clients’ time and money and offers a valuable 3D visualisation product.  Giving our clients easy access enables them to start designs with accurate 3D data rather than speculating before surveys, as well as give them the ability to generate streetscapes and landscaping models without needing to overlay other products.”

To read more about the 3D bundle, click here

Wednesday, 13 August 2014

Promap Masterclass - Article 3

This is the third offering in the Masterclass blogs and looks at tips to help with saving maps and maintaining your saved maps.  

This week we focus on:

  •          How to save maps to ensure they are easier to search through
  •          Maintaining your saved maps in Promap

How to save maps to ensure they are easier to search through

When saving maps there a number of things you can do to make searching through them later easier:

  1. Save your maps into the org folder rather than the private folder as maps saved into the private folders are not visible to any of Promap’s automated searches.
  2. Create your own filing system under the org folder by using the new folder icon to create subfolders.
  3. Enter as much information as you can about your map when saving as the keyword search in Promap looks at any words you have entered into the map name, description and reference sections

NOTE : Did you know that whenever you open a saved map on Promap the first thing it does is update it to the latest OS information available.

Maintaining your saved maps in Promap

If you go to the Browse section in the saved maps you will be given some options to maintain your maps. These are as follows:

  1. Move Files – This will allow you to move a map or groups of maps between folders
  2. New Folder – This will allow you to add new folders on the system and create your own filing system within Promap
  3. Delete File(s) or Folder – If you have multiple copies of the same map you can delete files and folders from the system using this option
  4. Rename – This will allow you to update your map details ensuring you keep all your information for that file up to date.
  5. Properties – Allows you to look at what information has been entered about your map and what map layers have been accessed on it.

If you found this blog useful, keep an eye out for our next Promap Masterclass blog which is due to be published on the 27th AUGUST 2014 . For more detailed advice on Promap why not book one of our training courses (which are all now FREE) or visit our training website by clicking here to find other useful tips and training aids.

To register for the free webinar showing the above features in action, click here.

If there are any other topics you would like to see included in the Masterclass blogs or if you have any other questions please call us on 0844 844 9965 or email us at

Monday, 11 August 2014

Landmark’s new Envirocheck Analysis fully digitises Phase 1 desk studies

Environmental consultants can now digitally access current and historic maps AND related environmental data to streamline the Phase 1 analysis process of Environmental Site Assessments 

Removes the need to cross-reference separate printed reports containing historical maps, current maps, aerial photography and environmental data

Significantly cuts assessment time, saving money, whilst also improving overall accuracy of historical map and environmental data analysis

We are today proud to announce the launch of a brand new edition of Envirocheck Analysis, which has been designed to fully digitise the desk study process of Phase 1 Environmental Site Assessments, which are conducted for land and property developments.

The new Envirocheck Analysis enables Environmental Consultants to digitally analyse current and historical maps and aerial photography, in conjunction with environmental data. This means that from within a single online platform, professionals can now accurately assess environmental risk factors related to a piece of land, without the need to overlay printed maps, manually draw boundaries or search through rafts of printed reports for potential sources, pathways or receptors of contamination.

Early customer feedback on the new Envirocheck Analysis platform has suggested that the time it takes to conduct the data analysis process is reduced by at least 25%.

Commenting on the launch of the new Envirocheck Analysis, Richard Puttock, Partner of Peter Brett Associates LLP said: "Envirocheck Analysis is really changing the way that we conduct our Phase 1 Site Assessments. In the past, we have ordered our environmental data and historical map reports through Envirocheck and spent our time analysing PDF reports and even printing the documents out to have physical copies to work through. Since adopting Envirocheck Analysis, we are already saving significant amounts of time in analysing historical mapping, and the measuring and drawing tools provide a great level of accuracy, in much less time. 

Continues Richard Puttock: “We have been involved in the entire user testing phase for the new Envirocheck Analysis, and we can't wait to start using it for all our Phase 1 desk studies. With all of Envirocheck's environmental data layers being added into the application, we no longer have to spend so long identifying symbols on maps and relating ID numbers back to separate datasheet reports. Now we can visualise everything in Envirocheck Analysis, alongside current and historical mapping, and make an assessment on the potential risk in much less time. Ultimately, this allows us to complete the job more efficiently without comprising accuracy or quality, which helps us provide an even better service to our clients."

The key features of the new Envirocheck Analysis include:
Overlay digital environmental data onto current or historical maps to determine potential contamination risks
Instantly review information behind every dataset to understand what is being highlighted and the potential risks
Decide how far away from the target site you want data displayed to by using the Distance Filter tool for every dataset
Access a range of aerial photography plus drawing and measuring tools to mark-up Phase 1 assessments
Draw Pins to instantly highlight historical land use or environmental concerns – each pin records a grid reference, plus the distance and direction from site using an accurate measuring tool
Instantly Export these Pins (and their associated information) as a table, directly into environmental site assessment reports.
View an instant summary of the number of potential risks via a handy ‘feature count’ tool
Create instant photo snapshots of the site that can be exported to reports
Saves hours per Phase 1 desk study on historical map and environmental data analysis

Mark Burnard, Senior Product Manager at Landmark Information Group, said: “Through extensive industry consultation, we've listened to what our customers want and are excited to today launch the new Envirocheck Analysis platform.  It enables consultants to be able to assess and analyse mapping and environmental data faster, with more accuracy and ultimately helps deliver detailed and highly accurate reports to clients, faster.  The aim is to remove the need for consultants to have to use light boxes, lots of paper, scale rules and sticky tape when analysing printed maps with environmental data: now this can be all done online.”

Concludes Mark Burnard: “The evolution of environmental reporting doesn't stop here. With the new Envirocheck Analysis platform fully digitising the historical map and environmental data analysis element of Phase 1 assessments, plans are already underway to integrate Site Walkovers into the online platform.  We have some more exciting developments coming very soon, which will integrate remote and mobile working. Watch this space for updates.”

Launch Promotion:
Envirocheck Analysis is available free of charge during August and September. For more information on Envirocheck Analysis, telephone 0844 844 9952 or email

Envirocheck Analysis - providing digital access to maps and environmental intelligence

Friday, 8 August 2014

Flood - Myth or reality?

With flooding increasingly in the news, you could be forgiven for thinking that the nature and extent of the problem in this country is getting worse. The issue is particularly pertinent for those contemplating a new property purchase. The recent Planning Practice Guidance from the Department for Communities and Local Government has certainly raised awareness of the need to take flooding hazards seriously, thereby significantly reinforcing the need for good quality data and advice.

So, should we believe the shock headlines?  What is the reality, and how does one establish whether a particular property will face costly and life-threatening hazards, or whether the perceived risk may be unfounded and won’t impact on the use or enjoyment of the property at all?

Being well briefed on the degree of risk is key to making investment decisions, and this is where the quality of information can make all the difference.  One company that has invested significantly in obtaining in-depth, reliable data is Landmark Information Group, which uses the statistics as the basis of its reports on flood mapping, which in turn are used by property developers and planning consultants to support property investment decisions.

However, we need to be clear on terms. There are many different flooding mechanisms, but flooding typically results from the interplay of a number of different variables at any one point. Breaking down flood risk according to only a single mechanism is unhelpful, and results largely from a fragmented approach to mapping the problem.  

What is a Flood and how does it impact on property?

A flood is described as "where land not normally covered by water becomes covered by water."

Flooding can happen even if you don't live near a river, sea or watercourse.  During periods of heavy rain the capacity of the ground to infiltrate rainfall can be exceeded, and drainage systems can become overwhelmed by the high rate of water reaching them in a short time. Furthermore if the ground is already saturated then the runoff will be enhanced and more rapid.

Flooding can devastate lives and cause serious damage to your property.  It is common sense to avoid purchasing a property in a flood risk area, but with careful consideration and accurate assessment it might be that the risks are minimal and acceptable and can be managed to prevent intolerable damage and risk of injury. In this case, you could still proceed with caution. 

First and foremost however, if you are a property owner in a flood prone area it is essential that you understand whether you are at risk, so access to good quality data is vital.  If you live in an area at risk it is important to plan in advance for flooding that could occur.

Being prepared can make all the difference and is your most powerful tool for dealing with flooding.  This can include:

  • Registering with the Environment Agency’s flood warning scheme (
  • Prepare a Flood Evacuation Plan;
  • Undertake a property level survey to establish likely points of water entry;
  • Incorporate permanent Flood Resistance measures designed to keep water out. Some examples include raising water resisting external doors and windows, raising thresholds, sealant around external doors, windows, walls and service entry point;
  • Incorporate temporary Flood Resistance measures designed to keep water out. Some examples include the use of sand bags, de-mountable or free-standing barriers and appliance vent covers;
  • Incorporate Flood Resilience measures – designed to permit water entry but designing the interior of buildings to minimise damage and speed up the clean-up operation.  Some examples include water compatible internal walls and floors, raised utilities, and removable fixtures and fittings.

The six types of flood risk that all prospective purchasers need to be aware of
1)    River (Fluvial) flooding: Inundation from rivers and watercourses, usually due to excessive runoff from rainfall, leading to overtopping of river banks. This can also occur from inundation of areas outside the floodplain due to the influence of bridges, embankments, and other features that artificially raise water levels.

River flooding usually impacts adjacent low-lying properties and can cause widespread and extensive damage due to the large volume of water and high velocity of flow.  Debris can also cause further damage and, depending on the setting, flooding can ‘back up’ in the catchment area and become longer-lasting and more difficult to drain away. Fast-flowing floodwaters can also be a threat to peoples' and animals' safety and can damage or even demolish buildings.  The Environment Agency estimates that, when combined with coastal flooding, about 2.4 million properties in England are at risk.

2)    Surface water (pluvial) flooding: Usually associated with extreme rainfall, but may also occur when rain falls on land that is already saturated or has a low permeability. In each case, the rainfall generates overland flow which can lead to flooding before the runoff is able to enter a drain, sewer or watercourse.

It may be triggered or made worse in urban areas where the ground consists of hard surfaces such as concrete or tarmac. It is estimated by the Environment Agency that beyond those in the fluvial risk areas above, a further 2.6 million properties are at risk of surface water flooding in England.  Extensive flash flooding of this type can follow periods of high intensity rainfall, and the harm to property is related to local features in the immediate vicinity rather than overall position in the catchment.  The lack of warning can be a particular problem.  However, due to the flash nature of this type of flood, it may recede as quickly as it arrived, and the damage to property may be less serious if the mopping-up and drying-out process can proceed quickly.  Also, it may affect your garden and the street rather than your home, and features as simple as a raised kerb may provide property level protection, although it would be wise to review how reliable these protections are.

3)    Groundwater flooding: Occurs when the water table rises after prolonged rainfall, only to emerge above ground level away from a watercourse, or where high river levels drive water through the river banks. This is most likely to occur in areas underlain by permeable rock, and can seep directly into properties or exacerbate other forms of flooding. 

This type of flooding can last for weeks, leading to a higher degree of harm to buildings because of the impact on the fabric of the building from prolonged saturation.  Groundwater flooding is more of a seasonal issue because most aquifers need several weeks of high recharge to fill up before the water table overflows. 

Irrespective of whether water shows at the surface, rising groundwater levels are posing an increased threat to buildings with basements. Such flooding may occur separately or in conjunction with flooding from other sources, such as surface water flooding. ESI estimates that up to one third of flooding problems in the UK are due to groundwater, which typically causes more property damage than other forms of flooding, making this one of the major flood risks when it comes to property.  However, the Environment Agency are yet to include this data on their maps, so we cannot yet put this risk into the same context as their mapped 5M properties in England within areas at risk of fluvial and pluvial flooding.

Thankfully, the slower flow rates associated with groundwater mean that risk to life is significantly lower.  Nevertheless, information on groundwater is clearly vital to the overall understanding of flood risk and, with the Environment Agency reporting that last winter 24% of flooding was caused by groundwater, prospective purchasers need to review the data carefully.

4)    Coastal flooding: Caused by high tides and/or inclement weather breaching sea defences and inundating the surrounding area.  It can also cause backing up in rivers and groundwater systems that will then flood upstream.  Coastal flooding may affect not only a property on the coast itself, but also property in tidal rivers some distance inland, due to floodwater being forced up the tidal reaches of rivers and estuaries by raised sea levels and gales. 

Coastal flooding is often associated with high energy storm events, posing a very real risk to life.  Those considering purchasing a coastal property, particularly where the coastline is very exposed to storms, should review mapped flood zones carefully and consider the wider disruption that could arise, as well as whether flood water could reach within their own property boundaries.

5)    Sewer flooding: Sewers are generally not sealed and during periods of extreme rainfall can overflow into the surrounding subsurface, ground surface, or into properties via drains, toilets and basements, causing considerable and costly damage, along with many unpleasant and harmful consequences.

Groundwater can be the decisive factor, and typically the cause is too much water entering the sewers from storm run off, or where rising groundwater may infiltrate the sewer network.  Many of the water companies have access to the ESI national groundwater flood risk data and this is helping them to implement sewer infiltration reduction plans that should help to reduce this problem over the next five years, but sewer flooding currently remains a very significant problem in some areas.

6)    Reservoir flooding: The UK has approximately 5,000 reservoirs, and flooding can occur if there is a catastrophic failure of a reservoir wall or embankment. Fortunately dam failures in the UK are rare, but have occurred to considerable catastrophic effect in the past.   While the chances of reservoir failure are very small, the consequences could be fatal and affect large areas many miles from the dam itself.

Is flood risk increasing?

There are several aspects to this:

1)    Some risks such as groundwater flooding have been largely ignored, but new data has demonstrated the full nature and extent of the problem, in turn leading to increased recognition of a risk that has always been present.  This is good news because the data enables risk management action to be taken and problem locations can either be avoided or mitigation measures incorporated.

2)    Climate change is leading to rising sea levels, and these in turn increase coastal flooding risk.  There is a very real increase in risk over time, but the fact that it is largely predictable means that the problems can be managed if attention is paid now.

3)    Climate change is leading to different rainfall patterns in the UK, with long-term averages over a 30-year period showing an increase in annual rainfall of about 5% from 1961-1990 to 1981-2010.   Preliminary research from the Met Office suggests we may have also seen a change in the nature of the rain we get, with 'extreme' daily rainfall becoming more frequent.

Increased rainfall can lead to an increased likelihood of flooding, and there is a very real threat that the risk will increase over time. However, it is highly uncertain in its impact due to limitations in climate prediction models.  The latest work from the Climate Change Committee, for example, suggests that the risk of flash flooding may increase in frequency due to more high intensity rainfall, but severity may remain at similar levels.

4)    In the case of groundwater there may be a real increase in the number of areas that are at risk due to the impact of seasonal recharge of the aquifer and the increase in wet winters.  Clearly more work is needed, but in the meantime a precautionary approach is sensible, and a ‘factor of safety’ is recommended.

5)    Catchments are changing.  Over many decades, urban development the increased amount of ‘impermeable surfaces’ and led to more runoff in catchments where the natural catchment response would be more attenuated and less flood-prone. The recent move towards sustainable urban drainage systems (SuDS) such as attenuation ponds and soakaways is intended to return catchments partly back to their natural state to reduce flood risk, but the regulations have been delayed by Defra so are not yet fully in force.

6)    Traditionally flood defence designs used over-sized flood channels engineered to remove water as fast as possible, but these did not sufficiently recognise the impact further downstream this may cause.

In summary, we have seen some increase in certain risks, but the biggest change in recent years is actually the recent increased access to better data, and in general this is helping us to more accurately identify risks that have always been present.  A flood risk map such as that provided by Landmark Information Group can form part of a structured risk assessment process enabling those advising on property purchases to decide whether the next steps indicated by the initial risk screening report towards site-specific risk assessment, or risk mitigation measures, or indeed in extreme cases, withdrawal from the purchase process, are warranted.

What to do next if your proposed purchase falls within any mapped flood zone?

If the property has been identified as located in an area at risk, it is important to appreciate that this does not automatically mean that the property will flood.

The risk is based on the probability that a flood event will occur based on the environmental setting of the property and the climatic conditions it is exposed to.  If your property is classified as being “at risk”, it simply means that your property is located in an area that is considered to be hazardous in terms of flood risk, but the risk isn’t actually present unless the correct environmental and climatic conditions occur and the local features immediately surrounding the property do not prevent it impacting the property.

There are a number of features including property level protection that may prevent a real risk arising, so the best response will be to discuss the matter with your legal advisor and, if appropriate, consider the next level of detail in a desktop mapping report to identify the true extent of the problem.

Author: Mark Fermor, Managing Director, ESI Limited

Further reading:  
Department for Communities and Local Government (2012). National Planning Policy Statement.
Department for Communities and Local Government (2014). Planning Practice Guidance.