Using and publishing GeoSmart’s GW200 screening map: a guide for public bodies
GW200 is a free groundwater flood risk screening map of Great Britain for public bodies. This guide covers what you can do with it, how to move from a screening result to a decision, what the licence requires, and what to include when you publish it.
What you can do with GW200
The map is intended to help you prioritise. Typical uses include:
- Sharing groundwater flood risk information with in-house teams, planning authorities and the public, in plain terms, on a website or in public documents, without implying a property-level judgement.
- Initial screening in strategic flood risk assessments, local plan evidence bases and planning consultation triage, to flag where further groundwater assessment should be requested.
- Targeting investigation, monitoring and local data collection on the areas the screen flags.
From screening result to decision
- Check GW200. A “potential risk” cell is a prompt for more detailed assessment. A “negligible risk” cell means the national model is not showing a risk, which is not the same as no risk.
- Review the detailed data. A review of the GW5 map will reveal where the national map has identified a risk. GW5 gives the 5 m picture of groundwater flood risk in four classes, consistent with GW200. FSAGW (FloodSmart Analytics Groundwater) adds where emerging groundwater flows and collects at the surface, and the two are designed to be used together.
- Get a site-specific assessment where the consequences are important, for example, building a home or a valuable asset, or locating a basement or critical infrastructure.
What is a site-specific groundwater assessment? It checks the mapped risk against local evidence: geology, borehole and groundwater monitoring records, topography and flood history. Where the consequences justify it, it can include ground investigation with groundwater monitoring over a suitable period. Our consultants carry out these assessments.
Remember: negligible risk means the national model is not showing a risk, not that there is no risk. Local groundwater conditions that are not modelled can cause flooding in these areas. Obtain a site-specific assessment where the consequences are important.
The licence
GW200 is free for non-commercial use by LLFAs, regulators and other public service organisations, under the Groundwater Flood Risk Screening Map – Local Authority and Public Service Organisation Data Licence. You accept it by ticking “I accept” on the download page, and the terms include your confirmation that you are a public service organisation and will use the data for non-commercial purposes.
You can:
- use the data internally for your public service functions;
- publish the map for the public to view on your website, in planning, flood risk, local plan, strategy and evidence-based documents, and in PDFs;
- let your contractors, consultants and other agents use it on your behalf, under your control, for your work only; and
- charge fees for your own services, as long as you do not charge for the data.
Each council and LLFA is a separate end user. Each downloads GW200 and accepts the terms itself. Do not pass the data file to another council or LLFA unless it is acting as your agent. An agent, such as a contractor or consultant, can use GW200 only on your behalf and under your control, and must not use it for itself or anyone else.
You cannot:
- sell the data or use it commercially;
- give the underlying GIS or database files to anyone outside the licence; or
- publish the data in a form that lets people download or query it. Web maps must be view-only, for example by serving rendered map images.
What to include when you publish
Every published map, page or document needs three things: the GeoSmart notice (with the map name, version and the anti-extraction wording); the BGS/UKRI disclaimer; and GeoSmart’s short guidance on negligible risk beside the map. You must not suggest that BGS or UKRI endorses your organisation or any conclusion drawn from the map, and you must not describe a negligible-risk area as safe or risk-free. The licence sets out the wording, and the publishing guide includes ready-to-paste text and a checklist.
Going further: GW5, FSAGW and FloodSmart Analytics at 50% off
LLFAs and other public bodies can license our detailed data and platform at 50% off our standard prices:
- GW5 (subsurface groundwater risk, 5 m);
- FSAGW (FloodSmart Analytics Groundwater: surface groundwater risk, where emerging groundwater flows, accumulates and ponds, 5 m); and
- The FloodSmart Analytics platform and property-level products, which give property (UPRN) level analysis for all sources of flooding, including estimates of annual damage for portfolios, communities, towns and cities, with the NaFRA2 surface water, rivers and coastal data alongside the groundwater data.
Each council and LLFA takes its own detailed-data licence, which covers its own use and use on its behalf by its contractors, consultants and other agents acting under its control. Each authority is free to decide whether to license these or to use only the free GW200 map.
The detailed data is supplied under a public body data licence. It is not for unrestricted public web publication, so use GW200 for public web mapping, which essentially redacts the higher resolution data. Extracts can be used in planning, flood investigation and similar documents, subject to the licence terms. We recommend licensing GW5 and FSAGW together, with the platform and property-level products, to get the full benefit of the most detailed data available while the coarser GW200 map is published online and in your reports to flag the areas that need more detailed attention.
Get started
- Download GW200.
- Take up the 50% offer, or arrange a call: tick the contact box on the form, email enquiries@geosmartinfo.co.uk, contact us or call 01743 298100.
- Obtain GW5 data or learn more about groundwater flood risk: www.geosmartinfo.co.uk
- Background: How the GW200 screening map works and Why groundwater flood risk is under-counted.
We welcome comments, corrections and local information, particularly records of groundwater flooding from authorities that hold them. These will feed into the next release.
GeoSmart Information Ltd is a flood risk specialist modeller and developer of flood risk maps for all sources of flooding.
