BGS Data Deep Dive: How Geological Maps Support Civil Engineering

Beneath the roads, foundations, tunnels and retaining walls of our built environment lies a hidden tapestry of rock types, sediments, faults and shifting soils. For civil engineers, tapping into that subterranean story is not optional, it’s essential. In the UK, that story is most authoritatively told through maps and datasets from sources such as the British Geological Survey, BGS. At CentremapsLive, we believe that bringing BGS data alive in practical workflows is a vital bridge between raw earth science and robust infrastructure.

This blog explores how geological maps and associated BGS products underpin civil engineering and how using them cleverly is both risk mitigation and value creation.

To start, what do these geological maps actually represent? Rather than merely artistic contours, BGS’s digital geology, for example their 1:50,000 “50k” dataset, translates classical paper maps into layers representing bedrock, superficial deposits, mass movements, artificial ground and linear features such as faults. Each layer conveys not just rock names, but attributes including relative age, lithology and in many cases structural information. These are not simply reference sheets, they become foundational data in computational models.

But a rock name itself doesn’t answer the question, “Will this ground bearing capacity suffice for a 10m deep basement?” That’s where engineering geological maps come in. BGS has produced two national maps at a 1:1 million scale, one for bedrock and another for superficial deposits, that reinterpret traditional lithostratigraphic units as “engineering geological units.” These maps include detailed notes on factors such as foundation suitability, ease of excavation and expected geotechnical performance. While they aren’t a substitute for site investigation, they provide a broad framework during early planning and concept design phases, a first cut at ground risk before expensive boreholes are drilled.

In civil engineering, the spatial scale and fidelity of subsurface data matters. Oversimplified maps may mislead, while overly fine detail may misrepresent uncertainty. One tool that helps navigate this balance is GeoIndex, a BGS web application that lets users stack geological map layers, borehole records, cross-sections and modelled slices beneath chosen locations. Through GeoIndex, a civil engineer can examine the probable sequence of subsurface layers, such as clay over sand over solid rock and access nearby borehole logs or cross-sections to confirm or refine that interpretation.

At CentremapsLive, we make BGS datasets accessible and practical for everyday civil engineering workflows. Through our web-based mapping interface, datasets can be easily ordered and provided in ready-made GIS format, allowing engineers to use data efficiently without needing to manually manipulate raw GIS files.

One standout product is GeoSure, a CentremapsLive solution that evaluates ground-related risk by integrating geological data, such as material strength, density and sediment characteristics, with environmental and hazard information. GeoSure provides engineers with predictive insights into areas prone to issues like landslip, shrink-swell, compressible ground or flooding. These insights guide site planning, foundation design and targeted mitigation measures, while also highlighting areas that may require closer monitoring during construction or long-term operation.

Another key tool available through CentremapsLive is the BGS 1:50,000 geological dataset, BGS 50k. This high-resolution dataset provides detailed digital maps of bedrock and superficial deposits, capturing lithology, age and structural information at a scale suitable for precise site assessment. Engineers can use BGS 50k to visualise subsurface conditions, assess layer sequences and identify potential challenges such as weak soils, fault lines or variable sediment thickness. In urban projects with complex subsurface conditions, BGS 50k enables engineers to map variations across the site, anticipate excavation difficulties and plan foundation strategies more accurately, reducing both risk and cost.

CentremapsLive provides all datasets and tools in ready to use GIS formats, enabling engineers, planners and surveyors to overlay and analyse subsurface data directly within their digital workflows, no advanced GIS expertise required. By delivering data in practical GIS formats, CentremapsLive turns BGS datasets from static resources into actionable insights for informed decision making.

It is important to note, however, that while these tools provide invaluable early-stage guidance, they do not replace detailed site investigations and expert geotechnical analysis. Geological maps provide regional context and help form hypotheses, but prudent engineering practice always combines these insights with local testing and ground-truth validation. The most effective workflows integrate CentremapsLive products with on-site borehole data, lab testing and iterative design modelling, enabling teams to explore sensitivity, predict failure modes and optimise groundwater or pressure management strategies.

Looking ahead, subsurface data literacy is poised to become as integral to civil engineering as structural analysis. Engineers who understand the composition and behaviour of the ground beneath their projects, rather than treating it as a uniform substrate, can design infrastructure that is safer, more resilient and cost effective.

CentremapsLive’s mission is to make this literacy practical, providing BGS datasets and modelling tools in formats that engineers can easily incorporate into their workflows, turning complex geological data into clear, actionable intellige