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First international workshop on digitally mapping the underground

At Geospatial World Forum 2019 the first international workshop on digitally mapping the underground Underground mapping for resilient infrastructure: Datafication of the Underground was organized by Rob van de Velde and Paul Janssen of Geonovum. The objective of the workshop was to discuss the complex challenges relating to underground geotechnics and infrastructure that dense urban habitation and the requirement to optimize the use of earth’s resources.

The workshop combined commercial, academic, and government perspectives on subsurface data requirements including use cases, data providers, procurement, organization and business cases, standardization, legislation, and international cooperation.  It was described by several participants as  a “breakthrough in governmental – business shared vision and action.”

I thought it would be worthwhile to include here the talk that I gave to kick off the discussion and set the context for the following talks by Alexander van Noort, Fugro; Martin Peersmann, Key Registry of the Underground of the Netherlands(BRO); Caroline Groot,Cable and Pipeline Information Centre (KLIC); Bart De Lathouwer, Open Geospatial Consortium (OGC); Tan Boon Khai, Singapore Land Authority; and Paul Janssen, Geonovum. In subsequent articles I plan to cover the material presented in these presentations at the workshop.

The subsurface is often ignored. This is partly a case of out-of-sight is out-of-mind. But it is also the result of broken business processes in the construction industry that place much greater value on physical assets than on what is now being called the digital twin representing the location, behaviour and status of underground assets. Knowing the location of underground energy infrastructure is critical for national security, for disaster planning and management, for public safety and for economic efficiency. Everyone is aware of at least one disaster resulting from or exacerbated by not knowing where our energy infrastructure is – the recent explosion in San Francisco in California (2019) and the massive explosion in Belgium (2004) immediately come to mind.  As was discussed in a recent workshop not knowing the geotechnics under alternative right-of-ways for a highway can result in much greater construction costs and unanticipated schedule overruns.

Impact of unknown and inaccurately located subsurface infrastructure and geotechnics

According to McKinsey we need to spend about $57 trillion over the next couple of decades on infrastructure, a considerable proportion of it underground, and the cost of doing this is inflated substantially by not knowing underground conditions.  The best example I know of the economic impact of not knowing accurately where underground infrastructure is the Sydney Light Rail Extension Project.

This is a $2.1 billion PPP project for 12 km of light rail to be completed by 2019. Prior to awarding the contract for construction the Department of Transport for New South Wales undertook 12 months of work to map 5,000 subsurface utilities along the route. 500 existing subsurface utilities were identified for relocation to make way for the new light rail infrastructure. During construction it was found that the as-built information from utility providers was frequently unreliable including incorrect location and incorrect materials.

The second problem was that during construction an additional 400 unknown services were encountered. As anyone in the construction industry will tell you – discovering unknown underground utility infrastructure occurs frequently on construction projects. Both of these caused disruption and delays with construction. In this case ACIL Allen, a respected Australian consulting firm, was asked to estimate what the impact of unknown and inaccurately located utilities was on the project.

Their study concluded that if a complete and reliable 3D map of underground infrastructure had been available at the project planning stage, the project could have been completed at least one and a half years sooner, at less cost with a much lower level of risk. While the project apparently remained ‘on time and on budget’, ACIL Allen says that this is only because the risk of delays and additional costs resulting from unidentified underground utilities were included in the contract pricing and schedule.

Another example highlighted the risk of not knowing underground geotechnics before embarking on highway design was reviewed in a workshop organized by Geodan and TNO in Amsterdam a couple of years ago. In the workshop two alternative routes for a new connector highway were assessed based on limited information about the underground geotechnics underlying the routes.

This was based on a historical event in the north of Holland. At the time it was decided to build the route using the shorter right-of-way through farmland rather than the longer route which followed existing road and rail lines. After extensive construction delays and rising costs because of the unforeseen poor soil conditions underlying the route through the countryside, it was ultimately decided to build an elevated roadway at much greater cost to the construction contractor and the regional government.

An example that shows the benefit of knowing where underground utility infrastructure is located is the I-20/I-59 Corridor project in Alabama. This is a $750 million interchange project in the heart of Birmingham’s business district.  For this project the Alabama Department of Transportation (ALDOT) took an unusual approach.

Using potholing, scanning with ground penetrating radar, and existing as-built records a 3D model of below-ground utilities. When the project was put out to tender each contract each bidder was provided with the 3D model. ALDOT estimated that it saved $10 million on the project with this approach. Perhaps more importantly the project remains on schedule and on budget – remarkable for a project of this complexity and magnitude in a dense urban environment.

The Common Ground Alliance collects statistics regarding damage to underground infrastructure during construction. Over the past 20 years, there have been 1,906 injuries and 421 deaths attributed to hitting underground utilities, almost entirely energy infrastructure.

There were 316,442 cases of utilities being hit during excavation in 2017 at at average cost of $4000 in direct costs per hit. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction. Several university studies have estimated the benefit in terms of an ROI of knowing accurately where underground infrastructure is located.

One of the most recent by Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure. In the U.S. the Federal Highway Authority (FHWA) cites studies that have shown that the cost of detecting underground utilities prior to construction typically costs less than 0.5 percent of the total project construction cost, saves more than $4 for every $1 spent, and can reduce project delivery time by as much as 20 percent. A study resulting from an underground survey in Milan in preparation for a World Fair there estimated that €16 were saved for every € invested in accurately locating underground infrastructure.

In the U.K. research by the University if Birmingham has estimated that the direct cost of a utility strike during construction ranges from £ 300 for water and sewer to £ 2,800 for fiber-optic cables. More importantly the indirect and social cost, which includes traffic disruption, injuries to workers and the public, and loss of business custom was estimated to be about 30X the direct cost.

Every construction project requires investing time and effort including expensive vacuum and hydro excavation equipment in detecting and exposing underground infrastructure prior to and during excavation.

Construction bids are routinely inflated by 10-30% to accommodate risk associated with unknown or poorly located underground utilities. In the U.S. this has engendered what is estimated to be a $10 billion per year industry. But this information is rarely shared and the location of underground infrastructure is captured over and over again. Together this represents a considerable drag on the construction industry.  In the U.S. if indirect and social costs are included this represents at least a $50 billion drag on the economy.

Worldwide initiatives to share location of underground infrastructure

There are successful examples around the world where municipal and regional governments have helped enable a shared underground utility network database. I have blogged about a few shared databases of utility location data (water, sanitary and storm sewers, electric power, telecommunications, gas, and district heating) I’ve encountered worldwide over the years: Sunderland, UK, Netherlands, France, Chicago, Alabama, Sydney, Milan, the KLIC system in the Netherlands, KLIP in Belgium, Penang, Sarajevo, Calgary, Edmonton, Jalisco, UK, Japan, Bahrain, Rio de Janeiro and Sao Paulo, Delhi, an open water network portal in New Zealand, the Integrated Cadastral Information Society (ICIS) in British Columbia, and the North East Underground Infrastructure Hub (NEUIH) in the UK.

The grandfather of shared underground infrastructure databases is the mainframe-based Road Administration Information Center (ROADIC) system, which was deployed first in Tokyo and then in 11 other major cities in Japan, and which provides information about the location of underground infrastructure including telecommunications and utilities.

A remarkable project of the City of Sao Paulo, one of the World’s largest megacities, is GeoCONVIAS. This integrates data from 20 to 30 utilities operating in the city of Sao Paulo/ The most important objectives of the GeoConVIAS project are to organize underground infrastructure to prevent accidents during excavation, reduce inconvenience to the public, and reduce the costs of maintaining underground infrastructure. The utilities in Sao Paulo are not asked to provide detailed information about their underground facilities, just “a simple line” showing the location of their facilities.  We were fortunate to have Marcos Romano of GeoCONVIAS present at the GWF2019 session in Amsterdam.

A major step forward in mapping underground infrastructure was a pilot project carried out using ground penetrating radar (GPR) on the site of the Expo Milano 2015 event in Milan. The total project area is about 230,000 square meters. All underground infrastructure including electric power, water, sewers, gas, district heating, street lighting, and telecommunication, were mapped using ground penetrating radar (GPR) which was compared to historical records. An analysis revealed an estimated return on investment is about €16 for every euro invested in improving the reliability information of underground infrastructure.

In France a national regulation requiring mapping of subsurface infrastructure titled Decree relating to excavations near underground, overhead or underwater transmission or distribution networks was promulgated on 15 February 2012. It requires mapping all critical underground infrastructure in urban areas by 2019 and in rural areas by 2026.

In 2016 the City of Chicago launched a pilot to deploy a platform for collecting data and creating and sharing a 3D map of underground. It is based on new technology developed by University of Illinois at Urbana-Champaign’s Real-Time and Automated Monitoring and Control Lab (RAAMAC) and Chicago start-up CityZenith. During excavation a dozen or more pictures are captured with an inexpensive digital camera. RAAMAC’s software uses the photos to create a 3D digital model of the underground infrastructure. These models can be securely shared between the City of Chicago and construction contractors to improve project planning and limiting accidents. The advantage of this approach to data collection is that it does not interfere with construction and does not add any significant cost.

But perhaps the initiative that everyone interested in improving knowledge of the underground should be following is a national program in the Netherlands which is supported by legislation and standards.

In 2015 a new law was passed by the States General which created theBasisregistratie Ondergrond (BRO) or Key Registry for the Subsurface.  This database is open and accessible to all citizens of the Netherlands. The law mandates that beginning in 2018 if you excavate or drill you have to share your data relating to geotechnics with the BRO registry. In addition if when using the data in the registry you find something is incorrect you are required to report it.

Standards for sharing information about the underground

The open Open Geospatial Consortium’s (OGC) underground information initiative, with the appropriate acronym MUDDI, is intended to provide an open standards-based way to share information about the below ground. The MUDDI project has identified several different broad use cases that the model is intended to support including routine street excavations (EX), emergency response (ER), utility maintenance programs (OM), large scale construction projects (AE), disaster planning and response (DP), and smart cities programs (SC). For each of these, several basic requirements that the model needs to satisfy have been identified. 

For street excavations the requirement is location of all entities with high horizontal, medium vertical accuracy (2.5D) of underground infrastructure; for large construction projects, detailed 3D geometry of underground infrastructure and detailed 3D geology; for emergency response, interdependencies between different networks; for utility maintenance, network topology and facility location and condition; and for smart cities the ability to monitor and relate streams of data from sensors.

The MUDDI model is intended to build on and be compatible with many existing reference/target models. For infrastructure these include CityGML with Utility Network ADE (Application Domain Extension) , INSPIRE Utility Networks, IMKL (Information model for cable and pipes), BIM-IFC, Land and Infrastructure Conceptual Model (LandInfra), Singapore Underground Geospatial Model, PipelineML, Underground Pipeline Information Management System, CIM (Common Information Model), Multispeak, ESRI Utility Model, and GEOfeature. For geotechnics, the reference/target models are GeoSciML, INSPIRE Geology, GroundwaterML, BGS National Geological Model, EarthResourceML, GeoTOP, SoilEML, IFC Geotechnical Extension, MINnD, and BoreholeIE.

To provide a way for the model to be used by different types of users, the concept of profiles has been introduced. Profiles have been used for other OGC standards and allow for different levels of complexity for different domains and applications. The proposed profiles include asset, excavation, emergency, planning and integration profiles.

National initiatives to map underground infrastructure

The Urban Redevelopment Authority (URA) of Singapore intends to release a masterplan of Singapore’s subsurface infrastructure in 2019.​ It will be released as part of the next national Master Plan for Singapore’s development in the medium term. When completed it will provide the first comprehensive 3D map at what lies beneath the surface from utilities a few meters deep to transportation tunnels, deep sewer lines, deep petrochemical storage, deep water reservoirs and even deep ammunition stores.

In the UK combining above and below-ground information into one national digital twin will allow industry to share business developments and innovation activities. Project Iceberg is an exploratory project undertaken by the British Geological Survey, Ordnance Survey and the Future Cities Catapult to investigate ways to integrate data and services relating to the underground with other city data. To date two reports Market Research into the Current State of Play and Global Case Studies and Defining the problem space for an integrated data operating system above and below ground have been published and are publicly available.The medium term objective is to take these concepts forward with project partners to develop new digital data demonstrator projects.

In the U.S. to begin to address the challenge of accurately mapping national critical infrastructure the National Academy of Public Administration (NAPA), Arizona State University (ASU), the American Geographical Society (AGS), and the National Academy of Construction (NAC) convened leaders in public administration, infrastructure development, geography, geospatial, and data integration/open data at Arizona State University in Tempe, Arizona.

At GWF2019 I learned of an initiative in Estonia, one of the most digitalized countries in the world to create a national digital twin of above and below-ground infrastructure.


In summary unreliable information about the location of underground infrastructure and underground geotechnics costs world economies billions of dollars every year. Missing or inaccurate information adds risk to every construction project.  In the U.S. locating subsurface infrastructure is a $10 billion per year industry. 

The information is rarely shared with the result that this information is recaptured over and over again. To provide a standard for sharing information about the underground including infrastructure and geotechnics the Open Geospatial Consortium has initiated a standards development effort called MUDDI which is being built on many existing standards. An important national initiative to share information about the underground has begun in the Netherlands.

Starting in 2018, information about subsurface geotechnics captured through drilling or excavation must be uploaded to the Key Registry of the Underground or BRO which is openly available to the public. A number of cities and regions around the world which have already recognized the importance of reliable information about the underground have developed ways of collecting and sharing information about the subsurface.

Recently the awareness about the importance of information about the subsurface has reached the national level.  France has mandated that the location of critical underground infrastructure must be known to within 40 cm. Recent initiatives in Estonia, Singapore, the U.K. and the U.S. are aimed at creating national digital twins including underground infrastructure.