We expect engineers to design with precision. Yet increasingly, engineering teams are being asked to design and build around information that cannot always be trusted.

That creates a serious risk. When historical records do not accurately show what lies beneath the ground, infrastructure can be damaged as soon as excavation begins.

The risk beneath the surface

Before construction starts, the project team needs to understand what is already in situ. The most expensive time to discover an underground service is after an excavator bucket has already found it. Beneath a road, within a servitude or underneath a proposed development may be bulk water pipelines, sewer networks, electricity cables, telecommunications infrastructure, stormwater systems, foundations and other services installed years or even decades ago.

Damaging these assets can interrupt essential services, delay construction, increase costs and create significant safety risks.

The challenge is that the information available about existing assets is not always complete, accurate or current. For consulting engineers, establishing what is already in place is not an administrative exercise. It is a fundamental part of responsible design and construction.

In our field of expertise, we routinely take extensive steps to establish what lies within a proposed construction area. Where necessary, we recommend specialist investigations, including topographical surveys, geotechnical investigations, ground-penetrating radar, electromagnetic locating and trial excavations.

Before a contractor breaks ground, the project team should know

In practice, however, consulting engineers often work with records that are incomplete, inaccurate, outdated or divided between different municipalities, utilities, consultants and contractors.

In many parts of South Africa, engineers are not failing to investigate what lies beneath a construction site. They are working with records that were incomplete when they inherited them, have not been updated, are difficult to access or do not accurately reflect what is actually in the ground.

The scale of the information gap

The difficulty of working with incomplete infrastructure records is reflected in South Africa’s recent municipal audit data.

In its 2023/24 report, the Auditor-General found that 61 municipalities, 25% of those audited, could not properly account for their property, infrastructure, plant and equipment. In many cases, asset registers had not been updated to reflect assets that had been acquired, constructed, disposed of, stolen or vandalised.

For an infrastructure owner, an asset register should form part of the evidence base used to plan maintenance, assess risk, prepare designs and protect existing services during construction.

The consequences of poor information are visible in everyday infrastructure work. Fibre contractors have frequently damaged municipal water pipes and electricity cables while trenching. Municipalities have received complaints about outages, leaks and disrupted services lasting from several hours to several days .

The reverse also occurs. Municipal or third-party contractors repairing roads, water, or electricity infrastructure can damage fibre networks when they skip mandatory kick-off meetings or fail to complete the required identification procedures.

Engineers cannot verify what was never recorded

There is often an assumption that when existing infrastructure is damaged during construction, the failure must lie with the engineer or contractor. That is not always the case.

A responsible engineering team should request historical drawings and as-built documentation, obtain wayleaves, consult municipalities and utility owners, review available surveys and geological information, visit the site and incorporate known services into the design.

South African specifications and guidance also place obligations on contractors to protect existing services and obtain relevant information before work begins. Department of Transport guidance, for example, restricts mechanical trenching near existing cables, pipes and ducts without the necessary approval of the engineer and service owner. Municipal wayleave processes similarly require drawings and approvals for work involving underground services in road reserves.

The controls, but they depend on the quality of the information available. A service may be absent from the records entirely. Its recorded position may be several metres from its actual location. A cable may be at an unexpected depth. A water pipe may have been installed before reliable surveying practices were adopted, or a later contractor may have changed its route without updating the asset owner’s records.

An old drawing can therefore provide useful information without providing certainty.

The absence of a service on a drawing cannot safely be interpreted as proof that the service does not exist.

The engineer’s role is to understand that uncertainty, identify the risks it creates and recommend appropriate verification. The client’s role is to ensure that the project scope and budget make that verification possible.

This is where infrastructure procurement needs to change.

Surveying must be part of the scope

One of the most important changes required in infrastructure procurement is to stop treating surveys as optional extras.

When a project involves excavation, connection to existing services, road construction, drainage, bridgework, bulk water, electricity or other underground infrastructure, the scope of works should include an appropriate existing-conditions survey from the outset.

The exact survey will depend on the project and may include topographical surveys, a cadastral and servitude investigation or a geotechnical investigation, among others.
The objective is not to produce paperwork for its own sake. It is to reduce uncertainty before design decisions are finalised and before heavy machinery arrives on site.

A project that excludes these investigations may appear cheaper during procurement. In reality, it may simply be transferring the cost to the construction phase, where the consequences are more severe and less predictable.

The client’s scope should therefore make existing-conditions investigations explicit. Where a project involves excavation, connections to existing services, road reserves, bulk water, electricity, drainage or other buried infrastructure, the necessary combination of investigations should be specified from the beginning.

These investigations should not be treated as discretionary items that can be removed to reduce the tender price. They are part of the information required to design and construct responsibly.

The cost of getting it wrong

When existing infrastructure is damaged, the immediate repair cost is only one part of the loss.

A damaged bulk-water pipeline can interrupt supply to households, businesses, hospitals and schools. A severed electricity cable can disrupt essential services and create serious safety risks. Damage to telecommunications infrastructure can affect emergency communications, businesses and public administration.

There are also indirect consequences, including construction delays, emergency procurement or additional labour and plant costs, contractual disputes and reputational damage.

The Auditor-General’s 2023-24 report, which audited 113 municipal infrastructure projects with a combined value of R12.64 billion, reported findings on 87 of them, or 77%. Of the projects audited, 52% were delayed, 30% had cost issues and 17% had poor build quality. The average delay was 21 months.

These findings cannot all be attributed to missing drawings or incomplete surveys. Infrastructure projects are affected by many factors, including procurement, funding, contractor performance, changes in scope and municipal capacity.

They do, however, demonstrate why uncertainty should be identified and managed before construction begins. The earlier an existing-service conflict, ground condition or design gap is identified, the more options the project team has to address it without disrupting the programme or increasing costs.

A shared responsibility

Consulting engineers have an important role to play. They must identify uncertainty, advise clients on appropriate investigations and design safeguards into construction documentation.

Contractors must follow approved procedures, use appropriate locating equipment and stop work when site conditions differ from the available information.

But infrastructure owners and clients must also provide the conditions for responsible delivery.

That means commissioning and preserving reliable surveys; maintaining current asset registers; allocating sufficient time and funding for investigations and making historic information accessible.

South Africa’s infrastructure challenge is partly a construction challenge. It is also an information challenge.

If the records are wrong, incomplete or inaccessible, even a competent engineering and construction team may be forced to make critical decisions in the dark. And when excavation begins, the consequences may be measured not only in repair bills, but in disrupted services, delayed projects and risks to public safety.

Every new project should leave behind a better record than the one it inherited.

Before construction starts, the records must be right.