Tim Faulkner, head of department – Birmingham & Manchester at Murphy Geospatial, looks at hydrographic mapping.

Rising heat and relentless storms are just some of the ways climate change is testing the limits of our infrastructure, a lot of which is ageing and doesn’t need the added pressure. These factors combined are forcing us to rethink how we design, build, and protect the environment around us.

As climate change accelerates, the UK is experiencing the reality of extreme weather. These are not distant threats, but events reshaping our landscape in real time. In 2022, Coningsby in Lincolnshire endured a historic 40.3°C heatwave, surpassing previous temperature records and putting unprecedented pressure on infrastructure, health services, and ecosystems. These aren’t isolated events. They’re part of a broader pattern of disruption that’s putting millions of homes, businesses, and vital infrastructure at risk.

Floods occur when intense rainfall exceeds the capacity of natural and man-made drainage systems. But the science behind flooding is becoming increasingly complex due to rising temperatures. Extreme heat plays a critical role by drying out the ground and making it less absorbent. When rain finally does fall, especially in heavy bursts, the hardened soil cannot soak it up quickly enough, resulting in rapid surface runoff. Additionally, prolonged heatwaves can reduce vegetation cover, further limiting the land’s natural ability to retain water, alongside years of clearing vegetation to make way for development and infrastructure. This sets the stage for flash floods and worsens the strain on ageing drainage systems. The cumulative effect is a heightened flood risk in both urban and rural settings, where infrastructure may not be prepared to handle sudden volumes of water.

This is compounded by the increasing presence of impermeable surfaces, such as concrete paving, artificial grass, and asphalt, which prevent water from naturally soaking into the ground. Older Victorian-era drainage systems, which were never designed to cope with today’s rainfall intensity or urban landscape, further amplify the problem. These outdated and overwhelmed systems contribute to flash flooding, standing water, and costly damage in both residential and commercial areas.

The latest National Flood Risk Assessment (NaFRA) report paints a sobering picture: around 6.3 million properties in England are at risk of flooding from rivers, the sea, and surface water - with projections suggesting this could rise to 8 million by 2050.

The impact of storms on waterways

Extreme storms add a further layer of complexity to water management. The 2023/24 storm season, which has been officially named as the most storm-active since the Met Office began naming storms in 2015, has demonstrated that heavy winds and torrential rains can devastate entire waterways. Storms can wash away towpaths, collapse riverbanks, and damage bridges, leading to significant economic losses and long-term repair costs running into millions.

The rising tide of infrastructure flooding costs

Across the UK, infrastructure is under mounting pressure from the effects of a changing climate. Key issues include:

  • Roads buckling under extreme heat, compromising transport and increasing repair costs.
  • Flooding accelerating the degradation of bridges, embankments, and culverts.
  • Persistent rainfall infiltrating sub-surface materials, weakening foundations and causing ground movement, which can result in sinkholes or collapses.
  • Storm surges and swollen rivers eroding embankments and scouring around bridge piers, threatening the structural integrity of key transport links.
  • Ageing drainage systems, often designed for less volatile conditions, frequently overwhelmed - leading to backflows, waterlogging, and property damage.

This convergence of climate stressors, wear and tear, and outdated design standards exposes critical infrastructure to greater risk of failure such as placing lives, economies, and ecosystems in harm’s way.

For local authorities, asset owners and managers, this presents an urgent call to action. Culverts, flood defences, and urban water networks need constant surveillance and data-led decision-making to ensure long-term resilience. It can’t be overstated that inaction now will lead to greater costs later, not only in financial terms but in public safety and service disruption.

Hydrographic mapping: What it is and how it helps

Hydrographic mapping is the systematic survey and detailed measurement of water bodies and their surrounding environments. Using advanced technologies such as UAV surveys, high-resolution sonar, and laser scanning, these mapping techniques can capture crucial data on water depth, flow dynamics, and underwater structural conditions. This information enables engineers and planners to:

  • Detect early warning signs: Identify areas where erosion, sediment build-up, or infrastructure weaknesses may lead to catastrophic failures.
  • Optimise maintenance: Prioritise repairs and adaptive measures before minor issues escalate into major hazards.
  • Enhance risk assessments: Integrate with updated flood and coastal erosion models, which now incorporate climate change projections from the Met Office, to predict future scenarios more accurately.

How proactive planning could have stopped a flood - Toddbrook Reservoir, Whaley Bridge, Derbyshire

In August 2019, the partial collapse of the spillway at Toddbrook Reservoir in Whaley Bridge triggered the evacuation of around 1,500 residents, amid fears the dam could fail entirely and flood the town. Emergency services were deployed, and a RAF Chinook helicopter was used to drop aggregate to stabilise the dam. The aftermath revealed not only the design flaws and maintenance issues that led to the failure, but also the staggering cost of repairs - estimated at up to £16 million.

A well-executed hydrographic survey could have identified weaknesses in the spillway's structure and flagged critical maintenance needs before they escalated. With regular surveying and data-led monitoring, asset owners could have proactively reinforced the structure or redesigned vulnerable elements, avoiding both the high financial cost and the risk to public safety.

This event serves as a powerful reminder of the consequences of neglect and the essential role hydrographic mapping plays in modern asset management.

Protecting the future

Proactive hydrographic mapping offers a way to bridge the gap between existing, infrastructure, current and future demands, and changing weather patterns. By regularly updating risk assessments and enabling early interventions, this technology ensures that assets are better prepared for an unpredictable climate. As policymakers and industry leaders align their strategies with cutting-edge data, the result is a more resilient, adaptable system that can withstand both deluges and droughts, all of which are becoming more frequent.