Cybersecurity in the UK Water Sector: Protecting Critical Infrastructure

The UK water sector is accelerating into a new digital era powered by smart infrastructure, automation, and real-time data.

From IoT sensors and AI analytics to remote monitoring, innovation is transforming operations and decision-making.

But every connection comes with a cost. Every new device, login, or data feed is a potential front door for a cyberattack.

In 2025, the National Cyber Security Centre (NCSC) issued a stark warning: UK utilities, including drinking-water systems, face an elevated risk from cyber threats.

The culprit? The collision of Operational Technology (OT) and Information Technology (IT). This digital fusion drives performance but also exposes the industry’s most critical heartbeat.

OT/IT Convergence and Cybersecurity in the UK Water Sector

Not long ago, OT and IT were parallel universes connected in purpose but worlds apart in risk.

OT controlled pumps, valves, and SCADA systems, the physical backbone of water operations.

 IT managed billing, analytics, and data — the digital brain.

Now those worlds have merged. The result: unprecedented visibility, efficiency, and automation — and an explosion of cyber exposure.

The real question: 

Can the water sector operate at a higher level of cyber security maturity, continuously evolving at pace to prevent threats to the water systems? 

Cybersecurity in the UK water sector must evolve in lockstep with digital transformation. 

The Rising Cyber Threat Landscape in UK Water Utilities

Globally, cyberattacks on water utilities are evident.  In Florida (2024), ransomware shut down a treatment facility.  In the UK, phishing and malware campaigns have breached suppliers and contractors.

Many UK utilities still rely on legacy OT systems designed for reliability, rather than resilience. Monitoring far-flung sites, many providers use remote access via unmanaged VPNs and often companies have a lack of qualified cybersecurity professionals to address issues during real time incidents.

A single breach in this ecosystem could disrupt supply, damage the environment, or put public health at risk.

Regulation and Accountability in UK Water Cybersecurity

Cyber resilience is now a regulated responsibility. The UK’s evolving frameworks are reshaping accountability across the water sector:

• Cyber Security and Resilience Bill (2025): Tightens obligations for operators of critical national infrastructure (CNI).

  
  

• Network and Information Systems (NIS) Regulations: Mandates active risk management and transparent reporting.

  
  

• Ofwat’s PR25 Framework: Embeds cyber readiness directly into business performance metrics.

Cybersecurity no longer hides in IT departments; it defines operational excellence. Every utility must treat it as a regulatory, operational, and reputational imperative.

Building Resilience: Five Actions That Matter

Defending water systems demands more than technology. It requires a living, layered defence with five critical steps:

1️⃣ Segment networks to isolate OT from IT and contain breaches.

2️⃣ Monitor continuously with real-time analytics to detect anomalies before they escalate.

3️⃣ Control access through patching, credential discipline, and least-privilege enforcement.

4️⃣ Plan and rehearse with tested incident response playbooks.

5️⃣ Educate teams — because awareness is the first and best line of defence.

Cyber resilience isn’t something you install; it’s something you live, breathe, and lead. Leadership, governance, and training are as critical as firewalls and encryption.

Stronger Together: Securing the Supply Chain

In a hyperconnected sector, no organisation stands alone. Every supplier, contractor, and integrator forms part of the same digital chain, and a chain is only as strong as its weakest node.

Water UK, DEFRA, and the NCSC are leading a collaborative shift through shared threat intelligence and joint working groups.

Meanwhile, utilities are demanding higher standards from their partners. Vendor due diligence, robust contracts, and regular cyber audits are now non-negotiable.

In today’s water industry, security isn’t a department; it’s a shared ecosystem. 

The Role of UK Water Consultancies

As cyber risk becomes central to operational resilience, companies and consultancies across the UK water sector are stepping forward as strategic partners providing trusted expertise and training to help organisations strengthen their technical and operational capabilities.

Backed by decades of water-industry experience, CV Water Consultancy delivers:

• Specialised training programmes, such as Introduction to the UK Water Industry and Products for Drinking Water.

This isn’t just about ticking boxes — it’s about earning trust in every drop that reaches the tap.

Securing the Future

The threat isn’t on the horizon; it’s already flowing through the system.

The UK water sector must effectively and efficiently operate at a higher-level of cyber security maturity now and without delay.

The path forward is clear:

• Integrate security into every system and process.

  
  

• Collaborate relentlessly across the supply chain.

  
  

• Treat cyber resilience as the foundation of innovation.

Because a truly modern water industry isn’t just smart — it’s secure, unshakeable, and built to outlast every threat ahead.