OT Security Architect: ICS & SCADA Risk & Design Lead

Southern Water; Brighton; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

Southern Water is seeking an experienced OT Security Architect to lead the design and governance of secure OT environments across our operations. This role focuses on securing industrial control systems while enabling digital transformation across sites.

Based in Falmer or Durrington with hybrid work (2 days per week), you will define architectures, manage cyber risk, and work with engineering, IT and cyber security teams to embed security-by-design principles in major programmes and projects.

Qualifications

• Design OT security architectures and frameworks.
• Lead OT security risk assessments and IEC/NIST/ISO/NIS2 compliance.
• Define secure integration between OT and IT environments.
• Communicate complex security concepts to stakeholders.

Responsibilities

• Design and maintain OT security architectures, standards and frameworks.
• Develop secure solutions across SCADA, PLC, DCS, HMI, historian, IIoT and edge environments.
• Creating secure network designs incorporating segmentation, firewalls, DMZs and Zero Trust principles.
• Leading OT security risk assessments and ensuring compliance with IEC 62443, NIST 800-82, ISO 27001 and NIS2.
• Supporting IT/OT convergence initiatives and defining secure integration patterns between operational and enterprise environments.
• Providing expert guidance, threat modelling and security design assurance for projects and programmes.
• Supporting cyber incident response planning, resilience testing and recovery strategies.

Skills

OT security

Industrial cyber

Stakeholder influence

Security-by-design

Threat modelling

Risk assessment

SCADA & OT networks

IEC 62443

NIST 800-82

ISO 27001

Tools

OPC-UA

Modbus

PROFINET

Ethernet/IP

BACnet

DNP3

Job description

Southern Water is seeking an experienced OT Security Architect to lead the design and governance of secure OT environments across our operations. This role focuses on securing industrial control systems while enabling digital transformation across sites.

Based in Falmer or Durrington with hybrid work (2 days per week), you will define architectures, manage cyber risk, and work with engineering, IT and cyber security teams to embed security-by-design principles in major programmes and projects.