Security Architect

Powered by Water, Driven by Purpose
South West Water keeps the South West flowing with safe, reliable drinking water and wastewater services across some of the UK’s most stunning landscapes.
We’re proud to be part of Pennon Group, a leader in the UK water sector, working towards a greener future. Our goals? As well as lowering our carbon footprint, we’re working with partners to plant 300,000 trees, restore peatlands and supporting farmers and landowners to improve water quality and wildlife.
Whether you’re starting out or seeking a new challenge, our scale and ambition create opportunities for you to shape your own career.
Ready to make a splash? Join our team today.
Security Architect
Location: Exeter with Hybrid Working
Salary: £55,000 - £65,000 per annum + annual bonus + excellent benefits
Contract: Full Time, Permanent
Shape the future of cyber security at South West Water
We're looking for an experienced Security Architect to lead the design and assurance of secure architectures across business and technology change. This is a highly influential role where you'll act as the senior security design authority, helping to shape strategic technology decisions and ensuring security is embedded from the earliest stages of delivery.
Working across both enterprise IT and Operational Technology (OT) environments, you'll provide expert guidance, lead threat modelling activities and define security standards that protect critical services relied upon by millions of customers.
What you'll be doing
As Security Architect, you will:
Lead the definition, development and assurance of secure architectures across business and technology change.
Own security architecture principles, standards, reference models and reusable design patterns.
Review and approve solution architectures, high-level designs and significant design decisions.
Facilitate threat modelling workshops using methodologies including STRIDE, attack trees and kill-chain analysis.
Ensure threats, risks, abuse cases and security requirements are identified, documented and addressed throughout delivery.
Provide architectural oversight from concept and design through to implementation and assurance.
Develop and maintain the security architecture roadmap and target-state security capabilities.
Support strategic technology decisions, procurement activities and product selection.
Maintain architecture artefacts and contribute to audit, governance, risk and regulatory assurance processes.
Extend appropriate security controls into Operational Technology environments, including network segmentation, secure remote access, monitoring and operational resilience.
Collaborate with architecture, engineering, delivery and operational teams to achieve consistent security outcomes across the organisation.
What we're looking for
You'll bring significant experience within cyber security architecture and be confident influencing stakeholders, balancing risk and enabling business outcomes.
Essential experience
Proven experience as a Security Architect or in a senior security design role.
Experience defining security architecture frameworks, standards, reference models and design patterns.
Strong threat modelling experience within project and architecture environments.
Experience reviewing and assuring enterprise and solution architectures.
Strong understanding of governance, risk management and control assurance processes.
Ability to translate business requirements and technical risks into secure architectural solutions.
Experience producing architecture artefacts, threat models, standards and technical guidance.
Excellent stakeholder management and workshop facilitation skills.
Broad technical knowledge across:
Identity & Access Management (IAM)
Network security and segmentation
Endpoint and server security
Cloud security
Security monitoring and detection
Essential qualifications
Must hold, or be eligible to obtain and maintain, UK Security Check (SC) Clearance.
Strong knowledge of:
Security architecture principles
Threat modelling methodologies
NCSC Cyber Assessment Framework (CAF)
Secure-by-design principles
NIS Regulations
ISO 27001
NIST Frameworks
Desirable
CISSP, SABSA, TOGAF, CCSP or equivalent professional certification.
Experience within utilities, water, critical national infrastructure or OT/ICS environments.
Experience supporting audit and regulatory assurance activities.
Why join us?
This role is ideal for someone who enjoys:
Influencing strategic technology decisions.
Defining clear direction where technology, risk and business requirements are complex.
Embedding security early in the design process rather than relying on retrospective controls.
Leading collaborative threat analysis and transforming risks into practical solutions.
Creating standards, patterns and architectures that improve consistency, resilience and security maturity.
Balancing business outcomes, operational resilience and security requirements within a regulated environment.
What's in it for you?
We believe in rewarding our people for their hard work and dedication. As our
Security Architect you'll enjoy:
What we offer
Attractive Salary & Benefits Package
Annual Bonus Scheme – Recognising company performance
Pension Scheme – Helping you plan for your future
Hybrid Working – A blend of office and home working, supporting flexibility while maintaining collaboration with your team
Employee Assistance Programme – Supporting your wellbeing
Employee Discounts – Access to discounts on a range of products and services
Annual Leave Allowance – Giving you time to rest and recharge
Annual Leave Buy & Sell Scheme – Flexibility to purchase additional holiday or sell unused leave to suit your lifestyle
Career Development Opportunities – Supporting your ongoing growth and development
Closing Date: 30th October 2026
We may close this vacancy early if we receive a high volume of applications. We encourage you to apply as soon as possible.
Please note that the successful candidate will be subject to a mandatory DBS check as part of the onboarding process.
Be yourself, we like it that way. Together, we will build a culture of belonging, where inclusion is instinctive. Diversity is our strength and a reflection of our communities. We care, we value everyone, we celebrate uniqueness.
Our core values, which are essential to our success, are:
Be Rock Solid - Build trust and be trusted. Be the one we all look to and can depend on.
Be You - We want you to bring your best everyday. Be yourself and make your mark in your individual way.
Be the Future - Embrace change. Drive Progress. Own the challenge.

- Division
- South West Water
- Department
- Digital and Technology
- Location
- Exeter (Peninsula House)
- Salary
- £55,000 - £65,000/year
- Employment type
- Full-time
About South West Water
We look after the water and wastewater services for 1.8 million customers across Cornwall, Devon, the Isles of Scilly and parts of Dorset and Somerset.
From treatment and maintenance, to innovation and improvements, we're busy every day finding and fixing leaks, unblocking sewers and going bigger and further in our environmental work to be a company you can be proud of.