Strengthening RIIO-GD3 submission through structured planning

Published: 22 September 2025

Overview

If you’re preparing a RIIO-GD3 business plan, you need a clear strategy to secure a significant amount of funding and meet Ofgem’s strict requirements. Cadent faced that test for its 2026–2031 submission. They had to tie investment needs to their corporate goals while data, evidence and risk justification were under heavy scrutiny. Group company, Aqua Consultants, joined Cadent’s team to frame strategy, shape regulatory cases and align every datapoint in preparing their submission.

Solution

Aqua embedded in Cadent’s team from day one. They framed the plan around Cadent’s corporate strategies, matching each investment case to long-term objectives. This led to the creation of ten Engineering Justification Papers and four Major Project Justification Papers, guiding the team through cost-risk trade-offs and technical evidence standards.

They acted as a critical friend. They challenged weak assumptions, tightened narrative and sharpened the link between need, solution and benefit. In doing so, they managed the programme end to end: setting the delivery roadmap, producing and checking all data tables, and keeping a transparent audit trail for every assumption and source.

When Ofgem issued its Draft Determination, Aqua ran a structured analysis of the feedback. Following that, they updated EJPs, MJPs and data tables, then coordinated Cadent’s formal response and stakeholder governance.

Project Outcomes

Cadent achieved an outstanding rating in Ofgem’s July 2025 Draft Determination. Ofgem praised the clarity of Cadent’s investment cases and the strength of its data assurance. In addition, this helped Cadent to secure approval for funding for reinforcement and repex. The rigorous cost-risk analysis in each justification paper won regulator trust and stakeholder buy-in. Cadent now has a clear, risk-based path to respond to final determinations and move into delivery.

Outstanding rating on the RIIO-GD3 Draft Determination.
Formal approval in network investment.
Robust audit trail for all data and assumptions.
Structured response plan for Ofgem feedback.

“Aqua Consultants were a real asset during the development of our RIIO-GD3 plan. They brought regulatory insight and business planning expertise, but more than that, they got stuck in and worked alongside us. Their flexible, hands-on support helped us tackle challenges and build a confident, high-quality submission.”

Sam Wilson

Head of Strategic Investment Planning, Cadent