Evidence Overload in England's Water Resources Management Plans: Model Abundance and the Transparency Failure

ABSTRACT

In England's water sector, statutory Water Resources Management Plans (WRMPs) have become increasingly model‐led and document heavy. While this expansion is intended to strengthen evidence‐based decision‐making, transparency, and accountability, in practice it has contributed to a transparency failure: an evidence base that is formally public yet has become increasingly difficult to scrutinize. Drawing on documentary analysis of WRMPs, technical appendices, regional plans, guidance, and consultation materials, we argue that modeling complexity is not only technical but institutional: a vast sea of evidence is fragmented across companies, consultants, regulators, and planning tiers, and uncertainties propagate across long modeling chains. In such conditions, transparency and accountability become formal and procedural rather than functional, undermining confidence in planning outputs that ultimately justify high‐cost investment and customer bills. We conclude that reforms focusing only on institutional restructuring may fall short unless they address the governance of modeling evidence, including traceability, accountability, and intelligible communication of uncertainty.