Enforcement Performance Metric

During 2025, the Inspectorate developed and tested a new metric, to measure company performance in respect of their obligations contained within legal instruments. The metric assists the Inspectorate in directing its limited enforcement resource to those companies that require the most attention, as well as publicly demonstrating company performance.

Every legal instrument served is scored, using a five by five matrix, which has a set of rules attached, which inspectors follow for consistency.

The first score, assigned when the legal instrument is created, is the seriousness score. This score reflects the origins of the legal instruments and ranges from voluntary programmes, through routine enforcement action, to escalated and transformation enforcement. The criteria are listed in table 1.

Seriousness	Score
Escalated enforcement – generally, enforcement orders but other forms too.	5
Further (additional) enforcement – “child” legal instruments, transformation legal instruments.	4
Routine enforcement (realised breaches) – e.g. compliance assessments, events, regulation 26 breaches, data driven, consumer complaints.	3
Routine enforcement (potential breaches) – e.g. likely to breach, risk of breach, audit findings, risk assessments.	2
Proactive schemes – e.g. AMP schemes, voluntary undertakings.	1

Table 1 – Seriousness score

The second score is a Red, Amber, Green (RAG) (expanded to include Amber + and Red +) status of the progress of the legal instrument. This score is assigned when the legal instrument is first created but is changed as required throughout its lifetime based on the progress of delivery. The criteria are listed in table 2.

Status	Rules
Red + (5)	DWI have rejected a change application for date extensions to the completion date of the notice.  Any delays that affect the end date of the notice.  Once a notice is in Red + status, it can only ever recover to Amber +.
Red (4)	Most recently submitted milestone is delayed or was delivered late. (This also applies to the initial response to the Minded to Enforce letter).  Most recently submitted milestone is insufficiently evidenced or incomplete (Doesn’t apply for routine follow-up questions).  DWI notified that a future intermediate milestone is going to be delayed and there is no way the company can meet it.  DWI have rejected a change application for date extensions for intermediate milestones.  Last minute notification of not going to meet targets, when company have known for some time).  Missed completion report.  Red applies until the next milestone is received, when the score may reduce to Amber or Amber +.
Amber + (3)	Escalated enforcement (see table 1) always begins at Amber+  Change application has been accepted with a new, later final delivery date.  Notice was previously at Red+ status, but company have resolved issues and improved management of notice.  New child notice from delayed notice begins at Amber+ (such as an individual Service Reservoir (SR) being removed from a wider SR notice). Cannot go lower than Amber + once here.
Amber (2)	Change application accepted for an intermediate delay which does not affect the final date of notice.  There have been delayed/late milestones but scheme is now on track.  Previously red, but company have resolved issues and improved management of the notice.  Cannot go lower than this once here.
Green (1)	Default option for non-escalated and non-child legal instruments.  All milestones are on target or completed on time.  Change of solution which does not affect the final delivery date (i.e. the company have found a cheaper or quicker way of delivering the scheme within the notice period.)  DWI direct a future change to a scheme (such as the publishing of new PFAS guidance, which affects PFAS undertakings)  DWI have initiated a change application.  Small administration changes (such as an annex update to an undertaking or notice).  Cannot return to green once amber or red.

Table 2 – RAG scores assigned to legal instruments

There is an acceptance that risk will always exist and the bigger the company (bigger catchment, more water treatment, more treated water storage, greater length of mains and more connections), the higher the residual risk.

Total scores for each company are compared to those of the whole sector and normalised based on the proportion of overall population supplied to give an expected score for each company. The expected scores are then plotted against actual scores, for each company, using a linear regression. The upper 95% confidence value line is added, to highlight where there are statistical outliers, producing the graph which is published in the Chief Inspectors Report.