a diagram of a greywater recycling system in an office building in the UK

News Reports & Policy • 9 Apr 2026

DWI Reveals Regulatory Roadmap for Rainwater Harvesting and Greywater Systems

About the Report

This article provides insight into the key recommendations relevant to engineers and other stakeholders designing water reuse systems. We recommend reading the full report on the DWI website.

In March 2026, the Drinking Water Inspectorate (DWI) launched a document titled: Governance Framework for Non-Drinking Water from Rainwater Harvesting and Greywater Recycling Systems: Recommendations.

This report is a key reference for the water reuse industry, outlining a clear blueprint for how the regulatory environment could develop in the future.

Stormsaver, as members of the UK Water Reuse Association, were able to support the expert working group by providing a fact-finding visit to our Nottinghamshire-based manufacturing facility.

Key Takeaways

The DWI has recommended:

An improved legislative environment for rainwater harvesting and greywater recycling, removing barriers to adoption for residential systems.
A single Approved Code of Practice for water reuse, similar to the National Standards for SuDS which is free and easily accessible.
The establishment of a risk-based framework aligned with the World Health Organisation’s Water Safety Plan.
Improved training and skills within the industry for water reuse and dual-pipe systems via an enhanced WaterSafe Scheme.
Standards for the maintenance and management of rainwater harvesting and greywater recycling systems, including regular water quality sampling and dye testing for cross-connections.
A further 12-month research project to determine minimal quality standards for non-potable water.

Why Now?

The DWI acts as an independent watchdog for public drinking water in England and Wales.

Alongside the Department for Environment, Food and Rural Affairs (DEFRA) and the Department for Communities and Local Government, the DWI was tasked with investigating how to increase uptake of water reuse systems in the UK.
This work forms part of the Revised Environmental Improvement Plan, published by the new government in 2025.

With a 5-billion-litre daily deficit forecast by 2055, and approximately 60% of this expected to be addressed through demand management interventions such as water reuse, action has never been more urgent.

What Does This Mean for Engineers?

For engineers, the new DWI Governance Recommendations provide a clear blueprint for how the industry could be regulated in the future to ensure the safe delivery of rainwater harvesting and greywater recycling systems.

While no immediate action is needed on live projects, we recommend keeping up to date with the latest information on water reuse.

This can be done through our accredited CPD sessions, by following us on LinkedIn, or by reading our expert articles.

The DWI has signalled a move toward more advanced monitoring of systems and their performance. Understanding the below list will support a smooth transition once this blueprint is fully implemented.