The UK is facing a significant water resources crisis. The Environment Act 2021 set a target to reduce the use of public water supply per head by 20% by 2038, with a longer-term goal of reducing per capita consumption to110 litres per person per day by 2050. To meet these objectives, AMP8 (2025-30) will see a substantial increase in water efficiency activities, including £258m in investment from water companies, wider government initiatives such as water efficiency labelling, and the establishment of Ofwat’s Water Efficiency Fund.
Without strong evidence of impact, the industry cannot know if this complex delivery setting has delivered deep water savings and ultimately if demand reduction targets are achievable. Therefore, it is essential that robust evaluation activities take place to provide high levels of certainty that water savings are achieved.
This is a challenge Artesia has been supporting industry with extensively, and led to the creation of our Water Efficiency Confidence Scale (WECS), pictured above. The WECS helps practitioners develop water efficiency evaluation methods and understand the level of confidence they provide. It consists of five levels, ranging from level 1 (a one-off measure without a control group) to level 5 (randomised control studies). As the level rises, evaluation outcomes move from possible to probable impacts, and the higher the level achieved on the scale, the higher the confidence to rule out other potential causes of water saving.
To assist practitioners in applying the WECS, we embarked on a collaborative project to develop a WECS Evaluation Framework. This aimed to provide structured guidance on how to develop an evaluation study for each level of the WECS. It takes users through a series of steps, from understanding your problem, to selecting an appropriate WECS level, to delivering your evaluation, to recording your learning.
The framework was designed to be accessible for all stakeholders involved in the completion, commissioning or management of water efficiency evaluation. As AMP8 progresses and the complex water efficiency delivery context delivers results, it is our intention that the WECS helps industry move towards more robust and standardised approaches to evaluation and ultimately, the delivery of a sustainable water future for all.
Find the latest version of the WECS Evaluation Framework here.
For more information on the wider project and to access illustrative case studies on the WECS Evaluation Framework, please see the project report here.
If you have any questions about the WECS or water efficiency evaluation more broadly then please reach out. Artesia can help you:
- Deliver independent and technically robust evaluations to disentangle the specific water savings of your water efficiency programmes and interventions.
- Design evaluation methodologies for you to implement that follow the Water Efficiency Confidence Scale (WECS).
- Review your existing evaluation approaches to understand their current position on the WECS and co-create a plan to improve.
Contact us here or get in touch with your familiar Artesia colleague.
We would like to reaffirm our gratitude to all stakeholders who supported the development of this framework and the financing of this project by the Water Efficiency Collaborative Fund.
The project was supported by a strong Project Steering Group throughout with contributions from: Anglian Water, Consumer Council for Water (CCW), Dŵr Cymru Welsh Water, Northern Ireland Water, Northumbrian Water, Thames Water, Waterwise, and Wessex Water.
