RIWS: Resilience in integrated water systems

Introduction

The RIWS project (Resilience for Integrated Water Systems) developed the WSIMOD
(Water Systems Integration Model) and successfully implemented it onto the DAFNI platform, making it available to a wider research community.

WSIMOD simulates the entire water cycle, allowing for comparison of resilience across different water system components, including supply, wastewater, flooding and water timely.

The release of WSIMOD onto DAFNI is timely as, in 2025, the government asked for one of the most comprehensive ever reviews of the UK water system, in the Cunliffe review, which culminated with the Independent Water Commission report published in June 2025.

Key recommendations include the need for water planning to have a coordinated approach based on integrated water systems and that “the UK and Welsh governments should each bring forward a new, long-term, cross-sectoral, and systems-focused National Water Strategy for England and Wales”. Quantitative evidence for coordinated and integrated water planning can be supplied from WSIMOD.

The recommendation that “a comprehensive systems planning framework should be introduced for England and Wales with responsibility for integrated and holistic water system planning” was also highlighted.

What would you identify as the main impact of the work?

The RIWS project has produced WSIMOD, a powerful integrated water systems modelling tool that simulates key processes across the entire terrestrial water cycle, allowing water companies, local governments and researchers to explore complex water system interactions and develop better-informed strategies. WSIMOD provides evidence that natural water systems are suffering due to infrastructure development and system spills and leakages.

This is the first time that a resilience model has been developed at a water systems level.

WSIMOD demonstrates its application and validation for adaptive planning approaches. As the recent Greater London Authority Infrastructure Team’s 2024 paper comments, “Integrated modelling, using WSIMOD in this case, provides the basis for improvements in policy, planning and decision making through the production of numerical system evidence”.

Key challenges that RIWS aims to solve

The team sought to create an integrated water systems model and add to DAFNI in order to create new possibilities for researchers.

An engagement workshop with stakeholders helped to finalise the definition of the
resilience framework before it was applied to the adaptive planning. Input from Thames Water, Mott McDonald, United Utilities and more was key in helping to identify issues.

What were the key aims of the project?

The main aims were to:

• Add technical integrated modelling to the DAFNI platform
• Extend knowledge in the context of resilience by developing integrated resilience
  assessment for both supply and wastewater and bringing them together in a united way.

Included in the project was development of an assessment framework which can be used to inform the future planning of water systems and create a new way of developing adapted planning, using resilience as an indicator.

What did DAFNI allow you to achieve that you couldn’t have achieved otherwise?

Results using analysis from WSIMOD demonstrate the resilience of different parts of the water system, now allowing researchers to directly compare both the supply and wastewater side.

The modelling also provides data on resilience of the water system to flooding as regards river pollution, an area not normally considered in resilience. WSIMOD allows researchers to quantify the resilience of infrastructure systems by measuring nitrate and phosphate levels. In England, this is a significant issue.

“DAFNI is a huge repository of tools, data and models, and having the WSIMOD tool on the platform will allow a much wider community of researchers to access it in an easier way. Researchers can use WSIMOD itself in a standardised implementation on DAFNI, not just a demonstrator.” Dr Ana Mijic, Professor in Water Systems Integration, Imperial College London.

Having the model on the DAFNI platform provides standardised access to the model,
making it more universally accessible for set-up, outputs and downloads than via GitHub.

The main outputs from DAFNI available on RIWS are:

The Water Systems Integration Modelling framework (WSIMOD) is now publicly available and free to use on the DAFNI platform. WSIMOD is a powerful integrated water systems modelling tool that simulates key processes across the entire terrestrial water cycle, including:

• Water supply & demand
• Drainage, wastewater & surface runoff
• Groundwater dynamics
• River flow & water quality

To help users get started, an example model of the Luton catchment is available,
showcasing how WSIMOD can support resilience planning and decision-making under
uncertainty.

Visualisation of the results can also be achieved through DAFNI, thanks to a script on the platform.

How could this work benefit society as a whole?

WSIMOD provides the opportunity for researchers to explore complex water system
interactions and develop better-informed strategies, leading to more available and cheaper drinking water, reduced flooding and overflows, as well as cleaner rivers and lakes.

The model simulates the whole water system and is already being used by city authorities such as the Greater London Authority, Greater Manchester and the Environment Agency.

WSIMOD provides evidence of performance at system level that allows users to see the interactions with stakeholders including local authorities and NGOs, leading to more collaborative decisions.

A key finding is that infrastructure systems have relatively high resilience whilst water quality parameters, especially nutrients, show very low resilience. WSIMOD will allow decision makers to start from the river and work backwards to ensure that the infrastructure is sound and avoids spills and pollution.

How do you anticipate policymakers, researchers and other stakeholders using this work?

Researchers and policymakers will be able to use WSIMOD on DAFNI in combination with other models to analyse interactions and make benchmarking easier.

The model is open source, allowing researchers to further develop it to suit their specific needs.

DAFNI is a collaborative platform, allowing researchers who are geographically disparate to work together more easily online.

Papers published to date are:
1. RIWS: Mijic, Ana, Barnaby Dobson, and Leyang Liu. (2024) “Towards adaptive resilience for the future of integrated water systems planning.” Cambridge Prisms: Water 2 (2024): e11. DOI: https://doi.org/10.1017/wat.2024.9
2. RIWS: Liu, L., & Mijic, A. (2025). Performance-based resilience assessment in integrated water systems: challenges and opportunities. Journal of Hydrology, 134042. https://doi.org/10.1016/j.jhydrol.2025.134042
3. RIWS: Liu, Leyang, Pianosi, Francesca, and Mijic, Ana. (2026). A benchmarking framework for refining decision-making under deep uncertainty approaches to improve planning cost-efficiency. Water Research, Under Review. Journal of Cleaner Production. https://doi.org/10.1016/j.jclepro.2026.147850