In an Expert Focus article for WaterBriefing, as the water sector in England and Wales enters a pivotal phase, Louise Ellis, Water Strategy, Regulation & Asset Management at Arup takes a look at the need for a whole system transformation - and how regional systems planning could be the missing link between national reform and catchment-based delivery.

Louise Ellis: The water sector in England and Wales is entering a pivotal phase with the Independent Water Commission providing much needed impetus and framing for a whole system transformation. Expectations are rising for cleaner rivers, resilient water supplies, reduced flood risk and healthier catchments, all to be delivered while keeping bills affordable and enabling growth.

It will take more than individual asset programmes. A coordinated, catchment-based action that connects water resources, wastewater, surface water, land use, nature recovery and wider infrastructure planning is essential.

The Independent Water Commission’s third recommendation last year calls for stronger regional, place-based coordination, a principle supported by the ambitions set out in the Water White Paper. The recommendation builds on a long called for resolution to the “missing middle”.

Could regional systems planning be the missing link?

Regional systems planning can be the missing link between national reform and catchment-based delivery, converging national ambition and catchment reality to ensure the greatest pressures are addressed in collaboration with local stakeholders. Catchment based delivery is key to unlocking nature recovery and supporting socio-economic ambitions.

By aligning evidence, priorities and investment decisions from the ground up as well as top down, regional systems planning provides the practical coordination mechanism to translate these national reforms into delivery at catchment level.

Why regional systems planning matters

Regional systems planning should remain central to the sector’s transition because it closes the gap between policy and the outcomes that communities care about. National targets set direction, but they do not resolve the on-the-ground trade-offs, such as where to prioritise drought resilience versus environmental improvement, where to target investment, or how to balance catchment interventions with built solutions.

A credible regional systems planner can provide shared evidence base and assumptions and convene partners to work through these decisions to target investment transparently and effectively towards local priorities.

Catchment-based approaches must be at the heart of planning to deliver resilience and long-term interventions that deliver multiple benefits, from water quality and biodiversity to social value and climate adaptation.

Workshops held by Arup, Ferns and the Rivers Trust with more than 20 water sector stakeholders, and the Department for Environment and Rural Affairs, highlighted practical design principles for an effective Regional Systems Planner and next steps for industry.

Discussions focused on two pragmatic questions: what is the minimum viable product to start delivering value, and what might an ideal future model look like as capabilities, data and governance mature? The message was consistent: start with a clear, useful core, and build from there.

Success factors for a regional systems planner

To maximise the chances of success, regional systems planning should not aim for perfection from the outset. Instead, it should establish a clear and workable core that can evolve over time, as early pioneers in the sector are already demonstrating. Their experience shows the value of focusing on clarity of purpose, a repeatable planning cycle and transparent decision making, rather than attempting to model every interaction from day one.

As this core takes shape, the importance of clearly defining scope and boundaries becomes apparent. Questions around whether the remit extends into flooding and surface water, and how the planner connects with Lead Local Flood Authorities and existing partnerships, need to be resolved early to avoid duplication and confusion. The same applies to interfaces, where clarity on who is responsible for decisions, who provides advice and how funding flows is just as important as the underlying technical analysis.

What ultimately determines the value of regional systems planning, however, is the extent to which it is connected to real decisions. Its role is not simply to coordinate evidence, but to shape investment sequencing, inform option selection and align priorities across organisations. This in turn requires a clear line of sight to funding and financing mechanisms, so that outputs translate into programmes that can be implemented rather than remaining theoretical.

In practice, demonstrating this value is best achieved through application rather than design alone, with well-designed regional pilots and Defra convened pioneer models offering a way to test governance, data sharing and planning approaches in live conditions. These pilots help build confidence among stakeholders while generating lessons that can be applied more widely.

Across all of this, trust and transparency remain critical. The case for regional systems planning is not only one of efficiency, but also of legitimacy, and making trade-offs visible and evidence led helps ensure that decisions are understood, investment is directed to the right places and confidence is built among partners and communities.

Combined, these insights point to a minimum viable product focused on convening, coordination and a few high-value outputs. These include a shared regional evidence base, a regional plan with clear outcomes and priorities, an options framework to compare nature-based, demand-side and engineered interventions and a transparent process for resolving conflicts and recommending trade-offs.

Over time, the model can deepen with better scenario analysis, wider datasets, stronger links to funding decisions and broader participation, while keeping the core simple and trusted.

Taking the next steps

Turning intent into capability requires locking in the mandate by agreeing the outcomes, the decisions the planner will shape, and what happens when partners disagree. Momentum should then be built through a small number of pilots which directly influence live programmes across capital, catchment and operational. The aim is to demonstrate how regional planning can change real investment decisions rather than generate further analysis

However, this only works if the evidence base is shared early and openly. Common data, common assumptions and clear uncertainty will reduce the time spent debating inputs, allowing partners to focus on choosing the right options. At the same time, regional systems planning must be embedded into consistent ways of working. Aligning planning cycles with statutory plans and AMP delivery will ensure outputs translate into funded activity.

Importantly, delivery will depend as much on capability as it does on frameworks. Resourcing facilitation, governance, engagement and systems thinking across organisations and the supply chain is essential if planning is to move at pace and retain credibility. Meanwhile, trust must be earned in public through showing the trade-offs, publishing the rationale and tracking outcomes to evidence that regional planning is speeding up delivery and raising performance.

Taken together, these steps move regional systems planning from concept to capability. The opportunity now is to act quickly, test what works and scale with confidence, so that national ambition is translated into measurable outcomes at a catchment level.