Borth to Ynyshir Coastal Adaptation Project

Overview

Darllenwch y dudalen hon yn Gymraeg | Read this page in Welsh

What is this project about?

Climate change and sea level rise will have a significant impact on future flooding in Wales. The standards of protection afforded by coastal infrastructure are reducing, and we must consider the future costs and sustainability of current alignments and standards of protection.

Natural Resources Wales (NRW) and Ceredigion County Council (CCC) are committed to working together to manage future flood risk and are seeking to develop a sustainable plan which highlights interventions that could be undertaken depending on the level of sea level rise observed over 100+ years.  

The Borth to Ynyshir Coastal Adaptation Project is starting to explore a range of possible options going forward. We seek to engage with community members to understand their views and to gather insights from their diverse experiences to inform future planning.

This project forms part of NRW’s wider Coastal Adaptation Programme, designed to work with Risk Management Authorities (such as local authorities) in planning for and funding long-term resilience in areas vulnerable to flooding and coastal change.

Who is Natural Resources Wales?

As Wales’ largest Welsh Government Sponsored Body, ​we work for the people of Wales, and it is our duty to pursue the sustainable management of natural resources (SMNR).

These guiding principles underpin everything we do, including how we use our connections and bring people together to create and deliver shared outcomes for nature and climate. They inform how our colleagues flex and respond to the diverse needs of our communities and the environment, taking a place-focussed approach to our work, applying the sustainable development principle and contributing to the seven well-being goals set out in the Well-being of Future Generations (Wales) Act 2015.

Managing flood risk, coastal change and the sustainable adaptation of people and nature are key parts of that effort. We also manage designated sites within Wales and advise on environmental impacts of development.

Who is Ceredigion County Council?

Ceredigion County Council is the Lead Local Flood Authority, responsible for managing both inland and coastal flood risks across the county. Inland, it oversees surface water, groundwater, and ordinary watercourse flooding, while on the coast it helps maintain sea defences, manage coastal erosion, and deliver protection schemes in partnership with Natural Resources Wales and Welsh Government. The council also develops local flood risk strategies, supports sustainable drainage (SuDS) in new developments, and coordinates emergency planning and community resilience efforts for all types of flooding.

Location

To help assess flood risk and consider future management approaches, we have divided the project area into four compartments (A-D). Each compartment is defined by the boundary of one of the main rivers,  (Afon Leri, Afon Clettwr and Afon Ddu).

What is the problem?

Like many coastal communities, this area is facing the combined challenges of rising sea levels, more frequent extreme storms and deteriorating assets as a result of climate change. These changing conditions are placing growing pressure on existing flood defences and increasing the risk of flooding.

Managing flood risk for people, homes, and infrastructure is a key priority for us which is becoming more challeging in a low-lying landscape with ageing defences, many of which have been breached in recent years.

This issue is shared by partner organisations, stakeholders, landowners and the local community. Sustainable options for managing flood protection and adaptation will be developed through consultation and based on clear evidence and sustainable approaches to managing this challenge.

For the Borth to Ynyshir project area, Welsh Government forecasts a sea level rise of approximately one metre over the next 100 years, based on the UK Climate Projections 2018 RCP8.5 scenario (developed as part of the Met Office Climate Centre).

To understand the impacts of sea level rise, changing weather, and tidal patterns, we have developed a hydraulic model and have undertaken various simulations to calculate current and future flood extents. We have set a baseline scenario as a basis to assess any change in management against. These baseline simulations are referred to as the “Business As Usual Scenario (BAU)” which assumes that existing ongoing maintenance activities are undertaken until the end of the current flood asset lives, and that no further flood risk management approaches will be undertaken thereafter.

The Business As Usual Scenario has been assessed for four time periods (years 2025-2029, 2030-2054, 2055-2074 and 2075-2125).

Our assessments show that a number of existing flood risk management assets are predicted to breach more frequently over the next 100 years.

Our model simulations also show (see figure below) that due to low land levels, much of the project area would be subjected to tidal and fluvial flooding (rivers bursting their banks) during a 1 in 2 yr (50% AEP) storm scenario by 2125. Flood extents are expected to increase gradually between the present day to the year 2125.

The figure above provides a useful understanding of the flood risk, the scale of the future challenge. We will use this to develop flood risk management options and approaches to support communities in the future.

We have also assessed an undefended model scenario with a Mean High Water Springs tide in the present day (2022), and 2122.

This scenario assumes that the flood assets (tidal river and estuary banks, with the exception of the coastal frontage) are removed. Whilst this is a theorectical scenario (as the watercourses and estuary are currently defended) it demonstrates the impact of the removal of defences on possible future flood extents.

How are we seeking to address the problem?

To respond to this challenge, NRW and CCC are aiming to produce an “Adaptive Management Plan”. This is a plan which provides a roadmap with multiple interventions depending on the level of sea level rise observed and the level of protection provided by assets. The sequence of options over the next 100 years will be implemented based on observed sea levels and protection provided by assets are known as ‘adaptive pathways’.

Instead of committing to one fixed solution, an adaptive pathway identifies decision points, often triggered by factors such as observing rising sea levels or increased flood frequency. These decision points allow us to make more informed decisions based on observed data rather than predicted data. This creates a flexible long-term strategy that allows investment to be timed appropriately and ensures the project can respond to future uncertainty. This Adaptive Management Plan will be developed through collaborative working between NRW, CCC, and local and national stakeholders such as those within the water and transport sector.

As part of this project, we will look at opportunities minimise impact and best adapt to the increasing flood risk to this unique and special landscape, e.g. Cors Fochno, Ynyshir Nature Reserve, Ynyslas Dunes. We will explore the wider benefits of amenity, the beach, tourism, and visual landscape, as well as local ecology.

A wide range of suggested adaptation management approaches are currently under development – these overarching approaches will be shared as part of the Spring 2026 Public Consultation.

Whilst we develop this Adaptative Management Plan, NRW and CCC are continuing with our routine day-to-day coastline (CCC) and inland (NRW) flood management, flood warning, and maintenance works.

We will update this page with new information as the project moves forward and you can view previous materials at the bottom of this page.

Project Objectives

The project objectives are summarised above.

Project Stages

This project will appraise flood risk management options in accordance with the HM Treasury Green Book. This guidance defines the process of drafting, developing and assessing options, ultimately reaching a preferred option (or an adaptive pathway for this project). The process is split into a number of stages, which comprise of:

• Drafting a long list of options (and ensuring no option is excluded)
• Refining the long list of options to a short list of options, where options that cannot feasibly be progressed are ruled out
• Undertaking detailed assessments to identify the preferred option.

We want to develop this project alongside the affected communities and relevant stakeholders during each stage of the project. There will be a number of rounds of public consultation to ensure that lived experiences from the community inform the strategies.