Floods are one of the most common environmental emergencies; with widespread and long-lasting health, environmental and financial impacts affecting homes and businesses and can significantly disrupt the normal functioning of whole communities.

The latest government reports (both UK and Wales) have identified flooding and coastal change risks to homes, communities, businesses and infrastructure as being one of the top areas of climate change risks. It is now generally accepted that future river and surface water flooding and coastal inundation from climate change impacts are a major high-level risk and that despite progress with flood defences, it is unlikely that we will ever be able to fully manage and mitigate against all events.

Over 34,000 properties in the Conwy and Denbighshire PSB area are currently at some level of flood risk; this number is almost certain to increase as climate change accelerates.

Flood risk management is driven strategically by Welsh Government’s National flood and coastal erosion risk management strategy in Wales. The principal aim is to reduce the risk to people and communities from flooding and coastal erosion, using five strategic objectives:

1. Improve our understanding and communication of risk
2. Preparedness and building resilience
3. Prioritising investment to most at risk communities
4. Preventing more people becoming exposed to risk
5. Providing an effective and sustained response to events

Flood Risk Management responsibilities

Flood Risk Management in Wales involves a number of organisations, termed Risk Management Authorities (RMAs).

• Natural Resources Wales (NRW) is responsible for managing flood risk from main rivers and the sea. It also has a strategic oversight and general supervision role in terms of having a Wales-wide understanding of all sources of flooding and as part of this role are responsible for providing advice and information to the other RMAs through their forecasting, warning and mapping activities.
• Conwy and Denbighshire Local Authorities as Lead Local Flood Authorities (LLFA) are responsible for managing flood risk from surface water, groundwater and from smaller streams called ordinary watercourses. They also manage drainage of local highways under the Highways Act. They have powers under the Coast Protection Act to carry out work to manage coastal flood and erosion risk.
• Water companies operating in Wales have operational responsibility for drainage via public sewers (foul, surface-water and/or combined).
• The Welsh Government, as the highway authority for trunk roads, has a responsibility for trunk road drainage under the Highways Act.

Impacts of flooding

Flooding and coastal erosion can have a variety of consequences and impacts, not only on well-being but wider economic, environmental and social factors.^[1] The 2020 floods were a stark reminder of the devastating consequences of intense rainfall events. However, even modest flooding events can significantly impact homes, businesses, key infrastructure and whole communities.

All types of flooding carry a risk to life.^[2] Short term physical health impacts are usually due to injuries, infections, exposure to chemical and sewage hazards and the disruption to the delivery of health and social care services along with other key services such as water and energy. A study by Public Health England recorded a significant association between the experience of flood damage and symptoms of depression, anxiety and post-traumatic stress.^[3] Displacement during repairs is likely to increases the impact on mental well-being and it was also shown that those not flooded but disrupted through such as lack of access to work, schooling and services, particularly health and social care, were  also likely to experience poor mental health conditions. These effects can continue for many years after the actual flooding.

From a health perspective, quite often the worst affected are the more vulnerable in society. A 2017 report for Joseph Rowntree Foundation found that socially vulnerable neighbourhoods are over-represented in areas prone to flooding, but most significantly in areas prone to coastal and tidal flooding.^[4] Certain parts of society are less able to cope with the effects of flooding and impacts are often distributed unequally with the greatest burdens generally falling on the most vulnerable and disproportionately borne by marginalised households.

Flooding of infrastructure, primarily road and rail networks, can be costly both in terms of repairs and the disruption to businesses; employees may not be able to access the workplace along with delayed movement of goods. Disrupted transport routes also affects people’s access to education, shops and health services; rural communities can be particularly vulnerable where there is often a large dependency on access.

Current flood risk in Conwy and Denbighshire

Properties at risk – In Conwy there are a total number 19,607 properties at risk of flooding from rivers, tidal and surface water sources, where properties include residential and non-residential. Highest number of properties being associated with tidal flooding 9,822 and 5,458 at river flood risk and 4,387 at risk from surface water flooding.

Denbighshire is shown to have 8,320 properties at tidal risk, 3,097 properties at risk from rivers and 3,776 properties at risk from surface water flooding, which totals 15,193 properties at risk within Local Authority boundary and present day defended risk.

These properties at risk figures are based on FRAW (Flood Risk Assessment Wales) , which is national modelling dataset and does not take account of local detailed modelling studies/evidence or the impact of climate change.

Communities at risk register – NRW has developed the Communities at Risk Register (CaRR) to identify the locations of greatest risk of flooding from all sources (Table 1). These combined rankings include all three tidal/fluvial and surface water sources of flooding without presence of defences.

Table 1 Combined Communities at Risk Register (CaRR) rankings for Conwy and Denbighshire. These combined rankings include all three tidal/fluvial and surface water sources of flooding without presence of defences. Bold type is significant flood risk areas as identified by Preliminary Flood Risk Areas 2018

Coastal/tidal flood risk –There are significant flood risk areas along the North Wales Coastline in both Conwy (Kinmel Bay, Towyn and Abergele) and Denbighshire (Rhyl and Prestatyn) as identified by the Preliminary Flood Risk Assessment 2018.

Climate change impacts such as sea level rise and more frequent and serious storms within the coastal zone will exacerbate the exposure of the coast to flooding and coastal erosion; and will increase the risk to the coastal assets and the costs to maintain them to acceptable standards.

Shoreline Management Plan 2 (SMPs) – SMPs look at how the coast is managed from a flood and coastal erosion risk management perspective in the face of climate change and other pressures to determine sustainable coastal management policies. They set out where defence of the coastline should continue and where it would be more sustainable to adapt over time. The coastline is split into sections known as ‘policy units’ that will be assigned 1 of 3 management policies for each of 3 time periods or epochs.

Conwy and Denbighshire have a number of areas where coastal adaptation is identified/required by policy change areas in the Shoreline Management Plans and Action Plans which are managed by the Coastal Forums.   In Epoch 1 (2005 – 2025) all units in Conwy and Denbighshire are managed under policy Hold the line (HTL) by maintaining or changing the existing standard of protection.

There are planned policy unit changes from 2025 (Epoch 2 2025 – 2055) for the following units, all of will move from Hold the Line to Managed Realignment (MR) which allows the shoreline to move backwards and forwards, with management to control or limit the movement.

Conwy – Tal Y Cafn; Tal-y-Cafn to Llanrwst

Conwy and Denbighshire – Forydd Railway Bridge to Rhuddlan Road Bridge Clwyd Estuary west (left) bank

Denbighshire –  Rhuddlan Road Bridge to Forydd Railway Bridge Clwyd estuary East (right) bank

Community flood plans

Through local community engagement campaigns, communities at risk of flooding have been encouraged to produce their own Community Flood Plans. The plans are voluntary, community lead and supported by NRW.  Plans exist for communities in Trefriw, Betws y Coed, Llanddulas, Splash Point Rhyl, Talacre, Ruthin and St.Asaph.

Flood risk management activities in Conwy and Denbighshire

NRW conducts routine maintenance activities of the assets that it manages; these typically take place annually. There is also a programme for replacement and improvement such as outfall and embankment repairs and flood gate replacement; these and larger works (that may span several years) are part of a rolling programme reliant on capital funding.

There are a number of communities in Conwy and Denbighshire which benefit from existing flood defences and investment from Welsh Government capital funding.

In Llanwrst and the Afon Conwy, NRW delivered a £7 million pound flood alleviation scheme in 2009-10 as a result of the flooding experiences in 2004 and 2005, where over 40 homes and business were flooded. This scheme involved a combination of flood walls, lowered spillways and on adjacent agricultural flood embankments and demountable defences. There is an existing flood warning system in place for the Afon Conwy in Llanwrst and Trefriw. There is also a North Wales Coastline flood service for potential tidal flooding.

In Llanfair TH and Nant Barrog catchment, which is part of the larger Elwy and Clwyd catchment, NRW are working on final phases of a flood alleviation project and Natural Flood Management project to help manage the residual fluvial flood risks to the community in the longer term.

NRW recent investment with improvements to the St Asaph (Afon Elwy) from £6 million pound  flood investment scheme completed in 2018 helped protect hundreds of properties during the storm events of Ciara and Dennis in 2020, which without the scheme up to 370 properties would have been at risk from serious flooding, as experienced in 2012.

There is an Elwy and Gele catchment flood alert system from Gwytherin to St.Asaph and including Abergele and registration is open to individual properties from the NRW website and residents can also check their local flood risk using postcode checker. Different levels of alerts have different meanings and actions required.

NRW has a number of ongoing flood risk capital and maintenance projects in Clwyd, including Tidal Clwyd, Rhyl and Prestatyn, Gele, Ruthin.

Denbighshire County Council has carried out flood risk management schemes at Ruthin, Llangollen, Corwen, Gwyddelwern, Denbigh and St Asaph, which reduces flood risk for 1,350 properties at a cost of around £16m. There are further schemes proposed at Dyserth and Rhyl (Ffordd Derwen). Denbighshire County Council has also carried out coastal defence schemes at West Rhyl, which reduces flood risk for 2,000 properties at a cost of £13m, and at East Rhyl, which reduces flood risk for 1,800 properties at a cost of £27m. There are further coastal defence schemes in development for Central Rhyl and Central Prestatyn.

Conwy Council are currently investing in improvements to coastal defences from Llanfairfechan to Kinmel Bay to reduce the future flood risk. Additionally, rural communities have benefitted from the completion of flood alleviation works at Llanrwst and Mochdre whilst other schemes are planned at Llansannan, Penmaenmawr, Dolwyddelan and Betws Y Coed.

Not all flood risks can be removed and there are communities which remain at risk despite the presence of defences. Conwy and Denbighshire have a significant number of existing communities at existing flood risk, which could experience increased frequency to flooding events in the future from the impacts of climate change.

[1] The National Strategy for Flood and Coastal Erosion Risk Management in Wales. Welsh Government October 2020

[2] The National Strategy for Flood and Coastal Erosion Risk Management in Wales. Welsh Government October 2020

[3] The English National Study for Flooding and Health: First year report. PHE Publications gateway number 2016575. CC 2017

[4] Present and future flood vulnerability, risk and disadvantage: A UK assessment, Sayers, P., Penning-Rowsell, E., Horritt, M. (2017).