Llanfair Talhaiarn flood risk management
Read the latest updates here
Latest update (January 2021) on actions following the February 2020 flooding
Due to the coronavirus pandemic, we have been unable to hold a drop-in session in Llanfair Talhaiarn to discuss flooding issues.
In the meantime, we are in regular contact with Llanfair Talhaiarn community council and provide regular updates on our work to help reduce flood risk in the village.
This is the latest update on our work, provided to the community council for their meeting on 19 January 2021.
We hope this helps keep you informed in these challenging times, before we can return to discuss matters with you face-to-face once again.
We are currently considering Conwy County Borough Council (CCBC)’s recently issued Flood Investigation Report and will review its recommendations. We will consult with the community and our partner organisations including CCBC to agree a way forward in addressing the recommendations.
Please forward your comments or any questions via email to: Flood.Risk.Llanfairtalhaiarn@naturalresourceswales.gov.uk
Llanfair Talhaiarn Post Floods Action Plan
- A number of actions have already been completed – these were detailed in our November 2020 update and are not referenced here.
- We have made improvements to the camera, which contributes to monitoring the river, upstream of the culvert. Also, an additional camera has been installed at the gravel trap area.
- We continue to look into the possibility of adding Nant Barrog river level data to NRW’s River Levels Online, found on the NRW website.
- We are working with the volunteer Flood Warden Group to update Llanfair Talhaiarn’s Community Flood Plan, including sharing information to residents about the Early Warning Service.
- We are reviewing the longer-term requirements for the debris screen at Capel Soar. As a short-term measure, we have adapted the current screen to reduce the risk of blockage. This involved removing some of the bars, to allow smaller debris to travel through the culvert. Larger debris, seen less often, will still be collected and cleared by NRW staff at the screen. The adapted screen is being monitored closely and being inspected regularly.
- A study to review property protection to homeowners at risk of flooding (such as flood boards) will be commissioned in the next month, subject to COVID restrictions.
- We continue to work on the potential for Natural Flood Management works. This means using natural solutions, such as planting trees or leaky dams, to help reduce the flow of the water upstream. Coed Cymru (CC) has started a project, fencing and planting trees in upstream areas. NRW will continue to work with Coed Cymru whilst progressing our own investigation and continuing to look if storing water upstream can play a part.
- A review of the Elwy flood embankment (School Lane area flooding) is nearing completion.
Medium Term Actions (Autumn 2020 – Winter 2021)
- We are working closely with the community council to develop a Catchment Wide Flood Partnership Group for the Nant Barrog. This is progressing well, despite COVID restrictions. We hope the group can be in place for the Spring.
- We are exploring options for providing a full Flood Warning Service on Nant Barrog for Llanfair Talhaiarn.
- We are reviewing the Elwy Weir’s impact on flood risk.
- We are reviewing the performance of the coarse debris screen (knows as the tree catcher) and will move ahead with improvements later this year if deemed necessary.
- Land between the culvert inlet and the tree catcher is being cleared to reduce the risk of blockage. This will hopefully be subject to a management plan with landowners to reduce blockage risk in the future.
- We will review the flood risk management scheme, (works adjacent to Capel Soar), in light of the flood investigation report - and confirm what will be delivered later this year, (Spring/Summer).
Long Term actions (January 2022 – December 2025)
- We will work with and contribute to the Flood Partnership Group once it is established.
- We will continue to monitor and review the long-term performance of the gravel trap, upstream of Capel Soar.
- There will be on-going work to manage the river catchment upstream, and further options explored for natural flood risk management.
If members of the community have not yet registered for the early warning service, you can do so by contacting Gwenno Talfryn on 07811023377.
We must remember that as climate change intensifies, we will experience more extreme weather events, including intense wet periods such as those experienced last winter. This makes flood risk management an increasing challenge for the years ahead.
You will also find answers to lots of questions here.
You can also discuss matters with:
Conwy County Borough Councillor Ifor Lloyd firstname.lastname@example.org
Senior Flood Warden, Julie Elliott
Phone: 01745 720 255 or 07789 965. Email: email@example.com
Assistant Flood Warden, Karen Minor
Phone: 01745 720 513 or 07919 458 835 Email:firstname.lastname@example.org
Update following Storm Christoph, 20 January 2021
As with all storm events, NRW is now reviewing what happened before, during and after Storm Christoph.
Initial information indicates that it was a significant weather event with very high rainfall. There was a real flooding risk to the community of Llanfair Talhaiarn again.
NRW officers were on site during the event, monitoring the situation and on hand to deal with issues as required.
The changes to Capel Soar screen, completed in 2019, had a positive impact on the flow of water down the culvert, allowing small debris to pass through, and reducing the risk of blockages.
We will continue to monitor this before we decide on the long-term design of the screen structure.
We also believe that the work in 2018, which increased the capacity of Water Street culvert, played its part in carrying the water faster through the culvert.
The upstream coarse screen was partially blocked with woodland debris, as expected and designed. Gravel was also deposited upstream. We have now cleared this area and will continue to monitor the performance of this screen also.
The flows in the Elwy were very high and we are aware that there was concern about School Lane becoming a flood route as the river came out of bank. This is being investigated.
We are aware of surface water flooding issues that occurred and will assist our colleagues in Conwy County Borough Council to investigate this as required.
Unfortunately, the impact of Storm Christoph demonstrates the challenges of a changing climate and the ongoing risk to the community.
We must remember that as climate change intensifies, we will experience more extreme weather events, including intense wet periods as we are currently experiencing. This makes flood risk management an increasing challenge for the years ahead.
Following Storm Christoph, catchments across north Wales remain wet and very sensitive to rainfall. This means, in the short term, many rivers may respond more quickly in response to small rainfall events.
We hope that the Community Catchment Flood Group, that is being developed, will further enable the community and public bodies to work together to address flooding issues, reduce flooding impact and become more resilient.
NRW is eager to get as much information as possible regarding the Storm Christoph event. If you have any comments or feedback/info/photos of flooding or flood related issues please forward to NRW via: Flood.Risk.Llanfairtalhaiarn@naturalresourceswales.gov.uk
Background (where we were before Storm Ciara March 2020)
November 2012 saw flooding to the village of Llanfair Talhaiarn (TH) when the Nant Barrog, swollen by extreme rainfall, overwhelmed the Water Street culvert and flooded 19 homes and businesses.
This followed previous flooding in the village, during April 2012 along with numerous other reported incidents in the past 50 years.
Based on modelling, the November 2012 flood was estimated to have had a two percent chance of happening in any given year.
But, as evidenced by the frequency of flooding incidents in the village, in 2012 Llanfair TH was actually thought be at risk from floods on the Nant Barrog with a four percent chance of happening in any given year, due to overwhelming the Water Street culvert.
This risk of flooding is exacerbated by blockage of the trash screen, across the inlet of the Water Street culvert.
The River Elwy flows along the northern edge of the village. The November 2012 flood on the Elwy was reported as being between a one percent and two percent chance of happening in any given year. Existing flood defences protected Llanfair TH from further flooding from the Elwy during November 2012 - the village was solely affected by flows on the Nant Barrog.
Developing a flood risk management scheme
Since the 2012 flood events, we've been undertaking work in the village to improve resilience to flood risk and reduce the risk.
In 2016, we completed an appraisal of the flood risk, to assess the flood risk and came up with proposals to further reduce this risk.
The flood risk management scheme improves the capacity of the Water Street culvert.
Once completed, it will also improve the performance of the trash screen and we will investigate options to make improvements upstream to protect the village against flooding.
The flood scheme currently proposed will provide the village with protection of one percent chance of flooding from the Nant Barrog happening in any given year, once completed. It will also mean that the debris screen will be easier to manage and will not be as sensitive to blockage as the existing screen.
The construction of the flood risk management scheme is phased, with Phase 1 completed in January 2019, increasing the capacity of the culvert to being able to carry flows equivalent to 1.33 percent chance of flooding happening in any given year.
Phase 2 is planned for later this year, 2020 subject to obtaining planning and other permissions and review following the 9th Feb.2020 floods.
Phase 1 works involved improving a key upstream section of the Nant Barrog Water Street Culvert and The Black Lion Nant Barrog Culvert section. We have removed the old culvert sections at these locations and replaced them with larger sections. We also did work to seal the culvert throughout its length.
NRW is grateful to the residents for their support and understanding throughout Phase 1.
This work improved the capacity of the culvert and it is now able to accommodate increased flows, giving the village a 1.33 percent flood risk in any given year.
There is still a risk posed by the existing debris screen. NRW officers attend the site during high flow/heavy rainfall events but the current screen is difficult to maintain and keep clear of debris.
Phase 2 works, as currently designed (to be reviewed), will involve improving the existing debris screen arrangement at Capel Soar. A new, additional, wider debris screen is proposed. Walls will also be constructed to keep more water within the channel to drive it through the culvert to optimise its capacity. We have considered all options to ensure that we come up with the most suitable and sustainable solution. However we will review plans after the February 2020 floods.
The flood scheme will be supported by work upstream to manage the peak flow of water through the village by using natural flood management methods, by working with partner organisations.
NRW is hoping to work with Coed Cymru to look at natural solutions including planting hedges and creating natural barriers to the flow of the water upstream.
We will hold a further consultation event in the village before the next stage of works.