Flood Risk Management activity in Pentre following Storm Dennis

Written by on 23rd March 2021

Rhondda Cynon Taf Council has provided an update on its Flood Risk Management response and continuing work in Pentre – as the village was one of the worst-hit areas during Storm Dennis and other subsequent storm events last year.

In February 2020, Storm Dennis saw record rainfall and caused record river levels and flows as Rhondda Cynon Taf saw its most significant flooding since the 1970s – with 1,476 properties internally flooded across the County Borough. It was one of four storms which took place in quick succession up to March 1, which also included Storm Ciara, an unnamed storm (February 21-24) and Storm Jorge.

On the one-year anniversary of Storm Dennis, Welsh Government announced £4.4m extra funding for Rhondda Cynon Taf, to help with the continued and ongoing effort to fix highways, bridges, culverts and retaining walls. Pentre was one of the worst-hit areas, and below is a summary of the Council’s significant activity in the village, including its response throughout the year and ongoing work today. 

  • Responded to 18 individual storm events, providing additional resources on each occasion to support residents, including through the proactive delivery of sandbags. Two standby pumps were provided for use over the winter, pre-empting poor weather at that time of year.
  • Investigated around 380 reports of flooding, which were among approximately 2,500 reports from across Rhondda Cynon Taf last year.
  • Surveyed around 3.2km of ordinary watercourses and 5.5km of surface water drainage infrastructure. This has been mapped and reviewed, resulting in targeted cleansing and repairs. Around 600 tonnes of debris have since been cleared from assets following Storm Dennis.
  • Continuing significant work at the Pentre Road inlet – this major work started on site in September 2020. It is installing a new culvert inlet, debris basin and multi overflow system following storm damage, to significantly reduce the local flood risk.
  • Continuing a flood routing scheme at Pleasant Street – on site works continue to upgrade the culverted ordinary watercourse infrastructure in the adjacent park by constructing a large catchpit manhole, to reduce the risk of debris blocking the culvert.
  • Completed overflow works at Lewis Street, which have constructed a high-level overflow to increase the capacity of the highway drainage infrastructure in collaboration with Dwr Cymru Welsh Water.
  • Completed repairs to existing ordinary watercourse manholes at several locations, following the identification of storm damage.
  • Progressing a future scheme to improve the Volunteer Street pumping station, with design work ongoing. The scheme will improve the efficiency of the system, with construction approved for 2021/22.
  • Progressing the future Nant y Pentre scheme, which is being designed to facilitate an Overland Flow control route. This will mitigate flows generated by ordinary watercourse manholes within the Lower Pentre area, with construction proposed again for 2021/22.
  • Progressing a business case for the Pentre Flood Alleviation Scheme, which would mitigate flood risk in the community, working closely with Natural Resources Wales and Dwr Cymru Welsh Water to fully understand and address the risks.
  • Progressing a business case for the Upper Rhondda Strategic Flood Risk Area, which will include a pilot project to identify and complete a number of further ‘quick win’ schemes to manage the local flood risk.
  • Continuing to develop a pilot study for Property Flood Resilience within the Upper Rhondda Fawr, which aims to better understand the full benefit of flood risk measures and suitable delivery mechanisms.

Councillor Andrew Morgan, Leader of Rhondda Cynon Taf Council and Cabinet Member with responsibility for Highways and Transportation, said: “On the anniversary of Storm Dennis on February 16, the Council provided an update on its significant response and huge continuing efforts to repair infrastructure damage across the County Borough – and this second update focuses on Pentre, which had multiple flooding incidents across several storm events throughout 2020. As a result, works activity in key locations including Pentre have been prioritised.

“Major work at Pentre Road to install a new culvert system and remote monitoring equipment is continuing. Also, an important flood routing scheme continues at Pleasant Street, with overflow works delivered at Lewis Street. In 2021/22, four future schemes will be progressed – including the replacement of the pumping station at Volunteer Street.

“Of the 2,500 reports of flooding the Council received last year, more than 380 of them were in Pentre alone – with Council Officers investigating each one. The update also confirms that 600 tonnes of debris has been removed from local assets in Pentre since Storm Dennis, identified through inspections of almost 9km across watercourses and surface water drainage infrastructure. 

“The Council has made it clear that the effects of Storm Dennis would be felt for years to come, and it remains committed to seeking funding for, and carrying out, infrastructure repairs in communities. It is also committed to making sure we are all better prepared for future storm events by working towards implementing the 11 recommendations agreed by Cabinet in September 2020.

“Key actions have been carried out as a result, including a Flood Risk Management consultation so we can better understand the historical patterns of flooding in our communities, and the setting up of a dedicated multi-partner control room for use during future storms to monitor and react quickly.”


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