25/11/2025
Yesterday I met with the County Councillors from St Clears. There were discussions on our flood areas, pinch points and 𝗱𝗿𝗲𝗱𝗴𝗶𝗻𝗴.
The County Council are planning to undertake a 𝗦𝗲𝗰𝘁𝗶𝗼𝗻 𝟭𝟵 which involves hydrology experts. They will want to meet local people who flooded and map problem areas. After the 1986 floods there were flood defences created for Whitland. In 1996 the new by pass had attenuation ponds and culverts with shutters to control water flow and pollutants built into the construction. A large part of the town did not flood this time as a result of these defences.
Remembering the time the water entered your home and from which direction will be of help to the hydrologists. For some I have visited it has been front, back, from the neighbours side and even from under the floor.
I will leave it to the experts to come up with flood mitigation schemes. These will involve other areas. A pinch point in St Clears may impact Whitland. Fast flow through Login, for example, may impact Henllanfallteg and then Whitland. As for Dredging this overview might be of interest
𝗗𝗿𝗲𝗱𝗴𝗶𝗻𝗴 can help in some situations, but it is not a reliable or long-term solution on its own. Flood experts and agencies often describe it as something that may help locally, but with clear limits.
𝗪𝗵𝗲𝗿𝗲 𝗱𝗿𝗲𝗱𝗴𝗶𝗻𝗴 𝗰𝗮𝗻 𝗵𝗲𝗹𝗽
▪️It increases the depth of a channel, so more water can pass through a narrow pinch point.
▪️It may reduce flooding right next to the dredged section, especially where a river has become silted up.
▪️It can help improve flow where bridges or culverts slow the river.
𝗪𝗵𝗲𝗿𝗲 𝗱𝗿𝗲𝗱𝗴𝗶𝗻𝗴 𝗱𝗼𝗲𝘀𝗻’𝘁 𝗵𝗲𝗹𝗽 𝗺𝘂𝗰𝗵
▪️In very heavy rainfall, the volume of water is far greater than what dredging can handle. A river can fill to capacity again within hours.
▪️Dredging one stretch does nothing if downstream bottlenecks remain.
▪️It can sometimes increase flow speed, pushing floodwater into towns downstream faster.
▪️It often needs repeated work — silt returns quickly.
𝗪𝗵𝗮𝘁 𝘁𝗲𝗻𝗱𝘀 𝘁𝗼 𝘄𝗼𝗿𝗸 𝗯𝗲𝘁𝘁𝗲𝗿
Modern flood strategies mix several tools:
▪️Natural flood management (slowing flow upstream, planting, wetlands).
▪️Maintaining culverts and drains.
▪️Flood storage areas that hold water temporarily.
▪️Defences such as walls or embankments in built-up areas.
▪️Planning rules to avoid building on floodplains.
𝗧𝗵𝗲 𝗼𝘃𝗲𝗿𝗮𝗹𝗹 𝗽𝗶𝗰𝘁𝘂𝗿𝗲
Dredging is not useless — it can help a bit in the right place — but it is rarely the main answer. Most agencies view it as one tool among many, not a cure for large-scale flooding.
The 𝗥𝗶𝘃𝗲𝗿 𝗧𝗮𝗳 is a classic West Wales catchment: steep-sided upper valleys, fast run-off in heavy rain, and narrow channels running through small towns like Whitland, St Clears and Laugharne. Those features make dredging only partially useful.
Here’s how dredging affects a river like the 𝗧𝗮𝗳:
𝗪𝗵𝗲𝗿𝗲 𝗱𝗿𝗲𝗱𝗴𝗶𝗻𝗴 𝗰𝗮𝗻 𝗵𝗲𝗹𝗽 𝗼𝗻 𝘁𝗵𝗲 𝗥𝗶𝘃𝗲𝗿 𝗧𝗮𝗳
▪️At tight choke points – for example, where bridges or culverts restrict the flow. Deepening or clearing those sections can stop water backing up locally.
▪️Where silt builds up naturally – tidal sections near St Clears and Laugharne can accumulate sand and silt; removing it may improve flow during moderate floods.
▪️Short-term reduction in localised overflow – immediately adjacent properties may see some benefit.
𝗪𝗵𝗲𝗿𝗲 𝗱𝗿𝗲𝗱𝗴𝗶𝗻𝗴 𝗱𝗼𝗲𝘀𝗻’𝘁 𝗵𝗲𝗹𝗽 𝗺𝘂𝗰𝗵 𝗼𝗻 𝘁𝗵𝗲 𝗧𝗮𝗳
1. 𝗧𝗵𝗲 𝗧𝗮𝗳 𝗿𝗲𝘀𝗽𝗼𝗻𝗱𝘀 𝘃𝗲𝗿𝘆 𝗿𝗮𝗽𝗶𝗱𝗹𝘆 𝘁𝗼 𝗿𝗮𝗶𝗻𝗳𝗮𝗹𝗹
Heavy rainfall from the Preseli, Llanfihangel, Llangynin and Crymych areas creates a huge surge of water. No amount of dredging can create enough extra capacity to contain that surge — the volume is simply too large.
2. 𝗙𝗮𝘀𝘁-𝗺𝗼𝘃𝗶𝗻𝗴 𝘄𝗮𝘁𝗲𝗿 𝗿𝗲𝗳𝗶𝗹𝗹𝘀 𝗱𝗿𝗲𝗱𝗴𝗲𝗱 𝘀𝗲𝗰𝘁𝗶𝗼𝗻𝘀 𝗾𝘂𝗶𝗰𝗸𝗹𝘆
The Taf carries a lot of sediment. Even after dredging, the river will naturally re-deposit gravel and silt, often within a year or two, especially around bends.
3. 𝗗𝗼𝘄𝗻𝘀𝘁𝗿𝗲𝗮𝗺 𝗿𝗲𝘀𝘁𝗿𝗶𝗰𝘁𝗶𝗼𝗻𝘀 𝗿𝗲𝗺𝗮𝗶𝗻
If the lower Taf near St Clears is still a bottleneck (tidal influence, narrow bridges), dredging upstream doesn’t solve the problem — the water just hits the next obstacle.
4. 𝗜𝘁 𝗰𝗮𝗻 𝘀𝗵𝗶𝗳𝘁 𝘁𝗵𝗲 𝗽𝗿𝗼𝗯𝗹𝗲𝗺 𝗲𝗹𝘀𝗲𝘄𝗵𝗲𝗿𝗲
Dredging increases flow speed. In a river like the Taf, this can push floodwater into downstream settlements more quickly.
𝗪𝗵𝗮𝘁 𝘁𝗲𝗻𝗱𝘀 𝘁𝗼 𝘄𝗼𝗿𝗸 𝗯𝗲𝘁𝘁𝗲𝗿 𝗼𝗻 𝘁𝗵𝗲 𝗧𝗮𝗳
Flood specialists usually look at a combination of measures:
▪️Upstream flow management
Blocking gullies, restoring wetlands and slowing run-off in the upper catchment can make a big difference.
▪️Maintenance of culverts and drains
Many flood events in West Wales are worsened by blocked culverts rather than the main channel itself.
▪️Floodplain storage areas
Temporary holding areas upstream of towns can absorb peak flows during storm events.
▪️Better forecasting and warning systems
Especially important in fast-responding catchments like the Taf
𝗢𝘃𝗲𝗿𝗮𝗹𝗹
For the River Taf, dredging might offer small, very local improvements, but it cannot prevent major flooding caused by extreme rainfall and fast run-off. Most of the flood risk comes from the sheer volume and speed of water coming down the catchment, not from lack of channel depth.
𝗧𝗼 𝗴𝗲𝘁 𝘁𝗵𝗲 𝗿𝗶𝗴𝗵𝘁 𝘁𝗵𝗶𝗻𝗴𝘀 𝗿𝗶𝗴𝗵𝘁 𝘄𝗶𝗹𝗹 𝗻𝗲𝗲𝗱 𝘆𝗼𝘂𝗿 𝗶𝗻𝗽𝘂𝘁 𝗮𝗻𝗱 𝘀𝘂𝗽𝗽𝗼𝗿𝘁.
