Select Page

As you know, Natural Resources Wales, NRW, are trying to tackle flooding in Dinas Powys caused by the River Cadoxton.

We know that properties have been flooded, and for those of us who have ever experienced a flood event in our own home, we understand how devastating this can be.

We also know that as our climate changes, we’re likely to experience higher rainfall and this, in turn, may cause an increase in flooding events in Dinas Powys.  I say, may, because as yet, NRW have not been able to demonstrate categorically that our village will experience the ‘one in one’ hundred event they keep warning us of (with no definition of what this actually is: 1:100 days, years…apples?) that warrants the construction of a dam the size of a football field and 3.5mtrs high, right in the middle of one of the most popular woodland areas in South Wales.

Dinas Powys Woods, our woods, attracts over 55,000 visits per year.  People regularly come from further afield than Dinas Powys and Michaelston.  They bring their dogs, their children, visiting family and friends, and many, me included, often just bring ourselves.  When life really does get a bit too challenging, a walk in those woods, come rain, shine or snow (my favourite) really does rejuvenate the soul.

If a representative of NRW were here today, he’d say that they haven’t yet decided on their ‘preferred option’.  Yet last year they held a community consultation in Dinas library that only presented one option – the dam.  In March of this year, NRW erected a huge notice board at the entrance to the woods, in the car park at the end of Millbrook Road, and the only option presented… the dam.

I had an email a few weeks ago from NRW, from their Projects Officer that only focuses on one solution: yep, you guessed it…the dam!  Any idea that natural flood management might be an option is dismissed out of hand.

Yet, in a Flood Alleviation Scheme options appraisal commissioned by NRW back in 2015, the dam didn’t come out on top.  The impounding of water on Sully Moors, combined with blocking culverts through the disused mineral railway area was costed at some £5.7m and given a Benefit Cost Ratio (BCR) of over 200.  The dam – or Water Storage Reservoir Upstream of Dinas Powys – was given a BRC of 5 and an outline price tag of £7m.  And it isn’t a reservoir – it’ll be flooded when there is too much water flowing down the river and emptied when there isn’t.  It might be flooded for 8 hours, or 24hr… or more.  No one knows.  The site will be closed to any visitors for 24hrs according to NRW, or 6 weeks according to the land owners, The Woodland Trust. This won’t be a puddle in a field: the water will be feet deep.  It’ll drown animals and plants and will flood all the way to Michaelston – it might even cut Michaelston off at certain times.

The trouble is, no one knows. They don’t know how long it’ll rain or how much water will fall.  They’ve used models to forecast, and models and forecasts can be wrong.

We’ve created this problem of climate change; we’ve built on flood plains.  This doesn’t make it right then to just keep cutting down trees and putting in more concrete? 

Stop the Dam in Dinas Powys (and Save Dinas Powys Woods and Protect Homes from Flooding) mission then, is to prevent NRW from building a dam in Dinas Powys that’ll destroy trees, including ancient woodland, and will devastate the ecology of the area to be flooded.

We know that there are other ways to prevent homes in Dinas Powys from flooding and we need your support to help us to persuade NRW that they must look at these other options seriously.

When this all came to light this spring, the cost of the dam had mysteriously dropped to £5m, from the original options appraisal figure of £7m.  It is one of the most expensive flood alleviation scheme currently being considered in Wales on a per home basis, at £24K plus. If the dam comes in at the original £7m, the cost per home will be over £33K – for something that very few of us actually want.

I had another email last week saying that the cost had dropped to £750,000 but they also got the measurements of the woodland to be destroyed wrong by 50% (the wrong way) and said that the dam would be 30m, not the 60m on their own drawings, so I’m taking that figure with a pinch of salt!

And finally, NRW says that there are 252 homes in Dinas Powys that are at medium or high risk of flooding.  But please take note that only 194 homes will be protected by the dam – the rest will still be at risk.


Don’t forget to join our Facebook group: Stop the Dam in Dinas Powys, or follow us on twitter: @stopdinasdam