How green are our valleys? The wildlife of abandoned spoil tips
We have mixed feelings about our coal tips – part industrial legacy, part looming threat. But experts are finding rare insects, plants and animals in these untouched landscapes, writes Kit Habianic
On a late afternoon in August in Rhondda Cynon Taf, sunshine is breaking through at last after days of torrential storms. Above the village of Beddau, a week of rain has bathed the hills in a shimmering cloak of green. I’m climbing up the slope with bug expert Liam Olds, whose granddad worked below ground in the local pit, managing the ponies.
Like his granddad, Olds has a passion for animals. Since childhood, he’s explored the Rhondda hills to document the wildlife that clings on here. The hill we’re climbing was carved by man, not by nature. Forty years ago, this hillside was a heap of pit rubble torn from the earth in Cwm Colliery. The greenery we see all around us is rooted in a former spoil tip.
Olds has promised me a slagheap safari – a chance to spot the rare plants and animals that flourish in these post-industrial habitats.
Where Wales mined coal, old coal tips remain – each colliery village had its slagheap or spoil tip, sometimes several. Margaret Thatcher’s Tory government closed Cwm Colliery in 1986. By 2008 Wales lost its last deep coal mine with the closure of Tower Colliery outside Hirwaun. Cwm produced its first coal in 1914. It expanded in the 1950s to join up with Coed Ely colliery five kilometres away.
At peak production in the 1970s, 1,500 men mined half a million tonnes of steam coal a year at Cwm. In the mid-1980s, the miners stood together during the year-long strike against pit closures. When Cwm Colliery closed, 800 local people lost their jobs. In 2002, Cwm coke works closed too. Since the winding gear has fallen silent, Cwm’s spoil tip has stood untouched.
But within a decade of the pit closures, scrub and vegetation conquered brute industry, greening and softening its scars. Now, all around us, new life has taken root, transforming dead earth into living. Nature has reclaimed these hillocks of rocks and debris torn out of the ground. And where green conquers grey, it creates new habitats for insects, fungi, birds and other animals.
It’s a process of rebirth and reclamation that has transformed Wales’ post-industrial landscapes into havens for rare insects, fungi and all manner of wildlife – some found nowhere else in the UK. ‘As a child, I walked my dog on the local tip,’ Olds explains. ‘I’d see grass snakes, common lizards and dragon flies – it felt like my own personal nature reserve.’
Having gained a zoology degree, Olds joined Amgueddfa Cymru as an apprentice specialising in colliery-spoil invertebrates. He spent three years scoping abandoned spoil tips, working with experts and citizen scientists to record the plants, insects, fungi, birds and animals living there. Although they surveyed only a handful of spoil tips, the results are astounding. Eight old tips in Rhondda Cynon Taf and seven in Neath Port Talbot offer sanctuary to nine hundred different species.
Legacy
It takes twenty minutes to reach the crest of Cwm’s tip, where the grassland flattens out to form a plateau. From here, the legacy of Cwm’s heavy industries is scattered all around us. Above the village stands the carcass of the coke works, its twin chimneys and brick outhouses. Developers plan to flatten the site. But for now, the landscape feels deserted. No one comes to these hills apart from dog walkers and occasional quad bikers. Most local people stay away.
Undisturbed, nature has reclaimed these unpromising soils. ‘The geology and pH levels are really complicated,’ Olds explains. ‘You get this strange mix of acid, neutral and calcaneus flora, all co-existing in the same area. It’s an open mosaic of habitats.’
It takes time to register this, to see detail in the stretch of green. But slowly the mosaic takes shape; scrub, young and mature broadleaf woodland, boggy mud, ponds with reed beds and ponds without. There are calcium-rich springs and streams stained orange with iron. This unnatural mix creates microhabitats, exposed and protected ground where rare plants, insects and amphibians have learned to thrive.
We spot more common species first: knapweed and wild carrot, scarlet pimpernel and blackberries, oaks and silver birch. Then, we notice the rogue invaders: cotoneaster bushes and trees and Himalayan balsam. Walking on, we find clumps of pearly everlasting, an Asian daisy prized for silver leaves that give it the nickname moonshine. It’s a magnet for pollinators – and a symbol of immortality that families would plant on miners’ graves.
Olds finds plants not seen here for six decades on the oldest sections of former spoil tips. ‘Parts of these tips become time capsules,’ Olds says. ‘We’ve lost so many habitats and species in our communities. Here, we find flora and fauna that have colonised from those lost habitats. It’s ironic.’
Soon, more exciting finds take shape. A common frog is hiding in the leaves. We stumble on an abandoned badger’s set and the crushed corpse of a mole. Huge golden-ringed dragonflies click past us at speed. A lone buzzard mews, catlike, high above us in the trees.
Olds’ special interest is bugs. He leads over to a dry, sunny bank dotted with small holes. We watch an ornate-tailed digger wasp pop out for lunch, skittering over the bare earth to hunt for beetles. Coal tips being mostly hot and dry, they draw species you’d expect to see on sand dunes. Clumps of kidney vetch feed small blue butterflies. Rare dingy skipper butterflies flock to birdsfoot trefoil.
The diversity of finds is astonishing. Olds has recorded slow worms and adders, brown-banded carder bees and water rail, a shy freshwater wading bird. He’s spotted thick-margined mini mining bees not seen in Wales since the 1960s.
Sanctuary
Wales has more than two thousand former spoil tips, most untouched since the pits closed and so left to revert to nature. Researchers have visited and documented only a handful of these sites. But it matters that these landscapes are teeming with wildlife, now more than ever.
We live in a time of crisis, facing twin emergencies of climate change and nature loss. In 2023, UK wildlife groups launched the State of Nature Report. It’s a sobering read. The UK is a world leader in nature loss. Since records began in 1970, our abundance of wildlife species has dropped by nearly a fifth. One in six of our plants, mammals, insects, birds and amphibians faces extinction as pressures from climate change, urban development, industrial farming and pollution push more species to breaking point. As our losses mount, it’s all the more astonishing to discover species clinging on in abandoned corners of Wales.
The diversity of coal-tip discoveries is astonishing. Olds and his colleagues have counted a hundred species of bees, sixty types of lichen and a hundred different mosses, many of them rare. New finds come thick and fast. Fungi experts found Cudoniella tenuispora – thought to be extinct in Wales – growing out of pine cones on Tower Colliery’s old spoil tip. Another tip has rare ballerina waxcaps, gorgeous pink fungi that should live on centuries-old pasture.
So far, researchers have discovered fifteen species new to Wales on coal-spoil sites across the Valleys, mostly fungi and invertebrates. Three are new to the UK. Two are new to science. Olds made national and international headlines nine years ago, when he and bug expert Christian Owen stumbled across the so-called Maerdy Monster on a spoil tip at the head of Rhondda Fach. A first to science, Turdulisoma helenreadae was also the first arthropod named in the UK in a generation. The following year, Olds and his colleague Chris Lawrence found another rare millipede at Beddau. Cranogona dalensi mauriès is a tiny, off-white millipede with seven or eight lenses in its eyes. It’s a species native to the Pyrenees and the sighting at Beddau was a UK first.
But with so many sites still undocumented, conservationists say it’s critical to protect our old spoil tips and to find out what plants, animals and fungi are living on them. Olds has launched the Colliery Spoil Biodiversity Initiative, to raise money and recruit volunteers to map wildlife on Wales’ former tips. He also works part-time for Buglife, the insect-conservation group, which has landed funding for a new project, Coal Spoil Connections, to connect local people and communities to their coal-spoil sites. That means inviting local people to visit, document and celebrate sites that their parents taught them to avoid.
Ambivalence
Wales’ willingness to abandon these old spoil sites highlights a troubled relationship with these former coal tips. And with good reason. In 1966, a spoil tip collapsed onto Pantglas school at Aberfan after heavy rain soaked through the heaped rock and shale. Wales’ deadliest industrial accident in living memory killed 116 children aged seven to ten, and 28 adults.
Now, climate change is bringing heavier, more intense storms and torrential rains, veering into longer stretches of summer drought. When Storm Dennis tore through south Wales in 2020, torrential rain saturated and weakened a spoil tip near Tylorstown in Rhondda. Part of the tip collapsed, creating a landslide that blocked the valley and damaged sewage and water supply. Luckily, no one was hurt.
Aberfan remains an open wound. The outcry about the slip at Tylorstown was such that the Welsh government agreed to review safety across the country’s 2,566 spoil tips against future risks from more frequent storms, floods and droughts thanks to climate change. The Law Commission found that 294 tips present a high risk and ruled that laws and regulations to manage spoil tips were ‘no longer fit for purpose’.
The Welsh government will not say which tips present the highest risk to public safety or property. We know that 70 are in Caerphilly, 64 in Rhondda Cynon Taf, 59 in Merthyr Tydfil, 42 in Bridgend, 35 in Neath Port Talbot, 16 in Blaenau Gwent and 8 in Swansea. The Welsh and UK governments have agreed to more frequent monitoring of the tips at highest risk – twice a year at 83 Welsh sites and annually at a further 267. The Welsh government has set up a coal tip safety taskforce to monitor all legacy sites. But critics are demanding more, calling for monitoring systems that use sensors to detect landslip and send early text warning messages to local people’s phones.
For wildlife experts, though, work to shore up old tips presents a whole new challenge. Repair work could damage these fragile, unmapped habitats. Olds and other conservationists counter that most of the country’s tips pose little to no risk. Our nature-loss emergency is every bit as urgent as the climate crisis, Olds argues. We urgently need to value and protect these sites as habitats.
At time of writing, Wales has designated one former spoil tip a nature reserve. Conservationists have surveyed just twenty of the country’s 2,500 tips. There is no funding to map and monitor all the country’s tips, to find out what we have living and growing there. And if we don’t know that, we can’t protect and value these habitats as our climate changes, which risks us losing more – perhaps yet-to-be-discovered – species.
Other countries – for example, Poland and Germany – have better data on their spoil-tip species, Olds says; gathering information in Wales is critical. ‘Almost all these sites have really high biodiversity value – locally, at county level and often nationally too,’ Olds says. ‘We’re talking about species designated a conservation priority in Wales and the UK. That’s incredibly important, but we’ve only looked at a really small proportion of these sites.
‘If just 10 percent of these sites have really high biodiversity value, that’s 250 sites whose quality may be better than most nature reserves. I honestly believe that. That’s a massive resource for Wales. If we’re serious about tackling the biodiversity crisis, we need to look after landscapes that harbour nature. In the South Wales Valleys that means our coal tips.’
That research needs funding and resources. It also needs Wales to rethink its relationship with its old spoil tips. And that presents a challenge. Can Welsh people and communities reframe tips as places of wonder not threat? Can we value these spaces for wildlife – and respect those spaces without putting new pressures on plants and animals that have thrived for decades undisturbed?
Because the pressures are many. People need homes. Rhondda Cynon Taf Borough Council has agreed millions of pounds worth of funding to tear down Cwm’s coking works to build six hundred houses. Nature is low on the priority list.
Experts now talk about an insect apocalypse, half of all bugs lost since 1970, two-fifths of our million known species flitting on the edge of extinction. Olds sweeps his nets over the grasslands one last time as we head back down the slope towards his car. But even a non-expert can see a tapestry of vegetation, hear the hum of crickets, sense the undergrowth teeming with bees and soldier beetles, hoverflies and butterflies, shield bugs and ants.
Mapping which species live where would be a start, Olds concludes. ‘It’s the complexity that makes these sites interesting,’ he says. ‘Each is very different. You can’t know what to expect. They’ve all been left to revegetate. It’s unrealistic to think we’ll protect all these sites from all the pressures they face, whether from development and land reclamation or public safety.
‘But we could at least protect the most biodiverse sites – perhaps one in every county. Rewilding is very popular now – but it’s already happened here, across the south Wales coalfield. This shows the power of nature. All of these rare species prove that nature can thrive – if only we let it.’
Kit Habianic writes about water, climate and environment. She is the author of the miners’ strike novel Until Our Blood is Dry (Parthian Books). All photographs are by the author.
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