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Colliery Spoil Biodiversity Initiative

Raising awareness of the biodiversity value of colliery spoil sites.

What wildlife do they support?
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For more than a century, the landscape of the South Wales Valleys and the fortunes of the people who lived here were shaped by coal mining. The scars of heavy industry were everywhere and black tips of coal waste brooded ominously over the Valleys. But times have changed. Mining and heavy industry have gone, nature has acted and the landscape has been transformed.

Historically, wildlife suffered in the Valleys as coal mining fueled Britain’s Industrial Revolution. Today, the spoil tips (and the former collieries themselves) provide extraordinarily-rich and unique habitats for wildlife that have established over several decades of natural colonisation and succession. Diverse communities of birds, mammals, amphibians, reptiles, vascular plants, fungi, lichens and invertebrates now consider these places ‘home’. 

Colliery spoil sites support habitats and wildlife of considerable local, regional and national importance. Despite this, they are gravely misunderstood and under-appreciated, and few have any form of legal protection. Each year, sites which are rich in wildlife and cultural significance are lost to development, reclamation and other pressures, both in South Wales and more widely across the United Kingdom. We cannot continue to stand-by and lose these precious sites. We must act now to ensure our remaining sites of biological, cultural and historical importance are protected. 

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Brief history of coal mining in

South Wales

The pivotal role of coal mining in shaping the British way of life cannot be underestimated. For centuries, coal mining was an essential part of British industry. At its peak, the British coal industry employed more than a million people, making it one of the country’s most important industries. Many regions were dependent upon it, including South Wales.

With its profusion of high quality coal, the South Wales Coalfield - which extends from St. Bride’s Bay in the west to Pontypool in the east - played a pivotal role in Britain’s Industrial Revolution. As Britain began to industrialise itself, coal was needed to produce the steam power upon which industry depended. The high demand for coal brought about a ‘boom’ in the South Wales coal industry. At its peak, the industry employed some 232,000 people in 620 coal mines across South Wales. In 1913, 57 million tons of coal came up from these mines – a fifth of the entire output of the United Kingdom.

The effects of World War I and the post-war depression, however, brought about a decline in the industry. By 1936, 241 collieries had closed and the workforce had halved. Following a brief revival post-Second World War, the industry continued to decline throughout the second half of the 20th century. By the end of that century, just one deep coal mine remained in Wales. The coal industry, the most important industrial, social and political force in modern Wales, had all but vanished.

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Threatened habitats

The Aberfan Disaster of 1966, where the collapse of a spoil tip above the village killed 144 people, 116 of which were children, changed the fortunes of many of South Wales’ colliery spoil tips.

Following the Aberfan Disaster of 1966, many colliery spoil tips were understandably removed or remodeled to address safety concerns. Those deemed stable remained, however, left undisturbed to naturally revegetate over time. Over decades, these tips have been naturally colonised by a wide variety of species and habitats. Once black eye-sores in the landscape, today they support habitats and wildlife of considerable conservation value.

Despite growing evidence of their wildlife conservation value, colliery spoil tips (and their associated former collieries) remain gravely overlooked and under-appreciated. Like many man-made or 'brownfield' sites, they are regarded as abandoned or derelict waste land and receive little to no protection to safeguard their future. The threats are numerous and varied, and include:

  • Development (housing and industrial)

  • Inappropriate reclamation or remediation

  • Removal due to perceived safety risks

  • Tree planting (broadleaf or coniferous)

  • Solar farms

  • Planting with crop biofuels

  • Use of colliery spoil as aggregate for the construction industry

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Why should we conserve these sites?

We are in the midst of a nature crisis. Wildlife populations have declined globally by a staggering 69% over the past 50 years. Closer to home, scientists estimate that the UK has lost around half of its biodiversity since the Industrial Revolution, with 1 in 6 species currently at risk of extinction. As our countryside becomes steadily more degraded, colliery spoil sites are becoming increasingly important as a refuge for wildlife in coalfields across the UK. By linking-up with more traditional habitats, they also provide vital habitat connectivity and act as stepping-stones, allow species to move through our landscapes - this is becoming increasingly important as our wildlife is forced to move in response to the effects of climate change.

If the biodiversity significance of colliery spoil sites was not a good enough reason to conserve these sites, they are also of geological, archaeological, historical, cultural, social and visual significance (see below).

  • Geological – they provide access to fossils and minerals.

  • Archaeological – historic structures and remains can be found amongst colliery spoil tips.

  • Historical – they offer a visual reminder of the coal mining industry that shaped Great Britain and local communities. They also tell stories and provide family landscape links.

  • Cultural – colliery spoil is an important part of the cultural identity of South Walians. The same can be said in other coalfields across the UK. 

  • Social – many colliery spoil sites have open access and are in close proximity to settlements; as such, they are readily used by local people for recreation, providing physical and mental health benefits to those communities. In some instances, they provide the only open access land for people to get outdoors with nature.

  • Visual – they form visible features which are significant in the local landscape and have strong cultural resonance. They are used in regional and local interpretation (i.e. they tell a ‘landscape story’).

Colliery spoil sites tell the story of their prehistoric, geological, archaeological, historical, social and ecological past and the contribution to the lives of the valley communities past, present and future.

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A small amount of money can go a long way in helping us to raise the profile of colliery spoil sites and ensuring that these special places, and their unique wildlife, persists for future generations to appreciate and enjoy. If you would like to support our work, donations are always gratefully received. Thank you!

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