Explained: Rise in Sand Mining Threatens Freshwater Ecosystem & Why It Does More Harm Than Good

Sand, mixed with cement to make concrete and tarmac, is the second most consumed material on Earth, after water. The amount accounts for the vast majority¡ªnearly 85 percent¡ªof global mining operations, says The United Nations Environment Programme (UNEP) report on Sand and Sustainability. Riverbeds and beaches are being stripped bare around the world, while farmlands and forests are torn up to get at the precious sand grains. It's a global catastrophe that not many have heard about.

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The main driver of this crisis is decades of mass urbanisation that have fuelled demand for sand to make concrete, glass and other material used in construction. Cities are expanding at a pace and on a scale never seen before in human history. Since 1950, the number of people living in urban areas has more than doubled, to about 4 billion today, according to the UN report.

On top of that, since the past 2 years, the amount of sand extracted has increased due to Covid. Many governments have used the pandemic as an excuse to push through projects that would not have been approved otherwise. Infact, experts claim that governments will begin to invest heavily in infrastructure in order to promote the economy, which will result in a surge in demand for sand and gravel.

China's soaring sand extraction

Cities require mind-boggling amounts of sand for about every apartment block, skyscraper, shopping malls and office towers that gets built anywhere from Beijing to Lagos. China, in particular, is constructing cities at a rate unprecedented in human history. The country has used more cement than the US used in the entire 20th century. In the year 2021 itself, China used enough construction sand to cover the whole state of New York an inch deep.

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Some foreign policy experts argue that mobilizing dredgers can be a part of Beijing¡¯s effort to use coercion without violence. For years, Beijing has steadily deployed thousands of Chinese dredging ships and colossal vessels that are capable of collecting tonnes of sand. China has hauled enough material from the shores of Taiwan to the coast of the Philippines to expand its territory and manufacture islands in contested waters.

Geopolitical objective

For a commodity like sand that appears to be available in infinite supply, it may seem like a curious geopolitical objective. However, the resource is more vital than one might imagine, and usable quantities are more limited. "Modern civilizations are literally built on sand,¡± said Pascal Peduzzi, the director of GRID-Geneva at the United Nations Environment Program.

Yet the aggregate (a term used for crushed rock, sand, and gravels used in construction materials) business and its environmental consequences are almost as murky as the major rivers that feed it. The floods that hit the Yangtze and Huai river basins in the year 2020 killed around 100 people and destroyed billions of dollars in property.

Floods threat

Floods are increasingly submerging parts of China¡¯s major coastal areas as well. Sand mining in the main river, its tributaries, and lakes are believed to be the cause of abnormally low water levels in the winters over the last two decades. Hence, farmers have less water for irrigation, and bird and fish habitats are dwindling as a result of low water levels. For authorities, controlling the flow of water throughout the summer has also become increasingly difficult.

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Already decimated by sand mining, the new plan to build a 3-km sluice gate between Poyang and the Yangtze, increases the threat to the ecosystem of the lake. Adding a sluice gate to regulate the water flow would disrupt the natural ebb and flow between the two rivers, potentially also threatening mud flats that serve as feeding stops for migratory birds. Poyang's ability to flush away nutrients may also be harmed if natural water circulation is lost, further increasing the risk of algae growth and disrupting the food chain.

Why is sand extraction a problem?

While countries all over the world feed their appetites for sand, soaring extraction has come at an alarming price: shrinking rivers, disappearing islands, collapsing ecosystems and even the rise of powerful sand mafias. Although desert sand is available in plenty, it cannot be used for construction as it is wind-smoothed, and therefore non-adherent.

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Now since, sand found in water bodies shields inland regions from flooding, over-mining endangers coastal communities and is a threat that will only grow as climate change drives rising sea levels. Sand is a creation of slow geological processes and has an uneven distribution. Hence, unsustainable sand extraction transforms the structure of rivers.

Sand mining carves a deeper, narrower bed by extracting more than the river can naturally replace with the sediment it carries downstream. This reduces the watershed's capacity to absorb excess water during floods by lowering the water level, speeding up flow, and eroding banks.

Sand mining has a negative influence on rivers, which is exacerbated by hydropower dams. The reservoirs behind hydropower dams were supposed to help control flood peaks in addition to powering turbines. But dams, on the other hand, don't just trap water, they also trap sand and another sediment. They are expected to trap 77-99% of the natural sediment flows of rivers, but what still gets through the barriers is mainly fine sediments like silt and clays, not sand or gravel. As a result, riverbeds and banks are not replenished, making sand mining downstream even more unsustainable and exponentially increasing river channel and bank erosion.

What can be done?

Even with the prevalence of these risks, governments don¡¯t know exactly how much sand is being mined¡ªor even realize that a crisis is looming.

There is a transparency and accountability issue that needs to cross boundaries and borders, right down the value chain. The UNEP report emphasizes that while we may know how much sand is being extracted from a region, we rarely know where it ends up. Similarly, an estimation of consumption can be made but one can't say where it originates from. Hence, the report suggests better spatial planning and reducing unnecessary construction such as speculative or prestige projects ¡ª to make better use of aggregates.

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The report also suggests investment in infrastructure maintenance and retrofitting rather than in demolishing and rebuilding cycle, embracing alternative design and construction methods, including avoiding cement and concrete where possible and using green infrastructure.

At the policy level, the report recommends ¨C strengthening standards and best practices to reduce irresponsible extraction, investment in sand production, and consumption measurement. With responsible management, the other key suggestion was to establish a dialogue based on transparency and accountability.

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