The extraction of sand and gravel from riverbeds is occurring faster than natural replenishment due to a booming demand for concrete, according to a study published in Reviews of Geophysics. This overextraction is contributing to weaker riverbanks, lower groundwater levels, coastal salt intrusion, and poorer water quality.
Researchers reviewed data on sand and gravel extraction dating back to 1974, finding that demand has more than doubled since 2000. In 2024, city-building and infrastructure projects worldwide used 28 billion tonnes of these materials for concrete. More than 80% of the current demand originates from Asia, particularly supporting urban development and road-building in China and India.
Much of this material is being extracted from rivers across Asia and Africa. The study indicates that where data exists, extraction often exceeds natural sediment replacement severalfold. Researchers suggest that satellite imaging and river mapping could help manage sand and gravel mining, while demand could be reduced by using materials more efficiently and developing alternatives like processed construction waste, recycled glass, and treated bottom ash.