In industry, gravel is mainly used to manufacture concrete. But while the demand is high, the number of mining sites has been falling for years. A study warns of shortages that could get even worse in the coming years.

The supply of gravel as the most important domestic building material is becoming increasingly difficult in Germany. After bottlenecks in the Ruhr area and Hamburg for the first time in recent years , the problems spread to other regions such as Mannheim / Karlsruhe and Berlin / Potsdam as well as parts of Lower Saxony and Bavaria. This is the result of a study by the Federal Institute for Geosciences and Natural Resources (BGR) in Hanover.

In some cases, orders for larger construction projects are no longer accepted, regular customers are served first and quantities of gravel are allocated according to availability. “The situation will worsen across Germany because the causes persist,” said the study’s lead author, Harald Elsner. Gravel is mainly used to make concrete.

Germany is rich in gravel – but 70 percent are not accessible at all

According to the Central Association of the German Construction Industry, there is “no emergency in terms of gravel and sand” in Germany – but there is a shortage because hardly any new mining areas are approved. In addition, delivery bottlenecks from abroad are currently being observed due to the new type of corona virus, but these are being offset by domestic companies.

Germany is geologically rich in gravel, but only some of the deposits are available for mining. According to the BGR, for example, around 70 percent of the gravel deposits in Baden-Württemberg are built on or are in protected areas. For farmers, arable farming is currently more profitable than what the raw materials industry offers.

A year ago, the construction industry had already warned that the real estate boom would run out of sand in some places. In comparison to this, however, the situation with gravel is much more tense, according to the BGR: “For geological reasons, gravel is rarer than sand, but the need is much higher.”

Gravel is even more important than sand – especially with concrete

The study cites the composition of concrete as an example: sand makes up around a third of the so-called rock aggregates, while gravel and chippings made from natural stones make up almost two thirds.

The difference between sand and gravel is in size. Both can consist of a wide variety of minerals – if the grains of the sediment are 2 to 63 millimeters in size, if we are talking about gravel, if they are smaller, it is sand. In contrast to gravel and crushed stone, gravel is also rounded.

The raw material is particularly important for the ready-mixed concrete industry. It needed more than 40 million tons of gravel in 2018, making this branch the largest consumer. However, the number of places where sand and gravel are extracted in Germany has been declining since the 1990s. According to the study, there were more than 3,000 works in 1995, today there are fewer than 2,000.

The amount extracted is increasing – but too few areas are approved

However, the supply bottlenecks do not result from insufficient supply. The amount extracted has even increased by ten percent since 2012. Due to private and public building projects, however, demand has been extremely high in recent years. As a result, gravel prices have risen by five to ten percent per year.

With a view to the future, according to the study authors, another problem looms: The approval of new mining areas is only progressing slowly. In the Chemnitz region alone, twelve important gravel sand deposits ran out in the next ten years. However, replacement areas have not yet been identified by regional planning.