The Bio-Geophysical Conditions for Ecocity Standards (www.ecocitystandards.org) include “Responsible Resources/Materials.” This includes careful stewardship of scarce resources whether they be renewable or non-renewable. It may seem counter-intuitive to put sand in this category. Sand, one of the world’s ubiquitous materials, is actually becoming a scarce resource. Sand is the main ingredient in glass and also important in making concrete. Demand for sand has grown with population and global development to the point that it commands a premium in world markets for construction materials. Compounding this challenge is the fact that the natural flow of sand is obstructed by large hydro dams. Starting with erosion of rocks in mountainous terrain, sand is carried in streams and rivers to deltas where it is pushed along shorelines to form beaches. However, most of the world’s major rivers today are dammed. In the USA, 80% of that country’s rivers do not flow freely to the sea. These dams block the natural flow of sand, compounding challenges of shoreline erosion. To learn more about why sand is becoming a scarce resource visit the United Nations Environmental Protection (UNEP) agency at: https://na.unep.net/geas/ge
I also recommend the educational video Sand Wars: www.sand-wars.com that provides a synopsis of the issues.