Singapore grew by a quarter in sixty years by building new land
Between 1960 and 2019, Singapore expanded from about 581 to nearly 726 square kilometres, not by conquest but by filling in the sea. People have been manufacturing land from water for four thousand years, and today airports, casinos, theme parks and much of central Helsinki stand on it.
The oldest known schemes were agricultural. Around 2000 to 1800 BC, rulers of Egypt's Twelfth Dynasty built levees and canals linking the Faiyum to the Bahr Yussef waterway, diverting water that would otherwise have fed Lake Moeris. As the lake's margins slowly evaporated, fresh farmland emerged. Farmers in Greece's Copaic Basin used dams and drainage channels in a similar way during the Middle Helladic period. In 1612 the Dutch drained the Beemster Polder, adding 70 square kilometres of land in one project.
Methods vary with the goal. The simplest is infilling: dumping heavy rock or cement, then topping it with clay and soil until the ground reaches the right height. Draining wetlands suits farming. Where dredged or drained material may be contaminated, engineers use deep cement mixing to lock it in place, and ongoing dredging keeps harbours and channels from silting back up.
Many famous cities are partly artificial. Mumbai took more than 150 years of projects, including the Hornby Vellard and the Colaba Causeway, to fuse seven separate, hilly, wooded islands into one landmass. About a fifth of the Tokyo Bay area is reclaimed, including Haneda Airport and Tokyo Disneyland, and Rio de Janeiro and Wellington were largely built on made ground. In Kent, Samphire Hoe was formed from 4.9 million cubic metres of chalk marl dug out for the Channel Tunnel between 1988 and 1994.
The practice carries costs. Nearly 65 percent of the tidal flats around the Yellow Sea are estimated to have been reclaimed, and Malaysia's Forest City development drew controversy for filling wetlands protected under the Ramsar Convention. Singapore's planned Long Island project is designed to sit higher to guard against rising seas.
Source: Land reclamation
