The windmills of Holland pump water from behind the dikes and back out to sea to keep the land dry.

© iStockphoto.com/pidjoe

Dikes of the Netherlands

In the decades that followed the deadly flood of 1953, Dutch engineers set out to build a new kind of barrier against the sea. They steadily replaced the old dike system, which had been in place since the medieval ages, and created 3­50 miles (563 km) of what many consider the safest levee system in the world.

The Dutch set the standard for levee construction by re-evaluating their entire system in several key ways:

  1. Thinking long term: While the 1965 team of engineers in New Orleans tried to build levees strong enough to withstand the strongest possible storm in 200 years, Dutch engineers designed a system strong enough to match the kind of catastrophic storm that only occurs once in 10,000 years.
  1. Less reliance on solid barriers: Instead of constructing increasingly bigger barriers like levees and floodwalls, Dutch engineers have sought to create better ways of absorbing floodwaters in marsh plains and specially constructed rivers. In some cases, this even involves setting dikes farther back from the water.
  1. New textiles: The Dutch also developed tough, synthetic textiles to better anchor earthen levees. These prevent soil movement and water penetration. The New Orleans levee system began using this technology following Hurricane Katrina.
  1. Better monitoring systems: In addition to commanding more stringent, centralized control and maintenance of their dikes, the Dutch also use automated surveillance systems to keep an eye on how their levees are holding up. They installed fiber-optic and electronic sensors in dike structures to report changes back to a central monitoring station. Several other systems monitor water pressure and water level.

Much of the Dutch levee system relies on the understanding that levees require regular maintenance, constant monitoring and a long-term appreciation for how rivers, oceans and storms behave. When these are in place, communities can thrive safely alongside the beauty and convenience of coastal and riverside areas. It's when we fail to remember this that rivers and oceans become destroyers.

­Explore the links on the next page to learn more about storms, the ocean and other feats of human and natural engineering.