This is an interesting article about how Singapore reclaims land and also uses land in intensive and effective ways. For example, Singapore will be using underground caverns for storage and industrial use as people will not want to live underground. The article recognizes that the conditions in Singapore are singular - its levels of prosperity and its stable one-party government. However, Singapore's example does show one that there are innovative ways of expanding and maximizing our land use.
Among the world’s smattering of small islands, then, Singapore, with a population of 5.6 million, is a special case: a country that’s also a city, a government that owns 90 percent of all real estate, a one-party state in all but name. But how it fends off the ocean will be of deep interest to many other populous and productive cities near the water: New York, Miami, Rio de Janeiro, Mumbai, Guangzhou, all miniature nations of a sort.