Massive reclamation projects seem to be the path the government has chosen to create the sites that will solve our housing crisis, but that path poses its own problems. Specifically, can we easily find sufficient available earth for all the reclamation for the planned 100,000 new public housing units to house 470,000 people?

The fact is that Hong Kong is a developer's nightmare. It is a rocky, mountainous region that, since the 1890s, has been forced to embark on one large reclamation after another to eke out its niggardly flat land mass and so provide sites for future growth. Over the decades most of our spare soil has been dug up and used for so many large reclamation projects across Hong Kong that now it's in short supply. So it seems we'll have trouble finding the huge amount of soil that all those new housing estates will require for providing the foundation sites and associated infrastructure.

The obvious solution is to get it from the Chinese mainland. But the mainland is now embarking on the world's biggest rehousing project, moving hundreds of millions of people from rural areas to secondary cities where they can enjoy a far better lifestyle. This has led to a serious shortfall in its earth requirements.

Meanwhile Hong Kong's overall reclamation needs for its new wave of housing will dwarf our biggest reclamation project so far, the creation of the Hong Kong International Airport off the northern coast of Lantau Island. The seven-year project began in 1991 and swallowed up two islands, Chek Lap Kok and Lam Chau, and reclaimed 9.38 sq km of the adjacent seabed. Thus was conjured a site totaling 12.48 sq km that quite astonishingly added 1 percent to the total land mass of Hong Kong.

The previous biggest reclamation was a four-year project required for site formation for the Jockey Club's Sha Tin racecourse. From 1973, earth-movers and bulldozers gradually gouged away four hills opposite the site while a fleet of 400 tip-trucks took the spoil back to the site. One of the biggest problems was to transform a muddy riverbank into the elevated backstretch of an ultra-modern racetrack held in place with a formidable seawall. Eventually another 101 hectares of land was added to Hong Kong's surface.

Almost certainly Hong Kong will "grow" in size quite a bit more if we have to fill in bays and inlets, or join together neighboring islands to create the land for all those new flats, or even create a totally new island off Lantau. And so where will we get the soil to make all this possible?

A possible answer can be found if we turn back the clock to the 1850s when the European traders in Guangzhou wanted to have an island of their own where they could experience the lifestyles they previously enjoyed in their homelands, mainly Britain and France. A stretch of water of the Pearl River in the vicinity of the "factories" where the Europeans conducted their business was occupied by a large fleet of sampans, and there was a sandbank nearby which the boat people treated as their refuse tip.

A foresighted trader saw an exciting use for that elliptical sandbank, which the locals called Shamian or "Sandy Surface". He argued that "if we could expand that sandbank into an island, we could build a European settlement there, and have our own residences, churches, parks, playgrounds, schools, hostels and even promenades for evening strollers."

The idea found many supporters, and negotiations with the authorities went satisfactorily - but where would the materials come from to build the artificial island?

Another wise man stroked his beard and pointed out that every year many hundreds of ships came to Canton to trade, and often carried sand as ballast which was tipped into the river on arrival. "Let us get them to tip out their sand onto the reclaimed land," said the wise man, "and gradually it will create the island we all desire so much."

And, exactly as envisioned, the "island" of what is now known as Shamian gradually grew into being and indeed became a European settlement with all the amenities originally suggested.

Fast forward to today, and consider how this idea could be adapted to Hong Kong's search to find the earth we need for all those reclamations.

Most container ships arrive here with little cargo apart from empty containers and perhaps some minor trade goods. It should be simple to arrange with the shippers for their ships to bring as ballast plain sand from their countries of origin, and dump it into a receiving depot at Kwai Chung container port. From there it could be trucked to reclamation sites. If more filling is needed for reclamation on the bigger islands, or for the formation of the proposed new island, the sand could be offloaded onto barges at Kwai Chung and then towed by sea to where it is needed.

Of course arrangements would have to be made in the ships' home countries to buy and transport the sand. But the ship owners would undoubtedly jump at the chance of filling their otherwise empty containers with sand and profit from this simple exercise. Wouldn't it be a great way to "kill two birds with one stone"?

The author is Op-Ed editor of China Daily Hong Kong Edition. albertlin@chinadailyhk.com

(HK Edition 10/25/2013 page9)