It is the largest water diversion project in the world.

It covers the longest distance, benefits the largest population, represents the biggest man-made attempt to offer access to water, and to achieve all this, initiated the most aggressive relocation movement for a single water project in world history.

China's South-to-North Water Diversion project (SNWD), with its east, middle and west routes running 5,599 kilometers, was designed to divert water from southern China's Yangtze River to the Yellow River, the Huaihe River and the Haihe River, whose water beds are slowly running dry.

Some 438 million people now live in this region, where water shortages could not only cause the economy to stagnate, but also bring social unrest.

These pressures are what forced the government to launch this massive diversion project on December 27, 2002.

With a total of $62 billion in investment and 10 years of construction, the central government expects the two routes (the east route, a water way from Jiangsu Province to the Tianjin Municipality, and the middle route, from Hubei Province to Beijing) to quench the thirst of the parched north.

But water alone is insufficient. Tourism, it would seem, is to be the new lifeblood of the area.

On December 19, 2012, a week from the 10th anniversary of the project, the Office of the SNWD Project Commission of the State Council released a new plan that zoned 12 cities along the middle route of the water project as key tourism development areas and vowed to make the middle route an eco-friendly economic zone.

However, there are few details on whether there will be any central government funding. Perhaps more worryingly, the development of tourism looks set to come at a high price, as potentially polluting industries are being restricted for fear of water contamination.

A sacrificial city

One of the tourism sites included is Danjiangkou in Hubei Province.

Sitting on the southern end of the middle route, Danjiangkou is located near the Yangtze River and is home to a giant dam and reservoir that will start providing clean water not only to Beijing but also to Henan and Hebei provinces for irrigation, opening thousands of hectares to agriculture.

More than 160,000 residents were relocated in the 1970s in Danjiangkou for the construction of the dam and more than 100,000 additional residents will be moved during the current phase of the project that is expected to be completed by the end of 2014.

"There are 400,000 people left in the city after a majority of the population were relocated to make space for the water project," Chen Xuwen, deputy director of the tourism bureau of Danjiangkou, told the Global Times, adding that as the starting point of the middle route and the home of water resources, the city has been ordered to halt development of industry and agriculture for fear that fertilizers or chemicals might pollute the water.

After receiving compensation payouts, many left. Those who stayed found themselves struggling in a fractured local economy. Left with no other options, the city government decided to turn to tourism for development.

With half of the parks near the dam still under construction, Chen said the local government had raised 300 million yuan ($48 million), a majority of which was from the private sector, to build tourism attractions to create jobs and rejuvenate the economy.

An anonymous source from the SNWD office with the State Council told the Global Times that the central government will sponsor Danjiangkou with 200 million yuan every year to make up for what the city has sacrificed for the country.

"We are encouraged to develop tourism but environmental protection must always stay first," said Chen.

The delicate environment

Danjiangkou is not the only city facing this dilemma.

Other cities listed on the State Council's middle route tourism development plan, such as Anyang in Henan Province, face a similar problem - maintaining economic growth while keeping a lid on pollution.

Located at the heart of the North China Plain, Anyang cut off its water supply on January 6 as 8.7 tons of aniline was leaked into the nearby river from further upstream in neighboring Shanxi Province.

"The water diversion project in the Anyang area was not affected by the pollution incident and will not be affected in the future," a spokesperson for the Anyang office of the project assured the Global Times.

Hao said the water route was designed to not come in contact with any local water bodies to prevent pollution.

Anyang has long been known as a hub for the production of construction materials and heavy industry companies. These industries, while contributing significantly to the local economy, have generated a tremendous amount of pollution over the years.

The local environmental protection bureau declined to answer questions from the Global Times as of Thursday.

"This new plan to create tourism zones along the water route is, for a majority part, an effort to stop water contamination," an official from the SNWD office at the State Council, who demanded anonymity, told the Global Times.

"The government is trying to find a sustainable model to change the pollution-prone local industries along the project's middle route that will benefit the water providers, the carriers and the users," the official said.

A thirsty nation

Even today, it is still not clear how much the government will charge residents for water that is delivered from thousands of miles away, by what is possibly the most expensive water project ever. And the situation is exacerbated by the fact that water quality in northern China has seen obvious deterioration in recent years.

The concentration of nitrite in Beijing's tap water has quadrupled since 2007 and reached nine milligrams per liter, shortly below the national standard of 10 milligrams.

Even if it is technically defined as safe, few people drink it these days.

"People in Beijing are eagerly looking forward to the clean water delivered by this project," Ma Jun, an environmental activist and chief of the Institute of Public and Environmental Affairs, told the Global Times, adding that the key question is how to deliver the clean water on the way. It is no easy task and something the government cannot afford to fail.