A decade ago, Yang Xiangyi grew 80 mu (5.3 hectares) of yellow ginger and could earn about 3,500 yuan ($580) per mu by selling the crop, which is used to make saponin, a dietary aid, and hormonal drugs.

In 2003, Yang, a farmer in Shiyan, Hubei province, was required to grow oranges instead - a much less profitable crop - as local authorities rooted out the highly polluting yellow ginger processing industry.

The move was designed to help protect a water source for China's massiveSouth-to-North Water Diversion Project.

But the switch from yellow ginger farming (along with other measures) has reduced the household earnings of many residents.

Yellow ginger was once a major business in Shiyan. Local farmers grew 860,000 mu of the cash crop, and hundreds of thousands of people were involved in the industry.

Now, Yang's problems are mounting. Some of his land will be submerged with the completion of the Danjiangkou Reservoir, located between Hubei and Henan provinces. Water will rise significantly in 2014.

The project will funnel water to the parched northern regions along man-made channels stretching 1,432 kilometers.

Yang's situation is common. Hundreds of thousands of people in Hubei and Henan were ordered to leave their homes near the reservoir to make way for its expansion.

Of the 340,000 people who were part of China's second-largest relocation program since the Three Gorges Project, 124,000 have been moved to higher areas around the reservoir as their low-lying homes and lands will also be submerged.

After eight years of construction, the height of the Danjiangkou dam, originally completed in 1973, was raised by 14.6 meters to 176.6 meters. The expansion will enable it to store up to 29 billion cubic meters of water.

At full capacity, the reservoir will have a surface area of 1,022 sq km, the second-largest in China, behind the Three Gorges Project. It is designed to transfer relatively clean water north from the Hanjiang River, a major tributary of the Yangtze River.

But the 124,000 displaced locals now have less land with which to support their families. In Henan province, 131,000 mu of farmland will be submerged by the expanded reservoir, said Zhang Yan, deputy director of the migration bureau in Xichuan county. Another 125,000 mu will be submerged in Hubei province.

Other headaches plague the displaced. For example, many of them have already consumed their savings, and even incurred debt, to acquire newer, better houses that replaced their old-fashioned dwellings.

In Danjiangkou's Junxian township, where some 10,000 displaced people have moved to higher ground, the migrants still owe 23 million yuan for debts incurred in their previous move, said Ke Qinglin, the township's Party chief.

The displaced people also have few employment opportunities, as many local factories have been closed for the sake of environmental protection around the water source, Ke said.