When a team of Soviet engineers recommended that China build a massive dam on the Yellow River in Henan province in 1954, they thought they were helping their communist comrades. Instead, they were sowing the seeds of a controversy that continues to rage a half-century later. When it accepted the advice and completed the 713.2-metre-long, 106-metre-high dam in 1960, the central government sparked an intense struggle between those who live above and below the dam. People upstream complain that silting behind the dam is causing disastrous floods, while downstream residents believe the dam provides critical flood protection and much-needed electricity. Shaanxi farmer Feng Wenhua and wife Wang Xiuxia are among the thousands who say the dam at Sanmenxia in Hunan has made their lives miserable. They live in Huayin county's Fengdong village, 10km inland from the Wei River. Last August, after 20 days of nonstop rain, the Wei broke its banks and flooded the surrounding area, including their home and their 13-acre plot of soybeans and peanuts. Mr Feng and Ms Wang were among the thousands forced to flee to higher ground. The floods ravaged Shaanxi, leaving more than 40 people dead, 46,000 homes destroyed and an estimated 4.76 million hectares of farmland inundated. The damage was estimated at more than 4 billion yuan. 'We lost everything last year. The water was five metres high,' said Mr Feng. His wife added: 'The flood cost us about 10,000 yuan. They should tear down the Sanmenxia dam.' Xi Sixian , a retired hydrological engineer at Shaanxi's Provincial Water Resource Bureau, says the dam is the main reason for the flooding of the Wei. The Wei flows through Shaanxi and into the Yellow River, but since the Sanmenxia dam went into operation 114km downstream in 1961, its river bed has risen five metres, causing flooding during heavy rains. Experts, particularly in Shaanxi, blame a build-up of silt in the Yellow River above the dam for hampering the flow of the Wei and causing the bed to rise. But downstream, fisherman Luo Qianlong has nothing but praise for the dam. He lives in Henan's Lijiabo village, 500 metres downstream from the structure, and fishes in the Yellow River. 'The dam is good. If it was not there, our village would disappear. It also gives us electricity,' he said. Its supporters say the Sanmenxia dam helps protect the region downstream of the Yellow River, serving as the key flood barrier for the 170 million people living in Henan, Hebei , Shandong , Anhui and Jiangsu while producing about 1 billion kWh of electricity a year. Jiao Enze , an expert on sedimentation with the Yellow River Commission's Hydrological Research Institute in Henan's Zhenzhou city, said the dam should be examined from an overall perspective. 'When looking at the Sanmenxia dam, one needs to look at benefits for the whole family, not the cost to just one child,' said Mr Jiao, who disputes claims that the dam causes flooding of the Wei River. Like many of his colleagues downstream, Mr Jiao believes the rise in the riverbed is mostly due to reduced flows caused by overuse of water, upstream dams and a drop in rainfall. The debate over the Sanmenxia dam is actually older then the dam itself. Construction plans originated in 1935 and the project became a reality after the founding of the People's Republic as the new government's first major water resources project. With plans moving ahead for the dam, a small group of experts warned in 1957 that the water storage height of 360 metres above sea level recommended by the Soviet advisers would prevent the structure from handling Yellow River silt. But their concerns were ignored and one critic, Huang Wanli , was labelled a rightist and made to undergo re-education. The dam was finally completed in 1960 with a water storage capacity of 64.7 billion cubic metres and hydroelectric capacity of 1160 megawatts. But the costs were high, with the forced relocation of more than 870,000 people and 3.5 million hectares submerged. Two years after it was completed, silt deposits behind the dam reached 1.5 billion tonnes and the level of the Wei climbed more than four metres, causing a series of deadly floods in Shaanxi. In 1964, then-premier Zhou Enlai ordered a series of retrofits, including the building of sluice gates which were completed in 1968 and 1971. The modifications did not stop the flooding, but for 30 years it did effectively hold back demands for the dam to be put out of commission. The controversy resurfaced in 2002 when Qian Zhengying , a vice-chairwoman of the Chinese People's Political Consultative Conference, publicly called for the dam to be closed and the Yellow River allowed to run free. The August 2003 Wei River floods, the worst in 50 years, further fuelled the debate. Zhang Guangdou , one of the main engineers during construction, announced after the floods that the project was a mistake and agreed that it should be decommissioned. 'People living along the Wei River have suffered too long,' said Mr Zhang, then 92 years old, when asked why he changed his mind in a November China Central Television interview. At the March National People's Congress meetings in Beijing, former Shaanxi party secretary An Qiyuan submitted for the fifth time a proposal to shut the dam. Henan officials fought back, with the province's 32 delegates submitting a proposal that the facility be maintained as a flood control measure and hydropower station. However, opponents of the dam argue that people living downstream would not be affected if it is shut down. Mr Xi, the Shaanxi hydrologist, said the Sanmenxia dam's flood-control utility could be handled by the newly completed Xiaolangdi dam on the Yellow River. But others, such as Mr Jiao, say the Xiaolangdi dam could not handle the extra silt if the Sanmenxia dam was shut. 'Sacrificing Sanmenxia would put the Xiaolangdi dam at risk and jeopardise people living downstream,' he said. The fight over the dam's fate won't be settled soon. Earlier this month, Shaanxi officials told their subordinates in the Wei River region to ready for the summer rains.