Leaky reservoirs

By Wen Ya Source:Global Times Published: 2012-8-23 0:00:07

People walk past the Shenjiakeng Reservoir in Daishan county, Zhejiang Province, which ruptured earlier this month.  Eleven people were killed in the ensuing flooding caused by the breach. Photo: CFP
People walk past the Shenjiakeng Reservoir in Daishan county, Zhejiang Province, which ruptured earlier this month. Eleven people were killed in the ensuing flooding caused by the breach. Photo: CFP

Rainstorms that wracked Hunan on Monday and Tuesday have caused 14 small reservoirs in the province to spill over, affecting 20,000 people and 106 buildings, according to local reports. There were no fatalities, though the spills highlighted the dangers associated with many small- and medium-sized reservoirs in China.

Sometimes, these dangers can prove fatal. When typhoon Haikui hit the Shenjiakeng reservoir in Daishan county, Zhejiang Province on August 8, the dam held fast against the tempest. Unfortunately, two days later the strain proved to be too much and the dam broke, leaving 11 people dead, the Xinhua News Agency reported.

These reservoirs are among the 80,000 smaller dams throughout the country, which have a holding capacities between 100,000 and 10 million cubic meters, according to the Southern Weekend.

Half of these reservoirs are believed to have defects. Most of them were built between the 1950s and 1970s using manual labor, according to the Ministry of Water Resources (MWR).

"During that period, construction standards were poor, and there wasn't much by way of geological analysis. Without sufficient ongoing maintenance, the reservoirs have many hidden risks and problems," Ding Liuqian, a vice president of the China Institute of Water Resources and Hydropower Research, told the Global Times.

The government has launched a program to reinforce these dams, however experts have cautioned that the pace of the project risks amplifying the problem.

A history of danger

"Since 1954, there have been 3,515 incidents of reservoirs breaking," Chen Lei, minister of water resources said at a national conference in April, 2011, adding that the vast majority were smaller dams.

"In 2010 alone, seven small dams broke and caused tragedies, which reminded us that we must improve small reservoirs not only to consolidate our flood control systems, but also to ensure drinking water in rural areas and agriculture water supply," Chen was quoted by the ministry's website as saying.

"Small reservoirs play an important role in drinking water supply and irrigation. They are a lifeline for these people," Xiong Yikan, a retired senior engineer with the Jiangxi Provincial Water Construction Planning and Design Institute, told the Global Times.

Taking action

Local authorities often dispatch staff to these reservoirs during flood season. 

Hunan Authorities have assigned a staff member for each of the more than 11,200 small reservoirs in the province, according to the Xiaoxiang Morning Herald.

As early as March, reservoirs were scrutinized in Zhejiang Province, to examine how they would cope with the risks associated with such problematic reservoirs, according to the website of the provincial water resources department of Zhejiang.

The problem is the most pronounced in Hunan and Jiangxi, which respectively have 9,300 and 7,900 reservoirs of the smallest class, according to Chen.

A project designed to reinforce small and medium reservoirs was launched by the central and local governments in April, 2011.

The central government invested 38.14 billion yuan ($6 billion) to reinforce 15,900 key small reservoirs by 2013, while the local government would be responsible for 25,000 smaller reservoirs that would need to be finished by 2015, according to Chen.

However, not everyone is pleased with the demands that the project be carried out rapidly.

"The pace is too fast," Xu said. "Reservoir-related projects need time to investigate and finish. However, the higher authorities usually require the projects be completed in a rush."

A number of medium-sized dams had previously been allocated 10 million yuan funds each to be reinforced; however, they are often required to be completed within three months.

Xu said that this is a problem, because in these cases it takes 28 days for concrete to properly solidify and during flood seasons no work can be completed, which means many reports on construction progress will be faked, while the work will be rushed.

It is unclear whether the three-month requirements still stand.

"Reservoirs are a special project for the good of the public. We try our best to ensure their quality." Xu said. "Because of this, we are under a lot of pressure since there so much work to do while we are short of hands."

A thankless task

"The small reservoirs were built using comparatively small investments, so they bring fewer benefits for the construction teams," said Xiong, adding that the age of the facilities and their lower status means it's difficult to get the right data to formulate construction plans.

"Even if I can find the data, dams from this period don't necessarily have accurate information. If the project then has problems, I'm the one that's responsible for them. No one wants to take on this kind of duty."

There are also financial issues at stake, due to the fact that provincial, city or county governments were responsible for constructing them. Even if the provincial government provides the half of the share, it's not easy for the local government to provide the rest, Li Liangwei, an official in construction and management with the Jiangxi Provincial Water Resources Department, told the Southern Weekend last week.

Some counties have 300 small reservoirs in Jiangxi. Assuming one of them requires an investment of around 800,000 yuan, there would need to a be a total investment of over 100 million yuan to cover all of them, which would represent a huge financial burden for the county.

These projects also generate conflicts with farmers, who are opposed to having the water discharged as that could lead to financial losses, particularly in cases where farmers have gotten used to renting fishing permits. There are no compensation funds in these cases, so it's up to construction teams to persuade the farmers, Li said.

In addition to these problems, the ownership status of these small reservoirs is often murky at best. Originally built by villages, for villagers and funded via local agricultural taxes, times have now changed given the fact that those taxes were removed in 2006.

Now local governments have limited funds for their maintenance.

"In some places in Guangxi, staff members with salaries below 1,000 yuan can't even receive their salaries on time," Xu said.

"Without clear ownership or benefits, no one wants the job of running it."

In an effort to address the issue, since 2005, several Guangxi authorities including civil affairs, agriculture and water resource authorities have backed a plan that would allow farmers associations to manage the reservoirs.

Xu said that this has worked well in some instances, but in other cases it's been less successful.


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