Global warming and extreme weather conditions have contributed to the deterioration of almost half of the country's 87,000 aging dams, a senior water official has said.

Many of the structures were built between the 1950s and 70s, and their construction quality is quickly degrading.

"Roughly 37,000 dams across the country are in a dangerous state," Deputy Water Resources Minister Jiao Yong told a national teleconference organized by the State Council and broadcast live on the government's website (www.gov.cn) on Tuesday.

Aside from the climate issue, the design and quality of some of the dams was "restricted by the conditions of the times in which they were built and they are therefore congenitally deficient", Jia said.

He said the reservoirs "have become the weakest link and most unstable factor in flood control", and made the government's freshly announced three-year repair initiative particularly challenging.

The central conference on agriculture in December ordered that all major at-risk dams and reservoirs be repaired within three years. But both the volume of work and problems with funding have alarmed many government departments.

The Water Resources Ministry plans to repair 6,240 aging dams over the three-year period.

"That means that our annual average workload will be 10 times more than that between 1998 and 2006," Jia said, adding that the forthcoming challenges are "unprecedented".

"Funding is key" to finishing the task on time, Vice-Premier Hui Liangyu, who also heads the Office of State Flood Control and Drought Relief Headquarters, said.

More than 2,300 of the most at-risk dams have been repaired since 1998.

But while central government funding was 24.4 billion yuan (US$3.37 billion) between 1998 and 2006, financial input from the provinces, autonomous regions and municipalities was just 6.93 billion yuan, far less than 21.1 billion yuan that was needed, Hui said.

He said 51 billion yuan is needed for the project, of which 27.7 billion yuan will come from the central government.

The rest should come from provincial authorities, he said.

The central government's contribution equates to more than 9.2 billion yuan a year over three years. Last year it spent about 6.4 billion yuan.

The National Reform and Development Commission has already earmarked 5 billion yuan for the repair of large- and medium-sized dams, Du Ying, its deputy chief, said.

The budget for small dams has yet to be set, but a source with the Water Resources Ministry said it is "highly unlikely" it will be 9 billion yuan.

(China Daily January 17, 2008)