Pakistan dam begins to overflow

Water from a massive landslide dam in Pakistan has entered a spillway and is expected to exert peak pressure on the dam at any time.

ISLAMABAD/KARIMABAD // Water from a massive landslide dam in a mountainous northern region of Pakistan has started to overflow and could cause flooding later today, officials said. Water from the dam entered a 24m-deep spillway excavated by army engineers at about 7.15am local time, they said. "The first 12 hours are critical," Nadeem Ahmed, the chairman of the National Disaster Management Authority (NDMA), told journalists in Aliabad, about 25km downstream of the dam. He said the lake, estimated by international experts to contain 500 million cubic metres of water, is expected to exert peak pressure on the unstable dam at any time. Officials hope the spillway, excavated to reduce pressure on the dam structure, will prevent the unlikely worst-case scenario of its sudden collapse, which would generate a 30m flash flood. The dam was formed on January 4 after a massive landslide destroyed the village of Ata-abad, killing 19 residents, and blocked the Hunza-Nagar valley, the inspiration for the mythical kingdom of Shangri-la. Its 22km lake has since marooned about 30,000 residents living upstream in areas bordering China. The NDMA said more than 27,000 people living as far as 600km downstream of the dam had been evacuated to higher ground as a precautionary measure. [e-mail]