After a week of rapid work, soldiers and armed police have completed a channel to drain a dangerously full reservoir and prevent flooding of a city of 205,700 people in northwest China.

Authorities on Wednesday said preparations to drain the Wenquan Reservoir, 130 km from Golmud City, Qinghai Province, were almost complete, but gave no specific time for the operation.

Previously, it was expected to start on Tuesday, but authorities decided to delay it to ensure preparations were properly completed and because water levels began to fall due to improving weather.

Golmud, which is Mongolian for "place with many rivers," is nestled in a mountainous area where melting snow from the Kunlun Mountains forms rivers that flow through to the Qaidam Basin.

Days of heavy rain this month coincided with the snow-melt and caused torrents of water to pour into the Wenquan Reservoir, pushing up the water level at one point to 1.18 meters above the warning line, officials with the provincial disaster relief headquarters said.

Soldiers have been using excavators to dig a waterway from the Wenquan Reservoir since July 7. Trucks carrying earth, mud and rocks have dotted the mountain pass leading to the reservoir, about 3,960 meters above sea-level.

If it bursts, the reservoir could inundate Golmud with water up to four meters deep. The city's power and water plants, the airport and the high-altitude Qinghai-Tibetan Raiway are also at risk, local officals say.

As of Wednesday afternoon, more than 11,311 residents Golmud had been relocated to a safe area and were living in 2,022 tents.

Officials expect the new channel and two existing channels to release 400 cubic meters of water a second, relieving pressure on the reservoir which contains about 240 million cubic meters of water, 30 million cubic meters more than its previous high.

But the provincial water resources bureau said the water volume dropped below 240 million cubic meters from Tuesday.

The provincial meteorological bureau forecast mainly cloudy weather and sporadic showers in Golmud from July 14 to 16.