Updated

The operators of a major Chinese reservoir at risk of overflowing because of torrential seasonal rains have opened three of its nine floodgates.

State-run Xinhua News Agency says the Xin'anjiang Reservoir in eastern China began discharging water after authorities ordered the action Tuesday.

Flood officials in Zhejiang province say it may take 30 to 40 hours before water in the reservoir is back to safe levels.

Xinhua quoted officials as saying the release of water into the Lanjiang river won't cause havoc downstream because water there has receded below the danger level.

Rain-triggered floods have swept Zhejiang and other parts of eastern and southern China this month, leaving at least 175 dead and 86 missing.