Ever since the initial feasibility study, there was wide-spread concern that, should an attack take place, the Three Gorges Reservoir holding water at a storage level of over 100 meters could present a serious flood risk to China's prosperous eastern provinces and cities.

Guo Tao, deputy manager of the China Yangtze River Three Gorges Project Development Corp., said the reservoir will have the capability of reducing its water level from the highest storage level of 175 meters to a safety height in a short time in the event of an attack.

He did not specify the time period required for reducing the water level to the safety line.

Tao Jingliang, a senior engineer with the company, said the project designers have taken into consideration the dam's defense requirements and have used engineering techniques to improve its fire resistant capacity.

Located 40 kilometers from Yichang City, in central China's Hubei Province, the Three Gorges Dam, upon completion in 2009, will be 2,309 meters long and 185 meters high.

Tao said that, despite the dam's strong, concrete structure, the discharging control system constitutes the most effective defense mechanism for the project.

Although the odds of an attack on the Three Gorges Dam are quite small, experts with the Ministry of Water Resources conducted several years of thorough research on defense measures. The officials concluded that discharge control in the event of an attack would limit flooding to the area from the dam to Jingzhou City in Hubei Province.

Defense experts agree that, in the event of an attack, there should be ample warning which would permit the reduction of the storage level to dispose of the flooding threat.

The research findings gave no indication of risk to central China's industrial center of Wuhan, the capital of Hubei Province, nor to cities further downstream in wealthier coastal provinces.

The Three Gorges Dam has been designed with a storage capacity of 39.3 billion cubic meters. There are 35 reservoirs in the world with storage capacities topping 30 billion cubic meters, and the Three Gorges Reservoir ranks 24th.

The reservoir contains the Yangtze River water in some 600 km of long, narrow cliff gorges, which help to slow the water flow.

(Xinhua News Agency November 4, 2002)