Three Gorges Dam

In late September 2007, the temperature in Chongqing (重庆) was still as high as 30 degree Celsius. As first time tourists in Chongqing, we have to struggle with the heat and humidity of the Sichuan (四川) Basin[1, 1a] while trying to enjoy ourselves amongst the famous local leisure seekers. The local people, many of whom are the Hakka (客家)[2, 2a], the Guest people, migrated from the Henan(河南)Province in batches of exodus in the past 2000 years or so, spend lots of their time in the shady parks, dancing, singing and playing games or sipping green tea while chitchatting. In a city of millions of residents, it is rare to see people who are not in a hurry; who have the admirable leisurely gait, delightful serenity, carefree style and calm composure of the villagers despite that they live in a big city and have to face stiff competition.

Sichuan is famous for its hot dishes. Yuan Yang Huo Guo(鸳鸯火锅)[3, 3a, 3b] is its representative and a must-try. It consists of a steam boat with two compartments, one filled with ordinary soup and the other with the red-colored hot chili and pepper soup into which diners dip their raw/cooked food to be cooked/warmed. The dish, of course, is delicious but hot, very hot. After a meal, most unaccustomed tongues will be numb and some of the diners might have stomach upset. But you have really not eaten Sichuan food if you have not tried the Yan Yang Huo Guo steamboat when you are in Sichuan.

From Chongqing we took a cruise down the Changjiang (长江)[4, 4a] to Yichang (宜昌), spending 3 nights on boat and alighting for sight-seeing along the way at small towns, including the famous Gui Men(夔门)[ 5a] and an old town Baidi Cheng[ 5ia]. Our main objective was to see the 2,309 meter long Da Ba(大坝), the Three Gorges Main Dam[6, 6a], which is the largest multipurpose dam ever undertaken by mankind till date. It is a controversial project the main benefits of which include flood mitigation, hydro-electric power generation and navigation and the down-sides include ecological disturbance, catastrophic consequence of dam failure for whatever cause, relocation of more than a million residents in the reservoir areas, submerging of cultural heritage sites. But to the Chinese Government, the benefits derived from flood mitigation and hydropower generation over shadowed all other things, including its US$25 billion formidable cost [7, 7a]. Without the Dam, the cost of damage to property by a 100 year recurrent flood is colossal, not to mention loss of human lives.
The designed maximum level of the reservoir is 185m AMSL and normal water level is 175m while the level now is controlled at 110m pending on more local residents to be relocated and reservoir bed to be prepared. The maximum reservoir capacity is 39.3 billion cubic meters, which was designed to cope with a 100 year recurrent flood volume of 22.1 billion cubic meters at water level of 175 m; electricity generation capacity 18.2 GW, navigational capacity is doubled. This is to say that the dam can hold back the amount of water enough to flood parts of the Hubei, Hunan, Jiangxi, Jingsu and Zhijiang Province downstream with a total population of 15 million and arable area of 150 square kilometers; produce as much electricity as 20 large nuclear power units[7i] of the day supplying about 4% of China’s total power requirement now and bring 20 thousand ton barges right up to Chongqing city at the confluence of the Changjiang and Jialingjiang.

The water in the Changjiang was turbid and looked like teh tarik [8] during our tour but the guide was quick to point out that the turbidity varies seasonally. In Xiao San Xia[9a], where the water is from undeveloped catchment, sure enough, it was crystal clear. The well known shallows and the rapids in the Three Gorges and the job of the Qianfu (haulers) [10a] are the things of historical and academic interest only now. The mountains, which make a gorge a gorge, along this stretch of Changjiang are awesome. Among them the Wunu Peak is the most famous and much written about. To describe them here is like reinventing the wheel with a crude product; I choose instead to show you photos and quotes you some famous poems [11, 11a].
The 5-stages dual-track ship locks [12, 12a] enable 10,000-toners to navigate pass the Dam, each stage raising/lowering the ships by some 20 meters vertically. The design principle is simple and the energy resource is flowing river water, but the technology to put the design in place is innovative and requires a break through. The design and construction of the main gates, each weighing 850 tons and the size of 2 basket ball courts, [13, 13a] stretch technology beyond the existing limits. For ships to be lowered, water level in the first upstream lock is drained down by 20 meters or so to match the water level of the adjoining lock so that the ships can move into it after the gate separating the 2 locks is open. By repeating the same process, the ships are lowered stage by stage until the water level in the downstream most lock matches downstream water level for the ships to leave the locks. For ships to navigate upstream a similar process is used, this time, water is let into the first downstream lock of the other set of locks to raise its level to match the level in the next lock. So simple and yet so technologically demanding in its construction.

The ship locks are for bigger ships which will take about 3 to 4 hours to go through the lock which is considered time consuming. Giant ship lifts [14, 14a] are being planed to carry an entire smaller ship of up to 3000 tons up and down in much shorter time intervals(45 minutes).

The cruise trip is an eye opener to a project which will bring tremendous benefits and yet not without its catastrophic threat and equally serious compromise, apart from providing sight seeing of the awesome views of the famous Changjiang Three Gorges after it was dammed up.

View some photos taken during this trip from my Facebook album


Submitted by Hiew