Do dams hold 20 million tons of water?

Answer 1

Yes, and much, much more than that. Today, the huge dams can control more than a hundred times that much water.

Here is a recent news story about plans for several dams in Korea:

"Korea to build four dams along Nakdong River

SEOUL - The South Korean government plans to construct four dams along the Nakdong River as part of flood-control measures for the nation's second-largest river, the Ministry of Construction and Transportation said on Monday.

Announcing a set of flood-control policies for the Nakdong, a 510-kilometer-long river that flows through the southeastern part of the Korean Peninsula, the ministry said the new dams will be built by 2011.

Construction of Hwabuk Dam, the largest of the four, is to begin in 2004, with its completion slated for 2008, the ministry said.

Hwabuk, a multipurpose dam to be built in Gunwi of North Gyeongsang province, about 310 kilometers southeast of Seoul, will measure 50 meters in height and 340 meters in length and hold about 49 MILLION TONS OF WATER.

Hwabuk Dam is to supply about 38 million tons of water annually to neighboring areas and generate 2,870 megawatt hours of electricity per year. In the event of a flood or typhoon, the dam's water storage capacity will increase by 3 million tons.

Here is a news story about the huge dams that controlled water for the Sudan and Egypt to control the floods of the Nile:

An agreement was made in 1928 that gave the Egyptian Government the right to control the waters of the Nile outside Egypt, and as a result work commenced in 1933 on a dam at Jabal Aulija in the Sudan, 20 miles south of Khartoum. As the White Nile Valley from south of Khartoum was extremely flat, it was possible to impound a great volume of water by a dam of modest height. Work on the dam was started in November 1933 and was completed in April 1937. The completed dam was the longest in the Egyptian system. The reservoir that resulted by the construction of the dam was 187 miles long and four miles wide in parts had been formed and THE DAM WAS CAPABLE OF HOLDING 3,000 MILLION TONS OF WATER. Its purpose was to pass on water to Aswan and served the same purpose as if the capacity of the Aswan reservoir were increased again.

Answer 2

That and a lot more. Water in lakes and such is usually measured in acre-feet, meaning an area of 1 acre that is 1 foot deep. 1 acre-foot weight 1360 tons. Take a mediocre fair-sized dam. The one where I grew up was about 10 square miles of water (6400 acres because a square mile is 640 acres) and 50 feet deep. That gives 1360 x 6400 x 50 = 435 million tons. Keep in mind that, just because there is that much weight behind a dam does not mean that there is 435 million tons of force on the dam itself. The force on the dam is a function of the actual dam area and the depth. There still is a lot of force on a dam. For a 1 mile long dam that is 50 feet high the total force is 200,000 tons, less than 1/1000 the weight of the water behind it.

Answer 3

Some do. Some hold more (Aswan Dam on the Nile.) Some hold less (dams on 1/10 acre farm ponds).

Wiki "Aswan Dam".

Answer 4

Depends entirely on the size of the dam.

Answer 5

depends on how large the dam is.

Answer 6

Yes.