The Black Death was a plague the spread across medieval Europe in 590CE to 1500CE. It was an infection caused by rats and then spread by fleas. The rats were carrying a lot of germs and bacteria at the time so a flea would bite the rat and then would and bite a person.
The average life expectancy of a dam is 50 years, and 25% of the dams in the Army Corps of Engineers National Inventory of Dams are now more than 50 years old.This number is projected to increase to 85% by the year 2020.he Glen Canyon Dam supplies over 5 million people with power (Glen Canyon Dam Adaptive Management Program, 2007). These two dams also have the capacity to store 32,471,000 acre-feet and 27,000,000 acre-feet of water, respectively. In order to harvest hydropower however, dams must be built.
World's Tallest Dam. Currently, the tallest dam in the world is Nurek Dam on the Vakhsh River in Tajikistan. It is 984 feet (300 meters) tall. Hoover Dam is 726.4 feet (221.3 meters) tall.Today, Hoover Dam still ranks in the top 20 of the tallest dams in the world, but only in the concrete gravity and arch categories.Many other rock and earthfill dams have surpassed Hoover in height.rom about 1938 until 1948 the Hoover Dam powerplant was the largest hydroelectric plant in the world. Since then, larger facilities have been built, and people often ask, What is the biggest dam in the world today?. The answer depends on what you mean by biggest.