5. It is made of concrete usually. And it is the cheapest kind of Dam because it uses the least materials. It’s arch-like shape holds back the water and makes it the second safest dam in North America. They are usually built in rocky area, like the famous Hoover Dam. It is made of reinforced concrete . They can be curved or flat, high or low, but it is always built by a LOT of supports. It has the buttresses, which keep it up. They are shaped like triangles and they are helpful when the water pushes onto the Dam because they push back with their unique shape. The most commonly built Dam in North America. Like Gravity Dams, they rely on their weight to stop the water. Unlike all the other Dams, because it is created of rock and earth, it has a waterproof core that prevents water from seeping through the earth and rock. These Dams may be bulky, But they are strong! The safest Dam in North America is expensive because it needs SO MUCH concrete! But I can’t believe some people like it’s big, bulky look!
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7. DID YOU KNOW? The biggest Dam in North America is the famous Arch Dam, the Hoover Dam, Also called “The Boulder Dam” or “The Red Bull” an it was approximately 726.4 feet tall and 1244 feet wide.
8. ? The safest dam? What is the safest dam in North America? Check the answer. Embankment Arch Gravity Buttress