This is because the pressure in a liquid increases with depth. This means that the pressure at the bottom of the dam is more. Hence it is more liable to break out from the dam as more pressure is exerted on the walls. So, the walls are thicker at the bottom.
to hold the water better but at the top it's thinner to get water in
Well man made dams like the Hoover dam can support the water from overflowing while beaver dams a just basically homes.
The pressure of the water (the weight) is greater at the bottom, due to the depth of the water. As the pressure is less near the top, the top of the dam wall doesn't need to be as thick as the bottom of the dam wall.
There were 3 TVA dams on the Tennessee River in Alabama
Bottom ones have to bear more weight
1.1 mm
beavers make dams
the air gets thinner as you get nearer the top.
electricity that is made from water-dams
i don't knowummmm how about Sand
because gravitatinal potential energy of water is used to rotate turbines.
It is made of wood which is been made thinner in process.