Well it is called rapids but I call it a waterfall
Rapids
Bigger.
rapids
A stretch of fast-flowing water is commonly referred to as a "rapids." Rapids are characterized by turbulent water and increased velocity, often occurring in rivers where the gradient steepens or there are obstacles like rocks. They can vary in intensity and are typically found in mountainous or hilly regions.
Rapids
A fast flowing stream is called a rapid. Rapids are where the water flows downhill very fast and over underwater obstacles.
stones and fast flowing water can block the water from flowing
erosion
Mayfly Nymphs live under stones in fast-flowing water or among plants in slow streams. Some species live in small burrows at the bottom of the stream. Some are flat and cling to the bottom of rocks in fast-flowing streams. They are mostly found in cool, more permanent water bodies like streams and lakes.
rapids
Whitewater.
Because the inside of the meander has deposited rocks and rubble building it up and making the water shallower whereas the outside of ther meander is being eroded by fast moving water.