Question

why are levees not fertile like floodplains?​

Answer 1

Answer:

Floodplains are not to be formed by fast-moving waters, which usually cut deeper rather than allowing floodwaters to flow more broadly. In a floodplain, the water flows more slowly, allowing the sediment to settle out. The heavier debris settles out first, often forming piles along the edges, which are called levees.