Can waterways which are prone to flooding be dug deeper to help prevent flooding? Like just digging big trenches through the bed of the waterway?
In: 6
No. It doesn’t work. Rivera are kept clear, there’s digging involved, but mostly to move the sediments and vegetation away from critical areas.
The control is done by controlling the amount of water. You chose an area like a lake or valley or farmland, you build earthworks like a dam but with a narrow exit, and keep that place low level the entire year. If a flood comes, that designed area get flooded while the narrow exit fills the river with a controlled rate. That’s the best flood control. If properly done, you can even store some flood water and use it later to fight a draught.
Digging the river would just create a deeper valley, with stagnant water in the new trench, that trench you made would quickly get filled by sediments, so you spend a lot for little benefit.
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