A fall is constructed to 

Explanation:

• A fall (like a drop structure or weir) is constructed in waterways to reduce the energy of flowing water.

• It helps in dissipating the surplus energy that the water gains due to a steep slope or sudden drop.

• This prevents erosion and damage downstream by controlling the flow velocity.

• It does not create or maintain energy but rather controls and reduces it for safe flow management.

 Additional InformationTypes of Falls 

Chute Fall

• Water flows down a steep, smooth channel (chute) into a stilling basin or a lower level.

• Used where there is a moderate drop in the channel bed.

• Energy is dissipated mainly by the turbulence generated when water hits the basin.

Shaft Fall (Vertical Drop)

• Water falls vertically through a shaft or drop structure.

• Common in areas with large vertical drops.

• Effective in dissipating energy due to free-fall and impact.

Cascade Fall

• Water flows over a series of small steps or cascades.

• Used where the slope is gentle but the total drop is significant.

• Energy is dissipated gradually over multiple small falls.

Screw Fall

• Water flows down a helical or spiral channel.

• Less common, used where space is limited.

• Provides controlled energy dissipation through friction and turbulence.