1.1 Huge walls built across rivers. A reservoir (artificial lake) is
formed from this. Floodwater is caught by the damn which
prevents flooding downstream.
1.1.1 Benefits- Turbines are often built into the dams which can generate electricity.
They are also used for recreational use. Furthermore, water release can be
monitored which allows the irrigation of land below the dam throughout the year.
1.1.2 Drawbacks- Land is flooded when a reservoir is first
created, destroying farmland, habitats, and forcing
humans to move elsewhere. Dams also trap sediment
which causes the dam to fail. Because there is less
protective sediment being deposited, erosion is
2 Channel straightening
2.1 Where meanders are removed by building artificial cut-throughs,
which make the water flow faster. It reduces flooding because
water drains downstream faster and doesn't build up to the point
where the river channel can no longer hold it.
2.1.1 Benefits- It takes less time to navigate the river as it is shorter.
2.1.2 Drawbacks- Flooding may happen
downstream instead as flood water is
carried there faster. Also, more erosion
occurs downstream because the river flows
faster. Furthermore, wildlife may be
disturbed because their habitat could be
3.1 Embankments built along rivers. The river can
hold more water without overflowing and so
flooding is less common.
3.1.1 Benefits- They allow the
flood plain to be built upon.
3.1.2 Drawbacks- They are expensive
and there is a risk of severe
flooding if the levees are
4 Diversion spillways
4.1 They have channels that take water elsewhere if the water level
in the river is too high. Water is normally divert around an
important area or to another river.
4.1.1 Strengths- The spillways often have gates
that can be opened. so the release of water is
4.1.2 Drawbacks- An increase in discharge when he diverted
water joins another river could cause flooding there. Also,
if spillways are overwhelmed, water will flood areas not
used to flooding.