Soft Engineering

Soft engineering defences use knowledge of the river basin and its processes to try to work with nature.

Strengths

• Cheaper to maintain
• Flooding more predictable
• Improves recreation opportunities
• More aesthetically pleasing

What it is

Planning restrictions are made so buildings and roads cannot be built on the floodplain - the space is used for playing fields etc. and more water is able to infiltrate = less runoff = less discharge.

Strengths

• Impact of flooding reduced as no new buildings/roads are damaged
• Provides recreational opportunities

Weaknesses

• Restricts development
• Can't be used in already urbanised areas

What it is

Wetlands are re-established or conserved to give natural protection from flooding - trees and shrubs also planted along river bank to increase interception.

Strengths

• Vegetation protects surface soil from erosion & provides habitats for wildlife

Weaknesses

• Less land available for farming

What it is

It is where the river is made more natural so the floodplain can flood more naturally.

Strengths

• Little maintenance required
• Provides better habitat for wildlife

Weaknesses

• Local flood risk increased

What it is

Porous pavements or soakways are built to increase infiltration and decrease runoff.

Strengths

• Pollutants in the water are filtered out by the soil before the water reaches the channel

Weaknesses

• Expensive

Warnings are transmitted to people via internet, TV and radio in order to warn people ahead of an expected flood so they can move possessions and evacuate.

However, some people don't have access to the communication network or may ignore warnings if they have been wrong in the past. Also, floods can occur too quickly for warnings (flash floods).