Flood Damage Assessment

Flood Damage Assessment
Case Study - Johnstone River Flooding

The Effects of Flooding on the Local Economy
Rural Damages
Urban Damages
Infrastructure Damages
Intangible Damages
Summary Total Cost Including 1 in 100 year floods
Summary including possible maximum flood

The Effects of Flooding on the Local Economy

The Lower Johnstone River region is a primary industry based economy serviced by a number of townships, the largest being Innisfail. The region comprises predominantly floodplain lands used for sugar cane, banana and pastoral activities. During flooding under existing conditions, agricultural
activities sustain substantial flood damage, reflecting the location of these activities in the floodplain.
Damages are not limited to the agricultural sector with significant damages also occurring to residential property, businesses and public infrastructure, particularly in larger floods.
Flood damages are classified as tangible or intangible, reflecting the ability to assign monetary values. Intangible damages arise from adverse social and environmental effects caused by flooding, including factors such as loss of life and limb, stress and anxiety.
Tangible damages are monetary losses directly attributable to flooding. They may occur as direct or indirect flood damages. Direct flood damages result from the actions of floodwaters, inundation and flow, on property and
structures. Indirect damages arise from the disruptions to physical and economic activities caused by flooding. Examples are the loss of sales, reduced productivity and the cost of alternative travel if road and rail links are broken.
For the purposes of this assessment, flood damages are classified into the following categories:
Tangible

Rural Damages

• cane farming
  
• banana farming
  
• beef grazing
  

Area of Rural Land Flooded

Urban Damages (residential, commercial and industrial)

Urban damages in the Johnstone Rivers system are concentrated in the Innisfail region and
Mourilyan. However, this analysis also includes damage to residential properties outside of these
townships such as smaller communities and farm houses.
The damage to urban areas is principally to property and can be categorised into residential,
commercial and industrial sectors.

Infastructure Damages

Infrastructure damages includes damages to telephone, electricity, roads, rail, flood structures and
other public utilities.

Example Road Damage

Intangible Damages

There are a number of intangible costs of flooding to the community including the following:

• loss of life and limb;
  
• preparedness (cost of flood warning, planning, community education);
  
• inconvenience;
  
• isolation/evacuation;
  
• stress and anxiety;
  
• disruption;
  
• health issues.
  

These intangible damages are not easily quantifiable and have not been included in the monetary
assessment of flood damages.

Summary Total Cost Including 1 in 100 year floods

 Summary including possible maximum flood

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