5.5C - Impacts of Flooding
Damage from flooding has both environmental impacts (soils and ecosystems) and socio-economic impacts (economic activity, infrastructure and settlement) (UK flood events, 2007 or 2012)
Socio-economic
- death and injury
- spread of water-borne diseases
- trauma
- damage to property, particularly housing
- disruption of transport and communications
- interruption of water and energy supplies
- destruction of crops and loss of supplies
- disturbance of everyday life, including work
Environmental
The environmental impacts of flooding receive much less publicity, perhaps because there are some positives:
Most ecosystems have a degree of ecological resilience that can cope with the effects of moderate flooding, It is where the environment has been degraded human activities that negative impacts are more evident. For example, the removal of soil and sediment by floodwaters can lead to the eutrophication of water bodies. That same floodwater can also leach pollutants into water courses with disastrous effects for wildlife, while diseases carried by floodwater can weaken or kill trees.
- recharged groundwater stores
- increased connectivity between aquatic habitats
- soil replenishment
- for many species, flood events trigger breeding, migration and dispersal
Most ecosystems have a degree of ecological resilience that can cope with the effects of moderate flooding, It is where the environment has been degraded human activities that negative impacts are more evident. For example, the removal of soil and sediment by floodwaters can lead to the eutrophication of water bodies. That same floodwater can also leach pollutants into water courses with disastrous effects for wildlife, while diseases carried by floodwater can weaken or kill trees.
UK Floods
The UK has experienced some severe floods in recent years, most notably in the summer of 2007 and the winter of 2015-16.
These unusually severe floods have had the same basic cause, namely prolonged heavy rainfall, but at different times of the year. During the 2016 floods, large areas of the UK received more than twice the average amount of rainfall for that time of year. Carlisle and Cockermouth in Cumbria were along the worst-hit places.
There were recriminations after the apparent inadequacy of flood protection measures. The following were singled out for blame:
What tends to be forgotten in post-flood enquiries is that flood protection measures are designed to cope with flood events of a given magnitude. When an event of a very rare order of magnitude occurs, no amount of money or engineering is going to prevent the hoped for degree of protection.
These unusually severe floods have had the same basic cause, namely prolonged heavy rainfall, but at different times of the year. During the 2016 floods, large areas of the UK received more than twice the average amount of rainfall for that time of year. Carlisle and Cockermouth in Cumbria were along the worst-hit places.
There were recriminations after the apparent inadequacy of flood protection measures. The following were singled out for blame:
- budget cuts in the amount of money being spent on flood defences
- an EU Directive that puts environmental conservation ahead of the regular dredging of rivers
- poor land management, resulting in blocked ditches
- global warming
What tends to be forgotten in post-flood enquiries is that flood protection measures are designed to cope with flood events of a given magnitude. When an event of a very rare order of magnitude occurs, no amount of money or engineering is going to prevent the hoped for degree of protection.