Whilst flood events are devastating to humans they are a natural occurrence that can provide negative and positive important environmental impacts.
Flooding helps spread organic material, nutrients, and sediments which enrich floodplain soils. They also replenish water resources and trigger life processes such as bird breeding events, migration, and seed dispersal in flora and fauna adapted to these cycles, while good soil moisture can allow crops and pastures to be established.
In 2016 NSW flooding triggered a mass breeding event, consequently tens of thousands of waterbirds flocked to wetlands in the NSW as floodwaters filled marshes for the first time in years.
Time is a major factor to consider with deciding upon flood impacts In the short term an individual flood event may appear to be an ecological disaster, with unsightly sediment and debris smothering beaches and natural areas. However, in the long term, flood events that are part of the natural cycle will ensure plants and animals adapted to flood-prone environments and the functioning of those ecosystems.
The speed of flooding is another major factor, flood waters that rise slowly allow animals to escape immediate effects. However the impact of fast flowing water, particularly on small or burrowing animals would have been more serious usually resulting in death.
Food and habitat shortages also present longer-term impacts on those that survived, and certain endangered species can be at risk after flooding events.
The major impacts on marine environments can be sedimentation and turbidity; litter and human-built waste deposited from the land; toxins, nutrients and mineral deposition.These impacts can affect the health of the seagrass and coral communities along the coast, and those species on which they depend.
Only time will tell and when the flood waters recede we will begin to understand the full impact of this environmental cycle.