Environmental Impacts of Flooding

Flood water can contain debris, pollutants and nutrients. Debris can include trees and stones, or even pieces of houses. Pollutants in flood water, such as bacteria and pesticides, can be carried far distances. Sedimentation and turbidity can result in the growth of algae and phytoplankton blooms that jeopardize water quality.  

Important nutrients and mineral deposits can also be dispersed by flood water, resulting in improved plant growth and overall ecosystem health. Over time, the nutrients, organic material and sediment carried by flood waters and deposited on the landscape can provide fertility benefits.

Replenishment of Surface and Groundwater 

One of the positive direct benefits of flooding is the replenishment of surface water and groundwater supplies. The replenishment of supplies can benefit soil, resulting in healthy crops and pastures.

Local Landscape and Habitat

Flooding can change local landscapes and habitats. For example, John Pomeroy, a professor and water researcher at the University of Saskatchewan, explained that the 2013 Alberta floods changed the Rocky Mountains and foothills region, thus altering everything from how future floods will play out to how animals will build habitats in these regions[4]. 

In urban areas, flooding can be extremely damaging and costly, as it can negatively impact infrastructure, homes and businesses. In the natural environment, however, flooding has a more positive impact on the natural environment as flood water provides nourishment to the landscape.  

[1]  “Environmental Aspects of Integrated Flood Management.” Associated Programme on Flood Management. WMO. Published August 2006 in Geneva, Switzerland. Pg. 34

[2]  Dumas, Daisy. ( 2011, January 14). Wildlife hit hard by Queensland floods. Australian Geographic. Retrieved from http://www.australiangeographic.com.au/news/2011/01/wildlife-hit-hard-by-queensland-floods/  

[3] Stream Notes. (n.d). Soil in our Streams, 1(1). Retrieved from http://www.bae.ncsu.edu/programs/extension/wqg/sri/sediment5.pdf 

[4] Livingstone, Andrew. (2013, June 24). Alberta Floods: Assessing the human, environmental and economic impacts. The Toronto Star. Retrieved from http://www.thestar.com/news/canada/2013/06/24/

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