What a summer’s worth of flooding means for the local environment

A lot can be said about the affects of flooding in a given area – the good, the band the ugly.  Flooding can be synonymous for destruction and devastation, but surely, there must be some good that comes from persistent flooding in an area?

Locally speaking, a spring laden with heavy precipitation and higher than average snowpack levels in both Canada and U.S., even in May, resulted in a runoff forecast for the Columbia basin that is 130% of normal.  This is quite obvious if you’ve taken a walk along the greenbelt in Revelstoke in any given point this spring and summer.  Both the Columbia and Illecillewaet Rivers are the highest that I’ve seen in the 3 years since moving to Revelstoke.

But what sort of impacts does this have on local ecology? Flooding can directly impact the health and well-being of wildlife and livestock, riverbank erosion and sedimentation, the dispersal of nutrients and pollutants, surface and groundwater supplies, and local landscapes and habitats.

The good: Flooding is a natural ecological process that plays an integral role in ensuring biological productivity and diversity in the flood plain. Flooding can also replenish surface water and groundwater supplies, which can benefit the soil and contribute to the growth of healthy crops and pastures.  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.

The bad:  Large quantities of water can negatively affect natural and ranching and farming habitats.  A large or persistent flood can result in a loss of wildlife and biodiversity in the region creating long-term impacts for surviving wildlife by eliminating habitat, food supplies, nesting areas, etc.  Riverbank erosion is another symptom of flooding that can impact recreational users – rideable trails, fishing spots, and camping areas can all be devastated by flooding.  Moving sediment can act as a source of water pollution – clogging riverbeds and streams, and reducing storage capacity for reservoirs and wetlands. Flood waters can carry large amounts of sediment and leave deposits behind once flood waters recede. If extreme enough, sedimentation can degrade water quality and temporarily affect municipal, industrial and recreational water supply.

The ugly: Pollutants in flood water, such as bacteria and pesticides, can be carried far distances, while sedimentation and turbidity can result in the growth of algae and phytoplankton blooms that jeopardize water quality.  Flooding can change local landscapes and habitats, altering how future floods will play out and how animals will build habitats in these region.  Finally, flooding can be extremely damaging and costly in developed urban areas, as it can negatively impact infrastructure, homes and businesses.



Revelstoke Mountaineer

Environmental Aspects of Integrated Flood Management



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