For southern Albertans, simply seeing or hearing the word “flood” reawakens ugly memories of the all-too-familiar natural disaster in June 2013.
People stranded for days and houses ruined by rushing water and debris resulted in the Province spending approximately $5 billion to restore infrastructure.
An ecology expert recently spoke of the causes that surrounded the overwhelming Alberta floods and says climate change models suggest future floods (and droughts) will only become worse.
The recent completion of Phase 3 – a phase to explore and assess temporal and spatial changes in the fiscal performance of natural capital accounts of the Upper Bow River Basin – offers a look at how managers will better understand the best practices for future risk mitigation and look at creating a potential integrated model.
“It’s human nature to think about ‘me, here, and now’,” said Dr. Brad Stelfox at the 2015 Living in the Natural Environment forum Feb. 6 hosted by the MD of Bighorn in Cochrane. He gave his thoughts on the active watershed, including how the province’s land uses and rapid growth over the past century have shaped the ecosystem for better or for worse.
Stelfox, an assistant professor with the Department of Biology at the University of Alberta and Department of Environmental Design at University of Calgary, said the “me, here, now” thought process has to change to a “community, regional and generational” process to give a different perspective to manage land uses that are shaping Alberta’s most densely populated watershed, the Bow River Basin.
“The resiliency of the Bow River watershed to absorb and hold meltwater has been impaired by land uses such as forestry, transportation and residential,” he said, adding human infrastructure (crops, forestry, residential, transportation) has accelerated the rate of water movement to the mainstream rivers.
“Although engineering solutions play a key role in flood mitigation, long-term and sustainable solutions to flood risk must incorporate a landscape/watershed level.”
A time series by ALCES Landscape and Land-Use Ltd. simulator predicts over double the amount of rural residential in the Upper Bow River Basin from 2010 to 2060, as well as a small decrease of its natural wetlands.
Effective watershed-scale flood mitigation requires a system-based approach, he said, that integrates all relevant science disciplines, instead of subjecting it to a single approach.
“The Bow River Basin is being shaped by all of these land uses and they’re all creating benefits and they’re all creating challenges. They express themselves in water flow, quality, quantity and we have to … manage them as an integrated system because that’s what it is,” Stelfox said.
Floods are natural occurring processes that keep watersheds strong and reservoirs, natural dams and wetlands all play a role in water storage and slowing a flood’s progress.
“(The 2013) flood was created by a well established low-pressure system that dropped an immense amount of precipitation and saturated those basins’ abilities to infiltrate that water and it ran off under gravity,” Stelfox said.
The approximate 15,500 square kilometre area was soaked by 150 mm of precipitation in an intense two-day period.
“We’ve taken the Bow and subjected it to all sorts of singles events to see if that solves the problem from a modelling perspective and none of them work by themselves,” Stelfox said.
“It’s going to be a collection of strategies right from our individual families to our municipalities to provincial government – some of which are going to be natural processes and natural landscapes and many of them are going to be engineering solutions that will give us the better opportunity to manage risk.”
