Working with nature can protect us from floods | Science Matters | David Suzuki Foundation
Photo: Working with nature can protect us from floods

The severe floods in Alberta used to be referred to as "once in a generation" or "once in a century" but scientists and insurance executives alike predict extreme weather events will increase in intensity and frequency. (Credit: Keltek Trust via Flickr)

By David Suzuki with contributions from Communications Specialist Theresa Beer

News of the devastating floods in Alberta hit Canadians hard. We've all been moved by extraordinary stories of first responders and neighbours stepping in to help and give selflessly at a time of great need. As people begin to pick up their lives, and talk turns to what Calgary and other communities can do to rebuild, safeguarding our irreplaceable, most precious flood-protection assets should be given top priority.

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The severe floods in Alberta used to be referred to as "once in a generation" or 'once in a century'. As recent floods in Europe and India are added to the list, that's scaled up to "once in a decade". Scientists and insurance executives alike predict extreme weather events will increase in intensity and frequency. Climate change is already having a dramatic impact on our planet. Communities around the world, like those in Alberta, are rallying to prepare.

While calls are mounting for the need to rebuild and strengthen infrastructure such as dikes, storm-water management systems and stream-channel diversion projects, we've overlooked one of our best climate change-fighting tools: nature. By protecting nature, we protect ourselves, our communities and our families.

The business case for maintaining and restoring nature's ecosystems is stronger than ever. Wetlands, forests, flood plains and other natural systems absorb and store water and reduce the risk of floods and storms, usually more efficiently and cost-effectively than built infrastructure. Wetlands help control floods by storing large amounts of water during heavy rains — something paved city surfaces just don't do.

A study of the Upper Mississippi and Missouri Basins showed wetland restoration would have provided enough flood water storage to accommodate excess river flows associated with flooding in the U.S. Midwest in 1993. Research done for the City of Calgary more than 30 years ago made similar suggestions about the value of protecting flood plains from overdevelopment. When wetlands are destroyed, the probability of a heavy rainfall causing flooding increases significantly. Yet we're losing wetlands around the world at a rate estimated at between one and three per cent a year.

By failing to work with nature in building our cities, we've disrupted hydrological cycles and the valuable services they provide. The readily available benefits of intact ecosystems must be replaced by man-made infrastructure that can fail and is costly to build, maintain and replace.

Protecting and restoring rich forests, flood plains and wetlands near our urban areas is critical to reduce carbon emissions and protect against the effects of climate change. Nature effectively sequesters and stores carbon, helping to reduce greenhouse gas emissions. It also regulates water. Forested basins, for example, have greater capacity to absorb water than clear-cut areas where higher peak stream flows, flooding, erosion and landslides are common.

How can we protect ecosystems rather than seeing conservation as an impediment to economic growth? The answer is to recognize their real value. The David Suzuki Foundation has evaluated some of Canada's natural assets. This approach calculates the economic contribution of natural services, such as flood protection and climate regulation, and adds that to our balance sheets. Because traditional economic calculations ignore these benefits and services, decisions often lead to the destruction of the very ecosystems upon which we rely. Unfortunately, we often appreciate the value of an ecosystem only when it's not there to do its job.

Cities around North America are discovering that maintaining ecosystems can save money, protect the environment and create healthier communities. A study of the Bowker Creek watershed on southern Vancouver Island showed that by incorporating rain gardens, green roofs and other green infrastructure, peak flows projected for 2080 from increased precipitation due to climate change could be reduced by 95 per cent. Opting to protect and restore watersheds in the 1990s rather than building costly filtration systems has saved New York City billions of dollars.

Intact ecosystems are vital in facing the climate change challenges ahead. They also give us health and quality-of-life benefits. Responsible decision-making needs to consider incentives for protecting and restoring nature, and disincentives for degrading it.

As Alberta rebuilds and people begin to heal from the flood's devastation, it's time to have a discussion about adding natural capital to the equation.

July 4, 2013
http://www.davidsuzuki.org/blogs/science-matters/2013/07/working-with-nature-can-protect-us-from-floods/

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11 Comments

Feb 18, 2014
7:53 AM

Good

Aug 09, 2013
7:56 PM

I strongly agree with the fact that nature plays an important role in the occurrence of floods in cities. This effect can be tied to the concept of urbanization and impacts of increased impervious area. As the impervious area increases, it results in faster rise in water runoff rate, higher speed of runoff, lower baseline flow and greater peak. Due to this runoff surface water sustainability is affected, which leads lower light infiltration and compromises drinking water. Using the alternative option of nature over infrastructure to control floods can serve better for the current and future generations. By protecting and increasing the natural systems the cost for infrastructure to control floods can be eliminated. Nature also plays an important role in reducing the water runoff and increasing the water stock efficiently. Through the previous properties of soils

Aug 09, 2013
12:08 PM

Creating ‘green’ infrastructure and buildings may cost more upfront but with reduced costs related to storm protection and reduced costs for building operations (think how a green roof insulates a building and reduces heating costs) they often result in net decrease in cost over the lifetime of the infrastructure or building. This will benefit the economy as well as the environment and society. Sometimes we forget we are a part of nature and forget that sometimes the best way of doing things has already been figured out by more than a millions of years of trial and error.

Jul 09, 2013
10:45 AM

As the ice melts or the rain comes down the worlds waterways goes up. where? Over the land. Can the land heat up enough to turn the water into vapor. Then what? Sounds like the circle of life but not at a reasonable rate.

Jul 09, 2013
6:44 AM

Permeable concrete… Nope, close though! Gotta build cut in’s on street curbs so that water flow into mulch basins rather than going directly to the sewer, storing the water and creating biodiversity and ecology at the same time. Man will NEVER, did I say it? NEVER!! build infrastructure smart enough to withstand mother natures wrath, unless it completely mimics natural water and soil cycles. The good news is that these are relatively easy practices of engineering within the permaculture world, and that we CAN build a difference in even a decades time… fossil fuels, climate change… Just pointing fingers rather than rolling up sleeves and sticking it to our municipal leaders! You don’t need a city permit to start building food forests in every yard in town. Abolish the slavery that your lawn bounds you to and make a difference people. End rant.

Jul 09, 2013
1:58 AM

Ultimate-Historic Irony Alert!! The profiteering zombies of Capitalism will likely save the planet

Jul 08, 2013
2:07 PM

I know that some summers are wetter than others, but this rain in Toronto seems stranger than other years. I can sense that this is glacial melt related. More water into the system, hotter temperatures, more evaporation. I was worrying about desertification first, but I guess North America will get wetter before it gets drier. And again, nothing mentioned in mainstream news about the real culprit — fossil fuel.

Jul 08, 2013
11:51 AM

I agree with the article,but why, oh why do we insist on having basements in our houses then building on flood plain. Then are surprised when they fill with water?? Does anyone have a good reason?

Jul 05, 2013
9:36 AM

tough love says private property::private risk the common good does not include restoring every home owner to whole the common good does not include insuring every peril common good mandates protect life and limb common good does mandate restoring natural sponges, including native topsoil and litter layer common good restricts paving and drainage common good calls for supplementary water capture on private land

Jul 05, 2013
8:10 AM

Permeable Pavement will be helpful in the future.

David Susuki, do you have any room in your world to assist a co2 neutral company on Vancouver Island…. Non Herbicide Driveways is one of our products. Design of the biz, be on our board, help us fund raise for entrepreneurs to work with us.

It is micro financing by the people. Government does not have programs that will help the people that need it… they do not understand what is necessary.

Jul 05, 2013
12:17 AM

We need to understand nature to survive on earth. We must know the “principle and design” on which she works. Earth works to conserve certain energy to matter ratio [heat and cold]. With industrialization we have exponentially increased the heat of the environment, with loss of forest and intrusion into the night cycle we further aggravated the situation to a critical point. It is common sense that heat vaporizes water and when cycle changes water fall back. Heat unwinds and water winds. The fire and flooding by which the world is seeing destruction needs no scientific data. All we need is common sense. Winding force invariably means we will have series of earth quakes and eventually huge volcanic eruptions. That can destroy much of the civilization. History speaks many civilization buried under water. Volcanic ash is known to cool earth and it can bring a sudden cooling heralding an ice-age — http://www.youtube.com/watch?v=YawfoULZdbw

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