Oshawa flooding possible due to climate change

Lucy Benham narrates a flood risk video. Photo credit: Central Lake Ontario Conservation Authority

Lucy Benham stands amidst a dreary backdrop of dark clouds, closely-knit buildings and flood water swaying around her ankles. A yellow Camaro is parked beside her, its tires sitting calmly in the same water that seems to be rising with every moment. The slow but steady rise continues until the water reaches past her shoulders and climbs further, submerging her and everything else around her.

The screen fades to black.

Benham, senior resource engineer at Central Lake Ontario Conservation Authority (CLOCA), is in charge of flood hazard protection which involves monitoring water levels around the City of Oshawa.

Lucy Benham (web).jpg
Lucy Benham is the senior resource engineer at Central Lake Ontario Conservation Authority (CLOCA). She is in charge of monitoring water levels around the city of Oshawa. Photo credit: Soyra Mokashi

Painted above are a few moments from a flood simulation video narrated by Benham. The video illustrates a potential threat and serves as a premonition of what could occur in the case of a severe flooding in Durham Region.

CLOCA’s core mandate is to undertake watershed-based programs to protect people and property from flooding and other natural hazards, and to conserve natural resources.

The institution is funded by the Region of Durham, which uses one per cent of its entire budget to fund a total of five conservations in its jurisdiction.

Benham says with sea levels rising around the planet, a couple of inches may not seem like much but affects a number of other factors, such as floods and flood lines.

According to the Specialists in Energy, Nuclear and Environmental Sciences report (SENES), climate change models are showing an increase in yearly temperature. SENES is a Canadian organization that provides environmental consulting, engineering and services.

Eighteen of the nineteen hottest years have happened since 2001: hottest of all have been the last five years. If this continues, it will cause a number of chain reactions on the earth’s weather patterns, oceans, flora and fauna such as the melting of permafrost, which will cause glaciers, rivers and other water bodies to disappear. In turn, landslides will occur in mountainous regions.

“What we’re doing is thickening our atmospheric blanket with all these green-house gases that we are dumping into the atmosphere…To the tune of a 100 million tons of man-made global pollution daily,” says Ginny Colling, climate activist and retired journalism professor. “That atmospheric blanket warms up the planet and that’s where we’re at right now.”

This means there’s going to be less snowfall but more precipitation. So, there’s a potential that we will see more flooding.

“The recurrence of an event that previously would occur once in 100 years or have a one per cent chance of taking place in any given year may go up,” says Benham.

While the frequency of severe floods could rise, the risk of houses situated in these areas being flooded and destroyed rises as well. While the possibility of a 100-year flood is alarming enough, the real problem lies in the fact that most people are not aware their house falls on a flood line. People are not aware of the potential threat they are facing.

Sea level rise is another direct impact of climate change, with coastal areas being most at risk. They are rising due to two main reasons linked to global warming – melting glaciers and ice sheets adding water to oceans and the expansion of seawater when it gets warmer.

Average sea levels have swelled over nine inches since 1980. For example, coastal areas flooded 2.1 days per year from 1956 to 1960. This shot up to 11.8 days per year between 2006 and 2010, according to a study titled ‘Earth’s Future’ by William.V.Sweet and Joseph Park.

National Geographic says forty per cent of Jakarta, Indonesia, which is home to 30 million people, already lies below sea level. By 2050, 17 per cent of Bangladesh is expected to flood, displacing 18 million people.

The closer the areas are to the sea, the higher the risk lies. Moreover, houses that lie on the flood lines have additional hazards.

“There’s a risk that at some point the house may become flooded and sustain flood damage,” says Benham. “It also makes it a little bit more tricky if you want to make an addition to your house or do some changes.”

CLOCA regularly monitors water quality and levels around the flood zones.

“Our first step is to delineate the flood lines so we know where they are,” says Benham.

Any houses within those areas are identified as flood damage centres.

According to Benham, a flood-risk assessment ranks the highest-risk flood damage centre to the lowest-risk in all of CLOCA’S jurisdiction. “By identifying our flood damage centres, we pinpoint where possible future improvements can be made.”

In addition, CLOCA also monitors extreme conditions including rain forecast. Benham says they are constantly looking at how the future forecasts will affect conditions on ground.

“If we feel that there’s a potential for flooding, we send out messages,” she says. “Those messages go to the media, to our municipal partners, the region of Durham, emergency services, police services, and schools as well. It’s just trying to give some early warning of possible flooding.”

The conservation also works with government authorities, such as City of Oshawa, to help manage watershed resources in areas under its jurisdiction. Oshawa is one of its municipal partners.

“The City of Oshawa has done a good job in the last ten years to work collaboratively…they get floodplain maps into zoning as well as the official plan,” says Patricia Lowe, director of community engagement at CLOCA.

A big storm like Hurricane Hazel would give approximately a day to five days warning but thunderstorms are harder to predict as they can occur really quickly, and anywhere over the watershed. Hurricane Hazel, which took place in 1954, is the deadliest storm to occur in Canada, costing the country a death toll of 81 people and $137,552,400 in damages, according to the Canadian Encyclopedia.

Benham says one of the best ways home-owners can get informed is to enquire with their office about the property when they are purchasing it. CLOCA can provide them with a map outlining the relevant flood lines. The service is free of charge.

CLOCA reviews development applications, looking for flood hazards, erosion hazards and storm water management to ensure the development meets their guidelines.

“We are working towards getting the flood lines online and available but have some concerns with how that information is interpreted,” she says. “If someone comes here and obtains the map, we can talk to them and explain what that means and how to apply it to their property.”

A good real-estate agent would be aware of these details as well and would be able to do that work for their clients, if asked.

“I’d encourage home-owners to be aware if they’re in a flood plain. Even if they’re not, flooding can still occur. It’s important to be aware where your property is located, what risks it could have and what measures to take to protect themselves,” says Benham.