Construction of the Springbank Reservoir will begin early next year. This is one of the most ambitious flood control projects in Canadian history, and a warning to cities that have been extensively developed in floodplains.
The Elbow River in Calgary. Jeff McIntosh/The Globe and Mail
Eight years ago, when rising water levels along the Elbow River forced an evacuation order from downtown Calgary and surrounding areas, Brenda Leeds Binder thought she had nothing to worry about.
Her home near Ancon Park in the city is not by the river, nor was it affected by the 2005 flood before she lived there. She and her husband moved something from the basement floor, expecting only a few inches of water at most. A few days later, they returned to the flooded basement. Their coffee tables and other objects were floating in five feet of water. These objects also destroyed the appliances and stove.
Despite this, Ms. Liz Binder still considers herself one of the lucky ones. The 2013 flood destroyed thousands of homes and businesses, including more than a dozen homes that needed to be completely demolished, and caused one death in Calgary and four deaths elsewhere in southern Alberta. This is the worst flood in Canadian history, with total losses estimated at 5 billion U.S. dollars.
The recent floods and mudslides in British Columbia that killed at least 4 people, destroyed part of the highway, and submerged important farmland in Abbotsford, once again reminded people how the situation would become if the built-up area was not fully protected Oops. The cost of the loss is still being calculated, but is expected to exceed the 2013 Calgary flood.
Calgary's solution to this problem: The proposed $432 million reservoir is located 15 kilometers west of the city and is designed to fetch water when the Cub River is high. Known as the Springbank Off-stream Reservoir or SR1, it will reduce the peak water volume that Calgary would otherwise have to deal with. Construction will start early next year and is expected to take three years.
"This will be one of the most important structural flood mitigation projects, of course in our region, if not in our country," said Frank Frigo, a water resource engineer who leads the Calgary basin analysis team. "This is very important to protect the communities along the Elbow River, including the city center."
In general, only large cities like Calgary have the ability to protect themselves with infrastructure of this scale. (Alberta will pay most of the construction costs of SR1, and the federal government will provide $168.5 million through its Disaster Mitigation and Adaptation Fund.) But critics point out that projects like SR1 are not foolproof.
Although dams can provide a sense of security, they may fail when they exceed their limits. They can also contribute to dangerous behavior, such as continued development in known floodplains. Such projects also often have far-reaching environmental impacts and must be managed carefully. There is always the risk of engineers overly relying on historical flood levels, and they have underestimated the possible floods caused by climate warming while battling with yesterday’s weather. And their build time is usually longer than expected.
The pattern of ignoring low-probability but serious harm has repeated itself in other parts of Alberta, with disastrous results. In 2013, a large-scale flood occurred in the town of High River, which closed the road and forced the evacuation of the area. Jeff McIntosh/Canada Press
Alberta's original plan was to make SR1 fully operational by the beginning of 2018. Regulatory delays, opposition from indigenous peoples and landowners, and two government changes have derailed the timetable. The project pits the interests of the province’s largest city against a group of vocal rural landowners and ranchers, including families who have lived there for a century.
Some flood control experts believe that SR1 is a high-cost solution due to decades of improper planning and decision-making, and tend to ignore low-probability but serious disasters until it is too late. This pattern was repeated in other parts of Alberta, including High River and Fort McMurray, with disastrous results. Experts believe that it is far better to move people out of floodplains than to engage in a never-ending and costly struggle with nature.
But the Alberta Natural Resources Conservation Commission concluded in June that the project was in the public interest and its benefits exceeded any environmental impact, including airborne dust, damage to fish, and loss of wildlife habitat. The Canadian Federal Impact Assessment Agency came to basically the same conclusion in July. Now, the province says it has obtained all the land it needs through a voluntary agreement with the landowner.
For many residents of the Calgary Rivers community, the completion of SR1 is not fast enough. Ms. Liz Binder feels anxious every year without adding a layer of protection.
"Every spring is anxious," said Ms. Liz Binder, co-chair of the Calgary River Community Action Group, who has been advocating upstream protection shortly after the flood.
"I won't breathe a sigh of relief until the project actually runs."
Springbank Reservoir: a huge reservoir
Most of downtown Calgary is located in the floodplain
Bow River and Ancon River. Government of Alberta
Plans to build a large reservoir called SR1 next to it
The Elbow River will be significantly reduced
The amount of water passing through Calgary during the main period
flood. Need a separate solution to reduce
Flood risk along the bow.
SR-1 has similarities with other flood control structures
In the world, it is called Liliu Reservoir in various places,
Reservoir, detention pond and retarding pond.
Although there does not seem to be the largest official list
With this structure, SR1 will be more
The St. Louis Dam in California, sometimes described as
America’s largest outflow reservoir...but it pales in comparison
Japan water enzyme retarding pool
Storage capacity, million cubic meters
matt mcclearn and john sopinski/earth and mail
Source: Alberta Transportation Authority qgis; Esri
Springbank Reservoir: a huge reservoir
Most of downtown Calgary is located in the floodplain
Bow River and Ancon River. Government of Alberta
Plans to build a large reservoir called SR1 next to it
The Elbow River will be significantly reduced
The amount of water passing through Calgary during the main period
flood. Need a separate solution to reduce
Flood risk along the bow.
SR-1 has similarities with other flood control structures
In the world, it is called Liliu Reservoir in various places,
Reservoir, detention pond and retarding pond.
Although there does not seem to be the largest official list
With this structure, SR1 will store more water than California
The St. Louis Dam in Nia, sometimes described as an American
The largest outflow reservoir...but it pales in comparison with the reservoirs in Japan
Storage capacity, million cubic meters
matt mcclearn and john sopinski/earth and mail
Source: Alberta Transportation Authority qgis; Esri
Springbank Reservoir: a huge reservoir
Much of downtown Calgary is located in the floodplains of the Bow River and the Elbow River. Albert -
Ta’s government plans to build a large reservoir called SR1 along the Elbow River
This will greatly reduce the amount of water passing through Calgary during the main period
flood. A separate solution is needed to reduce the risk of flooding along the bow line.
SR-1 has similarities with other flood control structures worldwide, and is also called non-river
Reservoirs, cisterns, detention ponds and retarding ponds. Although it doesn't seem to be
On the official list of the largest such structure, SR1 will store more water than the St. Louis Dam in California.
Sometimes described as the largest outflow reservoir in the United States...but it pales in comparison to Waterase in Japan
Storage capacity, million cubic meters
matt mcclearn and john sopinski/the global and mail, source: Alberta Transportation qgis; Esri
Calgary’s vulnerability to floods stems from its long history of being built on the floodplain where the Bow River and the Elbow River merge in the city center. Although many Canadian municipalities have made similar choices, Calgary's unique geographical environment ensures that the consequences will be extremely serious.
The Bow River and the Elbow River originate in the Rocky Mountains west of Calgary, where heavy rain from melting snow will cause the two rivers to expand rapidly. Flooding has always been a frequent visitor to this city, and significant events occurred in 1879, 1897, 1902, 1929, 1932, and 2005. Hydrologists call Elbow a particularly "shiny" river: the steep mountainous terrain in the west means that flooding conditions in the mountains reach Calgary almost without warning.
"The basin is very close to Calgary and is a fast-responding system," Mr. Frigo said. “Usually, if floods are forecasted in Winnipeg, a lead time of several weeks is required. In Calgary, we can go from completely normal summer conditions to 2013-scale activities in 9 to 12 hours.”
Like other rivers, the bend has been changing its course for thousands of years, leaving behind a scroll of abandoned rivers called "ancient rivers" that can still be found in a few blocks in the city center. During severe floods, rivers may overflow into these ancient channels, inundating seemingly unharmed communities.
As Calgary evolved from a border outpost to a major North American city, city officials over the years have apparently ignored these realities and allowed unconstrained construction in the floodplain. Gaps in Alberta's flood mitigation methods make this possible. A 2015 report by the province’s auditor general stated that the municipality “is not required to deal with flood disasters in land use regulations”. Some cities restrict the development of floodplains, while others do not. Calgary largely falls into the latter category. A municipal report pointed out that although some restrictions were imposed on the development of spillway in 1985, "sometimes these restrictions are relaxed due to development."
The 2013 flood exposed the cost of these decisions. In response, the province considered multiple options for protecting Calgary. At first, officials accepted the principles prevailing among flood control experts. For example, in a 2014 report, they recognized that “sometimes it’s more practical to keep people away from water than trying to keep water away from people.”
In 2014, the provincial government began to explore Dutch methods to manage flooding along tributaries of the Rhine (known as the "River House"). In short, this approach involves demolishing dams and restoring the landscape along the river so that it can contain and store floodwater when the river overflows its banks. A subsequent report by WaterSmart, a water management consulting company, told Albertans that the Dutch had learned some lessons from the floods in the 1990s. One of them was “the river is strong; it’s best to rely as little as possible on infrastructure that may fail. "Although the report explores temporary storage as a potential solution, it also urges the province to consider relocating people from high-risk areas.
Relocation is just one of many “non-structural” measures that have been popular (at least among flood protection experts) in the past two decades. Other measures include restricting the development of flood-risk areas, such as mandating retreat distances from waterways, or completely banning the construction of residential buildings in high-risk areas. Part of their appeal is that they are generally much cheaper than building large structural defense systems-provided they are adopted early enough.
After the Elbow River rose to its peak in June 2013, Calgary faced a city-wide emergency, which caused the evacuation of as many as 100,000 people. Chris Bolling/The Globe and Mail
On the other hand, moving people out of danger after decades of bad planning decisions is expensive and full of political pressure. In Calgary, this is completely impossible: a 2014 municipal report discouraged this choice, except for the most vulnerable areas, and provided little reason. It boils down to money: the city estimates that it will cost more than $2 billion to purchase all the real estate at risk of flooding. Documents from the Alberta Department of Transportation estimate that the demolition of houses, businesses, roads and other fragile infrastructure "may cost tens of billions of dollars in total."
Within a year, officials took SR1 as the way forward. Alberta will not leave room for the Elbow River, but will tame it once and for all.
Think of SR1 as a huge flood reservoir.
When the water level of the Elbow River is high, part of its flow will be diverted-at a rate of up to 600 cubic meters per second-through the diversion channel into the reservoir. This will reduce the peak flow into the Glenmore Reservoir, 18 kilometers downstream of Calgary, and reduce the risk of flooding in the city. When it is full, the reservoir will be 25 meters deep-the diversion gate will be closed at this time.
Alberta Transportation Policy Executive Director Matthew Herbert estimates that based on the historical record of flooding in the Cub River, the project may be run approximately once every ten years. Once the river returns to normal, the stored water will be gradually released back to the Cub River within a month or two. At all other times, the reservoir will be empty.
Looking north, a rendering of the Springbank diversion structure on the Elbow River. Handout
SR1 is huge in almost every dimension. Its $432 million budget is higher than its earlier estimate of $297 million. This will require 1,439 hectares of land currently occupied for pastures and farms, summer camps and some residential buildings. When filled, it can hold up to 78 million cubic meters, which is equivalent to more than 31,000 Olympic-sized swimming pools.
The project was designed to deal with the floods that occurred in 2013, when the floods on the Elbow River were considered a once-in-200-year event. (In contrast, Winnipeg's Red River Spillway is a 47-kilometer channel designed to allow floodwater to bypass the city. It has a rated capacity of up to 700-year floods.) Mr. Frigo said this This level of protection is necessary because it is expected that during this century, climate warming will increase the flow during major events by about 20%.
The scale of SR1 also implies significant environmental consequences that need to be carefully managed. Elbow is a silt river: once the reservoir is drained, it will be covered with silt, which may be blown across the area. (Plants and chemicals called tackifiers can be used to bond soil together, reduce wind erosion and inhibit dust.) During operation, reservoirs and diversion tanks will become death traps for fish; NRCB for Alberta The Provincial Transportation Bureau is satisfied with the measures proposed, including a "strong fish rescue plan." SR1's flood storage will also replace other wildlife, although the NRCB concluded that “at the regional level” habitat loss is negligible.
A report released in 2020 by the Geneva Association, an insurance industry think tank, pointed out that Canada tends to use most of the flood-related funds for the construction of structural defenses and post-flood reconstruction, while almost no funds are used for other measures, such as buyouts or Protecting personal property. The report concluded that this preference "remains an obstacle to more substantial reforms."
This is also a secret of delays. Osler’s supervisory lawyer Martin Ignasiak’s comments in 2020 attributed these delays to deficiencies in the Alberta Department of Transportation’s original environmental impact statement: he concluded that the province had been warned that it might be rejected but still submitted Up. More delays are due to the response to an "unprecedented" amount of information requests from provincial regulatory agencies.
The delay brought another risk that a flood might catch Calgary off guard. This is what happened in Fort McMurray. During the 2020 ice flood, the community was unable to defend because of the delay in the berm network. After 2013, Calgary took more than a dozen measures to protect itself, such as expanding the capacity of the Glenmore Reservoir and building flood barriers in vulnerable communities.
Some commentators believe that SR1 is an unprecedented gamble, but its basic concept is not new. Tetsuya Sumi, professor of engineering at Kyoto University, visited and wrote an article on global flood control structures. He said that the ancestors of this concept were born in 1913, when Dayton, Ohio was flooded, killing 360 people; shortly thereafter, local authorities built five buildings called "dry dams." It is still running today.
An annotated rendering of Springbank's diversion entrance on the Elbow River, looking south. Handout
Dr. Sumi said that since then, many flood storage reservoirs similar to SR1 have been built along rivers that span Europe and Japan. Compared with traditional dams, outflow reservoirs have environmental advantages: in particular, they do less damage to river ecosystems because they do not block river channels.
But critics believe that SR1 is a waste of space. In Japan, when floods are not stored, outflow reservoirs are usually used as rice fields. The Waterase Retarding Basin on the outskirts of Tokyo is used as a nature reserve and recreation area most of the time. In contrast, the footprint of SR1 is a no-go zone for almost everyone during the flood season (May to July). According to the draft land use plan, at other times, indigenous people exercising treaty rights can use it. It can also be used for grazing and hiking.
Future Calgarians may also see SR1 as a missed opportunity because it does not address the threat of drought. When Alberta began to explore options to prevent the Calgary flood from recurring, some critics urged it to solve both problems at the same time. But Mr. Frigo said that the small scale and poor water quality of the Cub River are not suitable for alleviating drought.
SR1 will not solve all the flooding problems in Calgary, because the city will still face flooding from the Bow River. City officials estimate that measures taken since 2013 have reduced flood risk by about half; Springbank will increase this ratio to about 70%. Other options for taming the bow are being considered, such as building large reservoirs, but officials say they will take ten years or more.
The Springbank project caused controversy almost as soon as it was proposed, because the landowners whose property was located in the footprint of the reservoir opposed being forced to leave their land, either by letting the provincial government buy them, or if they could not reach an agreement, they would be forced to sell through expropriation. The reservoir is supervised by three different provincial governments and became an issue in the 2019 provincial elections.
The United Conservative Party had previously hinted that the project would be cancelled, but eventually joined because of opposition from a small group of ranchers and landowners.
One of the most fierce opponents, Mary Robinson, is a rancher, and her family has been working there since 1888, and her land will be flooded. She has long believed that the reservoir would destroy land with rich heritage value, and accused Calgary of "a few wealthy people" for promoting its development.
Opponents also complained that the province failed to fully consider alternatives, namely the proposed dam and permanent reservoir in McLean Creek further upstream. They believe that building a dam at McLean Creek will affect fewer landowners, protect more communities, including Bragg Creek and Springbank, and leave a reservoir that can be used for canoeing and kayaking.
Karin Hunter of the Springbank Community Association believes that once politicians have finalized the SR1 project, they have no interest in considering anything else.
"It appeared very early because only a few landowners prevented flood mitigation for one million people.
Mary Robinson, the fifth-generation rancher, is worried about what will happen to her land along the Elbow River if the Springbank Dam continues to advance. Leah Hennel/The Globe and Mail
This is the problem: SR1 will disrupt the lives of the people living in its huge footprint so that the lives of Calgarians can proceed as usual. Twyla Kowalcyz, climate resilience expert at Associated Engineering Ltd., said that Springbank will greatly improve Calgary's flood protection capabilities. But she pointed out that even in communities that are extremely vulnerable to flooding, few residents accept voluntary buyouts. Therefore, the wealthy communities along the Elbow River look similar to what they were before 2013.
"Many of these houses are built directly by the river," she said. "So even there, the landscape along the curve in the city hasn't really changed."
Calgary City Councillor Gian-Carlo Carra's constituency includes the Inglewood neighborhood east of the city center, and he has little sympathy for rural landowners. He said they received "very good compensation" and accused them of delaying the project. He said their needs cannot exceed Calgary's needs.
"We are talking about providing ranch for several ranch families. A hundred years ago [when some of these families bought land], we didn't need any of these things. No city with a population of 1.4 million is the economic engine of our country."
Last year, after the provincial government agreed to provide 32 million US dollars in funding for flood control projects, the Tsuut'ina nation gave up its opposition. Rocky View County formally abandoned its opposition last year in exchange for $10 million and prioritized commitments to other infrastructure projects in the area.
The Alberta government announced in early November that it had reached an agreement with landowners to purchase all the required land without resorting to expropriation. This is particularly irritating for governments that have pledged to strengthen the rights of landowners. Worried choice. The project is now scheduled to start next year.
Transport Minister Rajan Sawhney admitted that the negotiations with the landowners were controversial, but she said the province needs to ensure that devastating floods do not happen again.
"This has never been an easy conversation," she said in an interview. "There is a lot of history behind this. There are also a lot of emotions behind this. But in the 2013 flood, it caused a loss of 5 billion U.S. dollars and people lost their lives."
Interested in more stories about climate change? Sign up for the Global Climate Newsletter to read our series of articles on climate change innovation and adaptation.
Build your personal news feed