Elbow River Flood Mitigation - An Update on Proposed Springbank Off-stream Reservoir Project

by Ann Sullivan

In 2014, one year after the largest flood since 1897, the Government of Alberta under leader Jim Prentice decided to move forward with the Springbank Off-stream Reservoir Project (SR1) as a way to mitigate future flooding. When complete, the dry reservoir, in conjunction with the Glenmore Reservoir, would be able to handle the same volume of water as in the flood of 2013.

The project is now seeking regulatory approval from the provincial Natural Resources Conservation Board (NRCB) and the federal Impact Assessment Agency of Canada (IAA), formerly called the Canadian Environmental Approval Agency (CEAA). The length of this process and its outcome are both unknown at present. Following approval, the Province will need to acquire land for the project, only 20 percent of which has been acquired so far.  Remaining landowners, some of whom strongly oppose SR1, could require expropriation.

“The regulatory process is unpredictable,” Matthew Hebert, executive director, transportation policy with Alberta Transportation, noted in a letter to the ERWP, “and setting definitive timelines is challenging as a result.” Once the project receives final approval, the project will take an estimated three years to construct. 

This is no small undertaking.

Components of the SR1 project include: a service spillway, diversion inlet, auxiliary spillway,

floodplain berm, diversion channel, new bridges at Township Road 242 and Highway 22, an emergency spillway, diversion channel outlet, storage dam and a low-level outlet that would allow water to flow from the reservoir back into the Elbow River via Unnamed Creek.

The diversion channel will be 4.7 km long and 170 m wide, and will be able to accommodate a maximum water depth of 25 m. The reservoir, located in central Springbank, will be bordered on the south and east sides by a 4-km long, 8-storey tall berm. The reservoir will hold water to a maximum depth of 28 m.

SR1 conceptual graphic published by the Alberta Government

Image taken from the Alberta Government's conceptual animation of SR1

The total footprint of the project will cover more than 2,700 ha (about 6,800 acres) and require raising both Springbank Road and Highway 22.

To get some idea of the scale of the project, and to see a visual interpretation, watch the Alberta Government’s conceptual animation of SR1 at https://www.youtube.com/watch?v=lNP5dKTiJ0Y 

The size of SR1 brings with it concerns about its effects on fish and wildlife within the project footprint. Hebert, in his letter to the ERWP, noted that the Environmental Impact Assessment of SR1 estimates that “the number of fish entering the reservoir would be directly proportional to the percentage of flow diverted.” During a flood comparable to the one in 2013, about half of the river’s flow (48 percent) would be diverted. In a 1-in-100-year flood, about 56 percent, and for a 1-in-10-year flood, about 14 percent.

Hebert said that, due to their weaker swimming capabilities, smaller fish such as minnows and young large-bodied fish would be more likely to be caught in the reservoir. He noted that “a proportion of the fish” are predicted to exit the reservoir when outlet gates are open, but he added, “Some fish mortalities are expected; these mortalities will be accounted for under the Project’s Fisheries Act Authorization and Offset Plan (i.e. compensation plan used to maintain fisheries productivity and sustainability.”

Opponents of the project, including Karin Hunter, president of the Springbank Community Association, question how the government can say that “Fish caught in the Springbank Reservoir during operation will be safely returned to the Elbow River.” (https://www.alberta.ca/environmental-assessment-springbank-off-stream-reservoir.aspx#toc-0) Hunter says an unknown number of fish will likely be entrained in the reservoir then remain in “this high-sediment, low-depth ‘lake’ between June and August.”

SR1 update conceptual graphic published by the Alberta Government

Image taken from the Alberta Government's conceptual animation of SR1

As for wildlife, four species listed as threatened or special concern under the Species at Risk Act (SARA) call the project area home: grizzly bear, Sprague’s pipit, olive-sided flycatcher and northern leopard frog. Barn swallows and bank swallows, both threatened species, were also observed in the wider project area (outside the reservoir footprint) during the breeding bird survey. The SR1 project area falls within the sharp-tailed grouse, golden eagle and prairie falcon zone. All three of these species are listed as vulnerable in Alberta by the Canadian Endangered Species Conservation Council.

AT’s Hebert noted that if construction activities are scheduled to take place during the restricted activity period (RAP) for migratory birds, “pre-construction bird nest surveys will be completed and site-specific mitigation developed to protect active nests . . .”

This still leaves opponents concerned about other species. Flooding in Alberta typically happens in late spring, when plants and animals are at their most vulnerable. At that time of year, the land within the proposed reservoir footprint contains flowering plants, pollinating insects, nests, and dens and burrows with eggs and young. Larger wildlife like deer, elk and bears might be able to escape, but smaller animals and their young would be at greater risk.

As well, part of the project area along the Elbow River falls within a Key Wildlife and Biodiversity Zone (as identified by Alberta Environment and Parks). These zones provide a valuable ungulate corridor, according to wildlife specialist Ryan Bennett, and would likely require ungulate surveys and restricted construction between December 15 and April 30.

Stewards of the watershed and nearby residents are also concerned about SR1’s potentially destructive impact on the aquifer and on the fluvial ecosystem downstream.

The Alberta Government says potential effects on groundwater quantity and quality “were determined to be not significant.” (Opponents dispute this claim.) Potential effects include changes in groundwater levels near the SR1 infrastructure (e.g., diversion channel, reservoir and dam). “These effects are limited to areas immediately adjacent to the Project and are not anticipated to propagate south of the Elbow River,” Hebert said in his letter to the ERWP. He added that a program will be put in place to monitor both baseline groundwater quality and longer term trends in water quality following operation of the project.

Water will be diverted from the Elbow River when it exceeds a flow rate of 160 m3s. Hebert noted that: “ . . . in the known record of about 110 years, the flows in the Elbow River have exceeded 160 m3s 10 times.” Once water is diverted, the time it takes to fill and empty the reservoir will depend on the severity of the flood. Modelling based on 2013 levels (1240 m3/s extrapolated from the Glenmore Dam calculation for 2013) showed that water would fill the reservoir in about four days, remain for about 20 days (while river levels decrease) and then take at least 38 days to drain back into the river. The whole cycle is estimated to take approximately 62 days.

Hebert also noted that operation of SR1 should not affect “channel forming flows” that move bedload and maintain aquatic habitats in the Elbow. “Allowing 160 m3s to go downstream means that SR1 still allows the Elbow River to maintain its channel forming processes and allows for seasonal wetting of riparian habitats as currently occur on the river.”

Dave Klepacki, a retired geophysicist and opponent of SR1, said he believes channel-forming flows could be much higher than the Alberta Government states, as high as “606 m3/s in a 1200 m3/s ‘design flood.’”

The SCA’s Hunter said that air quality will likely be negatively affected as the silt left behind by receding water dries. An estimated 2.3 million tonnes (4 m thick at the outlet) of silt would be left on the land after the reservoir fills with floodwater and then drains.

Opponents like Hunter are concerned that SR1 is “an experiment of gigantic proportions.”

Hebert’s response is that, although no two projects are identical, “offline storage for flood mitigation or irrigation is not a unique concept.” In a project update from June 2019, Alberta Transportation noted that it was listening to concerns from the public and Indigenous groups. For example, project designers have added a debris deflector to the project in response to concerns about large in-stream debris clogging the diversion channel during operation.

But opponents say this kind of response is too little, too late. They would like the government to consider other alternatives, such as an instream dam at McLean Creek (https://www.youtube.com/watch?v=vITAjUO0X4w

SR1, Hunter says, fails to consider “major checkpoints” such as the economy, society, the environment, culture and tourism. She calls it a “value-destroying undertaking,” and she questions why the government is not considering other projects. “We would just really like a fair assessment of the alternatives.”

Hebert confirmed that no alternatives to SR1 are being considered at this time.

Hunter said she and other opponents, including the Tsuut’ina as well as residents of Springbank, Redwood Meadows and Bragg Creek, have two fundamental issues with SR1:

  • The process used to choose the project was flawed in that it didn’t allow sufficient consultation, was rushed and didn’t look at other water issues (e.g., fire suppression, drought management, tourism potential).
  • The project will do nothing to protect upstream communities, and may, in fact, harm them.

“We’re all for flood mitigation,” Hunter said. “We just want it done right and done for all.”

According to former Rocky View County councillor and ERWP board member, Liz Breakey, the hamlet of Bragg Creek has received $33.4 million to build berms for flood mitigation for approximately 100 lots. Redwood Meadows berms have been enhanced to the 1-in-200 year flood level.  Funding for these projects was provided as part of the SR1 package.

At present, Alberta Transportation is completing: regulators’ requests for further information; First Nation consultation; Indigenous engagement; a stakeholder engagement program; and the acquisition of privately held agricultural land needed to complete the project.

Meanwhile, opponents of the project, now working together as the Elbow River Sustainability Alliance, are putting the finals edits on a 325-page document that will respond to Alberta Transportation’s reply to the Impact Assessment Agency of Canada (IAAC)’s request for more information. 

The IAAC’s timeline for review of a project is 365 days from the date they accept an Environmental Impact Assessment (EIA) to when they announce a ministerial decision. As of March 9, 196 days of the timeline had been used and 169 remained. However, the federal minister can extend the timeline or delay the process.

Click the link to download a PDF copy of this article.  pdf Newsletter article March 2020 (4.68 MB)

 SR1 update information poster

Image taken from the Alberta Government's information posters of SR1

SR1 information poster

Image taken from the Alberta Government's information posters of SR1

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