Bioengineering Demonstration and Education Project

The City of Calgary and The Government of Alberta, in 2018, partnered to create a project that demonstrates how bioengineering can be used to improve fish habitat and stabilize erodible river banks.

The Bioengineering Demonstration and Education Project (BDEP) is located between Pearce Estate Park and the Inglewood Bird Sanctuary on the Bow River in the community of Inglewood.

The site was initially identified by The Government of Alberta (GOA) as a candidate site for a bioengineering demonstration and education project under the department’s Fisheries Habitat Enhancement and Sustainability (FISHES) program.

The goal of the project is to increase awareness and understanding of how soil bioengineering structures are built, what benefits they can bring to watersheds, and how they might be used to mitigate the impacts of future flood events.

The Bioengineering Demonstration and Education Project has won the following awards:

  • 2020 Association of Professional Engineers and Geoscientists of Alberta (APEGA) Summit Awards – Environment and Sustainability Award
  • 2020 Consulting Engineers of Alberta Award of Excellence in the Water Resources Category
  • 2020 Consulting Engineers of Alberta Award of Merit in the Sustainable Design Category
  • 2018 City of Calgary “One City” award for the Environmental Category

 

The project, currently in the early monitoring phase, has produced a host of benefits to riparian health, fish and fish habitat, larger wildlife and habitat considerations, as well as bank and habitat stabilization.

Understanding and Assessing Impacts

The Bioengineering Demonstration and Education Project (BDEP) is part of the larger Riparian Action Program, which addresses multiple corporate priorities—including stormwater management, flood mitigation, biodiversity and climate change adaptation—while directly improving the quality of life for citizens and improving the resilience of our infrastructure and communities. While Water Resources has already undertaken many actions over the past decade to protect and restore riparian areas, the Riparian Action Program aims to better co-ordinate and focus municipal and community efforts.

The project is located along an 850m stretch of the Bow River in the historic community of Inglewood. The area was unique in southern Alberta as it was heavily eroded during the 2013 flood, had extremely unstable slopes, and prior classical “hard” engineering treatments installed immediately following the flood (rock groynes and rip rap bank protection), and could be used for comparison to the proposed bioengineering treatments. It is predicted that the effects of climate change will alter the frequency and magnitude of floods and droughts.

These physical elements provided an opportunity to apply a variety of bioengineering treatments to address riparian health, slope stability, bank erosion, and fisheries habitat issues which varied significantly from site to site across the project area. Early in the planning stages, it was recognized that the project aligned with and complemented a wide variety of City of Calgary and Government of Alberta policies and programs. The BDEP achieves key outcomes and specific actions under the City’s Flood Resilience Plan, the Riparian Strategy and Riparian Action Program, and the Government of Alberta’s FISHES Program and the Watershed Resiliency and Restoration Program’s Strategic Plan.

Identifying Actions

Until recently, due to factors such as a lack of familiarity with techniques, concerns about long term sustainability, cost, lack of available design and construction expertise and a lack of opportunity, bioengineering practices in Alberta have been limited.

The City of Calgary and the GOA are supporting and encouraging the adoption of bioengineering techniques to stabilize stream banks and restore riparian areas. With this project, a variety of bioengineering methods were used to achieve a number of bank stabilization goals while also creating critical fish and wildlife habitat and improving water quality. ​​This project aims to demonstrate how bioengineering techniques can be used for slope stabilization, erosion control, shoreline protection, surface protection, runoff control, and the reestablishment of fish and wildlife habitat.

The key objectives of this project included the following:

  1. Re-establish fish habitat degraded by recent flood recovery activities at the project location on the Bow River using bioengineering techniques.
  2. Stabilize slopes and control bank erosion at the project location.
  3. Restore riparian health and related functions at the project location to improve watershed resiliency.
  4. Demonstrate a range of soil bioengineering techniques and their applicability to different site conditions.
  5. Increase understanding and support knowledge transfer, research and partnerships among The City, the Province, professional practitioners, industry, academia and the public about bioengineering practices and techniques.
  6. Create an aesthetically pleasing river interface along the project area.
  7. Monitor, evaluate, and report on the effectiveness of the different bioengineering techniques used in the construction of the project

Implementation

Design consultants, Kerr Wood Leidal Associates Ltd. and Hemmera Envirochem Inc., were engaged by GOA to prepare bioengineering designs for each of the separate sites within the project area with an aim to demonstrate a diverse and broad variety of bioengineering treatments in different environments (i.e. moisture, soil and slope conditions). The existing topography, river hydraulics, geomorphology, habitat, and erosion protection influences the design of each sub-site, where different bioengineering techniques were selected to address these conditions and showcase a range of treatments.

14 different bioengineering techniques were constructed in 10 treatment areas across three sites that have a variety of hydraulic, geotechnical, and environmental conditions. Seven of the techniques are new to Calgary.

The new techniques are advancing the practice of bioengineering by addressing important objectives such as vegetating existing riprap, enabling summer construction outside the vegetation dormancy period, achieving toe (scour) protection using solely vegetative techniques, improving vegetation biodiversity and survival, and creating fish habitat.

Key design features:

  • Vegetated wildlife corridor and regional pathway
  • Vegetated riprap with rooted live cuttings
  • Vegetated timber crib wall
  • Fish habitat rock spurs
  • Fish habitat boulder clusters
  • Vegetated soil wrap
  • Brush Mattress with rock toe
  • Brush layer with Contour Fascine
  • Box Fascine
  • Brush Mattress with Contour Fascine
  • Hedge Brush Layers
  • Live Staking
  • Soil covered riprap with container shrub plantings
  • Void filled riprap using top soil and plug plantings
  • Void filled riprap using pit rub and live plant cuttings

Outcomes and Monitoring Progress

The City of Calgary is currently undertaking a long-term Riparian Monitoring Program (RMP) to better understand long-term riparian health trends. This program includes many flood affected and subsequently restored sites along river banks in the city. A 10 year monitoring plan of the BDEP is part of this program, the Bioengineering Efficacy Monitoring Plan (BEMP).

The BEMP is an important component of the BEDP and will provide valuable data to support the use of bioengineering techniques as effective and ecologically valuable alternatives to hard engineering practices for bank erosion protection.

The components being assessed are the following:

  • Fish abundance and fish habitat
  • Wildlife
  • Riparian health
  • Bioengineering structural activity

About 100 trees, 2,300 shrubs and 30,000 live cuttings were planted. About 2000 tonnes of concrete, wood, and steel were removed from the riparian area. Though early in the monitoring process, BDEP has improved the vegetation ratings in the riparian health inventory assessments by 2 to 2.5 times over a conventional riprap design site. Increases in fish and wildlife abundance, high rates of vegetation and cutting survival, overall increased riparian health, and sustained bank integrity and low instances of erosion are being attributed to the enhancements of the BDEP.

2020 Monitoring – Key Findings

Fish and Fish Habitat:

  • In 2020 fish were observed to be continuing to use the habitat enhancement structures provided by the BDEP as first observed in Year 1 (2019)
  • Fish were observed using and were captured within the vicinity of the habitat structures throughout the project area.
  • As expected, species composition and fish abundance observed during 2020 was higher than 2019 as the BDEP sites naturalize following the construction of the fish habitat enhancements.
  • Based on the fish use monitoring results, Sites 1 & 2 are providing higher quality fish habitat in comparison to Site 4, the conventional riprap design site.

Wildlife:

  • The year 2 (2020) breeding bird surveys resulted in the identification of 37 species, including one listed species at the BDEP sites (bank swallow).
  • The bank swallow colony identified in the baseline assessment at Site 2 was observed during 2019 and again in 2020 monitoring, indicating that construction did not result in fewer breeding colonies in the project area.
  • The most abundant species identified during the wildlife camera monitoring program were white-tailed deer, followed by coyote and white-tailed jackrabbit.
  • Deer and coyote presence observed on all four of the cameras throughout Site 1 and increased mean use from 2019 and 2020 suggests that the wildlife corridor in the project area is providing effective passage for large mammals.

Riparian Health:

  • All three BDEP sites show significantly improved riparian health in comparison to the baseline condition.
  • Overall, 2020 RHA (riparian health assessment) ratings for Sites 1, 2 and 4 ranges from 29% to 53% higher than the RHA ratings for a theoretical conventional riprap design site.

Bioengineering Structural Integrity:

  • In general, the physical condition of the bioengineering techniques, including fish habitat structures, appears to be stable, with no signs of major erosion, scour or displacement.
  • Materials used in the construction of the BDEP were generally found to be in good to excellent condition and are serving their purpose appropriately.
  • Overall, vegetation survival at the BDEP site was 76% in 2020.

Next Steps

The scope of the BEMP involves monitoring at the site in 2019, 2020, 2021, 2023, and 2028. Monitoring will be conducted during select seasons in each monitoring year to capture a range of environmental conditions.

Monitoring reports will be shared with the public on calgary.ca/BDEP. The City of Calgary looks forward to hosting webinars and appearing at conferences to review and discuss the results we are achieving at this project site.

Resources

Link to Full Case Study

Addition Resources: