Overcoming Unexpected Challenges: Design, implementation & post-construction
Monday June 26 1:20pm-3:00pm
LEADS: Michael Lawson (GEO Morphix Ltd) and Jason Krompart (Beacon Environmental)
This session will focus on the unanticipated challenges, opportunities and lessons learned, that may arise during the planning, design, implementation, and monitoring of natural channel design or ecological restoration projects. Project managers, designers and contractors strive to research and document as much background information as possible to develop and implement a successful channel or ecological design that functions in theory, concept and reality. This session seeks to identify miss-steps and retrospective critiques, culminating in lessons that can serve as examples to others working on projects with similar circumstances. Some examples may include unanticipated situations, design assumptions that didn’t reflect current site conditions due to time lapse between design and implementation, and cases of ‘right solution, wrong setting’, among others. Join us in a friendly discussion of how natural channel design and construction complications were overcome, all towards a better understanding of sound science, engineering and construction, and the uncertainties that come with implementation.
Keywords: Field fit, Site conditions, Constraints, Construction, Monitoring
Following the conference, presentations that have been made available will be linked here.
Dan Murray, Laura Lawlor and Jeffrey Doucette
GHD Limited, Mississauga, Canada
On March 7, 2015, a CN unit train carrying crude oil derailed within the community of Gogama releasing 37 rail cars of crude oil into the environment. The derailment involved crude oil releases to the air (primarily from the fires), to the ground surface, and to adjacent surface water bodies including a river and wetlands. Not only did all the crude oil have to be removed from the site as safely and quickly as possible, the damaged landscape had to be repaired.
During the response phase of the project, two key priorities were to remove the oil from the river and remove oil-impacted soil from the floodplain adjacent to the river before the freshet. Monitoring the river flows and water levels was critical to working safely and planning out the tasks associated these two key priorities. GHD prepared models of the river based on flows reported from the upstream OPG dam and precipitation data from the nearest weather station. Many other mitigation measures were implemented to protect the environment during the tasks including a large sheet pile wall to protect the existing shoreline and to guide the restoration phase of the work after the bulk of the impacts near the river had been removed.
Once the physical derailment structures were removed from the river, GHD started planning the restoration phase of the work in conjunction with the balance of the remediation works. The restoration phase focused on developing a plan and measures that worked with the landforms, respected the existing channel form, and traditional uses of the land in this generally remote location. The objectives of naturalized bank reconstruction and stabilization, riverine wetland restoration, new wetland creation, and restoration of ecological function of the area were achieved through collaborative design and adaptive management.
This presentation will summarize the environmental response to the events including response phase work to remove oil from the river, restoration phase work to restore and create wetlands. The presentation will also highlight a variety of lessons learned from the event.
Stantec Consulting Ltd, Waterloo, Canada
In spring of 2022, a landslide occurred next to a small creek in a deep valley. The landslide debris swept away trees, buried the creek, filled the creek valley, and caused flows to back up and create a large pond. The landslide debris disconnected the upstream portion of the channel from the downstream channel and created a fish barrier. This presentation will review the emergency regulatory and restoration process for this site. Unique site conditions included the potential for contaminated soils, the presence of a bridge and popular walking trail, and Species at Risk including Atlantic Salmon (endangered) and American Eel (special concern).
Given the unique site conditions and the time sensitive nature of the environmental impacts, a quick response was critical. A compressed regulatory timeline was followed and the restoration that was implemented was based on approval of a high level conceptual design plan. The design and construction of the restoration was fully field fit.
This presentation will review project timelines, permitting, design, layout, and construction of the restoration. A discussion on high-tech and low-tech design and layout approaches will be included. Discussion on communication and planning items that should be included even in emergency response situations will also be presented. Lessons learned from this field fit project that can be applied to other field fit sites will be shared.
Ed Gazendam. Ph.D., P.Eng.1 and Beth Anne Fischer 2
1 Water’s Edge, Cambridge, Ontario
2 Conservation Halton, Milton, Ontario
The creek at this gravel extraction area was historically dammed and used as an on-line wash pond and sedimentation pond for a gravel extraction operation. The creek was also the historic habitat for American Eel, Atlantic Salmon and other coldwater species. Conservation Halton and Water’s Edge prepared designs to remove on-line obstructions, recreate a sinuous creek system, and create new wetlands as a part of the pit’s progressive rehabilitation plan; while still allowing the gravel operation to continue its operations.
Upon completion of construction, Conservation Halton provided ongoing monitoring and analysis of the new creek and wetlands. The data collected to date indicate that the channel is restoring. Existing Brook Trout present upstream and downstream of the pit operation disturbance are now utilizing the restored channel.
The presentation outlines the success of creek rehabilitation impacted by historic aggregate removal practices, demonstrates a balance between pit operations and restoration and interest from industry to repair their impacts to the land and water.
Brad Fairley, MES
5 Smooth Stones Restoration, Kitchener, ON
An NGO had identified a culvert under a railroad as a significant barrier to migrating salmon. The NGO and railroad worked with local first nations to develop a design to replace the culvert with a natural channel. The channel failed shortly after construction. This failure offers some lessons for those involved. Lessons for the designer include the need for the following: correct channel dimensions, a suitable channel slope, a floodplain, erosion control, and properly sized boulders that are effectively keyed into the bed and banks. Lessons for the NGO and railway include the need for the following: a qualified designer, a sealed construction design, using the designer for construction inspection, and appropriate construction budget.
Lucas Warner, M.Sc., P.Bio.1 and Brad Fairley, MES2
15 Smooth Stones Restoration, Calgary, AB
25 Smooth Stones Restoration, Kitchener, ON
The Eagle River is a tributary to the Thompson River that flows east to west into Shuswap Lake, BC. When the Canadian Pacific Railway installed its track west of Revelstoke BC in the late 1800’s, it moved the Eagle River from the south side to the north side of the valley significantly shortening and steepening the channel. Coupled with the loss of 1.5 m3/s of flow through the railbed into the original channel, the river is impassable to chinook salmon. For the last 10 years, DFO has been pressuring CP Rail to restore fish passage. 5 Smooth Stones Restoration Inc. (5SSR) was retained to develop alternatives that would improve passage for salmon. 5SSR recommended that the remnant channel be reactivated, which requires the construction of a culvert under the track to put the Eagle River back to its original alignment. The challenges associated with project include access for construction equipment, the height and width of the railbed and, most importantly, the need to keep trains running during construction. All of which make the project expensive. It should be noted that the restoration will generate approximately 19,000 m2 of habitat which could be banked and used to offset the costs.