Trans Mountain Derr Creek Bridge Replacement

Trans Mountain is proposing to replace the existing Derr Creek bridge to allow heavy equipment traffic to access KP 400 along the existing Trans Mountain right-of-way. The current Derr Creek bridge has a load limit of 21 tonnes for a single unit maximum gross vehicle weight which is not sufficient for heavy equipment (e.g., excavators, hydrovacs, gravel trucks, drill units). By replacing the bridge, this will allow heavy equipment to access the valve site at KP 400 and provide safe access for potential operations and maintenance work in the area (e.g., integrity digs, fiber repairs).

Trans Mountain plans to replace the existing 60 foot clear span bridge with an upgraded 80 foot clear span bridge at the current location. Temporary pedestrian bridges will be installed on impermanent abutments adjacent to the existing bridge locations to reduce potential disruption to parks users and to facilitate construction. The existing bridge structure will be lifted from their abutments with a winch truck, excavator, crane or some combination of heavy equipment and sent to a Trans Mountain facility for storage. The old abutments will be extracted with excavators staged on either side of the bridge, and the waste material will be taken to an approved landfill and/or recycling facility on a salvage/gravel truck. The excavation will proceed until grade is set for the new abutments. The abutments will be constructed of interlocking blocks on a precast concrete slab with a compacted crushed aggregate base. The area around the abutments will be backfilled with material salvaged during the excavation of the old abutments, and additional imported fill if necessary. The backfilled abutments will be armoured with 250 kg class riprap. Voids within the riprap will be filled with salvaged material and/or additional imported soil, and the filled voids will be seeded and/or live staked with salvaged cuttings. A precast concrete sill will be grouted in place on the abutments and the new bridge will be placed on a rubber bearing pad on the sill with a winch truck, excavator, crane, or some combination of these equipment. Wingwalls of pressure-treated lumber will be  mounted to both ends of the bridge, and bridge aprons of compactable crush or other suitable road construction material will be fit to both ends of the bridge.

The excavation of abutments and clearance needed for the crane swing radius will require vegetation removal at both locations. Reclamation will include backfilling, seeding, and planting live willow and alder stakes that will be salvaged during the clearing and brushing activities. Care will be taken to minimize clearing for the project, with limbing and crown pruning selected rather than felling where feasible.

A review of the project proposal has determined that the proposed project will be subject to a Basic Impact Assessment (BIA).

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Latest update

September 26, 2024 - The assessment decision statement has been issued to the proponent.

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Contacts

Jasper National Park
Box 10
Jasper, Alberta T0E 1E0
Telephone: 780-852-6141
Email: evaluationdimpactjasper-jasperimpactassessment@pc.gc.ca


Disclaimer

This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.

  • Location

    • Jasper National Park of Canada (Alberta)
  • Nature of Activity

    • Bridges
  • Assessment Status

    Completed
  • Start Date

    2024-08-16
  • Proponent

    Trans Mountain Pipeline ULC
  • Authorities

    • Parks Canada Agency
  • Assessment Type

    Project on federal lands
  • Reference Number

    88826

Nearby assessments

...within 200 kilometres
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