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Sask. Cres. - 16th Street Slope Remediation

Slope instability has been a re-occurring issue along the east bank of the South Saskatchewan River for many years. In 2014, the lower Meewasin Trail and sidewalk near Saskatchewan Crescent and 16th Street began to show signs of movement. In the spring of 2016, the movement increased significantly and the City closed the affected section of Meewasin trail, sidewalk and street for public safety.

Construction to remediate the slope, Saskatchewan Crescent and the upper and lower Meewasin Trails began in August 2016. The majority of the work was completed by mid-November 2016 with final constructing completed in August 2017. This has included:

  • Installing H-piles, a concrete lagging retaining wall, and sub-drainage 
  • Repaving Saskatchewan Crescent and the Upper Meewasin Trail above the retaining wall
  • Rehabilitating the lower slope
  • Restoring and reopening of the Lower Meewasin Trail

Work on the upper slope area was delayed due to the snowfall in early October 2016.  As a result, further work on the sidewalk and handrail on the west side of Saskatchewan Crescent will be completed in spring 2017. This area will remain closed between 16th and 17th Street during the winter. 

Saskatchewan Crescent at 16th Street will be opened for the winter, and in spring 2017 will be closed to finish the following work:

  • Road paving to final grade
  • West sidewalk and curb
  • Retaining wall handrail
  • Retaining wall cap
  • Lower slope revegetation
What has the City done about the slope instability at 16th Street and Saskatchewan Crescent?

In March 2016, Golder Associates was contracted to conduct a geotechnical site investigation, install and monitor additional instrumentation, and assess remediation design options. The remediation has included construction of an H-pile and concrete lagging retaining wall, earthwork on the lower slope, rebuilding the lower Meewasin Trail, and installation of sub-drains. Final reconstruction of the upper Meewasin Trail and roadway along Saskatchewan Crescent will be completed in Spring 2017. 

Additional Retaining Wall Information

The retaining wall consists of 36 H-piles (depth of 18 metres) spanning 70 metres along Saskatchewan Crescent. The concrete wall is 44 metres with a maximum height of 3.2 metres. The retaining wall will be monitored over the winter.

What causes riverbank slope instability?
Three main factors contribute to riverbank slope movement: groundwater (high water table), geometry (steep slope) and geology (weaker soils on top of stronger soils can slip).  In the decade leading up to the slope failure, Saskatoon experienced record high rainfall, leading to high groundwater levels.
River

A time lapse video of the retaining wall construction can be found by clicking here: Sask Cr & 16th Street Riverbank Remediation Time Lapse 

For more information, contact our storm water management staff at stormwater@saskatoon.ca or 306-975-7698 during regular business hours.