Soil Bioengineering for Steep and Unstable Slopes

This presentation uses natural disturbance and recovery as a basis for treating steep and unstable slopes. It covers surface preparation and living plant treatments, with dated examples from Juniper Place, the Mackenzie Valley Fibre Link, mine sites, and landslides.

33:42 · 185 slides · Historical presentation · No recorded narration

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Juniper Place Landslide Restoration · Living Structural Systems in Soil Bioengineering · Site Assessment & Restoration Planning

About this presentation

Source: Soil Bioengineering for the Treatment of Steep and Unstable Slopes.pptx. Slides by David Polster; individual image and diagram credits remain in the presentation. This video includes the complete supplied deck. It is an archive slideshow, not a recording of the spoken conference session.

Dates, costs and examples reflect the original presentation. Treatment suitability depends on current site conditions and requirements.

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  1. Soil Bioengineering for the Treatment of Steep and Unstable Slopes
    David Polster, M.Sc. R.P.Bio.
    Polster Environmental Services Ltd.

  2. Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed.

  3. Successional model for restoration – start with disturbance.

  4. At one point not long ago most of Canada was covered by ice…

  5. …and now we have landscapes covered with a diversity of ecosystems.
    How did this happen?

  6. Compared to Continental Glaciation some of our largest disturbances look small.
    200 tonne trucks

  7. Natural disturbances dwarf human disturbances…

  8. …and give us opportunities to see how these disturbances recover.

  9. Natural landslides...

  10. Frank Slide
    Over time natural processes “restore” these sites

  11. Studying how this happens provides a foundation for the design of restoration programs for our largest disturbances

  12. By looking at natural solutions to revegetation we can develop effective restoration systems

  13. See any similarities???

  14. Fine textures at the top, free draining in the middle, larger rock at the bottom

  15. By pushing the fine textured materials over the face we can eliminate the limitations of the coarse substrate.

  16. By making the surface rough and loose we can control erosion

  17. How do natural processes prevent erosion?

  18. Trees turn up large clumps of soil, leaving pits in the forest floor

  19. As the old root mass weathers and breaks down,

  20. the mound of soil starts to attract vegetation,

  21. until it becomes a mound on the forest floor.

  22. Natural forest floors are rough and loose and have woody debris.

  23. How can we deal with erosion without grass and legume seeding?
    “D 10” Bulldozer

  24. Spreading soil material…
    “D 10” Bulldozer

  25. Erosion starting on smooth surface before spreading is even completed.

  26. Making the surface rough and loose

  27. Strips allow woody debris to be applied

  28. Roughened the whole surface

  29. Making surfaces rough and loose controls erosion and enhances native species establishment.
    Cost of rough and loose treatment at Kemess Mine was $715/ha while hydroseeding costs about $3,500/ha

  30. Rough and Loose Restoration Treatments
    Northern BC, September 22, 2014

  31. Creating ideal conditions for vegetation growth.

  32. NE Alberta
    August 27, 2012

  33. Happy willows
    NE Alberta,
    September 10, 2014

  34. Gas plant near Edmonton to be restored,
    March 11, 2010

  35. Rough and loose, April 14, 2010

  36. Planting pioneering vegetation,
    April 14, 2010, note fence.

  37. Cuttings growing, June 24, 2010

  38. September 11, 2010

  39. Red-osier Dogwood

  40. August 19, 2011
    Two growing seasons

  41. February 24, 2015

  42. September 25, 2015
    Six growing seasons after restoration

  43. February 23, 2016
    The use of natural processes can provide cost-effective solutions for the restoration of drastically disturbed sites.

  44. Rough and loose Outpost Island, Great Slave Lake, NWT, Canada

  45. Soil bioengineering is the use of living plant materials to perform some engineering function

  46. Soil bioengineering solutions for the Point Grey Cliffs

  47. UBC Slopes, March 6, 1989
    70o Slope

  48. Doesn’t change slope (70 degrees)
    Changes conditions for vegetation growth
    1989

  49. UBC slopes initial test planted winter of 1987/88, May 7, 1988

  50. Wattle Fences

  51. UBC Slopes, May 28, 1990

  52. UBC Slopes, January 18, 1990

  53. UBC Slopes, March 25, 1999

  54. UBC Slopes, July 4, 2012

  55. UBC Slopes, July 4, 2012

  56. UBC Slopes, November 26, 2012

  57. UBC Slopes, January 21, 2016

  58. Juniper Place Landslide Restoration

  59. Very steep (65o) with blackberries, February 10, 2016

  60. Lots of seepage water, February 12, 2016

  61. Some compacted soils, February 12, 2016

  62. This is a large slide, February 22, 2016

  63. February 22, 2016

  64. March 5, 2016

  65. March 31, 2016

  66. April 10, 2016
    Done!

  67. May 13, 2016
    Growing

  68. May 29, 2016

  69. Treatments of disturbances,
    Mackenzie Valley Fibre Link
    681.5 Area

  70. Trying to block, or re-route water causes problems
    681.5 Area

  71. 681.5 Area
    Seepage is an issue.

  72. Concentration of flows is an issue.
    681.5 Area

  73. Straw bales and sand bags have not solved the problems
    681.5 Area

  74. How do natural systems recover from disturbance?
    681.5 Area

  75. 681.5 Area
    Look at what is springing up after the fire!

  76. The native pioneering species,
    Bebb’s Willow

  77. Dense live staking slows flows and prevents erosion,

  78. and grows into a willowy wetland.

  79. Putting in a cutting or two per meter of line and backfilling the trench would fix this problem
    681.5 Area

  80. 1028.5 Area
    Sand bags haven’t helped here either

  81. 1028.5 Area
    Have the straw bales helped?

  82. Dense live staking
    Broadway Run Slide, Cowichan River

  83. Slows flow velocities, adds root strength and removes excess water. Assists recovery.
    March 14, 2015

  84. June 8, 2015, and they grow!

  85. What about steep slopes and flowing water?
    Great Bear Area

  86. Have straw bales, silt fences and sand bags helped here?
    Great Bear Area

  87. Sept. 22, 1987
    Sept. 22, 1987
    Lunchtime
    Steep slopes can be treated with wattle fences

  88. July, 1988
    And these grow as well

  89. July 9, 2005

  90. August 1, 2009

  91. September 25, 2015

  92. Most of the materials we need to fix these sites are already here.

  93. Natural processes can solve the problems on the Mackenzie Valley Fibre Link

  94. McIntyre Creek, Yukon bioengineering class, October, 2005

  95. End of Day

  96. Completion the next day

  97. The various freeze/thaw cycles through the winter of 05/06 killed the cuttings.

  98. None of them lived,
    a spring planting might have avoided this issue.

  99. Colomac Mine, NWT Restoration Strategy

  100. Identify filters:
    Compaction
    Un-natural landforms
    Steep slopes
    Coarse textured substrate
    Lack of local seeds

  101. Re-slope and re-contour waste rock dumps to address landform and texture limitations

  102. Make it rough and loose and plant pioneering species

  103. Plant pioneering species in riparian areas

  104. Seed in pioneering species
    Local Alder

  105. Plant specialist species

  106. Stand back and watch it grow…

  107. Growing a riparian ecosystem…

  108. How do we fix this?
    May 5, 2010

  109. Site 1, June 26, 2014
    Sullivan Creek Landslides, Boundary Dam, Seattle City Light

  110. Site 1, June 25, 2014
    What is preventing recovery?

  111. Site 1, Learning techniques October 8, 2015

  112. Site 1, Collecting cuttings, October 8, 2015

  113. Site 1, Building up the slope, October 8, 2015

  114. Site 1, Work completed for the year, October 29, 2015

  115. Site 1, June 2, 2016

  116. Site 1, Growing, June 2, 2016

  117. Site 1, Growing, June 2, 2016

  118. Collecting cuttings at Germaine Creek, YT, Fall, 2004

  119. Soaking cuttings at Germaine Creek, Fall, 2004

  120. Live gravel bar staking at Germaine Creek, Fall, 2004

  121. Live gravel bar staking at Germaine Creek, Fall, 2004

  122. Live gravel bar staking at Germaine Creek, Fall, 2004

  123. Klondike River at Germaine Creek, Break-up, 2005

  124. Klondike River at Germaine Creek, May 19, 2005

  125. Klondike River at Germaine Creek, June 3, 2005

  126. Live gravel bar staking at Germaine Creek, June, 2005

  127. Live gravel bar staking at Germaine Creek, September 6, 2005

  128. Live gravel bar staking at Germaine Creek, September 16, 2005

  129. Live gravel bar staking at Germaine Creek, August 8, 2006

  130. Live gravel bar staking at Germaine Creek, September 14, 2006, significant sand deposition.

  131. 30 cm in this area…

  132. August 12, 2007

  133. August 6, 2007
    Additional sediment and woody debris

  134. July 14, 2008

  135. August 5, 2014

  136. August 5, 2014

  137. August 5, 2014

  138. Brush layers
    Kemess Mine, Northern BC

  139. Kemess Mine, Northern BC

  140. Live Palisades

  141. Live Palisades Cross Section

  142. Cottonwood poles are collected and soaked

  143. Excavator used to dig trench to water table, Bulkley River, Northern BC

  144. Live palisade construction and live gravel bar staking

  145. Cuttings grow forming a wall of woody vegetation
    Mimics natural cottonwood stands

  146. Cottonwood growth after 3 years

  147. Live Pole Drains

  148. Intersecting the water

  149. Installing Live Pole Drains, 1985

  150. Drains moisture immediately
    1986, first spring after installation

  151. Cuttings sprout and grow, 1988

  152. July 16, 1999

  153. Business end of live pole drain,
    July 16, 1999

  154. Still draining water after 14 years, July 16, 1999
    Note rock shape

  155. August 1, 2009

  156. Business end of live pole drain, August 1, 2009

  157. Water flow area in a dry year, 24 years after installation, August 1, 2009

  158. Eventually these seepage areas are colonized by Devil’s Cub and Cedar

  159. Is this an effective erosion control system???

  160. What about this???

  161. Live silt fencing slows flows and allows sediments to drop out

  162. A high-tech solution, live silt fences, February 20, 1992

  163. February 20, 1992

  164. May 11, 1992

  165. January 30, 1993

  166. April 9, 1997

  167. April 9, 1997

  168. Natural mass movements associated with melting permafrost

  169. Large ice lenses form the scarp on these slides

  170. A history of permafrost melt slides,
    a history of pioneering species recovery.

  171. Natural processes provide solutions to even the toughest restoration problems

  172. Of course there are many other elements of restoration, but…

  173. … if you get the pioneering species, find and follow the natural solutions and build in the social and cultural values, restoring difficult sites is relatively straightforward.

  174. Remember…
    Whatever you do… Have Fun!

  175. Questions ???
    Contact: d.polster@telus.net

  176. Natural Processes for the Restoration of Timmins Area Sites

  177. Traditional reclamation treatments -
    - How much did this cost?

  178. Are these treatments effective?

  179. What about erosion control?

  180. Natural processes establish a variety of species for free on this compacted waste rock area.

  181. Imagine what could have happened if this site was rough and loose and had woody debris scattered on it?

  182. The dominant species is a poplar.

  183. There is also willow,

  184. and Aspen,

  185. and Spruce
    How much do you think all this cost?

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