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| Logo designed by Auckland-area artist, Savannah Carter-Green |
As noted in my blog post regarding the July 2012 IECA
Australasian Conference in Hamilton, New Zealand, our keynote speaker on the
first day was John McCullah, a watershed geologist and Certified Professional
in Erosion and Sediment Control (CPESC).
John runs Salix Applied Earthcare based in Redding, California and is
host of the popular erosion control video training series, Dirt Time. During his
keynote address, John talked about his participation in the Lucas Creek
Restoration Project in Albany, New Zealand, a northern suburb of Auckland. He explained that the creek had suffered from
severe stream bank erosion and high sediment loading as a result of
urbanization and neglect. Under John’s
direction, the stream was widened using natural bank structures such as tree
trunks and boulders. During
construction, they unsuccessfully tried diverting the creek. When that effort failed, the contractor
created a bank buffer separating construction activities from the stream.
I
have subsequently looked at an article from the Friends of Lucas Creek as well
as websites from the North Shore City Council and Dempsey Wood, a civil
engineering contractor which performed the construction work. According to Dempsey Wood, the project was a high-profile trial
for the implementation and development of “soft engineering” techniques that
had never been used in New Zealand before; combined with the creation of an
attractive public reserve with wetland areas.
In addition to stream bank restoration, the project
also involved removing weeds, introduction of native riparian plants, and
providing a walking path with viewing platforms along the creek. More than 28,000 native trees, shrubs, and
grasses were planted along the banks, an effort which involved local church groups
and other community participants organized by the Friends of Lucas Creek.
I was impressed by John’s photos of the project and wanted
to see it before leaving New Zealand.
Fortunately, my Auckland host, Pete (a local technical university
administrator) was kind enough to drive me across Auckland’s impressive Harbour
Bridge and up to Albany on a Saturday morning for a look at the results of the project.
Following are some photos of what I saw at Lucas Creek: |
Lucas Creek winds through an area of lush native plants
introduced as part of the project
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Natural fiber netting was anchored to the banks
providing new plants with a stable environment for growth |
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Boulders and cobbles were introduced to provide bank stability
while maintaining a natural appearance
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Supports for an introduced sapling
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| The stream now has a natural sequence of pools and riffles |
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| Looking downstream: Old, mature vegetation on the right bank, new introduced vegetation on the left |
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| New strormwater retention pond above the stream’s left bank |
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| Compost-filled erosion control “logs” are being used on the next phase of the projectlocated downstream of the initial work. |
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A batch of plants ready for use in the next phase of restoration downstream
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