WC134 JanFeb 2024 - Magazine - Page 34
WATER PROJECTS
In essence, the project is transformative, working towards
creating a built environment that coexists and enriches the natural world by integrating urban infrastructure with ecological
restoration, providing climate resilience for the area.
Challenges and innovations
Initial efforts for the project included understanding the site
context and its complexities. Past constructions, like jetties and
causeways—primarily erected to support the original treatment
plant and logging industry—have significantly impacted the
Salish Sea ecosystem, disrupting natural estuary processes.
Juvenile Chinook salmon populations, which typically spend
three months in the estuary as they transition from freshwater
to saltwater, were impacted by the building of the causeway
which blocked access for the salmon to the estuary, instead
pushing them out to deep saltwater before they adapted to this
new environment.
As stewards of the land, our work includes enhancing the
ecology and the built environment to re-establish some of these
natural ecosystems that have been interrupted over the years.
For example, by establishing strategic breaches in the
causeway and jetties, the goal is to restore the delicate balance
of saltwater and freshwater in the estuary, crucial for migratory
salmon. This has the potential to impact the salmon cycle
profoundly, reaching as far as Alaska and deep into British
Columbia.
Fortifying for the future
The living shoreline strategy at the IIWWTP is an innovative
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WATER C AN ADA • JANUARY/ FEBRUARY 2024
response to the challenges posed by climate change. Designed to
withstand the harsh realities of storm surges and rising sea levels,
this approach integrates natural elements with robust engineering. By creating living breakwaters and potential inter-tidal
marshes, the strategy not only guards against flooding but also
absorbs and dissipates the energy of incoming storm surges. It is
a proactive measure, envisioning a future where rising tides and
extreme weather events are more common. This forward-thinking approach not only protects the shoreline but also preserves
the natural beauty and ecological function of the estuary, ensuring that Iona Island remains resilient and vibrant in the face of
changing environmental conditions.
The IIIWWTP currently processes an average flow of 496
megalitres per day (ML/d). This is more than triple the plant’s
original design capacity of 160 ML/d when it was first commissioned in 1963.
Exemplifying ecological regeneration and climate adaptaGetty Images
Habitat enrichment
This plan also enhances terrestrial and freshwater habitats, with
a design that aims to improve native and novel habitats, including the coastal sand ecosystem, riparian cottonwood forest,
shrub grassland, and freshwater wetlands. These enhancements
are expected to benefit a wide range of species, particularly
birds that use the Pacific flyway as a migration stopover.
Part of the enhancement includes creating deeper
zones in freshwater habitats for cooler water temperatures
and incorporating elements for nesting and basking.
Complementing these efforts, a highly treated side-stream
of effluent from the treatment plant will be used to recharge
the freshwater wetlands, enhancing water quality before it
reconnects with the estuary.
The IIWWTP project includes various ecosystem-based
flood protection strategies to increase Iona Island’s resilience to
sea-level rise.
The plant itself will be elevated andconstructed at a height to
withstand any flooding. This strategy also includes plans to raise
the existing causeway, as it is currently at an elevation that would
make the plant vulnerable if there is any flooding.
WAT E R C A N A D A . N E T
