Victoria_Park_Re port Final.pdf - City of Charlottetown

VICTORIA PARK COMPREHENSIVE MASTER PLAN
Final Report • June 2013
Move Seaward
The futility of trying to predict future scenarios where there is a large human influence
is apparent. Even future climate is a function of what humans choose to make of it. In
some cases - where new areas are needed for new economic or ecological development
- a move seaward strategy can be adopted.
There is an obvious downside to this strategy. Coastal erosion is already widespread,
and there are many coasts where exceptional high tides or storm surges result in
encroachment on the shore, affecting human activity. If the sea rises, many coasts
that are developed with infrastructure along or close to the shoreline will be unable to
accommodate erosion. They will experience a so-called “coastal squeeze” where the
exposed zones that would normally retreat landwards encounter solid structures and are
squeezed out. Wetlands, salt marshes, mangroves and adjacent fresh water wetlands are
particularly likely to suffer from this squeeze.
An upside to the strategy is that moving seaward (and upward) can create land of high
value which can bring the investment required to cope with climate change.
Limited Intervention
Limited intervention is an action taken where decisions are made that only solve the
problem to some extent, usually in areas of low economic significance. Measures taken
using limited intervention often encourage the succession of salt marshes and sand
dunes. This will normally result in the land behind being more sufficiently protected, as
wave energy will be dissipated by the accumulated sediment and additional vegetation
residing in the newly formed habitat.
Seawall Best Practice
Seawalls are probably the second most traditional method used in coastal
management. Seawalls may be constructed from a variety of materials, including
reinforced concrete, boulders, steel, or gabions. Additional seawall construction
materials may include an earthen bank used to create a dike construction. Generally
seawalls can be a successful way to control coastal erosion, but only if they are
constructed well and out of materials which can withstand the force of ongoing wave
energy. Seawalls can offer a more long-term solution, additionally providing recreation
opportunities and protection from extreme events as well as everyday erosion.
A cost benefit approach is an effective way to determine whether a seawall is
appropriate and whether the benefits are worth the expense. Besides controlling
erosion, consideration must be given to the effects of hardening a shoreline on natural
coastal ecosystems and human property or activities. A seawall is a static feature
which can conflict with the dynamic nature of the coast and impede the exchange of
sediment between land and sea. These factors must be considered in assessing the
cost benefit ratio, which must be favorable in order to justify construction of a seawall.
Advantages of Seawalls
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Long-term solution in comparison to soft beach nourishment.
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Effectively minimizes loss of life in extreme events and damage to property caused by erosion.
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Can exist longer in high energy environments in comparison to ‘soft’ engineering methods.
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Can be used for recreation and sightseeing.
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Forms a hard and strong coastal defence.
In the case of Victoria Park the strategy that needs to be investigated is the hold the line
option as the do nothing, managed realignment, or limited intervention will not work due
to the value of the lands that are being protected or the purpose of the protection.
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