BC Adapts: Planning for Sea Level Rise


Climate change will bring increased
coastal sea level rise risks of flooding will increase near the end of life of
buildings and infrastructure that are being constructed right now there’s an
urgent need to integrate sea level rise planning into ongoing development and
municipal planning processes at the City of Vancouver we’ve been planning for sea
level rise for several years the initial step was to look at where things would
get wet when so where the floodplains of the future would be the second step was
to look at the consequences the buildings damaged the people displaced
and the economic disruption with all this information in hand we started to
explore the different adaptation options / area d of uses we have beaches sea walls
densely urban areas and parts and each of these requires a different set of
adaptation solutions our next step is to work with specific neighborhoods to
explore which solutions might be preferred in those areas the sea level
rise adaptation primer summarizes planning approaches and tools to
integrate coastal flood management into local government plans the town of
Qualicum Beach has been using the for planning steps to integrate sea level
rise into its waterfront plan Qualicum Beach like many coastal communities in
British Columbia is at a turning point over the next century will experience a
meter maybe more of sea level rise then this represents a real challenge for
communities where valuable infrastructure homes and businesses are
on the waterfront with a meter of sea level rise many of these properties will
be periodically flooded flooded on a regular basis or in some cases
permanently inundated so what do we do about it at their request we embarked on
a detailed examination of what the physical driving force is so long
shoreline do the winds the waves they tides currents storm surges and how they
move the sediments along the shoreline in the past natural supply of sediments
preserve the character of the of the beaches as the sea walls were slowly
built out over 50 year period these sea walls tended to cause the sediments to
move offshore be lost from the beach land-use changes in those years and
slowly rising sea levels have affected the spy of those natural sediments there
aren’t any easy solutions the typical responses that are outlined by the
province include retreat accommodation adaptation and defense allowing for one
metre of sea level rise engineering analysis reveals that by year 2100
extreme storms would flood lands across the street extending to this shoreline
bluff sea level rise will continue for centuries gradually rising further
qualicum beach is sea level rise planning area includes all the lands
that could be in the future storm-driven wave splash
is already over topping the existing seawall scour and erosion at the base of
the wall threaten this foundation allowing for one meter of sea level rise
will increase the wave heights in overtopping leading to frequent flooding
of the park road and building if protect is the chosen strategy for the
waterfront one option is to raise the beach a sloped fill often called beach
nourishment but attenuate wave energy if a flatter beach slope sandy materials
could be used if steeper beach slopes the materials will include more coarse
gravel raising the seawall is also considered but to get the same level of
protection as the Rays Beach the seawall will need to be very high to the point
that would cut off views and access to the beach if the beach is raised what
about the land and buildings beyond the berm should the road be raised as well
the utilities under the road or at the end of their life span storm sewers will
need flap gates to stop floodwaters from flowing back up the pipes and flooding
the inland buildings along the waterfront will also come to the end of
their structural life if these are rebuilt what elevation should be planned
living quarters will need to be safely above flood construction levels at that
time could lower floors or infrastructure adapt to a accommodate
occasional flooding several buildings in the study area already have residential
areas raised on to a second floor with parking and storage underneath the could
withstand a flood from time to time we’re building to right at the sea
consideration needs to be given for the power of wave splash either through
strengthening walls and windows or providing greater setbacks from the
shoreline over centuries it may be necessary to retreat in some parts of
the waterfront one option is to plan intensive parking and resort development
on higher ground at each end of the central beach in the central waterfront
more emphasis could be placed on walking cycling and beach strolling between
resorts than on cars whatever car technology might be at that
point eventually a one-way narrower higher road for small vehicles service
emergency and shuttle access may fit the space available after sea-level rise
this type of long-term strategic thinking is a key to guiding small
short-term steps to adapt to sea level rise it’s not realistic for a community
like ours or any other community to roll out major change for their entire
foreshore but decisions will be made we’ll figure out where the best places
are that we need to defend will it figure out where those areas are we
can’t defend and consider retreat will accommodate in other areas where it’s
possible to raise the level of homes and will adapt now there there will be
changes that we need to make it as a municipality to live and thrive with a
metre of sea level rise if we plan ahead for sea level rise we can adapt in
manageable steps many sea level rise adaptation actions can be incidental to
normal building and infrastructure redevelopment cycles an early action
that we took was to increase the flood construction level so that development
going in today would be adapted to sea level rise over its life span strategies
for sea level rise will often include combinations of protect accommodate
avoid or retreat that are phased over decades finding in a neighborhood scale
for adaptation provides more certainty for design of individual projects
whether those are public infrastructure or private land development
strategies for sea level rise will usually be incorporated into periodic
Community Plan and land-use planning reviews new land use or subdivision
applications should demonstrate how the proposed project will avoid sea level
rise risk or protect the land use or accommodate flooding for the full
lifespan of the development where existing development is subject to
frequent future flooding the treat may be the only option at some point as sea
level rise progresses retreat is not new many communities have had programs to
purchase waterfront properties for recreational purposes as well as to
reduce consequences of flooding the city of Campbell River purchased the
residences at this flood prone area of tyese fit and has converted the land to
a very popular public park eroding shorelines at the park were restored
with green shore approaches we learn a little bit each time we do a new project
and it led us to do a comprehensive study of the shoreline and we got a
memorandum understanding in place with Department of Fisheries and Oceans so
that we could move forward and then eventually in 2012 we adopted our ocp
with new foreshore guidelines and this is one really strong example where local
government was leading we were testing out the method we could see it in action
and then we could feel better about implementing those guidelines for
private users a review of zoning and other regulations is often required to
allow adaptation for example building setbacks from shorelines may need to
increase to allow for sea level rise and building height restrictions may need to
be eased to allow for raised buildings we need to look for multiple benefits
and cost effectiveness as we adapt both the public and the private sector need
to plan and invest with sea level rise in mind
directing new intensive land uses and emergency services to areas outside the
sea level rise floodplain can reduce the future costs by thinking ahead and
building sea level rise adaptation indoor projects we can save human lives
and property our coastal ecosystems and minimize trauma and expense of disaster
response in coastal floodplains even after sea-level rise

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