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The Chairman introduced the item, and Graeme Hansen introduced the
guests speaking to the Strategy, being Simon Bendall, Project Manager, Craig
Daley (Northern) and Keith Newman (Southern), Assessment Panel members. The
Stage 3 (develop the response) recommendations to the participating councils
represent a gateway to stage 4. The assessment panels’ work was
informed by Climate change, uncertainty of possible outcomes, inundation
likely greater threat to more properties than erosion, and significant social
impact and financial costs associated with doing nothing. Decision making and
assessment processes included:
·
Prioritisation of units or sections of the
coast according to inundation and erosion risks
·
Process of assessment was independently
facilitated and included iwi, business, recreational interests, coastal and
inland residents and DoC
·
Pathways for each priority unit are adaptive in
terms of timeframes and changing risks, and consist of short term (0-20
years), medium (20-50 years) and long (50-100 years) term
·
Social and economic impact assessments were
carried out for each priority unit and there was no comparison between units
carried out
·
Decision making process involved assessments
carried out against set criteria – called multi criteria decision
analysis
·
Ahuriri pathway recommendations are for Short
term status quo and maintain existing sea wall, Medium term extend and
upgrade sea wall in response to sea level rise and increased erosion and
inundation risks and Long term continue to defend with a sea
wall, increase crest height and upgrade seawall in response to sea level rise
·
Pandora pathway recommendations are Short term
provide protection at harbour entrance with stop bank to address inundation
risks; Medium term extend stop banks to increase inundation protection and Long
term stopbanks may need to be raised and/or armoured to maintain level of
protection in response to sea level rise
·
For Westshore, the pathways recommended by the
Panel are Short term Regular gravel and sand
renourishment to offset erosion losses in combination with beach maintenance
and planting as well as placing sand offshore, and allowing it to migrate
northwards and towards the beach, raising foreshore levels; Medium term the construction of groynes
and additional replenishment to maintain gravel beach levels at the required
size; and Long term groynes raised and or lengthened, replenishment increased
in order to maintain a larger beach.
·
Bay View recommendations are dependent on what
happens at Westshore, and are for Short term the status quo of limited
intervention is sufficient, although in later years beach replenishment may
be required to offset erosion losses; Medium term the
construction of groynes or other beach control structures and additional
replenishment would maintain beach levels at the required size; and Long
term in response to sea level rise and increased erosion and inundation
risks, structures raised and or lengthened, replenishment increased
·
Whirinaki is influenced by what is done at Bay
View and Westshore and recommendations are for Short term the status quo of
limited intervention is sufficient, although in later years beach
replenishment may be required to offset erosion losses; Medium term the
construction of groynes and additional replenishment would maintain beach
levels at the required size; and Long term in response to sea
level rise and increased erosion and inundation risks a seawall would provide
an increased protection standard.
·
Very challenging to look 100 years out, made
easier by considering the blocks of 0-20, 20-50 and 50-100 years
·
Work already under way in Clifton, and the
pathways recommended are Short term extended seawall to protect assets;
Medium term an upgrade of the seawall required to account for sea level rise
and erosion at the toe of the structure; and Long term an acceptance that
managed retreat is the most practical option.
·
At Te Awanga, recommendations are for Short
term offset erosion losses with renourishment, Groynes will reduce
erosion losses and the larger beach will reduce the impact of storms; and the
Medium – Long term groynes may be raised and
lengthened with more material added, to create a larger beach, to account for
sea level rise and maintain the standard of protection.
·
Recommendations for the Haumoana unit are Short
– Medium term create larger beach with renourishment,
groynes to reduce erosion losses and the impact of storms plus regular
renourishment to offset erosion losses and provide a higher standard of
protection than currently afforded; Long term acceptance that increasing the
beach and groyne size is only a practical solution for limited time, after
which Managed retreat is the recommended option.
·
Clive unit recommendations are for Short term the
status quo of beach maintenance and repairs to the rock structures; Medium
term beach renourishment and groynes added in response to sea level rise and
erosion rates; and Long term the most practical solution is to retreat the
line and realign the defence inland.
·
Stage 4 (action time) will assess the
recommended pathways in depth, in order to develop detailed designs and
costings for priority areas, and develop affordable ‘fit for
purpose’ adaptive solutions
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Impacts a public good issue affecting all of
Hawke’s Bay – private property, public reserves and
infrastructure, roading access, cycleways, access to power and water, and
tourism.
·
Suggestions that each council begins
contributing to a regional fund for prioritised and emergency protection
works and establishes a coastal hazards action group to work out how to
implement recommended pathways.
Debbie Hewitt left the meeting at
11.01am
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Mr Graeme Hansen provided an explanation of
how groynes work
·
Large volumes of material required for
renourishment and groyne construction, and where that could be sourced
·
Each ‘unit’ assessed individually,
including economics and land/capital values
·
Some solutions require significant up-front
costs (e.g. Westshore renourishment to make up deficit) that will then lead
to more cost effective long term benefits whereas others may be of a more
‘one-off’ nature (e.g. seawall construction)
Debbie Hewitt re-joined the meeting at
11.15am
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Cr Beaven, as Chair of the Joint Committee,
acknowledged the contributions of the assessment panel members to this
community led process, noting the uncertainty of the actual effects of
climate change – how high will sea levels rise? how much more frequent
will significant storms be?
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