Much of Thames' foreshore is less than 0.5m above sea level. Parts are subsiding rapidly.

1. • Risks For Thames -
Groundwater and Coastal Flooding
• January 5 Storm Surge
• Latest Government Guidance
• Thames Has High Risk Compared
With Other Cities and Towns
• We need to Plan for this
“slowly unfolding red zone”
Thames and Sea Level Rise
Presentation to Grey Power January 2018
Denis Tegg – www.teggtalk.wordpress.com

2. NewsHub 20 January 2018

3. Temperatures and
Sea Are Rising Faster

5. Relative to 2000, globally the sea is
very likely to rise:-
▪ 0.1m – 0.2m by 2030 (*locked in)
▪ 0.2m – 0.4m by 2050 (*locked in)
▪ 0.3 – 1.3m by 2100 – up to 2.5m is
“plausible”
* “future pathways have little effect
in first half of this century”
November 2017
Very Latest Projections

6. Sea Level Rise Poses Two Threats to Thames
Rising Groundwater
Rising groundwater flooding on
Thames’ foreshore, forced up by
rising sea level/storm surges
Coastal Flooding
Rising sea levels will lead to
much more frequent storm surge
events like 5 January - eventually
to permanent flooding

8. WRC Inundation
Tool maps to here
plus sea level rise
Waikato Regional Council Inundation Tool
http://coastalinundation.waikatoregion.govt.nz/

9. Thames with present day
storm tide and 0.2m of
sea level rise (2030?) has
extensive groundwater
affected areas
http://coastalinundation.waikatoregion.govt.nz/

10. Thames
with mid range
storm tide
and 0.5m of
sea level rise
but no wave effects
http://coastalinundation.waikatoregion.govt.nz/

11. Regional Council Sea Flood Simulator

12. Whitianga Sea Level Rise
Cooks Beach Sea Level Rise

13. Professor Tim Naish - Climate Scientist – Thames is Sinking

14. Thames Foreshore Is Sinking
Adds to Risk of Rising Seas
Location Rate of Settlement
1991 KRTA Report
Richmond St
300-500mm since
1977
1995 Frank Millington
Burke St
500mm
Ferguson Drive 16mm a year
1997 TCDC Memo
NW Corner
Moanataiari
subdivision
Slumped 1m since
1968
2017 Richmond
Apartment block site
13mm a year
Sea Level Rise is Added to
Subsidence Rate to Calculate
Local Sea Level Rise
5mm + 5mm =10mm a year - 0.5m in 50 years
10mm + 10mm = 20mm a year - 1.0m in 50 years

15. Present Day
1-in-100 Year
Extreme Storm Tides
Become a 6-Monthly
Event With a 50cm Rise
Daily Event With 1m of Sea Level Rise
Extreme Sea Floods More Frequent

16. when we get 2 or more extreme events in 20 years or less ?
How Soon Before Insurance Companies Withdraw Cover ?
How soon might that be ?
- with about 15 cm of sea level rise
How soon for 15 cm of sea level rise?
In 15 – 22 years depending on rate of sea rise?

17. Update on Climate Change
Adaptation work program
• Updated to include latest science on sea level
rise
• 285 pages - substantial new content on:
• Risk assessment
• Community engagement
• Adaptive planning
• Outlines a ten-step decision-making process
that councils and communities can follow when
planning for the effects of climate change on
coastal hazards.
2017 MfE Guidance to Councils
The Guidance should be adopted as
Council’s Strategy on Coastal Hazards
Draft copy available –
https://www.greens.org.nz/sites/default/files/CH_Guide_Draft4-webversion.pdf

18. Guidelines provide
minimum transitional
values provided to assist
councils in the short-term.
Major new developments
or intensification of
existing development
(Category A) need to
consider a high sea-level
rise value of 1.9 metres
and timeframe to 2150

19. 1.9 m Category A :-
➢ greenfield development
➢ change in land use
➢ intensification
➢ major new infrastructure
proposed new swimming
pool?
How will this effect new
major development
west of red line?
< 1.9m line

20. Building use count for Thames
for the 0 – 0.5 m zone
Building count comparison
for the 0 – 0.5 m zone
Residential 176
Commercial 1
Industrial 16
Critical 0
Community 17
Other 107
Thames 302
Tauranga 141
Nelson 125
Lower Hutt 102
Whakatane 495
Total 302
NIWA Report - 2015

21. Count of buildings
in the 0m – 1.5m
above sea level zone
Thames is ranked
the 8th at risk
urban area in New
Zealand.
Whitianga is 14th

22. Building use count for Thames
for the 0 – 1.5 m zone
Building use count for Thames
Coromandel District
for the 0 – 1.5 m zone
Residential 863
Commercial 108
Industrial 102
Critical 7
Community 17
Other 499
Residential 2,314
Commercial 142
Industrial 278
Critical 10
Community 35
Other 1180
Total 1,596 Total 3,959

23. On a buildings per capita
per town basis Napier and
Thames are the most at risk
urban areas in New
Zealand.
Whitianga is third.

24. Replacement Cost $2011
of Buildings for Thames
0m to 0.5m $43,868,520
0.5m to 1.0m $192,707,219
1.0m to 1.5m $148,777,225
0m to 1.5m $384,752,964
0m to 3.0m $557,533,142
Figures do not include:-
• land value
• water and waste systems
• power, telecom, fibre
• sewage treatment plant
• roads
• airfield
= $0.4 billion
= $0.6 billion

25. Nationwide

26. Thames has a very strong
case for funding and advice
from Central Government
and LGNZ
Our community, TCDC and
our MP need to combine
forces to ensure Thames
gets the help it needs
Thames has a Groundwater Problem
PLUS a Direct Sea Flooding Problem

27. New Government Has Promised Help
Climate Change will be a top priority
“Commence an urban redevelopment and
adaptation programme, with a focus on urban
communities subject to sea level rise – working with
those communities, their local authorities and other
stakeholders.” *
* Labour Party Manifesto 2017

28. Actions for Grey Power ?
Ask Council to:-
• sign LGNZ Climate Change Declaration
• adopt 2017 MfE Guidance as Coastal Hazard Strategy
• ensure Council has funds for:-
➢ urgent mapping and expert risk assessment
➢ engagement with community
➢ review District Plan/LIMs
➢ adaption planning
• lobby new Government for funds/expertise
Leadership

29. “Slowly Unfolding Red Zone”
Denial/Inaction leads to …
No Need to Panic
But it’s Reckless to
Delay Careful
Planning and Adaptation