Coastal erosion review nears completion

19 Jun 2014

A year-long, $180,000 review designed to ensure better long-term local authority planning for up to 2000 properties in erosion-prone Northland coastal areas is nearing completion.

Erosion at Omapere.Erosion has long been an issue in many coastal parts of Northland as this 2005 image from Omapere shows.

 

 

 

 

 

 

 

 

 

 

 

 

The review began last year and is designed to update the Northland Regional Council's existing coastal hazard zones, most of which were developed at least 10 years ago.

A staff progress report prepared for an upcoming (June 23) meeting of the Northland Regional Council's Environmental Management Committee says the review is needed to reflect a number of factors. These include changes in the understanding of coastal processes, changing sea level rise predictions and site-specific changes that have occurred since the last assessments.

"While erosion itself is a perfectly natural process, development of the region's coastal margins over the past 50 or 60 years has increased the associated risks," committee chairman Councillor Joe Carr says.

Councillor Carr says these risks have long been known to most of the property owners involved and in many parts of Northland, formal local authority coastal erosion hazard zone (CEHZ) setback lines have been in place for more than two decades.

"In 2006 more than 630 dwellings and 1090 properties, collectively worth several hundred million dollars, were in (or partially in) identified CEHZ."

He says CEHZ setback lines are implemented through District Plans and impose certain controls over at-risk land, which can include requiring developers to assess and mitigate those risks when planning developments there.

Regional council staff had worked with their district councils' counterparts to compile a list of 29 priority sites for the latest CEHZ review, but of these only two – Waitangi's Te Tii Bay and Matauri Bay – had not previously had a formal CEHZ assessment. There were no Kaipara sites in the study.

Councillor Carr says the high-tech and complex review takes into account a wide range of data and should enable the likely impacts of erosion and resulting shoreline positions to be modelled with a fairly high level of certainty until 2065.

"The review is being carried out by consultants Tonkin and Taylor and is being independently peer reviewed by a University of Auckland professor. It should give councils, property owners and would-be developers considerably more certainty in future."

Councillor Carr says regional council staff are currently reviewing the preliminary outputs from the CEHZ assessment and intend to hold a workshop with district council staff to discuss them in August. He says affected landowners will then be notified of the CEHZ setback lines, which will also be posted online.

The Coastal Erosion Hazard Zone assessment sites.

 

Site

District

Name

Existing CEHZ

Last assessed

1

Whangarei

Langs Beach

Yes

1988

2

Whangarei

Bream Bay (Waipu, Ruakaka & Marsden Point)

Yes

2010

3

Whangarei

Marsden Bay

Yes

1998

4

Whangarei

One Tree Point

Yes

1998

5

Whangarei

Taiharuru

Yes

1988

6

Whangarei

Pataua Estuary & Pataua North

Yes

1999

7

Whangarei

Whangaumu Beach (Wellingtons Bay)

Yes

1998

8

Whangarei

Matapouri Estuary & Bay

Yes

1999

9

Whangarei

Woolleys Bay

Yes

1988

10

Whangarei

Sandy Bay

Yes

1988

11

Whangarei

Whananaki Sandspit

Yes

1998

12

Whangarei

Teal Bay Beach (Ngawai Bay)

Yes

2002

13

Whangarei

Helena Bay Beach (Te Mimiha)

Yes

2002

14

Whangarei

Ohawini Bay (& Parutahi Beach)

Yes

1998

15

Whangarei

Oakura Bay

Yes

1998

16

Whangarei

Bland Bay

Yes

1988

17

Far North

Te Tii Bay Waitangi

No

N/A

18

Far North

Matauri Bay

No

N/A

19

Far North

Te Ngaire Beach

Yes

2003

20

Far North

Tauranga Bay

Yes

2002

21

Far North

Taupo Bay

Yes

2002

22

Far North

Hihi

Yes

2002

23

Far North

Coopers Beach

Yes

2002

24

Far North

Cable Bay

Yes

2002

25

Far North

Taipa

Yes

2002

26

Far North

Rangiputa

Yes

2002

27

Far North

Tokerau Beach (North)

Yes

1991

28

Far North

Ahipara

Yes

2003

29

Far North

Omapere & Opononi

Yes

1991