Coastal Waters Seminar

Coastal Waters Seminar

Stacey Spooner

John Hannah

Tuesday, 5 July 2016John Hannah, Vision NZ Ltd. 1

TIDAL CADASTRAL

BOUNDARIES

Definition and Location

Tuesday, 5 July 2016 2John Hannah, Vision NZ Ltd.

Emeritus Prof. John HannahVision NZ Ltd

Nelson

[email protected]

OUTLINE

Tuesday, 5 July 2016John Hannah, Vision NZ Ltd.

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1. Legal Definitions

2. The Problems

3. Possible Solutions

4. Legal Precedents

5. Examples

LEGAL DEFINITIONSAlmost always refer to one of two tidal boundaries

Mean High Water Mark (MHWM) under the Crown

Grants Act, 1866. “The mean height of all high waters.

Mean High Water Springs (MHWS) under the Resource

Management Act, 1991. “The mean height of each pair

of successive high waters during the 24 hour period in each

semi-lunation (approx. 14 days) when the range of tide is at

the greatest.”

In theory these tidal measurements should be taken over a complete

lunar cycle of 18.6 yrs.


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THE PROBLEMS1. The boundary is ambulatory:

(a) In the short term due to seasonal processes. A summer survey favours the landowner, while a winter survey favours the crown. Baker & Watkins (1991) note changes at Milford Beach of up to 17 m between summer and winter.


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Line of MHWS

Winter beach profile

Summer beach profile

Winter boundary

Summer boundary

THE PROBLEMS ctd(b) In the long term due to:

- accretion

- storm driven coastal erosion

- sea level change

Notes:

(i) Climate change is expected to produce more extreme storm events as well as an acceleration in sea level rise.

(ii) To what extent will the test of being, “gradual and imperceptible” apply?


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THE PROBLEMS ctd1. A

2. The boundary is ambiguous. A moving boundary is

an ambiguous boundary. In addition

(a) How to distinguish between MHWM

(Crown Grants Act, 1866) and MHWS (RMA,1991)?

(b) Who has 18.6 yrs of tidal observations?

3. The boundary is ambilateral. The parties on both

sides may have vested interests in seeing a

particular outcome to the position determination.


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Line of

vegetation

and/or stabalised

sands

Line of

drift

wood

MHWS plus

wave action

MHWS MHWM MSL

POSSIBLE SOLUTIONS1. PRACTICAL (physical features on the beach)

In the absence of a cliff-face, some possibilities:

The line of drift wood on the beach

The toe of the fore-dunes

The line where salt-water intrusion on salt-sensitive marsh grasses ceases.

Some other well defined physical feature (e.g., retaining wall) to which the tides reach.


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POSSIBLE SOLUTIONS

2. MATHEMATICAL (Tidal Datum Transfer)

(a) Spirit levelling e.g.,

Zero of local levelling datum = MSL at tide gauge MHWS at tide gauge = +0.52 m above MSL.

Height of BM (close to site) = 9.25 m above MSL. Local MSL will be 9.25 m lower. Local MHWS will thus be 8.73m below the BM.

(b) By GPS levelling. Similar to above, but don’t forget the change in geoidal undulation!


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POSSIBLE SOLUTIONS1. A

2. b

(c) Establish an Secondary Tide Gauge (needs at

least 3–6 days of data).

Important Assumptions:

(i) The tidal regime is the same at both sites.

(ii) The same weather conditions at both sites.

(iii) The same tidal cycles are used at both sites.

(iv) Use only the identical time period of tidal data.

Note: See Baker and Watkins, (1991)


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LEGAL PRECEDENTS

1. Christchurch Rivers case – Application by the

Christchurch City Council and Canterbury Regional Council

(Planning Tribunal Decision C 80/92). Reviewed on appeal

by the High Court in Minister of Conservation v Christchurch

City Council (1993) 2 NZRMA 593.

2. Wainui Beach case – The Gisborne District Council and the

Minister of Conservation v J I Falkner and others and Pare

Street Partnership. (Planning Tribunal Decision A 82/94)

[Used in Brooker’s Commentary]

3. Auckland case - Auckland Regional Council v Hastings

(Environment Court A130/2000)


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LEGAL PRECEDENTS ctd.

From the Wainui Beach case:

“It is our judgment (applying our combined experience in surveying

and planning practice) that the practical line of mean high water

springs as the landward boundary of the coastal marine area is

for the present the seaward face of the existing foredune

protection works.” p.39

From the Auckland case:

“We accept that a practical solution is required. From the surveying

evidence there is no definitive answer. Neither a strictly

mathematical surveying approach, nor any other approach, will

produce a solid irrefutable result. A judgement is needed, and

whatever decision is reached it will not be universally accepted.’


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HOKIO BEACH ACCRETION CLAIM

2005 Imagery from Goggle Earth


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2010 Imagery


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2011 Imagery


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1

2

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Our Solution


Explanation

• To the north MHWS toe of fore-dunes, MHWM, 4-5 m to the seaward side (in driftwood).

• To the south – both at the toe of the dunes.

• Across the embayment – problematic.o Option 1. As defined in 1923

o Option 2. Line on beach roughly equivalent to the MHWM wetting line.

o Option 3. Hybrid. MHWS generally at the toe of the new dunes being formed with MHWS 5m to seaward side.



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2015 Imagery

KINA BEACH ACCRETION CLAIM


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KINA BEACH – Looking NW


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KINA BEACH – Abutting Title

to NW


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4.2 m spring tide . Approximately the line of MHWS on 26 May, 2013

“Agreed” MHWS boundary (2007), 3.5 m

from retaining wall

KINA BEACH Accretion Claim

Site


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4.2 m spring tide . Approx. the line of

MHWS on 26 May, 2013

Line of drift wood, 1–3m from toe of fore-dunes. Final position MHWM

Approx. position of MHWM as

determined from tidal transfer

KINA BEACH – Underlying

Issues

• The local council (TDC) wanted the wider beach open to public access.

• The landowner wanted certainty of title, any land that had accreted and room to undertake protection works.

• LINZ needs a solution that meets legislative requirements as well as the CSD rules for Landonline.

• The courts expect a practical, and if possible, reproducible boundary.

ALL of the Above = COMPROMISE!!!!


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KINA BEACH – Residual Issues

• Strictly speaking, surveyors have rarely observed the legal definitions for coastal cadastral boundaries, preferring to use “practical” solutions.

• The Kina Beach “solution” has not used the theoretical MHWM boundary, but then where is that boundary?

• Was it the intention of the law that the landward side of the boundary be subject to regular inundation?

• To the best of my knowledge, these arguments have yet to be tested in the high court.

• What about the enduring liability of Surveyors under Sec 52 of the Cadastral Survey Act ?

Tuesday, 5 July 2016 27John Hannah, Vision NZ Ltd.

FINAL THOUGHTS

Definition is easiest when:

- the shore line is both steep and stable.

- there is a stable beach environment.

Suggested solutions:

1. Adopt from previous surveys (the quick solution), or

2. Resurvey using a practical approach (e.g., cliff face, toe of the fore-dunes, edge of vegetation, highest line of driftwood, offset from some semi-permanent feature.


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FINAL THOUGHTS ctd.

In sheltered estuarine land where there is little wave action a tidal datum transfer could be considered. Alternatively,

In tidal mudflats, the seaward edge of salt-grass Salicornia Australis appears to be is a reasonable indicator of MHWS. Consider other saltwater sensitive species.

Typically historical titles used practical solutions based upon physical features as a proxy for both MHWM and MHWS.


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REFERENCES

1. Baker, R.F., and M. Watkins, (1991). “Guidance Notes for the Determination of Mean High Water Mark for Land Title Surveys”, available from the NZIS, PO Box 831, Wellington.

2. Dewar, P.R., (2003). “The Accuracy of Tidal Datum Transfer Procedures Using Dunedin Wharf to Port Chalmers as a Case Study”, BSurv (Hons) Dissertation, University of Otago.

3. Grant S.T., and C.T. O’Reilly, (1986). A New Look at Tidal datum Transfers”, The Canadian Surveyors, Vol.40, No.4.


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Coastal Waters Seminar

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