Beach Profile Monitoring

The NRC beach-profile monitoring programme was initiated in 2003-04 and involves mapping the position of the foreshore and foredune and/or cliff at selected coastal locations in Northland. The programme provides valuable information on changes in the position of our beaches, i.e., whether they are eroding, in equilibrium (staying the same) or accreting (growing). Data gathered from this programme enables a better understanding of coastal systems in Northland, which assists the Council and community when looking at the suitability and effect of development in and adjacent the coast. It can also be used to identify ‘coastal hazard zones'.

Monitoring is undertaken at 6-montly intervals (once in winter and once in summer) at key ‘monitor' beaches in the region. A cross-section profile of the foreshore and foredune at each coastal location is taken and the exact location of the foredune ‘toe' is mapped using a Global Positioning System (GPS). Other beaches in Northland are also monitored on a less regular basis following events that may cause significant change, for example, landslides or storm events.

Map: Beach profile monitoring sites

The table below shows the history and state of the beaches surveyed by NRC. A ‘-‘ before the number denotes that the beach is eroding.

Beach Name Section Name
Date Range of Surveys 		No. of Years surveyed Number of Records Trend (metres per year)
From To
1 Cable Bay 13/05/1999 4/02/2008 9 7 0
2 Coopers Beach 9/09/2003 4/02/2008 5 5 0.04
3 Hihi 13/05/1999 4/02/2008 9 6 0.11
4 Matapouri M1 2/02/2001 7/01/2008 7 19 -0.15
M2 2/02/1998 4/12/2007 9 21 -2.43
M3 2/02/2001 7/01/2008 7 19 1.84
M4 2/02/2001 7/01/2008 7 19 1.68
5 Ngawai 10/05/1999 15/03/2007 8 4 0.42
6 Oakura 3/02/1998 15/03/2007 9 4 0.21
7 Ohawini OHW1 3/02/1998 22/03/2005 6 4 0.64
OHW2 22/03/2005 15/03/2007 2 2 -0.03
8 Omapere OM1 26/10/2001 17/04/2008 7 7 -0.20
OM2 26/10/2001 17/04/2008 7 6 -0.43
OM3 26/10/2001 17/04/2008 7 6 0.25
OM4 26/10/2001 17/04/2008 7 6 -0.57
OM5 26/10/2001 3/12/2007 6 4 -0.04
OM6 26/10/2001 3/12/2007 6 6 -0.53
9 Pouto P2 16/01/1989 20/02/2008 19 34 1.66
P3 16/01/1989 20/02/2008 19 34 15.97
P3A 20/02/1990 20/02/2008 18 34 0.85
P4 16/01/1989 20/02/2008 19 35 -8.87
P4A 21/02/2000 20/02/2008 8 16 -7.58
P5 16/01/1989 20/02/2008 19 34 0.08
P5A 21/02/2000 20/02/2008 8 16 -12.94
10 Rangiputa Rangiputa A 25/05/1999 4/02/2008 9 4 0.04
Rangiputa B 25/05/1999 16/03/2007 8 4 -0.51
Reef Lodge 25/05/1999 16/03/2007 8 4 -0.62
11 Taipa 22/02/1990 4/02/2008 18 11 -0.35
12 Taupo 12/05/1999 4/02/2008 9 9 -5.98
13 Tauranga 4/07/2002 4/02/2008 6 9 2.35
14 Te Mimiha 10/05/1999 16/03/2007 8 4 0.76
15 Te Ngarie 10/07/2002 4/02/2008 6 8 -0.13
16 Wellingtons Bay 10/03/1998 7/01/2008 10 6 0.32
17 Whananaki 16/08/2004 13/08/2007 3 5 0.89
18 Bream Bay RM 7 14/07/1976 23/06/1983 7 31 -0.46
RM 8 14/07/1976 12/09/2007 31 52 -0.32
RM 9 14/07/1976 7/07/1982 6 30 0.8
RM 10 14/07/1976 23/16/1983 7 39 -0.25
RM 11 8/12/1977 12/09/2007 30 29 0.05
RM 12 21/09/1976 23/06/1983 7 34 0.99
RM 13 13/07/1976 12/09/2007 31 43 0.56
RM 14 13/07/1976 23/06/1983 7 40 -0.27
RM 15 13/07/1976 12/09/2007 31 42 -0.3
RM 16 13/07/1976 23/06/1983 7 48 1.92
RM 17 29/11/1977 12/09/2007 30 36 -0.21
RM 18 2/11/1976 23/06/1983 7 36 -0.44
Beach Name Section Name
Date Range of Surveys 		No. of Years surveyed Number of Records Trend (metres per year)
RM 19 21/10/1976 1/03/1998 12 36 0.71
RM 20 24/08/1976 23/06/1983 7 32 2
RM 21 23/08/1976 24/06/1983 7 31 1.85
RM 22 30/06/1977 24/06/1983 6 35 0.07
19 Mangawhai M5 27/07/2000 28/08/2007 7 15 3.19
M6 27/07/2000 28/08/2007 7 14 0.38
20 Glinks Gulley 29/09/1994 1/08/2008 14 21 1.44
20 Ocean Beach OB1 15/07/1976 12/09/1977 1 12 24..46
OB1A 4/05/1977 10/07/1979 2 25 0.61
OB2 23/08/1976 10/07/1979 3 30 -0.26
OB3 22/11/1976 10/07/1979 3 36 0.35
OB4 22/11/1976 10/07/1979 3 35 1.62
OB5 23/08/1976 10/07/1979 3 31 -1.21
OB6 23/08/1976 18/03/1981 5 44 4.05

As can be seen from the table, the general trend is for only small rates of accretion or erosion at most sites.

During 2007-08, the beach at Matapouri underwent beach nourishment and so the beach is still finding its natural state. The foreshore at Omapere was subject to significant erosion during the year and rockwork was required to stabilise a house located on the beach front. The beach at Pouto, a highly dynamic system, was cut back extensively to the east of the cliffs.

Photo: Beach nourishment at Matapouri