Shoreline Change: Beach Profile Data

A data set of the profiles of coastal beaches resulting from land surveying and (occasional) echo sounding. At present, the beach profiles network is primarily being used to describe the cut and fill envelope for eastern Coromandel beaches. There has also been monitoring on the West Coast at Raglan since 2009. Historically surveys have been infrequent and focus on periods of extreme erosion or accretion. Over the last 10-15 years, surveys have been taken at all beaches six monthly intervals (and in many cases three monthly). There has been ongoing investment into maintaining and upgrading the network, establishing appropriate beach markers, checking and archiving historical data (inherited from predecessor bodies), and producing finder diagrams. The data collected is used primarily for State of the Environment monitoring and for coastal erosion hazard assessments.

Most profiles have been obtained from beaches on the Eastern Coromandel Peninsula (Stony Bay to Whiritoa inclusive). Historically, survey data was collected from two sites on the western side, at Port Jackson and Te Puru School, but these sites are no longer surveyed regularly. Since 2009, beach profile data has been collected at 3-monthly intervals at Ngarunui and Ruapuke Beaches, near Raglan. The data set consists of site locations (aerial photographs and finder diagrams), and surveyed profiles of shore-perpendicular transects recorded over time. Surveying work was also undertaken to etablish profile levels relative to mean sea level.

Predominantly sandy beaches of the Eastern Coromandel Peninsula. In January 2009, surveys commenced on the West Coast at Ngaranui Beach, Raglan (5 sites). Ruapuke Beach (south of Raglan) has been surveyed since the mid 1990s by a private party.

NZMG GPS Co-ordinates: These co-ordinates should be used in conjunction with the Regional Council's finder diagrams for accurate location of the profile. Fletcher Bay CCS 1 CCS 1A 2724720.7 6522093 Port Jackson CCS 2 BM A2 2720858.3 6521865.5 Port Jackson CCS 2/1 CCS 2/1 2721056.2 6522322.3 Port Jackson CCS 3 CCS 3A 2720313.1 6521419.2 Stony Bay CCS 4 CCS 4B 2727415.4 6518104.7 Sandy Bay CCS 5 CCS 5 2730604.1 6516424.3 Port Charles CCS 6 BM 0602 2732309.8 6515733 Port Charles CCS 6/1 CCS 6/1A 2732465.7 6516404.2 Waikawau CCS 7 CCS 7A 2736064.9 6508523.9 Waikawau CCS 7/1 CCS 7/1A 2736574.9 6508046.7 Waikawau CCS 8 CCS 8 2737093.3 6507644.5 Little Bay CCS 9/1 CCS 9/1B 2738380.6 6507623.8 Kennedy Bay CCS 10/1 CCS 10/1 2738805.4 6498617.6 Kennedy Bay CCS 10 CCS 10C 2738722.3 6499121.4 Whangapoua CCS 11/1 CCS 11/1B 2744330.2 6494996.8 Whangapoua CCS 11 CCS 11A 2743968.7 6495356.1 Whangapoua CCS 12 CCS 12B 2743695.4 6495616.4 Matarangi CCS 13 CCS 13B 2748802.9 6493355 Matarangi CCS 14 CCS 14A 2747863.6 6493507.6 Matarangi CCS 15 CCS 15B 2747197 6493645.9 Matarangi CCS 16 CCS 16D 2746734.4 6493777.7 Matarangi CCS 17 CCS 17 2745665.4 6493705.8 Rings CCS 18 CCS 18 2750609.9 6493393.7 Kuaotunu West 19/1 CCS 19/1A 2751962.8 6493502.8 Kuaotunu West 19/4 CCS 19/4B 2751791.1 6493497.4 Kuaotunu West 19/5 CCS 19/5 2752311.8 6493490.3 Kuaotunu East 20/2 CCS 20/2A 2753681.2 6493883.3 Kuaotunu East 20 CCS 20C 2753280.6 6493768 Kuaotunu East 21 BM D6A 2753963.4 6493955.7 Wharekaho CCS22/1 CCS 22/1A 2753792.2 6486270.7 Wharekaho CCS22 CCS 22B 2753422.7 6485653.8 Wharekaho CCS23 CCS 23A 2753376.3 6485181.7 Buffalo CCS 24 BUGP 2751748 6484830.4 Buffalo CCS 25 CCS 25C 2751315.9 6484379.5 Buffalo CCS 25/1 CCS 25/1 2751309.7 6483670.6 Buffalo CCS 26 CCS 26C 2751285.7 6483138.9 Buffalo CCS 27 CCS 27B 2751447.4 6482657.7 Maramaratotara CCS 28 CCS 28A 2752593.3 6482139.6 Cooks CCS 29 CCS 29A 2754200.8 6481644.4 Cooks CCS 30 CCS 30B 2754912.6 6481233.1 Cooks CCS 31/1 CCS 31/1 2755935.4 6481174.9 Cooks CCS 31/2 CCS 31/2A 2756188.3 6481226.4 Cooks CCS 31 CCS 31B 2755698.2 6481128.4 Hahei CCS 32 CCS 32A 2760576.9 6480933.1 Hahei CCS 33 CCS 33A 2761045.8 6480573.1 Hot Water CCS 34 BM3402 2762016.6 6475293 Hot Water CCS 35/1 CCS 35/1 2761467.7 6476639.7 Hot Water CCS 35 CCS 35C 2761687.7 6475852.9 Tairua CCS 36/1 CCS 36/1 2764687.6 6463705.4 Tairua CCS 36 CCS 36A 2765063.5 6463262.2 Tairua CCS 37 CCS 37A 2764592.9 6463856.9 Pauanui CCS 38/1 CCS 38/1A 2765272.6 6461609 Pauanui CCS 39/1 CCS 39/1A 2765443.7 6461019 Pauanui CCS 39/2 CCS 39/2 2765600.8 6460538.2 Pauanui CCS 39 CCS 39B 2765362 6461290.6 Pauanui CCS 40A CCS 40A 2765725.3 6460202.7 Opoutere CCS 41 CCS 41 2766862.4 6450680.4 Opoutere CCS 42 CCS 42B 2766868.6 6451192.5 Opoutere CCS 43 CCS 43A 2766839.5 6452842.9 Opoutere CCS 44 CCS 44A 2767084 6454477.9 Otama CCS 45 CCS 45A 2755981.1 6495397.3 Otama CCS 46 CCS 46A 2756879.3 6495345.2 Opito CCS 47/1 CCS 47/1 2760885.7 6493901.3 Opito CCS 48 CCS 48 2761348.5 6493757.1 Opito CCS 48/1 CCS 48/1A 2761882.8 6493796.4 Opito CCS 49/1 CCS 49/1 2760380.3 6494231.2 Opito CCS 49 CCS 49A 2759847.7 6494949.8 Opoutere CCS 53 CCS 53C 2766090.9 6445890 Opoutere CCS 54 CCS 54B 2765999.3 6446101.3 Whangamata CCS 55/1 CCS 55/1 2765620.2 6439930 Whangamata CCS 56 CCS 56C 2765809.2 6438976.4 Whangamata CCS 57/2 CCS 57/2A 2765936.6 6437867.5 Whangamata CCS 57/3 CCS 57/3 2766076.8 6438125.1 Whangamata CCS 57 CCS 57A 2766209.3 6438378.4 Whangamata CCS 58 CCS 58C 2765787.5 6437505.6 Whiritoa CCS 59 CCS 59 2767481.8 6431606.3 Whiritoa CCS 60 BM ORM36 2767899.7 6430584.7 Whiritoa CCS 61 CCS 61 2767616.4 6431357.9 Whiritoa CCS 62 CCS 62C 2767764.5 6431080.6 Whiritoa CCS 63 CCS 63B 2767841.9 6430868.1

Coromandel beach network initiated in 1978 by the Hauraki Catchment Board and has since been managed by Environment Waikato and the Waikato Regional Council. Raglan data collection initiated by Waikato Regional Council in 2009.

Surveying of sites by level and staff and other techniques (e.g. Emery pole) from established beach markers. Transects generally less than 200 meters long. Echo sounding data at some sites for up to two kilometers offshore. Spacing of profiles along the beach is determined by potential damage to properties on the frontal dune (McMullan, 1995). More recently data at many sites has been collected using differential GPS. Data is collected at all sites on the eastern Coromandel and Raglan at six monthly intervals (minimum). Historical data collection was much less regular. Two to three surveys of most sites between 1978 and 1990. More data is available for a few sites where there were issues. Since 1990, most sites have been surveyed at least once every two years, and some sites 2-3 times/year. Since 2002 all beach sites have been surveyed six monthly September and March). Some years quarterly surveys have been undertaken. Additional surveys have been undertaken following major storm events.

Each profile represents a distinct location on a beach. Beach profile data can not provide a complete record of all along-shore variablity in beach behaviour. Some errors or uncertainties exist in the older data as discussed above. Field measurements have an accuracy of ±5-10 cm. Mistakes are checked for by over plotting. Annual quality assurance checks. Much of the data inherited from Hauraki Catchment Board was neither checked nor archived. The data is subject to uncertainties due to changes in beach-markers and unclear field notes. Much of this data has now been checked/corrected and archived, but some uncertainties remain relating to data at some sites. The frequency of the surveys since 1978 and the length of the record are such that it is no presently a useful/reliable means of assessing long-term trends in shoreline movements. However, the data at a few sites might be helpful in this regard – if used as an adjunct to other data (e.g. photogrammetric data on shoreline changes from aerial photographs). The vertical level of all beach markers (and hence profile data) has now been established at all sites relative to mean sea level (Moturiki).

Digital, printed graphs aerial photos locating sites, finder diagrams. Surveys are stored in MS Excel and BPAT. Available in NZMG on GIS layer, See EW DOCS#717983.

To improve understanding of the nature and scale of shoreline movements for various coastal management purposes, including the estimation and monitoring of coastal erosion hazard zones. Over time the dataset is becoming increasingly valuable as decadal cycles and variations are recorded. The data is also used frequently for the design and monitoring of coastal protection works.

Data pre-dating 1990 (i.e. that inherited from predecessor bodies) is not available until various uncertainties in this data have been checked/corrected. All data collected since then that is owned by Waikato Regional Council is available without restriction.

Ongoing

The council's data set has recently been merged with a private data set for the same sites, considerably increasing the data set. An additional, two monthly dataset exists since 1997, owned and maintained by private individuals. Some of this data is purchased by the Waikato Regional Council to maintain regular records, but additional information is collected which is not held by the Council.