New Brighton Beach Scraping
‘Beach Scraping’ is the transfer of sand from the inter-tidal area to parts of the beach above high tide. The practice is designed to speed up the rebuilding of the dune system - following a storm event, or at any other time.
Beach scraping can assist with:
- reshaping and increasing the volume of the dunal system,
- building up the dune to a certain height to prevent wave overtopping and inundation of coastal lands,
- improving beach accessibility and amenity, through re-shaping of the dune profile.
The above processes may occur naturally, usually as a result of wind driven sand deposition (aeolian transport), but at a much slower rate.
Beach scraping is unlikely to be a long-term solution to address coastal erosion and shoreline recession, especially under rising sea level, however, it may provide benefit over the short to medium-term.
In the 1960s and 1970s, significant coastal erosion was experienced at New Brighton Beach. Several homes at the southern end of New Brighton were abandoned. Further south, the village of Sheltering Palms, comprised of approximately 17 lots and houses, was lost to coastal erosion.
Coastal hazard assessments have predicted that a large, ‘design’ storm could result in the erosion of the beach at New Brighton by some 40 to 50 metres landward, or 200m3/m. As a consequence, parts of The Esplanade Road and private property are under an ‘immediate’ threat from coastal hazards.
The New Brighton beach is also subject to long term recession, between 0.08 and 0.15 metres/year. The predicted position of the shoreline following a design storm (immediate hazard line) is shown at Figure 1, as well as the predicted position of the shoreline at 2050 and 2100, following a design storm. The 2050 and 2100 hazard lines factor in long term recession, as well as anthropogenic sea level rise (0.4 cm by 2050, 0.9 m by 2100).
Beach scraping was undertaken at New Brighton from the 1970s through to the 1990s. After a significant hiatus, a successful beach scraping trial was undertaken in 2010.
Figure 1 New Brighton Immediate Hazard Line (BMT WBM, 2013)
Beach scraping 2010 and 2013
As an outcome of the 2010 New Brighton Beach Scraping Trial, Council resolved to implement a beach scraping program at New Brighton in 2013/2014. Council also resolved to consider a permanent bi-annual allocation in future budgets to fund an ongoing New Brighton Beach Scraping Program.
The objective of the New Brighton beach scraping program is to effect a modest reduction in the ‘immediate’ coastal erosion threat, and to maintain, in the short term:
- greater foredune volume,
- a preferred dune profile,
- beach accessibility and amenity.
The program is not designed to remove the immediate coastline hazard threat to infrastructure and private property from a design storm event (100 year ARI), but is likely to modestly reduce the severity of this threat.
Beach scraping works were successfully undertaken during November and December 2013. The works were part funded by the NSW state government under the Coastal Management Program. The outcomes of the works are detailed in Report No. 13.8., Ordinary Meeting 1 May 2014.
Typical dune cross section before and after the beach scraping works 2013 (location approximately adjacent River Street/Pacific Street intersection XS 33), depicting greater foredune volume
Before (11/11/13) and after (18/03/14) photos at Strand Avenue, New Brighton, depicting improved beach access and amenity.
Trial Beach Scraping works at New Brighton Beach – September 2010
During September 2010 Byron Shire Council undertook a trial beach scraping project at New Brighton Beach. Prior to the onground works phase, Council considered a report that examined costings, approvals, ecological and logistic issues associated with the project. Please refer to Council's Meeting Agenda and Minutes of 12 August 2010. Annexured to the report is the Beach Scraping Summary Report which incorporates the Review of Environmental Factors.
The beach scraping was undertaken successfully and followed completion of a technical proposal into the viability of beach scraping as a coastal hazards management strategy (please see ‘Project Detail’ section below). The trial beach scraping project was jointly funded by the Federal and State Government Natural Disaster Resilience Grants Scheme, and Byron Shire Council.
As part of the project, a comprehensive biological monitoring program, beach and dune survey program, and dune rehabilitation program were undertaken. Photo monitoring of the scraped dune condition and behaviour over time is ongoing.
Outcomes of the Trial Beach Scraping works at New Brighton Beach – September 2010
The outcomes of the beach scraping trial were documented and reported to Council on 9 February 2012 (refer Report No 12.22). The report was accompanied by the following monitoring studies which were undertaken to assess the physical and ecological impact of the works:
- The Effects of Beach Scraping on the Infauna of New Brighton Beach, Northern NSW (Smith et al, 2011)
- New Brighton Beach Scraping Trial: Analysis of Dune and Beach Profile Data (Rayner et al, 2011)
At the Extraordinary Meeting of 23 February 2012, it was subsequently resolved:
1. That Council note that, overall, the Trial Beach Scraping Episode at New Brighton Beach reduced coastal hazard threat by increasing dune volume and resulted in minimal environmental harm, but that the works were not sufficient to fully offset coastal hazards and /or future climate change and that such works are unlikely to be a long term coastal management solution at this location.
2. That Council commences the implementation of a beach scraping program at New Brighton in 2013/2014 to attempt to maintain, in the short term, a preferred dune profile, volume, beach accessibility and recreational amenity; noting that:
a) the proposed program will not remove the immediate coastline hazard threat to infrastructure and private property from a design storm event (100 year ARI), but is likely to modestly reduce the severity of this threat;
b) adequate funding arrangements need to be established, as such a further report is to be tabled for Council’s consideration, by no later than October 2012, canvassing options for funding the program including the option to apply for a special rate increase;
c) prior to the implementation of any scraping works, it needs to be established that appropriate physical conditions are met;
d) an adaptive management approach is to underpin the program, and will be used to inform the ongoing viability of the works as well as other issues such as the scheduling of works and amount of sand to be scraped each episode.
For further information on this project please contact;
Coastal and Estuary Officer
Byron Shire Council
Ph: 02) 6626 7135