1. University of Queensland
ENVM3200
Semester 1 2016
Coastal Processes and Management
An Overview of the Southern Palm Beach System
Greg Forster
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Table of Contents
1.0 Introduction________________________________________________________________ 2
2.0 Regional Setting ____________________________________________________________ 2
3.0 Results ____________________________________________________________________ 3
3.1 Coastal Characteristics ____________________________________________________________ 3
3.2 Beach Nourishment_______________________________________________________________ 6
3.3 Coastal Hazards __________________________________________________________________ 6
4.0 Discussion _________________________________________________________________ 7
5.0 Conclusion _________________________________________________________________ 9
6.0 References ________________________________________________________________ 10

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1.0 Introduction
Since European colonisation, Australian coastal development has expanded in line with the general
population. The beauty and opportunity of such locations is desirable, and attracts regional migration and
millions of tourists every year. Considering this potential, it is of no surprise that resort development has
boomed in recent times. Palm Beach is just one Gold Coast location blessed with coastal systems which
allow this tourism potential. Its extent is only four kilometres of the 35 kilometre Gold Coast stretch,
however reports define it as one of the most popular beaches to the 4.9million visiting tourists each year
(Strauss, Splinter & Tomlinson 2011). Although pristine to the human eye, such geomorphic settings are
actually the interface between sea and land, and a buffer for the dynamic forces of the ocean (Jones &
Mangun 2001). Unfortunately, this reality creates a range of hazards for tourism and resort development
at such locations, and Palm Beach is of no exception.
This report will analyse the processes within the southern Palm Beach coastal system (PB), and make
recommendations regarding resort construction behind the southern PB spit. Firstly, a description of the
regional setting will be provided. Following this, the coastal character, current beach nourishment
processes and potential coastal hazards will be described in relation to in situ field work, government
data, and scientifically relevant papers. These characteristics will then be discussed in relation to resort
operations at the proposed site. As a conclusion, the specific site choice will be assessed and a
recommendation provided in relation to future project direction.
2.0 Regional Setting
The southern PB is a 2km stretch of wave dominated East Australian coastline, and is recognised for world
class surf, high volume longshore drift, and extensive erosion issues (Figure 1 and 2). Its southern tip is a
sandy and vegetated spit, which terminates at the wave and flood dominated tidal inlet of Currumbin
Creek (CC) (Castelle et al. 2007). This inlet is trained by southern and northern groyne constructions in an
attempt to minimise CC infill, and increase sediment transport north towards PB. However, forces are
highly variable within tide change, swell activity and sediment budgets; and annual dredging is required
for persistent channel navigation and nourishment of PB. Mean regional temperatures have been
recorded in a range of 24.2degC to 15.1degC, with mean annul precipitation of 1502mm over a 48km2
catchment (Bureau of Meteorology 2016). The tidal range is reported as 0.6m to 1.8m (1m mean), with
weak CC spring discharges of 95m/s(flood) and 45m/s(ebb) (Shaeri et al. 2014).

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.
3.0 Results
3.1 Coastal Characteristics
The fieldwork transect represents PB on an outgoing tide, approximately 440m from the CC northern
groyne. Swash zone to dune head was 46.6m, with a depositional berm 21m from the lower swash. The
elevation drop was approximately 4.63, which is illustrated in the complete beach profile below (Figure 3).
Grain size analysis depicted a negative trend in mass median diameter (Dx50) (Figure 4), revealing median
grain sizes of 342um, 325um and 279um up the beach. All results are medium sand in the Udden-
Wentworth scale, and the mean of 315um relates to a settling velocity (quartz) of 0.04m/s.
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 5 10 15 20 25 30 35 40 45
Elevation(m)
Distance (m)
Palm Beach Cross Section
244
342
487
245
325
429
194
279
396
-300
200
700
Dx (10) Dx (50) Dx (90)
ParticleSize(um)
Range
Particle Size Distributions
Swash Zone High Tide Dune
Figure 1- Palm Beach Regional Setting Figure 2- South Palm Beach and Currumbin
Creek
Figure 3- South Palm Beach ongoing tide profile
Figure 4- Grain size analysis results

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Excel skewness calculations resulted in 3.9 (swash), 4.4 (high tide) and 3.8 (dune). This indicates strong
positive skewness within the distribution of all samples, and a tendency for grain sizes to vary within the
fine range. Kurtosis calculations resulted in 14.6, 19.9 and 13.6 from the swash to dune locations
respectively, and revealed a higher degree of sorting at the high tide mark. Figure 5 illustrates this
variability in grain size distributions.
The CC is characterised by a complex and dynamic internal channel, and the interrelated variability in
sediment deposition can influence the profile of PB (Castelle et al. 2007). During calm swells, the southern
CC groyne may minimise longshore drift and create a negative sediment budget for PB; while with higher
energy, the sediment load is transported into the CC channel and north towards PB (Castelle et al. 2007)..
Figure 6 summarises the variety CC currents which influence deposition and the morphological state of
the CC and PB alike.
At any given time, PB and CC morphology responds to hydrodynamic and sediment flux variability; which
in turn is related to currents, bathymetry, tides, swell intensity, swell direction, and storm activity
(Weathers & Voulgaris 2013). This illustrates the complex interrelationships within coastal morphology
dynamics, and the undercurrents of oceanic and meteorological forces which create the observable
0
5
10
15
20
25
0 200 400 600 800 1000
Volume(%)
Grain Size (um)
Frequency Distribution of Grain Sizes
Swash High Tide Dune
Figure 5- Distribution of sampled grain sizes.
Figure 6- Current variability with influence on deposition and system profile (GCCC 2015)

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formations. These influences can follow general seasonal trends as illustrated in Figure 7 and 8 below.
Generally, the wet season increases CC discharge, and intensifies coastal swell.
Sediment budgets and PB/CC morphology can therefore be linked to synoptic conditions and swell
generation. The easterly migration of high pressure systems may cause south-easterly swell during winter
and spring (Gold Coast City Council 2015b). Tropical cyclones occur between November and April, creating
northeast to easterly swells (Castelle et al. 2007). East coast lows are common during March to July, and
produce northeast to south-easterly swells (Castelle et al. 2007). Such variability will influence longshore
drift volumes, erosion and deposition characteristics.
As a concluding classification, the relative tidal range (RTR) and dimensionless fall velocity (Ω) were
calculated (QSpatial 2016; Shaeri et al. 2014). This resulted in a RTR of 1.6, indicating a wave dominated
coastline; and Ω equal to 4.28, suggesting high intermediate surf zone conditions often characterised by
bar and rip processes (Masselink & Short 1993). A previous PB report by Blacka, Anderson and Lopez
(2008) offers support to these calculations, with observations of fluctuating transitions through each
intermediate surf zone classification over a 6 month period (Table 1). This may confirm the highly dynamic
nature of PB, and the relative unpredictability of future beach conditions.
Table 1- Morphology between Intermediate beach classifications- May to October 2008 (Blacka, Anderson & Lopez 2008)
Month (2008) Hs Morphological State Summary
May 1 to 3m Rhythmic bar and beach
June 0.5 to 2m Long shore bar trough to Transverse bar and rip
July 0.5 to 5m Long shore bar trough
August 0.7 to 1.5m Reflective to Low tide terrace
September 3.5m peak Long shore bar trough to Transverse bar and rip
October 1 to 1.5 m Reflective to Transverse bar and rip
0
50
100
150
200
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Rainfall(mm)
Month
Monthly Mean Precipitation
Mean Precipitation…
0
0.5
1
1.5
2
2.5
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
WaveHeight(m)
Month
Mean Wave Data- Gold Coast
Significant Wave Height
Figure 7- Mean precipitation- Coolangatta (BOM, 2016) Figure 8- Significant and Maximum wave height (QSpatial, 2016)

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3.2 Beach Nourishment
Since 1974, a total of 1.85million m3 of sand has been dredged from CC and deposited on southern PB
(Gold Coast City Council 2015a). The method involves dredging a 600m line along the length of the
Currumbin inlet and depositing the sand on the southern spit of PB (Gold Coast City Council 2015a).
Unfortunately, the process only opens the CC channel and replenishes PB in the short term, and any storm
event quickly erodes the new deposits (Strauss, Splinter & Tomlinson 2011). This sequence of artificial
stabilization and coastal process fluctuation can be observed in the temporal change of beach width
(Figure 9).
3.3 Coastal Hazards
Being dominated by wave forces, PB rips are common during some morphological formations. Specifically,
this is due to the natural process of water returning seaward in relation to existing physical formations
(Short 2007). Rips have been reported as strongest in falling tides, and are often associated with rhythmic
bar and beach (RBB) or transverse bar and rip (TBR) intermediate formations (Figure 10 and 11) (Gold
Coast City Council 2015b; Short 2007). Bearing in mind both these states were identified by the Blacka,
Anderson and Lopez (2008) research, the potential for PB rip formation is high.
Figure 9- South Palm Beach width fluctuations 2004 to 2008 (Blacka, Anderson & Lopez 2008)
Figure 10- Rhythmic bars and rip formations (Gold
Coast City Council 2015b)
Figure 11- Transverse bars and rip formations (Gold Coast
City Council 2015b)

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Storms and tropical cyclones present another risk to the coastal environment at PB. Extreme events can
cause human injury and sever infrastructure damage from the connected high swells, storm surges and
winds (Harper et al. 2000). In conjunction, heavy precipitation can trigger flooding due to increased
terrestrial runoff (Figure 12), with severity dependant on storm intensity and the degree of CC infill. The
oceanic force of such storms has also been attributed to severe beach erosion (Castelle et al. 2007). Since
1902, there have been approximately 1.2 tropical cyclones per year (Harper et al. 2000) . Whereas the
occurrence of east coast lows has been estimated at 3.7 per since 1960 (Harper et al. 2000). Typically,
cyclones and flooding take place during the wet season as illustrated in figure 13.
4.0 Discussion
The PB/CC system can be described as a morphologically diverse and ever evolving in response to oceanic
and meteorological influences. Project results suggest a midlevel of wave dominant forces (RTR=1.6), with
high intermediate surf zone conditions (Ω =4.28). However, this may represent only one beach profile out
of the range of intermediate bed form possibilities. These results were supported by the Blacka, Anderson
and Lopez (2008) six month observation of PB, which illustrated a continuous change through all four
forms of intermediate classifications. Considering consistent and safe beach conditions may be a prime
attraction to resort guests, this unpredictability may influence the overall attraction of tourists to the
proposed location.
Although the in situ beach profile indicated suitable width and attractive conditions, this should be
deemed variable with swell, tide and storm activity. As the seasonal variation of synoptic systems
influences swell and storms, this location must be viewed as an ever changing landscape which is only
partially controllable by stabilization techniques. This is clearly illustrated by the approximate 50m beach
Figure 12- Flood Prone area for Currumbin Creek
(Gold Coast City Council 2003)
Figure 13- Number of Cyclones and distance of eye from SEQ (Harper
et al. 2000)

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width variation during 2004/2005, and reports that although CC dredging moved 385km2 of sand to south
PB during 2004 , there was no increase in overall width from 2004 and 2007 (Blacka, Anderson & Lopez
2008; Strauss, Splinter & Tomlinson 2011). Evidence regarding the infilling of CC only three months after
dredging is another example of minimal control through training and maintenance (Shaeri et al. 2014).
This illustrates the high degree of variability surrounding the main natural asset of the proposed resort,
and implies considerable risk to consistent quality of tourist recreation.
The PB beach nourishment program presents another issue to consistent resort recreation. Although this
method is favoured globally for its effectiveness and natural manner of erosion mitigation (Jones &
Mangun 2001), it may be judged intrusive to the experience of hotel guests. The program is implemented
over eight weeks during the beginning of prime tourist season, and involves heavy machinery working
within the CC and PB (Gold Coast City Council 2015a). Its duration also depends on the fluctuating extent
of erosion and infill, and the procedure is unavoidable due to flood mitigation and beach maintenance
(Shaeri et al. 2014). This implies unpredictable maintenance intrusion duration, and may influence the
opportunities and experience available to hotel guests. Although a permanent artificial pump bypass may
be a solution to this issue, the high cost and infrastructure may outweigh any benefits (Strauss, Splinter &
Tomlinson 2011).
Coastal hazards are another issue for this location. As rip producing RBB and TBR formations may develop,
swimming risks are inevitable with an intensity related to unmanageable swell and tide qualities (Blacka,
Anderson & Lopez 2008; Short 2007). Storm and tropical cyclones are also unpredictable, with
consequences such as guest injury, severe infrastructure damage and extensive PB erosion (Harper et al.
2000). Heavy precipitation from these events can also cause flooding at the proposed site, with severity
dependant on the extent of CC infill which is only manageable by the intrusion of dredging. These natural
hazards are common throughout the summer wet season and peak tourist time, and may be considered
detrimental to the experience of hotel guests.
Seasonal variation of PB erosion and coastal hazards follow a trend of heightened intensity during
summer, and coincides with peak tourism season. This is related to the prevalence of tropical cyclones
and storms as illustrated in the long run averages and historic reports (Bureau of Meteorology 2016;
Harper et al. 2000). While increased creek discharge from precipitation may partially flush some CC infill
and increase the sediment budget for PB, the channel clearance is usually short lived (GCCC 2015b), and
any positives may be outweighed by flood risk and increased beach erosion.. Such unpredictable variation
in beach conditions and heightened risk to infrastructure and hotel guests may be considered detrimental
to the overall resort operations at this location.

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The proposed resort borders a morphologically diverse system that is for ever evolving in response to
oceanic and meteorological influences, and the consequence of these characteristics require continual
high cost maintenance to preserve safe and quality recreation. Seasonal fluctuations of environmental
hazards also introduce an unpredictable nature to this site. In light of these conclusions, the proposed site
cannot be recommended as suitable for resort construction. Further research regarding the southern bank
of CC is recommended due to its higher elevation, and the accumulation of longshore drift at the southern
rock groyne.
5.0 Conclusion
Coastal processes and geomorphic dynamics are forever variable within the ocean and land interfaces
chosen for development and human use. These characteristics pose substantial risk to future sustainability
if the entire system of socioeconomic and environmental interaction is not evaluated. Taking into account
this assessment of the coastal processes which define PB, it has been concluded that the proposed
construction site cannot be recommended as suitable for future development. The dynamic interactions
of this system create substantial risk to both guests and investment, the required beach nourishment is
high cost and potentially intrusive to tourist recreation, and coastal hazards remain unpredictable with a
heightened potential during peak tourism periods. Further consultation is required to assess the potential
of secondary locations within this region. While coexistence of human and physical earth forces is
obviously possible, coastal development should proceed with caution in light of future global change and
the potential intensification of already existing natural forces.

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6.0 References
Blacka, M, Anderson, D & Lopez, L 2008, Analysis of Shoreline Variability and
Erosion/AccretionTrends: June-October 2008, The University of New South Wales.
Bureau of Meteorology 2016, Climate statistics for Australian locations, viewed 15th of April
2016, <http://www.bom.gov.au/climate/averages/tables/cw_040242.shtml>.
Castelle, B, Bourget, J, Molnar, N, Strauss, D, Deschamps, S & Tomlinson, R 2007, 'Dynamics of a
Wave-Dominated Tidal Inlet and Influence on Adjacent Beaches, Currumbin Creek, Gold Coast,
Australia', Coastal Engineering, vol. 54, no. 1, pp. 77-90.
Gold Coast City Council 2003, Potential Flood Inundation Overlay Map, viewed 1st of May 2016,
<http://www.goldcoast.qld.gov.au/gcplanningscheme_0803/maps/overlay_maps/OM_17.pdf>.
Gold Coast City Council 2015a, Currumbin Creek Dredging, viewed 1st of May 2016,
<https://www.griffith.edu.au/__data/assets/pdf_file/0016/322801/Currumbin-Creek-
Dredging.pdf>.
Gold Coast City Council 2015b, Palm Beach Shoreline Project, viewed 1st of May 2016,
<http://www.goldcoast.qld.gov.au/thegoldcoast/palm-beach-shoreline-project-10919.html>.
Harper, B, Granger, K, Jones, T, Stehle, J & Lacey, R 2000, Chapter 4: Tropical Cyclone Risks
Chapter 5: East Coast Lows, Geoscience Australia,
<http://www.ga.gov.au/webtemp/image_cache/GA4200.pdf>.
Jones, SR & Mangun, WR 2001, 'Beach Nourishment and Public Policy After Hurricane Floyd:
Where Do We Go From Here?', Ocean and Coastal Management, vol. 44, no. 3, pp. 207-20.
Masselink, G & Short, AD 1993, 'The Effect of Tide Range on Beach Morphodynamics and
Morphology: A Conceptual Beach Model', Journal of Coastal Research, vol. 9, no. 3, pp. 785-800.
QSpatial 2016, Queensland Spatial Catalogue, Queensland Government., viewed 1st of May
2016, <https://data.qld.gov.au/dataset?q=Coastal+Data+System+%E2%80%93+Waves>.
Shaeri, S, Tomlinson, RB, Etemad-Shahidi, A, Strauss, D & Hughes, LP 2014, 'Hydrodynamics of a
Small Trained Tidal Inlet (Currumbin Creek, Australia)', Advances in Geosciences, vol. 39, p. 45.
Short, A 2007, 'Australian Rip Systems- Friend or Foes?', Journal of Coastal Research, no. 50, pp.
7-11.
Strauss, D, Splinter, K & Tomlinson, R 2011, 'Beach Nourishment and Coastal Protection Along the
Gold Coast, Australia: A Case Study at Palm Beach ', DOI 10.1142/9789814355537_0006.
Weathers, HD & Voulgaris, G 2013, 'Evaluation of Beach Nourishment Evolution Models Using
Data From Two South Carolina, USA Beaches: Folly Beach and Hunting Island', Journal of Coastal
Research, vol. SI, no. 69, p. 84.