• CoastCare Information
• Beach Erosions
• Available Technologies
• Trend In Detail
• The CoastCare System
• Major features of the CoastCare System
(click topic to view in detail)
CoastCare HBS System
Soft Engineering Coastal Solutions
Popular Caribbean beach resort where hotels are exposed to erosion hazard
By choosing CoastCare to engineer your beach stabilisation project, you choose a multidisciplinary
partner committed to protect the environment by applying sustainable green engineering technologies
and by working in close interaction with authorities and stakeholders.
The CoastCare System is a passive beach stabilisation system based on the hydrodynamic beach
stabilisation principle with the following advantages:
• Regulated by natural hydraulic forces generated by waves and tides
• Environmentally friendly /Green Engineering
• No hazard to public visiting the beaches or swimming
• Discreet installation
• Maintenance and monitoring package
• Low implementation cost
Beach erosion at the Danish west coast and a Caribbean island
Beaches are temporary features. There is always sand being removed and sand being added to them.
Often, they change drastically during the year, depending upon the frequency of storms.
Beaches erode because the supply of sand to the beach cannot keep up with the loss of sand to
the sea. Most sand is transported from inland via rivers and streams. Damming of waterways
prevents a major supply of sand from getting to beaches. Sand can also be transported from
beach to beach along a shoreline, but this is mostly just a redistribution of sand that is
already on the coast.
The problem of beach loss can be exaggerated if sea level rises relative to the land (either
due to true sea level change or geological sinking of the coast line).
On an uninhabited shoreline, new beach can be created further inland. But, when the
encroaching sea comes against people’s property, the tendency is for people to try and stop
the encroaching sea. They armour the shoreline with seawalls, revetments, jetties, etc.
These have a negative effect on beaches because once seawater reaches them; it "bounces"
off them with more energy than a wave washing back off a normal sand beach. More sand is
carried off shore, promoting beach loss. Additionally, jetties placed perpendicular to the
beach, disrupt along-beach currents and cause sand loss downstream of the jetty. The same
can be the case with many “hard engineering” structures.
Land based activities and natural physical processes have resulted in significant modifications
of the shorelines in many countries, with drastic effects on the coastal geomorphology as well
as on the coastal infrastructures.
Beaches naturally change profiles due to seasonal changes, but usually have a natural
equilibrium in harmony with prevailing conditions governing the coastline. Accretion is
dependent upon availability of sediment, which can be deposited onto the beach.
This sediment can be deposited on the beach by long shore sediment transport, storm activity,
runoffs due to rain or by rivers and streams emptying into the sea.
Any interruption of the sediment supply will manifest itself in the form of a change in the
beach profile. This change can be seen as a regression of the shoreline in response to sediment
starvation.
Therefore there is an urgent need to introduce new and cost-effective measures that can reduce
and mitigate the impacts on the shorelines.
Conventional solutions to coastal defence comprise physical constructions such as boulders,
groynes, breakwaters, etc., as well as rehabilitation of beaches with nourishment of sand
and dewatering systems with pumps. These methods are all associated with high logistics
and implementation costs as well as high maintenance expenses.
There are two main types of approaches to coastal defence:
Hard engineering: establishment of structures, which aim to resist the energy of the waves
and tides. Such structures include; breakwaters and seawalls designed to oppose wave energy
inputs, groynes designed to increase sediment storage on the shore, and flood embankments
and barrages designed as water tight barriers.
Hard engineering solution at site with erosion rate of 50 m/yr. As can be seen, the
groynes failed to stop the erosion at this site.
Soft engineering: establishment of elements, which aim to work with nature by manipulating
natural systems by adjusting to the energy of the waves, tides and wind. This approach has
economic benefits while minimising the environmental impact of traditional engineering structures.
The methods, which can be used, include artificial nourishment, beach dewatering, groundwater
pressure equalisation, hydrodynamic stabilisation, set back of structures and plantations of
osier hedges and marram grass.
No matter which solution is chosen, there will always be an environmental impact to a greater
or lesser degree.
Current trends favour the concept of shoreline management, working with the dynamic nature of the
coastal environment rather than fighting against the forces of the sea. This is best exemplified
by the widespread move away from hard engineering methods of coastal defence, which act to restrain
coastal processes, towards soft engineering approaches, which recognise the dynamic nature of the
coastal environment by utilising these processes to advantage. Soft engineering methods tend to
have a lesser impact on the environment, usually require lesser maintenance and can be more
attractive economically.
Hydrodynamic beach stabilisation, which is a passive soft engineering approach to combating
erosion, is radically different to dredging, sand nourishment and groyne building methods hitherto
being employed. It makes the lowest impact on the aesthetic beauty of the beach area without
disfiguring it with boulders and other visible hard structures.
It is worth noting that the hydrodynamic beach stabilisation principle, apart from being a
stand-alone system, can also be applied as a complementary solution in conjunction with other
conventional technologies such as groynes, nourishments, etc. It is very versatile.
More and more, nourishment is applied to combat beach erosion by replenishing lost beach due to
erosion. However nourishing is not stopping erosion, but compensating for the loss of beach
caused by the adverse effects of erosion. A nourished beach needs to be replenished periodically
to replace the sediment lost to annual erosion unless of course the erosion itself has abated to
a degree where no sediment losses occur. The erosion usually continues as before, unless the
nourished beach is stabilised in some manner.
Hydrodynamic beach stabilisation principle can be applied to nourished beaches as a step towards
reducing/ arresting the existing erosion, which over a period of time will deplete the beach of
the nourished sand.
No matter what solution one considers, it is generally accepted that more and more one has to
consider integrated approaches to combat coastal erosion. Especially since causes of erosion
are varied and site specific.
The CoastCare System is a hydrodynamic stabilisation system. It is an environmentally friendly
soft engineering approach to beach erosion abatement. It is non-polluting and has a very low
impact on the visible beach aesthetics. The system is implemented as a discrete non-obtrusive
subsoil installation with virtually no visible parts on the beach surface.
The CoastCare System is an erosion abatement system applying a groundbreaking technology
based on stabilising the hydro-dynamics of the beach profile in question.
It can either be applied as a stand-alone installation or can be implemented as a supportive
system to stabilise a beach section subsequent to beach nourishment. The system can also be
implemented at locations with hard structures such as groynes, breakwaters, etc.
All components of the system are always installed on the landside of the beach using GPS
positioning techniques. There is no disfigurement of the beach and no requirement of moving
parts, energy input, or heavy engineering.
First and foremost, the CoastCare system is seen as an approach to arrest or abate erosion
by stabilising the beach profile. The fact that accretion can also occur is seen as a result
of the erosion arresting effect of the system due to its beach stabilisation effect and of
course availability of sediment budget.
The system increases the rate of infiltration of seawater into the sediment bed of the beach
face by changing the capillary pore pressure. This allows the sand to settle and stabilise
earlier so that the sediment transported away from the beach by retreating seawater in the
swash zone is reduced, while at the same time increasing the ability of the beach to trap a
part of the sediment washed in by wave action.
When the water level is low on the coast during the period from low tide to high tide, the
water circulation in the swash zone increases, which again increases the depositing of materials
on the foreshore, thereby building up the beach from the sediments transported along the coast.
This basic property of the CoastCare system promotes sedimentation of materials along the
coastal profile where it is implemented.
Major features of the CoastCare System
CoastCare reserves its rights to change all information and specifications without prior notice.