Beach nourishment involves replacing sand lost to erosion from external sources to widen beaches. It reduces storm damage by dissipating wave energy and protects structures. Nourishment must be repeated as it doesn't stop erosion forces. Sand used must match native beaches in size and texture. Nourishment widens beaches for recreation while providing flood and erosion protection. It is expensive to implement but supports local economies. Alternative stabilization methods include hard structures or soft techniques but don't fully restore eroded beaches like nourishment does.

1. GUIDED BY :-
PROF. S. G. ADHAU
PRESENTED BY :-
NISHAD A. WANKHADE
DEPARTMENT OF CIVIL
ENGINEERING,

2. Introduction
 Beach nourishment also referred to as beach
restoration or beach replenishment describes a
process by which sediment (usually sand) lost through
erosion is replaced from sources outside of the eroding
beach.
 A wider beach can reduce storm damage to coastal
structures by dissipating energy across the surf zone,
protecting upland structures and infrastructure from
storm surges, tsunamis and unusually high tides.
 Nourishment is typically a repetitive process, since it
does not remove the physical forces that cause erosion,
but simply mitigates their effects

3.  The first nourishment project in the U.S. was at Coney
Island, New York in 1922-23 and is now a common
shore protection measure utilized .
 Nourishment gained popularity because it preserved
beach resources , widens the beach , and protects the
shore from floods .
 Nourishment creates a “soft” (i.e., non-permanent)
structure by creating a larger sand reservoir, pushing
the shoreline seaward . Hence , people get to use beach
as a recreational purposes .

4. Why it is necessary ?
 More than 70% of Earth's shorelines are retreating due
to rising sea levels.
 As shorelines move landward, structures located on or
near the beach may be in danger because floods or
tsunamis will have more severe effect and they will be
destroyed.
 In addition , beaches may not seem attractive to
people and hence , communities may lose significant
amounts of income if they lose the use of their
beaches

5. For a good nourishment , the purpose of the
nourishment has to be clearly defined.
In general, there are three reasons for beach
nourishment:
1. combatting coastal erosion (chronic erosion)
2. preventing flooding (safety)
3. maintaining a wide recreational beach.

6. Causes of erosion
 Beaches can erode both naturally and due to human
intervention .
 Erosion is a natural response to storm activity. Some
beaches do not have enough sand available to coastal
processes to respond naturally to storms. When there
is not enough sand left available on a beach, then there
is no recovery of the beach following storms.
 Many areas of high erosion are due to human
activities. Reasons can include , coastal structures like
ports and harbors that prevent longshore transport,
dams and other river management structures.

7. Requirements for effective nourishment
 Sediment texture (grain size and sorting) is critical for
success.
 Sand fill must be compatible with native beach sand.
In some cases, beaches have been nourished using a
finer sand than the original . Monitoring reveals that
storms can erode such beaches far more quickly than
the natural beach .
 Projects that did not match grain sizes performed
relatively poorly. Nourishment sand that is only
slightly smaller than native sand can result in
significantly narrower equilibrated dry beach widths
compared to sand the same size as native sand.

8.  Evaluating material fit requires a sand survey that
usually includes geophysical profiles and surface and
core sample . This was observed at the Waikiki
nourishment project in Hawii .
 The selection of suitable material for a particular
project depends upon the design needs,
environmental factors, transport costs considering
both short and long-term implications.

9. How Beach Nourishment works -
 During a beach nourishment project , a large volume
of beach-quality sand , called beach fill, are added
from outside sources to restore an eroding beach . or a
beach where only a small beach , or beach existed .
 Ultimately, beach nourishment widens a beach and
advances the shoreline seaward .
 Beach nourishment projects are designed and
engineered to work like natural beaches , allowing
sand to shift continuously in response to changing
waves and water levels .

10.  This sand once placed gets redistributed gradually by
natural processes .
 Ultimately , the wider , nourished beach , which slopes
gently downward below the shore by acting as
naturally protective buffers .
 Engineers may decide to place the beach fill as
1] directly on the beach ,also called as profile
nourishment ,
2] or as dunes also known as dune nourishment .

11. Profile Nourishment
 Beach Profile Nourishment describes programs that
nourish the full beach profile.
 In this instance, "profile" means the slope of the
uneroded beach from above the water to well out to
sea, not just the visible portion.
 The Gold Coast profile nourishment program placed
75% of its total sand volume below low water level.

12. Profile Nourishment

13. Dune Nourishment
 Dune nourishment is particularly effective in
protecting upland development against storm waves.
 The placement of material high above the waterline
does not expand the width of the dry beach,
 However, and therefore is not appropriate when the
enhancement of recreational opportunities is an
important project objective

14. Dune
Nourishment

15. Before Nourishment After Nourishment

16. Advantages :
1. It widens the bed
2. Structures behind beach are protected as long as the
added sand remains.
3. Most importantly, beach nourishment reduces the
detrimental impacts of coastal erosion by providing
additional sediment which satisfies erosional forces.

17. DISADVANTAGES :
 1.Beach nourishment sand may erode .
 2.Beach nourishment is expensive, and must be
repeated periodically.
 3.The beach turns into a construction zone during
nourishment.

18. Alternatives to nourishment
 Nourishment is not the only technique used to address
eroding beaches. Others can be used singly or in
combination with nourishment, considering
economic, environmental conditions
 Structural approach is one alternative to nourishment .
 It is divided into two types :-
1) Hard structures , which includes , wood and rock
groins, seawalls, revetments and breakwaters .
2) Soft structures , which includes sand bags
,geotubes ,planting vegetation .

19. Seawalls :-
•Seawalls are normally
constructed of rock and
concrete .
• Seawalls protect
property and
infrastructure from wave
assault .
• Results in no sandy
beach and requires long-
term maintenance .

20. Groines :-
• It runs
perpendicular to the
shore .
• It lowers or breaks
the energy of wave .
• Thus it prevent the
shore from erosion .

21. Soft Structures
Sand Bags
 Sand bags are kept one on
another as shown in figure
.
 They are more of a
temporary emergency
feature

22. Geo-tubes :-
 Geotubes consists of sacks made by geotextile that are filled
with sand or gravel .
 Geotubes are more durable emergency protection features
which serve as dune cores . . This anchors the sand and
sediment,It is not recommended for continuous exposure to
high wave energy environments .
Planting Vegetation :-
 This is also called as ‘soft stabilization‘ , because it does not
use a structure .
 This anchors the sand and sediment, which slows erosion
caused by wind and waves.
 Because these methods use only organic materials, the
aesthetics and natural habitats of the beach are maintained .

23. Beachface Dewatering
 Beachface dewatering basically consists of
continuously pumping water away from the
beachface.
 Wet beaches tend to lose sand. Waves
infiltrate dry beaches easily and deposit
sandy sediment.
 Beach drainage (beach dewatering) uses
Pressure Equalizing Modules (PEMs) allow
the beach to drain more effectively during
tide. Fewer hours of wet beach translate to
less erosion. Permeable PEM tubes inserted
vertically into the foreshore connect the
different layers of groundwater. The
groundwater enters the PEM tube allowing
gravity to conduct it to a coarser sand layer,
where it can drain more quickly .

24. New techniques
Rainbowing technique -
 Rainbowing technique is getting famous nowadays . In
rainbowing technique , sand from the nearby seabed , and
discharges the sand to needed shore .
 The process of rainbowing begins with the excavation of
sediment, typically sand, from the seabed by a dredger.
Dredgers excavate the sediment using mechanical or
hydraulic methods or a combination of both.
 The methodology for beach nourishment by Rainbowing
technique was prepared jointly by DCI and Vizag Port. It
consists of filling up the hopper with sand by stationary
dredging in the new sand trap area.
 The dredger would hold her positionat this point and
discharge the mixture to a distance of approx 100 m so that
the material falls within the shore zone .

25.  On completion of the discharge within about 1.5 hrs the dredger
returns to the new sand trap area and positions for the next load.
At least 5 loads were pumped every day with cumulative quantities
ranging from 20000 – 22000 cu.m. per day.
 Direct Rainbowing onto the beach resulted in savings in time due
to reduced discharge time and time loss on account of positioning
with anchors. There is also an advantage of pumping in locations
with greater erosion selectively. Further, there has been no
disruption to container shipping or idle time of the dredger.

26. Costs
 Nourishment is typically a repetitive process, since
nourishment does not remove the physical forces that
cause erosion; it simply mitigates their effects. A benign
environment increases the interval between nourishment
projects, reducing costs. Conversely, high erosion rates may
render nourishment financially impractical
 In many coastal areas, the economic impacts of a wide
beach can be substantial. The 10 miles (16 km)–long
shoreline fronting Miami Beach, Florida was replenished
over the period 1976–1981. The project cost approximately
$64,000,000 and revitalized the area's economy.

27. Conclusion
 After considering all the aspects of beach nourishment , we came
to know some important things .Beach nourishment is not
permanent solution for eroding beaches . It is very costly and
have some demerits and some environmental issues .
 Whereas, The soft stabilizing methods like sand bags , geotubes
, planting vegetation don’t have any adverse effect on
environment . But they don’t restore the eroded beach , they just
prevent the beach from further erosion .
 On the other hand ,beach nourishment has been very successful
, even on highly eroded beaches . Nourishment provides us with
widened beach that used for various recreational purposes . Even
if it is somewhat costly , it proved to be very useful .
 After studying various aspects , I would conclude that “BEACH
NOURISHMENT” is very beneficial and to protect and restore
our beautiful beaches it is the best option .

28. References :-
 www.wikipedia.com
 Beach stabilization :-structure & beach nourishment
alternatives .(Paper presented by Steven Hafner )
 Beach and Dune Restoration by Karl Nordstrom
(Book)
 www.beachapedia.com

29. THANK
YOU