Beach Nouris
635
Part C | 29
29. Beach Nourishment
Robert G. Dean, Thomas J. Campbell
Although beach nourishment is a relatively young
technology, some major projects have been in
place for 80 years and monitored sufficiently to
provide a basis for design and performance prediction with a reasonable degree of confidence.
Of the various methods available for shoreline
stabilization, beach nourishment is unique in addressing the sand deficit and with the capability
to restore the recreational, storm protection, and
ecological functions of a natural beach. The quality
and quantity of sand placed in beach nourishment
are shown to be essential to effective performance.
Design and performance prediction methods are
reviewed including the analytical method of Pelnard Considère, which provides interrelationships
between various design parameters and is an excellent pedagogical tool for both understanding
these relationships and guiding the more detailed
methods which are evolving toward greater and
greater complexity. Legacy projects are defined
as those that were nourished many years ago,
require very little maintenance, have been documented to the degree that their performance
is well established and are generally not recognized as constructed beaches by the typical beach
user. Two of these legacy projects are reviewed in
some detail as well as several other projects for
which the performance is well established. The
challenges facing beach nourishment in the future
include: rising energy costs, environmental issues,
public perception and limited sand resources.
29.1 Advantages of Beach Nourishment
Over Other Approaches......................... 636
29.2 Methods of Delivery of Sand
for Beach Nourishment ........................ 636
29.2.1 Characteristics and
Considerations in Design of
Beach Nourishment Projects ....... 637
29.2.2 Significance
of Good Quality Sand ................. 638
29.2.3 Various Settings
for Beach Nourishment .............. 638
29.3 Role of Structures
in Beach Nourishment ......................... 639
29.3.1 Terminal Structures.................... 639
29.3.2 Groins ...................................... 640
29.3.3 Detached Breakwaters ............... 640
29.4 Design and Prediction Approaches
and Methods ....................................... 640
29.4.1 Pelnard Considère Methodology.. 641
29.4.2 One-Line Numerical Models ....... 643
29.4.3 N-Line
and more Detailed Models ......... 643
29.5 Additional Design Considerations ......... 643
29.5.1 Erosional Hot Spots ................... 643
29.5.2 Nearshore Placement ................. 644
29.5.3 Ad-Hoc Transformation for
Modeling .................................. 645
29.6 Legacy Beach Nourishment Projects ...... 645
29.6.1 Examples and Discussions
of Legacy Projects ...................... 645
29.7 Other Beach Nourishment Projects........ 648
29.7.1 Seabright
to Manasquan Inlet, NJ.............. 648
29.7.2 Captiva Island, FL ...................... 648
29.7.3 Treasure Island, FL ..................... 649
29.8 Summary and Conclusions ................... 649
29.9 Nomenclature...................................... 650
References................................................... 650
Beach nourishment, the placement of large volumes
of good quality sand along the shoreline to advance it
seaward, is a comparatively young technology. Apart
from some early projects of opportunity with sand available from construction projects, the first large-scale
designed nourishment projects in the United States
commenced in the mid-1970s. The earliest projects
were placed with comparatively little design background, regulations, or concerns for environmental effects. Yet, some of these projects continue to function
635
Part C | 29
29. Beach Nourishment
Robert G. Dean, Thomas J. Campbell
Although beach nourishment is a relatively young
technology, some major projects have been in
place for 80 years and monitored sufficiently to
provide a basis for design and performance prediction with a reasonable degree of confidence.
Of the various methods available for shoreline
stabilization, beach nourishment is unique in addressing the sand deficit and with the capability
to restore the recreational, storm protection, and
ecological functions of a natural beach. The quality
and quantity of sand placed in beach nourishment
are shown to be essential to effective performance.
Design and performance prediction methods are
reviewed including the analytical method of Pelnard Considère, which provides interrelationships
between various design parameters and is an excellent pedagogical tool for both understanding
these relationships and guiding the more detailed
methods which are evolving toward greater and
greater complexity. Legacy projects are defined
as those that were nourished many years ago,
require very little maintenance, have been documented to the degree that their performance
is well established and are generally not recognized as constructed beaches by the typical beach
user. Two of these legacy projects are reviewed in
some detail as well as several other projects for
which the performance is well established. The
challenges facing beach nourishment in the future
include: rising energy costs, environmental issues,
public perception and limited sand resources.
29.1 Advantages of Beach Nourishment
Over Other Approaches......................... 636
29.2 Methods of Delivery of Sand
for Beach Nourishment ........................ 636
29.2.1 Characteristics and
Considerations in Design of
Beach Nourishment Projects ....... 637
29.2.2 Significance
of Good Quality Sand ................. 638
29.2.3 Various Settings
for Beach Nourishment .............. 638
29.3 Role of Structures
in Beach Nourishment ......................... 639
29.3.1 Terminal Structures.................... 639
29.3.2 Groins ...................................... 640
29.3.3 Detached Breakwaters ............... 640
29.4 Design and Prediction Approaches
and Methods ....................................... 640
29.4.1 Pelnard Considère Methodology.. 641
29.4.2 One-Line Numerical Models ....... 643
29.4.3 N-Line
and more Detailed Models ......... 643
29.5 Additional Design Considerations ......... 643
29.5.1 Erosional Hot Spots ................... 643
29.5.2 Nearshore Placement ................. 644
29.5.3 Ad-Hoc Transformation for
Modeling .................................. 645
29.6 Legacy Beach Nourishment Projects ...... 645
29.6.1 Examples and Discussions
of Legacy Projects ...................... 645
29.7 Other Beach Nourishment Projects........ 648
29.7.1 Seabright
to Manasquan Inlet, NJ.............. 648
29.7.2 Captiva Island, FL ...................... 648
29.7.3 Treasure Island, FL ..................... 649
29.8 Summary and Conclusions ................... 649
29.9 Nomenclature...................................... 650
References................................................... 650
Beach nourishment, the placement of large volumes
of good quality sand along the shoreline to advance it
seaward, is a comparatively young technology. Apart
from some early projects of opportunity with sand available from construction projects, the first large-scale
designed nourishment projects in the United States
commenced in the mid-1970s. The earliest projects
were placed with comparatively little design background, regulations, or concerns for environmental effects. Yet, some of these projects continue to function