Environment and development
in coastal regions and in small islands
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Wise practices for coping with beach erosion: Dominica

Forestry, Wildlife and Parks Division, Dominica
University of Puerto Rico, Sea Grant College Program
Caribbean Development Bank
UNESCO Environment and Development in Coastal Regions and in Small Islands

FORCES TO BE RECKONED WITH

Beaches are continuously changing – from day to day, month to month and year to year – as the natural forces of wind and water meet the land. These changes, which have been taking place for millions of years, are linked to variations in wind, waves, currents and sea level.

But it is not just natural forces that change the beach. Humans have a big role to play in this process as well, through mining stones, gravel and sand from the beaches, polluting and damaging coral reefs, and constructing buildings and walls too close to the sea.

Changes in the beaches affect everyone. The coast is a place we are all attracted to for recreation, sports and simple enjoyment. This constantly changing and hazard-prone coastal environment is also where the greatest financial investment is concentrated, as roads, airports, buildings and tourism properties continue to be constructed on the only flat area in Dominica - the land behind the beach.

Natural forces  

  • Hurricanes and tropical storms, occurring between June and November, cause dramatic beach changes usually resulting in serious beach erosion.
  • High waves during ‘winter’ months resulting from storms in the North Atlantic Ocean, and known as swell waves, or locally as ‘groundseas’.
  • Sea-level rise, which is a long-term factor, taking place very slowly over decades causes shorelines to retreat inland.  

Since 1995, the Atlantic Basin (including the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico) has entered a more active hurricane cycle, which may continue for more than 20 years.  

Hurricane frequency between 1990 and 1999 in the Atlantic Basin

Source: Gray et al. http://typhoon.atmos.colostate.edu/forecasts/1999/nov99/ 

In the Atlantic Basin the number of really severe hurricanes (categories 3, 4 and 5) increased from one per year (1990 –1994) to four per year (1995 – 1999).

Human forces

A baby leatherback
turtle makes its
way across the
beach to the sea
near Roseau
Harbour, 1987

  • Removing sand and other materials from beaches and adjacent areas for construction purposes causes erosion and the loss of beaches and coastal lands, destroying the natural heritage of the coast and reducing the vibrancy of the tourism industry.
  • Building too close to the beach interferes with the natural sand movement and may impede beach recovery after a serious storm or hurricane.
  • Badly planned sea defences may cause the loss of the beach, and of neighbouring beaches.
  • Pollution from human activities on the land may damage coral reefs and seagrass beds; these biological systems protect, and provide sand to the beaches.
  • Removing vegetation from coastal areas destabilises beaches; and clearing sites inland results in increased soil and dirt particles being washed offshore and smothering coral reef systems.

***********

WHATS HAPPENING WITH DOMINICA'S BEACHES?


Beach monitoring in
progress at Woodford
Hill, 1994

 

In order to manage these changes, Dominica’s beaches have been monitored since 1987 by the Forestry, Wildlife and Parks Division who measure the beach slope and width regularly at numerous sites around the island.

 


A windswept east
coast beach at
Londonderry, 1994


Location of monitored beaches in Dominica

***********

SAND IN, SAND OUT  

Several hurricanes have hit Dominica in recent decades, and beach sand and stones are lost during each event. Following the hurricane event, the beaches recover to some extent, but not to pre-hurricane levels.

BEACH PROFILE
Toucarie Bay, Dominica. Beach erosion

Toucarie Bay in 1987

In 2000, after three
major hurricanes,
Toucarie Bay was
a narrow strip
of stones and the
coastal highway was
seriously damaged

***********

HURRICANES WREAK HAVOC

On the southwestern corner of Dominica, before Hurricane David in 1979, there used to be a tree-lined ridge connecting the small islet of Scotts Head to the mainland. Now, after several hurricanes, all that remains is a low stone bank which is easily breached by small storms.


Only a low stone 
bank connects 
Dominica to the 
Scotts Head Islet 
in 1994

 

Coastal highway under the Tarou Cliffs, 2000.The
telephone poles show where the road used to run
before the recent hurricanes

Waves building at
Roseau waterfront 
as Hurricane Luis 
approaches, 1995

***********

HERE TODAY, GONE TOMORROW  

The table shows generalised rates of change at the measured beaches in Dominica. During the period 1988-1999, nearly all the beaches showed erosion, a result, at least in part, of the impact of several severe hurricanes since 1989. However, most of the beaches in Dominica show erosion along one part of the beach and accretion (or build-up) at adjacent sections, thus these figures must be treated as average trends.

Beach change rates in Dominica 1987 - 2000 (metres per year)

A negative rate of change () indicates erosion and retreat of the shoreline, a positive rate of
change (
) indicates accretion or advancement of the shoreline towards the sea

  

A once popular picnic
place and sandy beach
at Belle Hall has 
become a rocky strip 
(in 2000) after the 
ravishes of several 
hurricanes

***********

WISE PRACTICES FOR A HEALTHY BEACH


Bout Sable - only
specific salt resistant
plants such as
seagrape can exist
on Dominica’s
windswept east
coast (1994)

  

The state of the beach affects everyone’s lives. There are no simple or universal solutions to shoreline erosion, since there are often several factors, both human and natural, contributing to the problem at a particular beach. Each beach behaves differently, so it is advisable to find out as much information as possible about a particular beach before taking any corrective action. It is necessary to consult the Physical Planning and Development Division before undertaking any action at a beach.

Some forces of change, such as hurricanes and winter swells are natural, and there is little we can do to stop them, yet there are ways we can help to slow down the rate of erosion:

  • Planning new development so that it is a ‘safe’ distance behind the beach will reduce the need for expensive sea defence measures in the future.
  • Revegetating beach areas with native vegetation e.g. grasses, vines salt-resistant, deep-rooting trees, such as sea-grape.
  

Ensuring new
development is a
‘safe’ distance
from the dynamic
beach zone, helps
conserve the
beach and
the buildings

  

Buildings close to the beach are vulnerable to erosion

Buildings at a safedistance from the beach are less 
vulnerable to erosion

 

  

Hard engineering structures
such as this seawall at
Roseau, serve to protect
the city’s seafront 
buildings, but do not 
promote the build-up 
of sand

 

   

  • Resorting to ‘hard’ engineering structures such as seawalls, revetments and bulkheads, only when there is a need to protect beachfront property from wave action. Such structures, even with careful design, result in the loss or narrowing of the beach over time.
  • Considering all other beach enhancement measures such as offshore breakwaters, groynes and beach nourishment (placing sand from the offshore zone or from an inland source on the beach) at a particular site. All such measures require careful design and environmental impact assessments, so always first consult the Physical Planning and Development Division.  

 

  

A waterfront hotel
at Castle Comfort
(2000), even
protected by a
seawall, is very
vulnerable
to storms and
hurricanes

Rebuilding on the
beach after a
hurricane,
as seen here at
Prince Rupert Bay
in 2000, is an
unwise practice
and leaves the building vulnerable
to future storms

***********

WISE PRACTICES CHECKLIST
Plan for existing and future coastline change by positioning all new development (large and small) a ‘safe’ distance landward of the vegetation line (consult the Physical Planning Division for information on ‘safe’ distances).  
Review and carefully consider ALL options when planning ways to slow down the rate of coastline change, these should include planning, ecological and engineering measures.
Continue to monitor the rate of coastline change and share the findings with all other stakeholders.
Seek to change community attitudes about the disposal of solid waste.

Coordinate an integrated approach to beach management, by ensuring that individuals, groups and agencies work together.

Promote the concept of coastal stewardship and the need for individuals to have a personal commitment to the benefit of the country.

Respect the rights of all beach users.

Stop the mining of sand, gravel and stones from beaches and adjacent areas and utilise alternative sources of construction material.

Conserve and restore vegetative cover, both adjacent to the beach in order to stabilise the sand, and further inland to reduce sediment reaching the reefs and seagrass beds.

 

For more information on shoreline 
change in
DOMINICA consult:

Forestry,Wildlife and Parks Division
Ministry of Agriculture and Environment
Botanical Gardens
Roseau, Dominica
T: +1 767 448 2401 
F: +1 767 448 7999
E: forestry@cwdom.dm

Physical Planning Division
Economic Development Unit
Charles Avenue
Goodwill, Roseau
Dominica
T: + 1 767 448 2401
F: + 1 767 448 7744

For more information on shoreline 
change in the
CARIBBEAN consult:

Coping with Beach Erosion
by Gillian Cambers
UNESCO Publishing, 1998
ISBN 93-3-103561-4  

 

This booklet is a result of 
co-operation between UNESCO, 
the Caribbean  Development 
Bank and Dominica’s  
Governmental agencies  

Illustrations: Barbara Navi – Photographs: Gillian Cambers, Arlington James – Design: Eric Loddé

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