Environment and development
in coastal regions and in small islands
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Beach erosion in Anguilla

Coast and Beach Stability in the Lesser Antilles (COSALC) project Sponsored by UNESCO and the University of Puerto Rico Sea Grant College Program

Background

Anguilla's beaches are essential to the social, economic and environmental well being. They:

However, beach erosion is a growing cause for concern. Even before Hurricane Luis hit Anguilia in September 1995, beach erosion was a problem at several sites. For instance, Shoal Bay's sandy point was moving westward due to erosion on the east side. At Cove Bay, the beach eroded so much that the track had to be relocated. And Sile Bay's sand dunes were destroyed as a result of sand mining for construction material.

  By 1992, mining had destroyd the dunes at Sile Bay,
leaving only isolated remnants. A sea wall was built
to try and protect the shoreline. Today, even the
remnant dunes have washed into the sea.

In 1992, Anguilla joined a regional project called COSALC (Coast and Beach Stability in the Lesser Antilles). This project is sponsored by UNESCO and the University of Puerto Rico Sea Grant College Program. As part of COSALC, beaches are measured on a regular basis in Anguilla and its surrounding cays by:

Every three months, personnel from these agencies use standard surveying techniques in order to measure the area and width of Anguilla's beaches. Technicians from the Department of Fisheries & Marine Resources then analyze the data using a computer spreadsheet programme. The trends observed help to determine whether a beach is eroding (getting smaller) or accreting (gaining in size).

  Measuring the eroded dunes at Rendezvous Bay
after Hurricane Luis in 1995.

Information about changes in Anguilla's beaches is stored at the Department of Fisheries & Marine Resources. The data base on beach changes in Anguilla dates back to September 1992.

The effects of Hurricane Luis on the beaches of Anguilla

Hurricane Luis, a huge, category-4 hurricane, passed over Anguilla on September 4 to 6 of 1995. All of the beaches were eroded by the hurricane's forceful waves, and Sandy Island and Scilly Cay were completely flooded over. Underwater damage was evident for all to see, as beaches were carpeted with dead sea grass and debris torn from the coral reefs.

The damage to the beaches was enormous. At Maunday's Bay, the erosion of both beach and dunes left villas perched precariously near the edge of ten-foot sand cliffs. On the opposite side of Anguilla, Bames Bay was completely stripped of sand, leaving only a bare rock platform.

At nearby Meads Bay, the dune edge had been pushed 98 feet (30 m) inland, partly destroying a hotel and a private residence.

photo from essaouira
  Beach profile at Meads Bay Central before and after
Hurricane Luis. After the hurricane, 30 metres (98feet)
of dune had eroded. Anguillia lost 30 meters of land at
this beach.

When the data is analyzed for Anguilla, it appears that the dune edge has retreated inland at an average of 30 feet (9 m) as a result of the hurricane. This is a very serious loss for Anguilla, as the dunes represent a reservoir of sand that has been built up very slowly over the years.

Following the hurricane, the beaches began to rebuild as some of the sand was moved back onshore. However, the dune edge - and the beaches - are now further inland. Anguilla is shrinking, as coastal land has been lost, maybe forever. For on Dominica and Nevis, beaches heavily eroded during Hurricane Hugo in 1989 have still not grown back to pre-hurricane levels.

Are hurricanes the only cause of beach erosion?

While hurricanes are not the only cause of beach erosion, they are certainly a major factor. The high waves caused by hurricanes move sand into deep water offshore, where it can never be returned to the beach system. This same wave action also damages coral reefs and sea grass beds. Coral and sea grass ecosystems normally supply and stabilize sediment, providing the beaches with natural protection from wave action.

Other factors causing erosion:

  1. Sand extraction from beaches and dunes is a major cause of erosion. Heavily mined sites such as Sile Bay and Meads Bay were especially vulnerable to the waves of Hurricane Luis. Sand mining is now prohibited on all beaches and dunes except at Windward Point.
  2. Pollution and boat anchors damage coral reefs, which supply nearly all of Anguilia's beach sand. As the reefs are damaged, they provide beaches with less sand, and are less able to protect the beaches from high wave energy.
  3. Winter storms in the North Atlantic generate high swell waves known as "groundseas," which especially affect the northern coasts of Anguilla and her cays.
  4. Although official information on sea level changes in Anguilla is not yet available, scientists concur that sea level rise related to the "greenhouse effect" also causes beach erosion. Tectonic movements are also contributing.
  5. Some sea defence structures may result in beach erosion. Groynes and jetties may result in accretion on one side, while causing erosion on the other. All sea defences should be carefully designed.
  Barney Bay, a beautiful sand beach,
September 1994
  The same beach, September 1995,
three weeks after Hurricane Luis.
Almost all the sand had been stripped,
exposing a bare rock platform.

When can we expect another hurricane?

Nobody knows the answer to this question… Prior to Luis, the last major hurricane to affect Anguilia was Hurricane Donna in 1960. But this does not mean that we can rest easy for the next 35 years. Scientists predict that we are entering a period of 20 to 30 years of more intense hurricane activity. These predictions are based on a study of weather patterns and climate records over the past century.

Tropical storms and hurricanes passing over other islands may also affect Anguilla and its beaches, as when Tropical Storm Klaus passed in 1984.

We need to plan the development of our coasts very carefully so that our buildings are a safe distance back from the beach. This way, our beaches will have space to change naturally, and will be better preserved. Experience at Maunday's Bay and other sites around Anguilla has shown that it is very expensive to try and repair the damage caused by beach erosion. It is far more cost effective to plan for erosion by placing new developments well behind the active beach zone.

What can be done about beach erosion?

  1. Be aware! While beaches "come and go" as part of a natural seasonal cycle, long term erosion is also occurring.
  2. Make allowances for hurricanes and beach changes when planning new coastal developments. Consult the Physical Planning Unit before designing or commencing any construction activity.
  3. Seek alternatives to beach sand for construction.
  4. Keep beaches and coastal waters free of pollution.
  5. Preserve sand dunes, especially primary dunes, in their natural state. Avoid building on dunes. Where dunes are eroding, help to stabilize them with vegetation, and construct wooden walkways to prevent wear and tear by beachgoers and hikers.
  6. Preserve the coastal vegetation, including trees, shrubs, vines and grasses. When we clear land without saving these plants, an increased amount of eroded soil washes onto the coral reefs, damaging and killing them.
  7. Plant trees, especially deep rooting species, for shade, beauty and the stability of our beaches.

For more information, call ...
The Department of Fisheries & Marine Resources: Tel. (809) 497-2871
The Physical Planning Unit, Land & Surveys Department: Tel. (809) 497-2424 or 497-2153
COSALC Coordinating Centre, Puerto Rico: Tel. (787) 832-3585; Fax (787) 265-2880.

and/or

UNESCO CSI, email: csi@unesco.org

Local/regional contact

TRINIDAD AND TOBAGO
PORT OF SPAIN
Tel. 0018096220536, Mr. W. Wiltshire (Head of Office)
c/o UNDP POBox812, 19 Keate Stree
PORT OF SPAIN
TRINIDAD AND TOBAGO
Fax. 18096231658, Telex 22257 UNDP WG
Covers: Aruba, Guyana, Neth, Antilles, Suriname, Trinidad and Tobago

Source: Brochure published by: Sea Grant Printers, 1997
Amended for the CSI home page in February 1977

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