Bournemouth Beach
Top-up (BIS4.3) March 2008
 A
section of beach between Boscombe and Southbourne was replenished
this winter by the Fareham-based
Westminster
Dredging Company and the Dutch
dredger Oranje.
The project suffered bad-weather delays.
Originally projected to take just 3 days, the eight hopper loads of sandy
beach material were delivered to the beach
over a period of one week.
Beach material was dredged off the Isle
of Wight and brought by the dredger close to the beach at Groyne 30 (see map).
The dredge/sail/discharge cycle
from the IoW took approximately 11 hours.
Because the waters of Poole Bay
are so shallow, the dredger needed to pump the sand ashore through a
long pipe that lay on the sea bed, known as a 'sinkerline', and the beach
was then levelled by bulldozers.
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For more detailed
replenishment process information and pictures see
BIS4.1
(opens in a new window) |
 Contact
Dr David Harlow, Coast Protection Manager
Bournemouth Borough Council
Town Hall Annexe
St Stephens Road
Bournemouth BH2 6EA
Tel: 01202 451389
Fax: 01202 451008
Email David Harlow
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About Beach
Improvement Schemes
During the 20th Century, the cliffs were protected from coastal
erosion by building concrete seawalls and groynes. This allowed houses and
roads to be built on the cliff tops, but it also stopped the natural
supply of sand and gravel to the shore. So beach material that is
lost to natural coastal processes cannot be replaced by any other than
artificial means.
Bournemouth beach loses approximately 70,000 m3 of material annually (1 million m3 every 13 years.
Since the predominant direction of longshore
transport in Poole Bay is from west to east, sand gradually feeds
the beaches at Southbourne and Hengistbury Head to the east, and
beyond into Christchurch Bay.
The
shoreline has been
replenished on several occasions in recent years; these projects are referred to as 'Beach
Improvement Schemes' (BIS):
|
Scheme |
Year |
Quantity of Sand (m3) |
|
BIS1 |
1970 |
84,000 |
|
BIS2 |
1974/75 |
1,400,000 |
|
BIS3 |
1988/89 |
1,000,000 |
|
BIS4.1 |
2005/06 |
600,000 |
|
BIS4.2 |
2006/07 |
898,000* |
|
BIS4.3 |
2008 |
70,000 |
|
*included 15,000m3 stockpiled for the
Boscombe
surf reef |
|
In the past Bournemouth Council has carried out
"boom & bust" replenishment schemes, where the beach is delivered
with a large quantity of material (e.g. 1974/75) and left until much
of it is lost before further replenishment (e.g. 1988/89).
The first stage of Beach Improvement
Scheme 4 (BIS4.1, 2005/06) was
part of a wider scheme that included the replenishment of beaches at
Swanage and Poole using sand dredged from Poole Harbour. The
project continued at Bournemouth during the winter of 2006/2007, between Boscombe and Alum Chine, using a further
supply of sand from a Licensed Dredging Area off the Isle of Wight
[BIS4.2].
During the three years 2008-2010 the council pledged to make good the
annual losses to keep the beach at a constant level and volume
(BIS4.3,
BIS4.4 and BIS4.5).
Replenishment is localised and takes just a few days.
It is undertaken during winter
months in order to minimise disturbance to public access &
enjoyment. |
