SCOPAC contributed £15,000 towards the monitoring of a trial testing a new approach
to beach replenishment in Poole Bay. The concept was to make use of locally dredged
sediment and place it near the shore, allowing the prevailing waves and tidal currents
to move material toward and along the beach.
The Sand Motor (or Sand Engine) concept has been widely used in the Netherlands since
the 1990's given that it is cheaper and less intrusive compared with traditional
beach renourishment approaches (The Sand Engine: a solution for vulnerable deltas
in the 21st Century?Coastal Dynamics 2013). The works at Poole Bay are of national
importance given that the Sand Motor concept had never before been trialled on beaches
in the United Kingdom.
Poole Borough Council £15,000 contribution (2014-2017)
Poole Bay Nearshore Replenishment Trial
The Marine Management Organisation (MMO) granted the licence to allow the placing
of sand in the sea. The works were undertaken between the 9th and 14th February 2015,
when 30,000m³ of sand was placed on the sea bed approximately 400m offshore at Canford
Cliffs Chine (Poole), in water between 5-8m deep.
Poole Harbour Commissioners provided the sand from maintenance dredging of Poole
Harbour entrance, thereby recycling beach material back into the system, rather than
dumping it offshore at a disposal site.
Seven survey sets were collected by the Channel Coast Observatory (CCO) over time.
Each set consisted of a topographic survey of the beach and a bathymetric survey
of the sea bed. In addition, fluorescent tracer studies were undertaken to establish
a link between the sediment deposited on the sea bed and the beach.
An Acoustic Doppler Current Profiler (ADCP) measured the speed, direction and turbidity
of water currents using sound waves. With the ADCP installed, any turbidity difference
between the trial and conventional beach recharge could be assessed.
A ‘lessons learned’ leaflet was produced by the steering group for practitioners