Building a barrier across a river estuary can cause many problems with the environment. for example, some rivers are home to rare species of fish and birds. Their habitat may be damaged in the process of building.
Also systems like this can cost lots of money to build and will require large investments from businesses who may not necessarily see the long-term benefits of this type of development.
Across an estuary.
a spit
At the moment flooding is prevented by a man made structure placed across the Thames estuary called the "Thames Barrier". However rising sea level mean that this will not protect the city for ever. See related link below.
estuary means a water passage where the tide meets a river current. so you could say "it was hard to get across the estuary, because the current was so ruff."
Across the Humber Estuary on the north east coast of England near Hull.
It is called a roadblock.
The integration of the electric field across the depletion region is what develops the barrier voltage.
a Levi and a dam
Tidal power is harnessed by constructing a dam across the mouth of an estuary or a bay.
The potential across a pn junction is called potential barrier because majority charge carriers have to overcome this potential before crossing the junction.
distributes loads across the wall
baymouth bar