This document discusses the management of coastal erosion at St Bees Head on the west coast of Cumbria, England. It describes how a variety of hard engineering structures were implemented to protect the coast, including sea walls, groynes, and revetments. However, these structures are now deteriorating due to lack of maintenance and are struggling to retain beach material. The natural coastal processes are working to overcome the human interventions, and softer engineering solutions may be more suitable going forward.

1. When relationships go wrong
The story of a broken coast

2. St Bees on the West Coast of
Cumbria
 Cumbria is a diamond
shape
 St Bees is at the
westernmost tip
 It is renowned for its
headland – St Bees
Head

4. Management
 The location is visited by many field groups
as it has good examples of most types of
hard engineering protection measures
 Promenade, Groynes, Rip rap Rock Armour,
Geo netting and a revetment
 At Sea Mill lane [to the south of the golf
course] there are also gabions.

5. Which are which?

6. However the love affair society has
with the coast is a troubled one
 Like most affairs, over the years attitudes
change and what was once a beautiful
untarnished thang is now jaded by over
exposure.
 Before the promenade St Bees was covered
in Sand Dunes …

7.  The natural ecosystem was on blown sand
 Consolidated by vegetation
 Moving
 Flexible
 Adaptable but also a valuable asset
 Sand and gravel were extracted and the
very good natural defences were
compromised.

8. The Response
 A variety of different management strategies
were introduced primarily a sea wall with
promenade, 9 groynes at right angles and a
revetment to the South.
 Following a collapse of the railway
embankment to the far south the slope
south of the prom was re-graded, geo-
netting introduced to stabilise the slope and
the later rock armour added at the toe.

9. Something for Nothing?
 Like most relationships after the initial
commitment some investment of time and
money is needed to keep things sweet.
 Sadly, West Cumbria has suffered from the
same budget cuts as elsewhere and the
hard engineering is beginning to show signs
of a troubled time ahead.

10. Promenade
 The sea wall has
experienced some
slight movement and in
places the mastic
between the block has
been stripped out by
the sea.

11.  Originally a flat surface
stones lie in the
remaining hollow
No expansion
filling

12.  In places the wall is inadequate and has been
overtopped with the beach material re-deposited
on the surface

13.  The sea wall no longer works as a barrier but as
an extension to the beach. The retaining blocks
behind are now battered.

14. Further up the sea wall…
 A lifeboat ramp
has been built. An
immoveable
barrier which
reflects the waves
energy, scouring
out the beach and
transferring the
material off shore.

15. Groynes
 Generally these are in
a bad state of repair
despite some attempt
at maintenance.
 In some places the
buckle under the sheer
weight of stones.
 In others sections are
missing or fixings
badly corroded.

16. You can see some of
the new sections –
sourced from tropical
hard wood?
 And in other places
holes right through
But what is the alternative?
Plastic replacements used re-cycled bale wrap but would not
biodegrade when they eventually come loose.

17. North of the promenade
 At the end of the sea wall a bridge passes
over Rottington Beck and is secured on a
block of unprotected concrete.
 The energy transferred northwards attacks
the mouth of the beck undermining the
foundations

19.  Nature continues to work around the man made
obstacles, the beach re-grades and the mouth of
the beck cuts out to sea.

20.  The lined channel accelerates heavily
sedimented material towards the coast
To the sea

21.  Despite all this
management slips and
slides still occur on
newly deposited
material.

22. Accretion and deposition
 Material moved in
shore up the mouth
gradually build up on
the river bank
 At the mouth a small
delta appears due to
too much material
 A spur growth across
the mouth

23. In Conclusion
 A natural system was  Natural systems still
managed using a hard work hard to overcome
engineering solution. the human intervention
 Maintenance of the  Micro forms of some of
this facility has been the landforms appear
poor and in winter it especially at the
struggles to keep fluvial / coast interface
material in check.

24. The future?
 The adoption of soft engineering solutions
are now more widespread
 Further south where the cliff material is
unconsolidated glacial clay a ‘do nothing’
approach has been utilised effectively.
 Imaginative new approaches are still being
developed – recycled plastic shuttering to
line a different beck's mouth.

26. Who knows, our
rocky relationship
may stand the test of
time …