Whitby Strategy - Further Studies
The period for this consultation has now
ended. The analysis of the consultation is now taking
place and results will be posted on the website
Whitby Coastal Strategy
The Whitby Coastal Strategy was completed in
July 2002. It covered the coastline from Sandsend to Abbey
Cliff and the lower reaches of the River Esk estuary.
The Strategy recognised the critical
importance of the Whitby Harbour structures to:
- providing a coastal defence to the town of
Whitby against coastal erosion;
- reducing tidal flood risk along the lower
reaches of the River Esk estuary;
- providing navigational shelter to vessels
- retaining beaches along Whitby Sands and
- enabling important economic activities such
as tourism, fishing, and the marina.
One of the most significant findings of the
Strategy was the identification of the poor condition and
performance of the Whitby Harbour structures.
The Strategy made recommendations for a major
scheme of investment to the structures to significantly improve the
wave protection and flood defence performance of the
It also recommended further investigations at
Whitby Harbour to fully characterise the extent and nature of the
structural problems. This information also helps define the
engineering works required and the costs and timescales for their
The further investigations on the Whitby
Harbour structures have now been undertaken and findings have been
used to re-evaluate assessments of their condition and proposed
ways forward with a major scheme to improve their condition and
Further Investigations of Structural
A comprehensive series of surveys and
physical investigations was designed and undertaken between
February and October 2008. This included:
- Topographic, digital measured and
- Dive survey and visual inspections;
- Ground probing radar and microgravity
- Ground investigation; and
- Hydrographic, geophysical and seismic
Further Investigations of Defence
A series of modelling and assessment
investigations was designed and undertaken throughout 2008.
These have improved understanding of the present-day coastal
processes in the vicinity of Whitby Harbour. The
vulnerability of the structures to failure has also been assessed,
along with the implications of different management options on the
coastal processes. This included:
- Wave and water level modelling;
- Beach behaviour analysis;
- Wave overtopping assessments; and
- Flood level assessments along the lower
reaches of the River Esk estuary.
Overview Assessment of Existing
From the further surveys and investigations,
the following conclusions have been made:
Main West Pier
The overall condition is poor, with movement
of sandstone blocks, opening of joints, scour at sea bed level,
cracking and chipping of blocks, and voiding behind facing
blocks. Overtopping discharges are in excess of target
thresholds for serviceability and will worsen over time due to sea
West Pier Extension
The overall condition is poor, with opening of
concrete joints and extensive voiding in the protective steel sheet
piling. Overtopping discharges are likely to be in excess of
target thresholds for avoidance of structural damage.
The overall condition is poor, with cracking,
chipping, displacement and settlement of sandstone blocks, opening
of joints, and voids behind facing blocks. There is evidence
of the onset of corrosion to sections of protective sheet
piling. There is also a series of three hollows in the sea
bed adjacent to the pier. Overtopping discharges are in
excess of target thresholds for serviceability and are greatest at
the landward end of the pier. Overtopping will worsen over
time due to sea level rise.
East Pier Extension
The overall condition is very poor, with a
major void at the south-east corner that results in an entire
section of concrete visible above water being suspended via a
cantilevering action from the rest of the structure. In
addition, there are numerous voids in the sheet piles caused
through corrosion of the steel and loss of backing concrete.
Overtopping discharges are great along this structure and well in
excess of target thresholds for avoidance of structural damage.
The present investigations have highlighted
that the existing piers are in poor condition and that the landward
end of the East Pier Extension particularly is at risk of failure
and could possibly collapse in the short term.
To address the present condition and
performance problems of the Whitby Harbour structures, there are
three principal categories of options, namely:
- Do Nothing - this is only
considered here to provide a base case against which other options
can be compared. It would involve no further management or
maintenance of the piers or pier extensions and eventually lead to
their breaching and collapse.
- Do Minimum – this will
continue present practice, where modest maintenance is undertaken
annually. This mainly focuses on local reactive repairs for
operational and health and safety purposes.
- Do Something – this covers a
wide range of potential options aimed at improving the present
condition and performance through major scheme intervention.
There are various means of implementing this option.
The management options that have been
considered for Whitby Harbour are:
- The ‘walk-away’ base case against which other options are
- Continue with present practice involving modest reactive
maintenance, primarily for reasons of harbour operations and health
- Advance the Line - protect the existing harbour structures
through construction of a new structure(s) to seaward.
- Managed Realignment – changes in harbour plan form alignment to
- Modify existing structures to improve present structural
- Modify existing structures to improve present defence
performance (especially with respect to overtopping
- Modify existing structures to improve present structural
condition and present defence performance.
- Managed Removal - removal of harbour structures and management
of flood and erosion risk through other means.
- Managed Relocation of vulnerable assets – relocation of
properties, businesses, infrastructure and other assets at risk of
erosion and flooding.
- Demolish and Rebuild – the existing piers and extensions would
be demolished and rebuilt on their existing alignment.
Following an assessment of these options
against technical, economic and environmental criteria, a preferred
approach has been identified involving a combination of
improvements to the condition and improvements in the performance
of the structures. This would involve the following:
- Pointing, grouting and partial sheet pile protection to the
- Sheet piling and concrete fill to the pier extensions;
- Rock armour revetment to the seaward side of the main piers and
extensions, with the possible use of a wave return wall along the
crest of the West Pier as an alternative to rock armour depending
on feedback from public consultation and discussion with regulatory
Why are you consulting?
Scarborough Borough Council recognises that
the only successful recipe for the delivery of coastal defence
studies and works is a partnership between the authority,
Consultants, Contractors, Stakeholders and the local community.
What do you want to find out from the Survey?
Public engagement and consultation to assist
in shaping the project and to enable the construction team to
develop a real understanding of the key issues of the local
To determine the issues and concerns that
stakeholders have about the options proposed.
|When is the
consultation taking place?
16th February 2009
End: 6th March 2009
or groups are being consulted?
|How are we
|Area covered by
How will the results be used?
Final report is due to be completed by
27.06.09. Stakeholders will be kept informed via local media.
All consultation responses will be tabulated
to provide feedback to Consultees, both in acknowledgement of their
contribution to the process and to allow them to understand how
responses have been taken into consideration in developing the
final report. Issues raised will be commented upon and how
they have been taken into account will be included in the final
Outcomes of the Consultation