West Wight Coastal Strategy March 2016

8/17/2019 West Wight Coastal Strategy March 2016

1/168

West Wight Coastal Flood andErosion Risk Management Strategy

MAIN STRATEGY DOCUMENT

DRAFT FOR CONSULTATION

MARCH 2016


2/168

This Strategy was produced for Isle of Wight Council with technical

assistance from the engineering and environmental consultantCAPITA | AECOM.

This project was funded by the Environment Agency from

Flood and Coastal Risk Management Grant-in-Aid.

Photos (C) Isle of Wight Council 2016 (& pages cover, 56, 95, 128, 163 & 168 courtesy of S.Lee)


3/168

3West Wight Coastal Flood and Erosion Risk Management Strategy

CHAPTER 1

INTRODUCTION8

Contents

12 Strategy objectives

13 The shoreline management planning hierarchy

14 The need for a strategic approach

16 Purpose and structure of this document

17 Supporting information

CHAPTER 2 WHAT IS AT RISK IF WE DO NOTHING?

19

21 Why we need the Strategy - what is at risk ifwe 'Do Nothing'

22 Sea level rise and increasing risk

CHAPTER 3 HOW THE STRATEGY HAS BEEN DEVELOPED

24

26 Overview of the study area- key features, issues and opportunities

26 Coastal processes overview - wave, tides,sediment transport

GLOSSARY AND ACRONYMS6

CHAPTER 4 OVERVIEW

48

50 A phased approach to management based on risk

52 Links with the planning process and redevelopment

52 Environmental impacts summary

28 Potentially contaminated land

31 Environment and heritage designations

31 Stakeholder engagement- understanding what people want from the coast

32 Summary of the existing defences33 Option development

35 Strategy Management Zones

43 Strategic Options

45 Strategic Option Appraisal

CHAPTER 5

STRATEGY MANAGEMENT ZONE 1 56

58 Baseline - what would happen if we did nothing?

61 Strategy preferred option - commentary

Needles Headland

Fort Redoubt to southern limit of Totland Bay


4/168

4 West Wight Coastal Flood and Erosion Risk Management Strategy

CHAPTER 11 FUNDING

156

CHAPTER 9

STRATEGY MANAGEMENT ZONE 5 110

112 5a Baseline - what would happen if we did nothing?

117 5a Strategy preferred option - commentary120 5b Baseline - what would happen if we did nothing?

125 5b Strategy preferred option - commentary

Gurnard and Cowes Headland

Gurnard Luck to Cowes Parade

CHAPTER 12 WHAT NEXT?

164

CHAPTER 6 STRATEGY MANAGEMENT ZONE 2

64



Totland and Colwell Bays

Southern limit of Totland Bay to Fort Victoria

CHAPTER 7

STRATEGY MANAGEMENT ZONE 372


79 3a Strategy preferred option - commentary

86 3b Baseline - what would happen if we did nothing?


94 3c Baseline - what would happen if we did nothing?

99 3c Strategy preferred option - commentary

Yarmouth and Western Yar

Yarmouth coast (Fort Victoria to Port la Salle) and theWestern Yar valley (including Freshwater Bay)

CHAPTER 8


102



Newtown Coast

Bouldnor Cliff to Thorness Bay (including Newtown Estuary)

CHAPTER 10



135 6a Strategy preferred option - commentary

140 6b Baseline - what would happen if we did nothing?


148 6c Baseline - what would happen if we did nothing?

153 6c Strategy preferred option - commentary

Cowes, East Cowes and the Medina

Cowes Parade to Old Castle Point, East Cowes


5/168


SMZ locations

Reproduced from the Ordnance Survey digital data with the permission of the controller HMSO. © Crown copyright and database rights 2016 Ordnance Survey 100019229

SMZ 6

SMZ 1

SMZ 5

SMZ 3

SMZ 2

2 kilometresN

SMZ 3

SMZ 4


6/168


Glossary and Acronyms

Baseline

Denes an existing condition/situation (usually Do Nothing) against

which options or scenarios are compared.

Benets

The savings (damages avoided) delivered by implementing strategy

options.

Broader Outcomes

Rather than solely considering ood and coastal risks, the Strategy

has taken account of other benets to the community such as

regeneration, tourism, recreation, amenity and coastal accessopportunities.

Costs

The amount of money required to implement the strategy options.

Do Minimum

A management option dened as the minimum amount of action or

intervention necessary to deliver the legal requirement or sustain thestandard of service of the asset.

Do Nothing (No Active Intervention)

A management option dened as taking no action whatsoever; where

there are existing defences, do nothing assumes that no furthermaintenance or repair work is undertaken.

Grant in Aid

Money coming from the central government to fund a coast protectionof ood protection scheme.

HTL (Hold the Line)

A policy with an overarching intent to build or maintain coastal defencesso that the position of the shoreline remains where itcurrently is.

Maintain

A management option in which maintenance of the existing defencesis undertaken. This option does not change the defence or its

performance, but simply maintains it in good working order or restoresit to its previous condition in the event of a breakdown.

MR (Managed Realignment)

Allowing the shoreline to move naturally, but managing the processto direct it in certain areas. This is usually done in low-lying areas,but may occasionally apply to cliffs.

ODU (Option Development Unit)

A section of the coastline in which local scale options to manage ood

and erosion risk are developed.

Partnership Funding

This describes the way coastal defences are often paid for wherevarious "partners" have input into the project. Typically this refers to jointfunding between government and private sources.

Potentially contaminated land

Land potentially containing substances in or under the land which couldpollute controlled waters or cause signicant harm to other receptors

such as humans, animals or the environment.

Present Value

An economics term which refers to the current worth of a future sumof money.


7/168


Priority Schemes

The initial works required following the Strategy to address ood

and erosion risk in key areas.

Property Level Protection (PLP)

Flood mitigation measures applied to individual properties thatreduce the risk of ooding on a property level (i.e. door ood

defenders etc).

Residual li fe

The time left (typically in years) that a defence structure is expectedto be able to provide ood and erosion protection before it comes

to the end of its service life. The residual life is estimated from adefence condition survey and assumes that no maintenance workswill be carried out in the future.

Scheme

A measure, or combination of measures, undertaken to increase

the level of protection against ooding and/or erosion to a local area(e.g. a new oodwall structure).

SMP (Shoreline Management Plan)

A high-level non-statutory planning document which providesa broad scale assessment of the risk associated with coastalprocesses and presents the a long-term policy framework to reducethese risks to people and the developed, historic and naturalenvironment in a sustainable manner. The Isle of Wight SMP2 waspublished in 2010 and approved in 2011.

SMZ (Strategy Management Zone)

A group of units (ODUs) with similar characteristics in whichoverarching, wider scale options to manage the ood and

erosion risk are developed.

Standard of Protection (SoP)

The level of ood risk that a coastal defence structure is designed to

protect against. For example, a defence structure with a 1:100 yearSoP indicates that the structure will protect against ooding from a ood

event which typically occurs once every 100 years.

Sustain (e.g. the standard of protection)

This is a ood risk management term which refers to options that keep

pace with change and potential increases in risk in the future (i.e.from climate change and sea level rise). This is achieved by raising orupgrading defences in the future to sustain the standard of protection.

Abbreviations

STRATEGY LANDOWNERSHA Highways AuthorityPO Private Ownership

ENVIRONMENTAL DESIGNATIONSSPA Special Protection AreasSSSI Sites of Special Scientic Interest

SAC Special Areas of ConservationSAM Scheduled Ancient MonumentsNNR National Nature ReserveLNR Local Nature Reserve

ENVIRONMENTAL ASSESSMENTSWFD Water Framework DirectiveQRA Qualitative Risk AssessmentHRA Habitats Regulations AssessmentSEA Strategic Environmental Assessment

OTHERCAPITA/AECOM Environmental and Engineering Consultants


8/168View towards Cowes from across the Medina


9/168

i n t r o

Chapter 1

intro

IntroductionSett ing the scene


10/168


Introduction

The Isle of Wight Council (IWC) and the Environment Agencywith Capita | AECOM engineering consultants have developed

a Coastal Flood and Erosion Risk Management Strategy.

The West Wight Coastal Flood and Erosion Risk ManagementStrategy recommends the preferred strategic approaches formanaging coastal ood and erosion risk for an 84km frontage of the

Isle of Wight coast running from Freshwater Bay clockwise round toOld Castle Point, East Cowes (see gure overleaf).

The Strategy frontage features a wide variety of natural,rural and urban landscapes. The frontage includes sheltered

estuarine environments of the Western Yar, Newtown estuary andthe Medina, the bays of Freshwater, Totland, Colwell, Thornessand Gurnard, the headlands around Cowes, and then the morerugged exposed open coast around the Needles.

Three of the Island's largest urban areas are within the Strategyfrontage; Cowes, East Cowes and Newport (key employment

centres). Totland, Yarmouth and Freshwater are the main settlementsin the west of the Island, also all located on the coast.

The Strategy frontage is home to a rich variety of important habitatsand species and has a wealth of internationally, nationally and andlocally important nature conservation sites along the majority of itscoast and coastal waters. These include European Natura 2000sites that are protected by international legislation as well as national

designations. Many of the current settlements on the Island arehistoric, with 32 Conservation Areas and almost 2,000 Listed Buildings.

In a planning context the Isle of Wight is unique, being an islandwith a large proportion of environmental designations, a coastaland maritime economy, and a fundamental reliance on ferry portsand coastal roads as its key strategic transport links. Large parts ofthe area are designated as an Area of Outstanding Natural Beauty

(AONB) and much of the coastline is designated Heritage Coast.

With such a diverse coastline and range of facilities, tourism is a keyindustry for the Isle of Wight. Residents and visitors are well servedby a number of ferry routes with East Cowes and Yarmouth hostingtwo of the three vehicle ferry links to the Isle of Wight, plus a keypassenger ferry terminal in West Cowes.

There is a wide range of existing coastal defences around the WestWight frontage which help prevent erosion and reduce ood risk.

However many of these aging defences were built in times of greatereconomic prosperity and the future maintenance or replacementof these structures provides a signicant problem in these more

challenging economic times. National 'Grant in Aid' funding isavailable to help fund defence works in the areas most at risknationally. However the outcomes on which this public 'Grant in Aid'funding is calculated and administered are heavily focussed aroundprotection of residential communities, rather than businesses, or toprovide tourism or recreational benets.

intro


11/168


Strategy Frontage

KEY

Strategy Frontage

Land

Sea2 kilometres

N

The Solent

East Cowes

West Cowes

Totland

Yarmouth

Newtown

Newport

Gurnard

Freshwater

Bay

The Needles


12/168


There is therefore a realisation that future public investment indefences will have to be rationalised and prioritised in key areas.However, as recognised in the development of the Strategy, thereare signicant opportunities to help pay for new defences through

a partnership approach, a new approach to funding required bynational government. For example, working with developers and thepotential beneciaries of future schemes to fund future defences,

and contribute to broader outcomes for communities at risk.This kind of approach will be key to the delivery of the Strategy.

For further information about the Isle of Wight please visit

www.iwight.com

Strategy Objectives

The aim of the West Wight Coastal Flood and Erosion RiskManagement Strategy is to reduce risks to people, the developedand natural environment from ooding and coastal erosion through

the development and implementation of a sustainable Strategy thatencourages provision of technically, economically and environmentallysound management measures.

The objectives were enshrined in the Strategy development processand were key considerations in the appraisal of potential managementoptions. Given the wide range of objectives, and the competing

interests of the coast, it is not possible for the Strategy to meet anddeliver all of these aims. However, it was important that the Strategyseeks to facilitate as many of these as possible. The primary (musthave) objectives are listed below:

Primary objectives

• To build on the work of the Isle of Wight Shoreline ManagementPlan 2, 2010;

• To identify the consequences of implementing the preferred Policiesfrom the IW SMP2, and to seek and select the most appropriateand achievable methods to do so;

• To determine the optimum economic level of coastal oodand erosion protection for the West Wight through assessmentof options;

• To provide a co-ordinated approach between the authorities andorganisations managing the coastline;

• To rene the understanding of coastal ooding and erosion risks topeople and the developed, historic and natural environments using

the latest information;• To balance the needs of people and the environment, in a dynamic

coastal environment with ood, erosion and landslide risks;

• To identify any required Schemes, including their location, timing,feasibility, costs, benets and associated Partnership Funding

scores and Outcome Measures;

• To consult with the community to seek acceptable and achievablemethods to implement the IW SMP2 Policies;

• To identify the operating authority or landowners responsiblefor new and existing infrastructure and begin work with them todevelop proposals;

• To identify the requirements and opportunities for nancialcontributions for any proposed schemes, in line with PartnershipFunding requirements;

• To comply with environmental legislation and identify opportunitiesfor environmental enhancement, allowing where possible the

WITH THE MAJORITY OF COMMUNITIES ANDFEATURES OF INTEREST SITUATED AROUNDTHE COASTLINE, COASTAL FLOOD AND EROSIONPRESENTS A SIGNIFICANT RISK. WITHOUTACTIVELY IMPLEMENTING MEASURES TO MANAGETHESE RISKS IN ROBUST AND STRATEGIC WAYS,THERE WILL BE OVER 4,000 PEOPLE AND 1,500

PROPERTIES AT INCREASED RISK BY 2115.


13/168


natural process and evolution of the shoreline;

• To consider opportunities for broader outcomes linked to initiativessuch as regeneration, development, tourism, recreation andamenity; and

• To dene and prioritise an implementation plan of technically,economically and environmentally sound and sustainable proposalsfor managing coastal ood and erosion risks over the 100 year

appraisal period.

The Shoreline Management Planning Hierarchy

The following section outlines how the Strategy ts into the coastal

management hierarchy in the UK and outlines the approach todeveloping the draft strategic management options for consultation.

The Shoreline Management Plan – sets the policy

Shoreline Management Plans (SMPs) sit at the top of the hierarchyof plans for managing coastal ooding and erosion. A Shoreline

Management Plan (SMP) is a high-level non-statutory planning

document which provides a large-scale assessment of the risksassociated with coastal processes and presents a long-term policyframework to reduce these risks to people and the developed, historicand natural environment in a sustainable manner. An SMP aims tomanage risk by employing a range of methods which reect both

national and local priorities, to:

• Reduce the threat of coastal ooding and erosion to people andtheir property; and

• Benet the environment, society and the economy as far

as possible, in line with the Government’s ‘sustainabledevelopment principles ’.

The Isle of Wight Shoreline Management Plan (2011) presents theshoreline management policies for the Strategy study area. Given theurban areas, and the potential threat of erosion and coastal ooding,

the policy for a signicant part of the frontage is to ‘Hold the Line’ for

Shoreline Management Plan(Identies policies to manage risks)

Coastal Strategy(Identies appropriate Schemes

to implement the policy)

Local level risk reduction(Scheme construction, adaptation,

ood warning, property level protection)

The Coastal Management Hierarchy

the coming century. This policy does not necessarily mean defenceswill be built or maintained in these areas, as funding (especially publicfunding) is often a limitation, however if there is available fundingthis policy is recommended to robustly manage the future risks.This policy can also mean it is appropriate to continue to defend theshoreline with private defences. In order to maintain key habitats andnatural environment there are also signicant areas of the frontage

where the policy is to allow natural process to continue ('No Active

Intervention', or do nothing). In local appropriate areas a 'ManagedRealignment' Policy has been recommended in order to helpbalance habitat losses created by continuing to defend the coastlineelsewhere.


14/168


The need for a strategic approach

Coastal strategies sit at the next tier in the hierarchy and it is the roleof strategies to identify the appropriate scheme or ood risk mitigation

option for implementing the SMP policies. The Strategy will review theSMP policies in more detail to ensure these high level policies remainappropriate at the local scale.

The Strategy considers how ood and erosion risk is likely to

change in the future in response to changes in climate and developssustainable and robust options to manage the risks associatedwith coastal ooding and erosion. This approach ensures that

technically feasible, environmentally acceptable and economicallyviable options are recommended, to reduce the risks from coastalooding and erosion to people, their properties and the environment.

This also ensures that the options are compatible with the preferredmanagement strategies of adjacent areas. The Strategy is alsorequired in order to gain approval for future schemes, and helpssecure public Grant in Aid monies to contribute to the costof defences.

Without such an approach, it is likely that future coast defence workswould be managed on an ‘ad-hoc’ or reactive basis which would leadto poor cost efciency and a general increase in the ood and erosion

risk over time. A strategy is also important in providing an integratedapproach to the management of our coastline and prioritising risksand responses. The holistic wider-level thinking behind strategydecisions ensures that the management options implemented in one

area do not increase the ood and erosion risk in adjacent areas, andthat opportunities to deliver wider benets are not missed.

The outputs

Following a strategy, a variety of outputs can result depending onthe level of risk and the preferred options put forward. To deliver thestrategic management option it may be necessary to implement works

to address coastal ood and erosion risks. In other areas, where

little is at risk, the future action may be to ‘do nothing’ and let naturalprocesses continue. There may also be actions such as monitoring,setting planning policy and further detailed studies required in order togather additional evidence to make robust future decisions.

Where schemes are required, a further element of work comparingthe various options in more detail is then undertaken to select thepreferred measures, methods and optimal standard of protection.The detailed business case will be developed to gain funding andapproval. On approval of the scheme, detailed design is carried outand then the works can be implemented the ground. Schemes do notonly deliver raised defences such as new sea walls; other options

Hold the Line Policy

Preferred option:Sustain a minimum

1:100 year standard of

protection against ooding

Implement:

a new sea wall raising the

existing defence level

I N C RE A S I N G DE T A I L

How the Strategy ts in the management of coastal ood and erosion risk

EXAMPLE OUTPUT LEVEL

SMP

Strategy

Scheme


15/168


The high level coastal management polic ies being examined by thisStrategy: set by the Isle of Wight Shoreline Management Plan, 2011

2 kilometresN

The Solent

East Cowes

West Cowes

Totland

Yarmouth

Newtown

Newport

Gurnard

Freshwater

Bay

The Needles

KEY/POLICY

Hold the Line

Hold the Line (2005-2025), then No Active Intervention

Hold the Line (2005-2025), Managed Realignment(2025-2055), then No Active Intervention

Hold the Line (2005-2055), then No Active Intervention

Land

No Active Intervention


16/168


include ood warning systems, property level protection, adaptation

options and environmental enhancement.

Purpose and structure of this document

This document presents the draft Strategy for public consultation andsets out the recommendations and preferred options for managingcoastal ood and erosion risk along the study frontage for the next

100 years. In developing the Strategy, an understanding of thepresent day risk has been developed along with how it might changein the future and the ways in which we can manage and adapt tothese changes. Specically, this document includes:

Chapter 2 – Understanding what is at risk

• A summary of what is at risk now and in the future (dening

the baseline). Including an assessment of what would happen ifwe ‘do nothing’ and how the risks change over time as a result of

predicted climate change and sea level rise. This sets the contextfor why we need the Strategy.

Chapter 3 – Developing the Strategy

• Overview of the study area - Key Features, Issues andOpportunities. This identies the key aspects and characteristics

of the study area which the Strategy has considered. This includes:coastal processes, potentially contaminated land, the environment,stakeholder engagement and aspirations, and a summary of the

existing defences.• A descript ion of the option development and appraisalprocess. Including a summary of how the strategic optionswere developed and appraised considering their economic andenvironmental sustainability.

Chapter 4 – Strategy overview

• A summary of the Strategy – including the phasing of options overtime based on the level of risk.

• Links wi th planning and redevelopment – including how theStrategy has been developed to take account of these key issues.

• Environmental Impacts Summary – including how the Strategyhas been developed to ensure that it is environmentally robust and

sustainable..

Chapters 5 to 10 – Management Zones 1 – 6

• The preferred options by Management Zone. An area by areasummary of the Strategy options being put forward to reducefuture coastal ood and erosion risk. Urgent priority works are also

identied within this section.

Chapter 11 - Funding

• An overview of funding sources for coastal schemes.

• A summary of the priori ty schemes arising f rom the Strategy.

Chapter 12 – What next?

• A summary of what happens next and how you can ndout more.


17/168


Supporting Information

This document provides a concise summary of the Strategy ndings

and proposals. For more detailed information please refer to thefollowing Appendices.

These are available online at www.coastalwight.gov.uk

Appendix A

Defence Condition Review

Appendix B

Desktop Contaminated Land Review

Appendix C

Coastal Processes Review

Appendix D

Flood Modelling and Risk Mapping

Appendix E

Stakeholder Engagement Feedback

Appendix F

Economic Appraisal

Appendix G

Strategic Environmental Assessment Report

Appendix H

Habitats Regulations Assessment Appropriate Assessment

Appendix I

Water Framework Directive Summary Statement

Appendix J

Option Development and Appraisal

The two Risk Management Agencies in the Strategy area are theIsle of Wight Council and the Environment Agency. For furtherinformation please visit their websites below:• www.iwight.com

• www.gov.uk/government/organisations/environment-agency


18/168

Newport Quay Flooding


19/168

r i s

k s

Chapter 2

risks

What is at risk if

we do nothing?Why do we need the Strategy?


20/168


Sample of the key assets at risk of erosion and ooding*

*Flooding extent from an event with a 0.5% chance of occurring at 2115 assuming current defences are in placeReproduced from the Ordnance Survey digital data with the permission of the controller HMSO. © Crown copyright and database rights 2016 Ordnance Survey 100019229

2 kilometresN

KEY

1

23

4

5

6

7

8 9

10

Erosion Area

2115 - 1:200 year (0.5%annual chance) ood event

1. Totland at risk of erosion

2. Yarmouth at risk of ooding

and erosion

3. Bouldnor Road

at risk of erosion

4. Freshwater

at risk of ooding

5. Freshwater Bay

at risk of ooding

and erosion

6. Gurnard Luck

at risk of oodingand erosion

7. Gurnard - Cowes

at risk of erosion,landslide reactivationand ooding

8. Cowesat risk of ooding

and erosion

9. East Cowesat risk of ooding

and erosion

10. Newport at risk of ooding


21/168


Time Horizons

2015 2025 2055 2115

Residential properties (ood risk) 202 225 244 359

Commercial properties (ood risk) 276 306 316 336

Total properties at risk of ooding 478 531 560 695

Total properties at risk of erosion(Residential and Commercial)

0 6 347 1404

Total Value of Assets at Risk

(£M cash)£97M £115M £227M £472M

Why we need the Strategy - what is at ri sk if we ‘Do Nothing’?

Gaining an understanding of the ood and erosion risk along the

shoreline is imperative in order to dene a baseline for developing

the coastal strategy. It allows comparisons to be made between thepotential management options. The baseline was established byconsidering a ‘Do Nothing’ scenario.

The ‘Do Nothing’ scenario is dened as: “Where there is no further

intervention of any kind, including no emergency response or warningsystem, and nature is allowed to take its course. Where there are

assets present or where maintenance activities or other interventions

are carried out, the option will be to withdraw all activities".

In essence, the ‘Do Nothing’ scenario represents a hypotheticalsituation whereby all existing defences are abandoned in termsor maintenance or repair, and no remedial or additional protectionworks are carried out. In addition, adaptation to sea level rise or otherclimate change responses are not addressed.

Summary of people and assets potentially at risk of coastal ooding

and erosion over the coming century

Over 1,100 residential properties

Over 300 commercial properties (shops, ofces etc.)

Over 100 warehouses

38 industrial sites

46 public buildings

31 restaurants/pubs/cafes

2 supermarkets

142 leisure facilities

13 car parks

28 electricity sub-stations

1 school

3 ferry terminals linking the island to the mainland

Multiple marinas

Numerous coastal footpaths

Major roads including the A3054 and A3055

Heritage assets and listed buildings

Environmentally designated habitats

Coastal waterbodies

Local and national nature reserves

Country parks

Tens of kilometres of coastal promenades, slipways

N22 cyclepath between Freshwater and Yarmouth

Beaches used by residents and as visitor attractions

Properties at risk of ooding and erosion over the coming century if we 'Do Nothing'.

Based on 1:200 year (0.5% annual chance) ood event.


22/168


What is meant by ood risk?

The likelihood that a certain level of ooding will occur is described as

‘ood risk’ or the ‘chance’ that a location will ood in any once year.

This risk can be expressed in terms of an average return period in years.For example a large event occurring on average once per century maybe referred to as a 1 in 100 year event (there is a 1% chance of a ood

of this scale in any one year). An extreme event which typically onlyoccurs once in any 200 year period is termed a 1 in 200 year event

(this means there is a 0.5% annual chance of an event of this scaleoccurring), and so on.

The chance is related to the scale of the ooding. In any one year a

large (1 in 200 year) ood event has statistically less chance of

happening than a smaller 1 in 100 or 1 in 50 ood event. It is important

to understand that a 1 in 100 chance of ooding does not mean that a

ood will only happen once every 100 years. The chance remains the

same every year. Throughout this document the scale of ood risk is

described in terms of the average return period in years.

When protecting against ooding, the risk level that a schemeprotects against is described as the Standard of Protection (SoP).For example, if a scheme provides a 1:100 year SoP it means there is ahigh degree of certainty that it will prevent ooding from all events up to

this magnitude.

What is meant by erosion ri sk?

For the purposes of the Strategy, properties or assets at risk of erosionare those which could potentially be lost to the sea through shorelineretreat or landslide. The baseline risk has been estimated assuming

no further works are done to repair or maintain defences whichcurrently provide protection.

Understanding the potential erosion risk under a hypothetical‘Do Nothing’ scenario’ is important for comparing the relative meritsof options to maintain or improve protection.

For the purpose of the Strategy, the risks posed by coastal ooding

and erosion over the next 100 years have been established usingEnvironment Agency approved numerical ood modelling and

updated Shoreline Management Plan erosion predictions (toaccount for Environment Agency guidance change on sea level riseallowances). It should be noted that even with the existing defences inplace; future ood risk will increase signicantly due to climate change

and rising sea levels.

Through determining the present and future ood and erosion

risks under a ‘Do Nothing’ scenario, the properties, features,

assets and key infrastructu re that are in need of p rotection over

the next 100 years have be identied and valued. The preferred

options to manage the risks strategically have then been

developed.

Sea level rise and increasing risk

As a consequence of climate change and continued warming of the

global oceans, sea levels are expected to increase in the future.This will increase ood and erosion risk across the Strategy frontageover the next 100 years.

To consider sea level rise, the Strategy has incorporated the latestsea level rise projections (UK Climate Projections 2009) into theood modelling to produce ‘Do Nothing’ ood scenarios for 2025,

2055 and 2115. Following the latest guidelines, under the ‘mediumemissions’ sea level rise scenario, mean sea levels across the strategyfrontage are expected to increase by approximately 0.75m over thecoming century.

The gure (opposite) shows the cumulative relative sea level rise

projections (m) at Cowes over the next 100 years that have beenadopted by the strategy.


23/168


1600

N o .

P r o p e r t i e

s

Years

20202000 20602040 2080 21202100

1400

1200

1000

80 0

60 0

40 0

20 0

0

I n c r e a s e i n m e a n s e a l e v e l ( m )

Increase in sea levels expected (compared to pr esent) as a result of cli mate change

Year

For more detailed information on the extreme waterlevels used in the Strategy please refer to Appendix C:Coastal Processes Review

For more detailed ood mapping see Appendix D:Flood Modelling and Risk Mapping

Coastal ood and erosion risk would increase signicantly in the

future across the Strategy frontage under a ‘Do Nothing’ scenariodue to sea level rise.

As well as residential and commercial properties, there are manyother important features and valuable assets at risk. This includesindustrial sites, public buildings, leisure facilities, a school, ferryterminals, marinas, coastal footpaths, environmentally designated

sites, a cyclepath and beaches.

Increasing number of properties at risk of ooding and erosion over time


24/168

Road between Yarmouth and Shaleet


25/168

a p pr o a c h

Chapter 3

approach

How the

Strategy hasbeen developed Approach to option development


26/168


Overview of the s tudy area and the Strategy

development process

Before strategic approaches to managing ood and erosion threats

can be identied and evaluated, it is important to understand the

key features, issues and opportunities that exist within the Strategyarea. In order to achieve this, a number of studies and activitieswere undertaken during the early part of the Strategy development.

These included:• Site walkovers and visual inspections – to determine the

location, type and condition of existing coastal defences andassets (See Appendix A for detailed ndings);

• Desktop assessment of potentially con taminated land – toidentify potentially contaminated land uses along the frontagewhich may require defences to prevent them polluting theenvironment (see Appendix B for more details);

• A desktop review of coastal processes – required tounderstand waves, tides, sediment movements and their

interaction around the study area (see Appendix C);• Review and operation of Environment Agency approved

numerical hydraulic models to update previous ood risk

projections and estimate damages from a Do Nothing scenario(see Appendix D for further details).

• Identication of important environmental and heritage

features around the coast – so that key environmentalobjectives and legal requirements to protect the environmentcan be accounted for in the Strategy (see Appendices G, H and Ifor details).

• Engagement with key stakeholders – meaningful engagementwith numerous community groups, organisations and individualsto identify key issues, opportunities and potential for fundingcontributions, and broader outcomes along the shoreline whichcan help to shape future coastal management (see Appendix Efor more details).

A summary of the ndings of these activities required to understand

the baseline for the Strategy is provided in the sections below.

Coastal processes overview – wave, tides, sediment transport

The Strategy frontage is highly diverse and varies in not only incharacter but also with regard to the forcing conditions it experiences,driven by the weather and tides, including prevailing south-westerlywinds. Wave heights vary considerably with large storm waves (5m+)

affecting the exposed open coast environments around FreshwaterBay and the Needles with only small wind driven waves (typically


27/168


EO1

EO1EO2

O1

EO3

EO4

0 1 km

N

O1

O1

EO1

LT11

LT12

LT12

LT13

LT13 LT14

LT8 LT9

LT10

LT10

LT10

LT4

LT4

LT5

LT6

LT7

LT4

FL2

E11

E11

E12

F4

E9E10

E10

FL2

FL2

F4

FL2

E7E8

E9

E9

F4

F2

F3

E5

E6

E6E6

F1

F4

F4

i l l l i i

Totland

Freshwater

YarmouthBouldnor

Cowes

Lymington

Keyhaven

TheNeedles

Alum Bay Headon Hill

TotlandBay

ColwellBay Brambles Chine

Fort Albert

FortVictoria

NortonSpit

B o u l d

n o r

C l i f f Newtown

Harbour

BrickfieldFarm

BurntWood

ThornessBay

Gurnard Bay

Gurnard

EgyptPoint

R i v e

r

M e d

i n a

Hurst Spit

PenningtonMarshes

(s)

WarrenFarm Spit

NeedsOar Point

GullIsland

InchmerryHouse

Stone

Point

Stansore Point

BourneGap

Hillhead

CalshotSpit

Beaulieu

B e a u l i e u R i v e r

LymingtonBanks

(s)

SolentBank(s)

LepeMiddleBank

(s)

BramblesBank

(s)

PrinceConsortShoal (s)

(s)

NewtownGravelBeds

PittsDeep

ParkShore

(s)

(s)

ShinglesBank(s)

Warden Point

Western Yar (s)

Reliability of Information

Low Medium

1 Photographs of key sites andprocesses

Sediment sink(s)

Sediment Types Involved in Transport

Silt and/or Clay

Sand

Sand and Silt/Clay

Shingle

Shingle and Sand

Gravel and Sand

Gravel, Sand and Silt/Clay

Sediment Transport Mechanism

Littoral (beach) drift

Offshore sediment transport

Cliff or coastal slope erosion input

Estuarine sediment transport

Fluvial input

Wave driven nearshore andoffshore zone transport

LT

O

E

EO

FL

F

Volume of Sediment Flow

No quantitative data

Littoral drift divergenceboundary

Littoral drift partial boundary1

5

10

3

4 2

611

8

12

9

7

1314

Sediment transport patterns and pathways around West Wight

Source: SCOPAC Sediment transport study - http://www.scopac.org.uk/sediment-transport.html


28/168


such as humans, animals, sh, birds and habitats, which could

potentially be affected, were identied.

Next, with use of the erosion predictions, and the ood mapping,

the likelihood of the ‘potentially contaminated land’ areas being atrisk of eroding or ooding was established.

Following this approach, the desktop study identied areas where

there is a high risk of contaminants being released in the future(see Appendix B for full details). The sites identied as high risk inthis review were considered in the appraisal of options; however

it is noted that due to either an inert status or lack of identied

pathways to link sources to receptors these sites have notsignicantly inuenced strategy option choices.

It should be noted that any future coastal defence works near orin potentially contaminated sites should include a more detailedassessment of the contamination risk as part of the Project Appraisal process.

Potentially Contaminated Land

When considering options to manage future ood and erosion risk

it is necessary to consider potential risks to areas of potentiallycontaminated land. Contaminated land is dened as any land

which appears to the Local Authority to be in such a condition, byreason of the substances in, on or under the land, that:

a) Signicant harm is being caused or there is a signicant

possibility of such harm being caused; or b) Pollution of controlledwaters is being, or is likely to be caused.

For land to be formally designated as being ‘contaminated’ it mustbe clearly demonstrated that there is:• a contaminative source present (above a threshold level)• a receptor which can be affected by the source; and• a pathway linking a source to a receptor

Contaminated land often arises from present or historic land

uses such as landlling, industrial processes, military operations,as well as accidents or spills of contaminants, waste disposalor leaking underground storage tanks. In the coastal zone thepresence of contaminated land is a risk because erosion of theshoreline, or ooding, can release the contaminants into the

environment through exposure and leaching. If not dealt withadequately, contaminated material can pose a threat to humanhealth, the environment and sustainable economic development.

In order to determine the risk of contaminated material beingreleased into the environment, the likelihood of contaminated landbeing present along the frontage was rst established. To do thisthe desktop study used former land use data to identify whetherland is likely to be contaminated or not. If an area was thoughtto have potentially contaminating substances, the area wasdesignated as ‘potentially contaminated land’. Then receptors,

For more information see Appendix B:Desktop Contaminated Land Review


29/168


30/168


DRAFT SPA

DRAFT SPA

DRAFT SPA

DRAFT SPA

DRAFT SPA

DRAFT SPA

Solent & Southampton Water SPA/Ramsar

Isle of Wight Downs SAC

Solent Maritime SAC

Solent & Dorest Coast SPA (All Draft)

South Wight Maritime SAC

Important environmental designations around the Strategy frontage

Reproduced from the Ordnance Survey digital data with the permission of the controller HMSO. © Crown copyright and database rights 2016 Ordnance Survey 100019229

1 kilometre

N

SMZ 5

SMZ 1

SMZ 3

SMZ 2

SMZ 6

SMZ 4

SMZ 3

KEY

Project Frontage

Special Areas of Conservation

Ramsar

Special Protection Area

SMZ

Site of Special Scientic Interest


31/168


Environment and heritage designations

West Wight has an abundance of natural features and open spaces.The largely unspoilt, unique and iconic nature of the landscapearound Freshwater Bay, the Needles, the Western Yar Valleyand the Hampstead coast has been recognised throughdesignation as an Area of Outstanding Natural Beauty and alsoas a Heritage Coast.

A number of internationally important sites (see gure left) arefound within the area, including Ramsar sites, Special Protection Areas (SPA) and Special Areas of Conservation (SAC). Areas ofnational importance, such as Sites of Special Scientic Interest

(SSSI) and National Nature Reserves (NNR) can also be found.Many of these important sites are situated along the Strategycoastline and as such it was essential to consider these areaswhen developing the Strategy.

Within many of these important sites there are a number ofdifferent habitats such as marshes, reed-beds, lagoons andintertidal sand and mudats which support a wide diversity of

wildlife. The intertidal mudats are particularly important feeding

habitat for birds, whilst other areas such as the Medina, Yar andNewtown Creek provide an important habitat and nursery area forsh such as bass, ounders and mullet.

Unfortunately, with predicted sea level rise, there will be increasingpressure on many of the important intertidal habitats which get‘squeezed’ against coastal defence structures such as seawalls.This can decrease the size and health of the intertidal habitats

and place additional stresses on the species that rely uponthem. These natural features and associated wildlife also drawand support signicant numbers of visitors for walking, cycling,

ornithology, shing and other recreation.

To help offset these anticipated losses in the future, it is essential forthe Strategy to consider environmental enhancement opportunities.Particular areas signposted for potential environmental mitigationand/or enhancement along the frontage include Thorley Brook

(Yarmouth) and southwest of the Causeway (eastern Freshwater).In addition, allowing natural process to continue where possible isof utmost importance to ensure the coastline and habitats changeand evolve naturally over time.

There is also a range of heritage assets around the West Wightcoastline and ooding and erosion poses a signicant threat to

some of these features of historic importance, and the Strategyhas recognised these in the development of preferredmanagement options.

Stakeholder engagement – understanding what people

want from the coast

Many individuals and organisations have a key interest or stake in

the Strategy shoreline for many different reasons. Each stakeholderis therefore likely to have a unique view on its use, development andfuture protection. Stakeholders or consultees can be an indispensablesource of information which can dene coastal issues and objectives,

steer Strategy development and achieve consensus on the futuremanagement of the shoreline.

A key part of developing the Strategy has involved engaging withkey stakeholders. This has been achieved through publicworkshops, a dedicated key stakeholder bus tour of the frontage,

the establishment of a project Steering Group, and through specicmeetings. This has ensured local communities and working groups,Harbour Authorities, potential developers, local planners, NaturalEngland, the Environment Agency, Heritage England and publicbodies with a vested interest in the West Wight coastline have allbeen consulted and involved.


32/168


The overall strategic aims of the Strategy engagement processwere;

• to raise an awareness and understanding of coastal ood anderosion risk,

• to identify the challenges and constraints, and• to involve others in the decision making process for managing

the coastline.

Early in the Strategy development phase two dedicated stakeholderworkshops were held in Yarmouth and Cowes to raise awarenessof the Strategy, the problem being addressed and the new systemof partnership funding for future coastal defences. The workshopswere well attended by over 80 people and important stakeholderfeedback was obtained on potential issues and opportunities for theStrategy to consider.

In addition to the stakeholder workshop the Strategy team have

held discussions with a number of individuals and organisationsto discuss the project and to learn more about any concerns andaspirations they might have with regards to the coastline.The Strategy team have learnt a huge amount about how peoplewish to see the shoreline evolve. All of the feedback received todate, where relevant, has been used to inform the development ofthe Strategy to ensure that it takes account of, and captures keystakeholder input and ideas.

The Strategy is now entering a three month period of public

consultation in spring 2016. During this time key stakeholdersand the public are invited to view the proposals and attendpublic exhibitions to review and provide feedback on thedraft Strategy proposals. Please visit www.iwight.com andwww.coastalwight.gov.uk for further details.

Summary of the existing defences

To help establish the baseline ood and erosion risk along the

Strategy frontage it was necessary to identify the standard ofprotection offered by the existing coastal defences, their condition,and how long they are likely to last without maintenance. This wasdone by undertaking a walkover survey of the Strategy shorelineand reviewing the thorough visual assessment of defence conditionundertaken by IWC in line with the Environment Agency’s DefenceCondition Assessment Manual.

Given the number of towns, dwellings and important coastalfeatures, for example in Cowes and Yarmouth, a signicant portion

(around 20km) of the Strategy shoreline is currently defended.There is a wide range of different defence types, from low sea wallsand quays lining the sheltered estuarine and creek areas to largesea walls and esplanades along the more exposed open coast

to protect against erosion and wave overtopping. There are alsostretches of private structures lining waterfronts of residential andcommercial properties, providing individual waterside access anda managed (man-made) shoreline, although often not constructedas defence structures originally. In addition, the open coast isafforded protection by the beaches which act as a barrier to thewaves. There are also long undefended areas with ‘no formaldefences’. In these areas, cliff erosion is often a key risk.

Typically, many of the defences are in a fair condition. There are

also some sections of new defence in very good condition.However, there are also some notable areas where the defencesare in a poor state or provide a low standard of protection againstooding and erosion e.g. Totland, and parts of Yarmouth and Cowes.

For more information see Appendix E:Stakeholder Engagement Feedback

For more information see Appendix A:Defence Condition Review


33/168


Option Development

Overview

Following dening the baseline risks (if we 'do nothing'), and having

gained a detailed understanding of the processes, features andissues operating along the coast, the development and appraisal ofstrategic management options was undertaken.

The 'option appraisal process' refers to the tasks involved inselecting the preferred management options along the Strategyfrontage. The process followed the Environment Agency’s NationalFlood and Coastal Erosion Risk Management guidelines.

Coastal ood and erosion risk management options have been

considered on two interlinked levels; the strategic level options and

the local level measures required to implement these options.

Thinking strategically – management zones

The Strategy frontage was divided into six zones; termed StrategyManagement Zones (SMZs). Each zone (and sub-zone whererequired) is characterised by consistent themes and characteristicssuch as coastal processes, levels of ood and erosion risk,

land uses and Shoreline Management Plan policies. The SMZareas are shown on the map on page 5 and presented in the tableon pages 40 and 41.

For each SMZ, strategic level options were developed andappraised against technical, economic, social and environmental

criteria. The preferred options for consultation were chosen on thebasis of this evaluation.

Option Development Units and identifying

potential local measures

To ensure that the management options proposed by the Strategy arerobust and relevant at the local level it was necessary to split the SMZfrontages into smaller units (termed Option Development Units). Thisprovided the exibility to rene the strategic options to account for

local level variations and requirements.

In total 32 Option Development Units (ODUs) were devised mainlyfollowing the Shoreline Management Plan Policy Units. For clarity,these are numbered 1 to 32 clockwise around the coast (and labelled'W' for the 'West Wight' Strategy. The ODUs are shown on the mapon page 51). Within each of these units the ‘packages of measures’necessary to implement the wider strategic options were established.Each ‘package’ outlined the type of management intervention orworks required over three time periods to implement the strategicoption for the next 100 years.

The locations and key characteristics of each unit are summarised ina table on pages 35 to 39. The boundaries of each unit are shown inthe maps in Chapters 5 to 10.

A workow summary of the option development process, and

subsequent stages, is presented on the opposite page. The followingsections provide a commentary of the key aspects of the process.

For more detail see Appendix J:Option Development and Appraisal


34/168


Dene

Baseline

Scopingand datacollection

Dene Strategy

ManagementZones (SMZs)

Identify Option

DevelopmentUnits (ODUs)

Develop

baseline foreach SMZand ODU

Develop longlist of potentialoptions

Screening of

long list optionsto develop ashort list ofstrategic options

Detailed appraisalof strategy options(economics, SEA,

HRA, WFD)

Selection andconrmation

of the draftpreferred

options

SteeringGroup, IWCand ProjectBoard approvalof DraftStrategy forconsultation

PublicConsultation3 months;

Spring 2016

Reviewconsultationfeedbackand update /

nalise Strategy

Large ProjectReview GroupReview and

Approval(late 2016)

Key Stakeholderinput▼

Baselinemodelling▼

Key Stakeholderliaison▼

◄ Steering groupinput and review atkey stages

◄ Key Stakeholderliaison

Overview of Strategy development activities

▲ Optioneering sitewalkovers

Identify a package of suitablemeasures in each ODU toimplement strategic options

◄ Explore broader /contributions

outcomes (ongoing)


35/168


Overview table of Option Development Units (ODUs)

ODU Unit Name SMP PU

SMP Policy

toDefence

Residual

Life (years)

Frontage

Maintainer

Indicative ErosionRisk (years from now)

Indicative Flood Risk(years from now)

Coastal

ProcessesLand Use

2025 2055 2115 0-10 10-40 40-100 0-10 10-40 40-100

W1

TennysonDown,

Alum Bay andHeadon Warren

PU6A.2 NAI NAI NAI UndefendedNational Trust+ Private

High waveenergy,exposed cliffline

Open space,attractions (NeedlesPark), farmland,coastal footpath

W2

Southernand CentralTotland Bay

PU6B.1 HTL HTL HTL


36/168


Overview table of Option Development Units (ODUs) continued


SMP Policy

toDefence

Residual

Life (years)

Frontage

Maintainer



Coastal

ProcessesLand Use

2025 2055 2115 0-10 10-40 40-100 0-10 10-40 40-100

W9 Norton Spit PU6C.1 HTL HTL HTL 10-20 PrivateLow waveenergy (fetchlimited)

Recreation, harbour

W10

Western YarEstuary -western shore

PU6C.2 NAI NAI NAIMainly

UndefendedPrivate

Estuarine,sheltered

Recreation (boatyard), farmland

W11 The Causeway PU6C.3 HTL HTL HTL 10-20+Environment

AgencyEstuarine,sheltered

Residential,open space

W12 Freshwater Bay PU6A.1 HTL HTL HTL 10-20+ IWC + Private

Bay receivessedimentfrom the west.

Accretion inmiddle, erosion

at anks. Highwave energy

Recreation,residential(apartments)

W13

Western YarEstuary -eastern shore

PU6C.4 NAI NAI NAI Undefended IWCEstuarine,sheltered

Farmland, cyclepath

W14

Thorley Brookand Barnelds

StreamPU6C.5 HTL MR NAI 15-20+

Environment Agency, IWC+ Private

Estuarine,sheltered

Open space (natureconservation)

W15Thorley Brook

to Yar BridgePU6C.6 HTL HTL HTL 15-20+ IWC + Private

Estuarine,

sheltered

Residential,

recreation, school

Erosion & Flood risk: Indicative risk to peopleor assets under a ‘Do Nothing’ Scenario’

Low Moderate HighKEYSMP Policy: HTL = Hold the Line;

NAI = No Active Intervention; MR = Managed Realignment


37/168




SMP Policy

toDefence

Residual

Life (years)

Frontage

Maintainer



Coastal

ProcessesLand Use

2025 2055 2115 0-10 10-40 40-100 0-10 10-40 40-100

W16

Yar Bridgeto YarmouthCommon

PU6C.6 HTL HTL HTLMainly15-20+

PrivateLow waveenergy (fetchlimited)

Harbour includingferry terminal,behind the harbourare commercialand residentialproperties

W17

YarmouthCommon toPort la Salle

PU6C.6 HTL HTL HTL


38/168




SMP Policy

toDefence

Residual

Life (years)

Frontage

Maintainer



Coastal

ProcessesLand Use

2025 2055 2115 0-10 10-40 40-100 0-10 10-40 40-100

W23Gurnard toCowes Parade

PU1A.3 HTL HTL HTLMainly15-20+

IWC + Private

Low waveenergy (fetchlimited), weaknet eastwardslittoral drift,landslidereactivationpotential

Residential,recreation (beach

huts), commerical

W24

Cowes TownCentre toFountain Yard

PU1A.4 HTL HTL HTL 15-20+ PrivateLow waveenergy (fetchlimited)

Residential,commerical (largeHigh Street)

W25

Cowes(Fountain Yardto MedinaWharf)


PrivateMostlyestuarine,sheltered

Industrial propertieswith residentialstreets landward,commercialbuildings, harbour,wharfs and a ferryterminal

W26

Central Medina- northwestshore

PU1B.1 NAI NAI NAI Undefended IWC + PrivateEstuarine,sheltered

Farmland, cyclepath

W27West MedinaMills

PU1B.2 HTL HTL HTL 10-20+ PrivateEstuarine,sheltered

Small industrialarea, with privatedefences

W28

Central Medina

- southwestshore PU1B.3 NAI NAI NAI

Mainly

Undefended IWC + Private

Estuarine,

sheltered

Farmland, smallresidential areas,

industrial area tothe south is setbackfrom the frontage





39/168




SMP Policy

toDefence

Residual

Life (years)

Frontage

Maintainer



Coastal

ProcessesLand Use

2025 2055 2115 0-10 10-40 40-100 0-10 10-40 40-100

W29NewportHarbour

PU1B.4 HTL HTL HTL 10-20+ IWC + PrivateEstuarine,sheltered

Industrialareas, harbour,commercial,residential

W30Central Medina- eastern shore

PU1B.5 NAI NAI NAIMainly

UndefendedIWC + Private

Estuarine,sheltered

Farmland, wastewater pumpingstation, recreation(harbour andholiday park),disused industrialfacility

W31

East Cowes(Kingston RoadPower Stationto ShrapeBreakwater)


PrivateLow waveenergy (fetchlimited)

Industrial facilities(including fueldepot and powerstation), residential,commericialbuildings andwharfs, harbour,ferry terminal

W32

East Cowesouter Esplanade(ShrapeBreakwaterto Old CastlePoint)

PU1A.6 HTL NAI NAI 15-20+ IWCLow waveenergy (fetchlimited)

Recreation areawith residentialpropertieslandward, woodland





40/168


Summary of the Management Zones

Zone 1 2 3a 3b 3c 4

Name Needles

Headland

Totland and

Colwell Bays

Yarmouth Coast Western Yar Estuary Freshwater Newtown Coast

Geographic

Extent

Fort Redoubt tosouthern limit of

Totland Bay

Southern limit ofTotland Bay to Fort

Victoria

Yarmouth town andFort Victoria to Port la

Salle

Western Yar Estuaryshoreline including

Thorley Brook andBarnelds Stream

Freshwater Bay,Freshwater Village

and the Causeway

Bouldnor cliff toThorness Bay,

including NewtownEstuary

Option

Development

Units

W1 W2 to W7 W8 to W9 andW15 to W17

W10, W13 and W14 W11 and W12 W18 to W20

SMP Policy

(2011)

No Active Intervention Mixed (Hold theLine in the south.Transferring from Holdthe Line to No ActiveIntervention in thenorth)

Mixed (Hold the Linearound Yarmouthand to the east.Transferring from Holdthe Line to No ActiveIntervention in the

west)

No Active Intervention,with ManagedRealignment atThorley Brook

Hold the Line No Active Intervention

Zones

Characterised

by (Common

themes /

issues)

• Undefended, cliffedcoastline

• Exposed to largewaves

• Small number ofassets at risk fromerosion at theclifftop

• No ood risk• Leisure /

recreational use

• Cliffs subject tolandsliding

• Residential andcommercialproperties at risk oferosion

• Popularrecreational area

• No ood risk

• Yarmouth is a keyresidential areaand town centre

• Signicant oodand erosion risks

• Roads thatprovide accessto other parts ofthe Island at riskfrom ooding and

erosion• Ferry terminal

provides link tomainland

• Recreation areaand farmland

• Cyclepath situatedon the eastern sideof the estuary

• Predominantlyundefended

• Small and localisedood and erosionrisks

• Mostly shelteredand estuarine

• Residential andcommercialproperties at riskfrom ooding

• Low lying area atood risk betweenCauseway andFreshwater Bay

• Freshwater Bayexposed to largeswell waves thatcan result inovertopping of thedefences

• Erosion risk atFreshwater Bay

• A3055 at risk ofooding

• Open space• Undefended• Environmentally

important area• Small localised risk

of erosion• No ood risk


41/168


Summary of the Management Zones (continued)

Zone 5a 5b 6a 6b 6c

Name Gurnard Luck

and Gurnard cliff

Gurnard to

Cowes Parade

Cowes and

East Cowes

Medina Estuary (and East

Cowes Outer Esplanade)

Newport Harbour

Geographic

Extent

Gurnard Luck / Gurnardmarsh area

Cowes headland, fromGurnard Bay to Cowes

Parade

Cowes: Cowes Parade toMedina Wharf.

East Cowes: Shrapebreakwater to KingstonRoad power station

Medina Wharf andKingston Road Power

Station south to NewportHarbour and ShrapeBreakwater to Old CastlePoint

Newport Harbourand quayside

Option

Development

Units

W21 to W22 W23 W24 to W25 and W31 W26 to W28, W30, W32 W29

SMP Policy

(2011)

Mixed (Hold the Linechanging to No ActiveIntervention at GurnardLuck. No Active

Intervention to the east)

Hold the Line Hold the Line Mixed (mainly No ActiveIntervention, plus Holdthe Line at West MedinaMills and Hold the Line

transferring to No ActiveIntervention at East Cowesouter esplanade)

Hold the Line

Zones

Characterised

by (Common

themes /

issues)

• Signicant riskof ooding atGurnard Luck

• Erosion risk because ofthe close proximatelyof properties to thecoastline

• Existing private defenceshave relatively low crestlevels

• The developed coastalslopes have potential forlandslide reactivation

• Erosion is more of asignicant risk than

ooding

• There are existingsea wall defences,overtopped at low pointsat high tide events

• Cowes and East Cowesare key urban centres

• Signicant residentialand commercialproperties at risk fromboth ooding and

erosion• Waterfront access is

important• Two ferry terminals

provide links to themainland

• Land is predominantlyfarmland andrecreational land

• Small landslides haveblocked access nearOld Castle Point

• Few properties at riskfrom ooding anderosion

• Waterfront access isimportant

• Commercial andindustrial propertiesclose to the waterfrontand at risk of ooding

• If the harbour wallsfailed a number ofproperties are at risk ofdamage


42/168


Seawall

Steel Sheet Piling

Beach Nourishment/Recycling

Earth Embankment

Armorl oc Revetement

Groynes

Temporary Flood Barriers

Property Level Protection

Land raising

Setback Floodwall

Timber Clad Sheet Pile Wall

Rock Revetment

Potential measures to implement the strategic management options

Image courtesy by Fluvial Innovations

D l i th St t i O ti


43/168


Developing the Strategic Options

In order to be able to assess the relative merits of different Strategyoptions, the baseline ood and erosion risks associated with a

‘Do Nothing’ approach were derived in each SMZ for the presentday, 2025, 2055 and 2115. This allowed the risk areas within eachSMZ to be identied, and the timing of risks to be dened. This

understanding formed a basis from which to develop a numberof potential ‘strategic options’ for the management of ood and

erosion risk. The scope, or long list, of strategic options consideredacross the SMZs included:

• Do Nothing – no active intervention (baseline scenariodeveloped in each SMZ).

• Do Minimum – e.g. maintain health and safety obligations,minor reactive maintenance / repairs.

• Maintain – continue to protect against erosion. However, thestandard of protection (SoP) against ooding would be expected to

fall over time as sea levels rise.

• Adaptation / resilience / relocation – through the implementationof a coastal change management area plan.

• Sustain – maintain a minimum SoP by raising defences over timeto keep pace with sea level rise.

• Improve SoP – improve the SoP compared to the present day.• Environmental mitigation / Improvement – including managed

realignment and habitat creation.

Variations of the above options were also considered.

From the long list of strategic options, a short list of potentiallysuitable methods for achieving them were selected and dened for

appraisal in each SMZ (typically four or ve of the most appropriate

methods were identied for each SMZ). A table summarising the

potential strategic options assessed for each SMZ is presented inthe following table,

Strategic options considered for each Strategy Management Zone (SMZ):

SMZ 1 (W1) Potential Strategic OptionsNeedles Headland

Do nothing – No active intervention. Baseline scenario.

SMZ 2 (W2 – W7) Potential Strategic OptionsTotland and Colwell Bays


Do minimum – Maintain H&S and access as long as possible and develop coastalchange management area plan (W2-W6).

Maintain then Improve from 2025 – Phased seawall improvement and cliffstabilisation. Maintain defences (W2-W4) until end of design life then implement phasedcliff drainage and sea wall stabilisation works (for example a mass rock revetment).Do minimum elsewhere.

Improve (now) – Seawall stabilisation works (for example a mass rock revetment)and cliff stabilisation and drainage now (W2-W4). Do minimum elsewhere.

SMZ 3a (W8-9, W15-17) Potenti al Strategi c OptionsYarmouth coast (Fort Victoria to Port la Salle)


Do minimum – H&S and access. Flood warning and emergency response plan.

Maintain (and Temporary Flood Barriers) then Improve from 2055 – Use TemporaryFlood Barriers to manage and reduce ooding to areas at signicant risk by sustaining a1 in 75 year (1.33 % AEP) standard of protection. Prevent erosion to critical infrastructureserving the town and the West Wight. From 2055, if funding can be secured, raise /implement new defences (bunds and oodwalls) to manage long term increase in oodand erosion risk posed by sea level rise.

Maintain (and PLP) then Improve from 2055 – Use Property Level Protection tomanage and reduce ooding to residential properties at very signicant risk. Preventerosion to critical infrastructure serving the town and the West Wight. From 2055,if funding can be secured, raise / implement new defences (bunds and oodwalls) to

manage long term increase in ood and erosion risk posed by sea level rise.Improve (now) – Raise / implement new defences (bunds and oodwalls) now tomanage longer term increase in ood and erosion risk posed by sea level rise.

SMZs 3,4, 5 and 6 overleaf ►


44/168


Strategic options considered for each Strategy Management Zone (SMZ)

(continued):

SMZ 3b (W10, W13-14) Potential Strategic Opt ionsWestern Yar Estuary

Do Nothing – No active intervention. Baseline scenario.

Do Minimum – H&S and access (minor repairs to cyclepath i.e. debris removal).

Do Minimum with Managed Realignment between 2025 and 2055 – Maintainexisting structures, H&S and cycle and footpath access. If funding can be secured,

managed realignment at Thorley Brook between 2025 and 2055 to provideenvironmental mitigation and create intertidal habitat.

Maintain – Maintenance of existing structures (including cycle path repairs) andrefurbishment at end of design life.

SMZ 3c (W11-12) Potenti al Strategic OptionsFreshwater (The Causeway and Freshwater Bay)


Do Minimum – H&S and access. Flood warning and emergency response plan.

Adaption and Resil ience (and PLP) / Do Minimum – Recommend Property LevelProtection and ood warning / emergency response plan for residential properties at

very signicant risk.

Maintain (and PLP) then Improve (2055) – Maintenance of existing structures andrecommend Property Level Protection to the residential properties at signicant oodrisk. Refurbishment of existing defences at Freshwater Bay at end of design life toprevent erosion risk and implement new defences at Freshwater Village in the longterm to mitigate ood risk and improve the standard of protection.

Maintain and Improve (now) – Maintain existing defences at Freshwater Bay, improvestandard of protection at Freshwater Village. Refurbishment and Improve existingdefences at end of design life at Freshwater Bay to mitigate erosion risk and implementnew defences at Freshwater Village to improve the standard of ood protection.

SMZ 4 (W18-20) Potential Strategic Options

Newtown CoastDo nothing – No active intervention. Baseline scenario.

SMZ 5a (W21-22) Potenti al Strategic OptionsGurnard Luck and Gurnard cliff


Do Minimum – H&S and access. Provide ood warning and emergencyresponse plan.

Do Minimum and Resilience then Adapt – Recommend community and propertylevel ood resistance at Gurnard Luck. Private maintenance of existing assetspermitted (subject to usual consents). In the long term ood risk will increase due to

sea level rise but provide a coastal change management area plan to support the SMP(2010) No Active Intervention Policy. Do minimum (maintain H&S) at Gurnard cliff.

Maintain – Maintenance of existing structures at Gurnard Luck and refurbishment atend of design life. Flood risk will increase over time due to sea level rise. Develop oodwarning and emergency response plan. Do minimum (maintain H&S) at Gurnard cliff.

SMZ 5b (W23) Potential Strategic OptionsGurnard to Cowes Parade


Do Minimum – Maintain H&S and access and also provide coastal changemanagement area plan.

Maintain – Maintenance of existing structures and refurbishment or replacement at theend of their residual life to reduce risks of erosion and landslide reactivation. Flood riskwill increase due to sea level rise.

Improve (now) – Implement seawall stabilisation works along Cowes – Gurnard toreduce erosion risk and increase standard of ood protection.

SMZ 6a (W24-25, W31) Potenti al Strategic OptionsCowes and East Cowes


Do Minimum – H&S and access. Provide ood warning and emergencyresponse plan.

Do Minimum (and PLP) then Adapt – Recommend Property Level Protection forresidential properties at very signicant risk and maintain H&S and access. Adapt andprovide ood warning / emergency response plan.

Maintain – Maintenance of existing structures and refurbishment at end of design life. Accept standard of protection will fall over time.


45/168


Strategic options considered for each Strategy Management Zone (SMZ)

(continued):

Sustain (with Temporary Flood Barri ers and PLP) then Improve from 2055 –In the short and medium term maintain the existing defences and use TemporaryFlood Barriers and Property Level Protection to sustain a 1 in 75 year (1.33% AEP)standard of protection in the areas at signicant ood risk. Use redevelopmentopportunities to facilitate the raising / implementation of new strategic defences.In the long term (from 2055), if the funding can be secured, implement new defencessuch as seawalls or setback oodwalls to manage the increase in ood and erosionrisk posed by sea level rise.

Sustain (with PLP) then Improve fr om 2055 – In the short and medium termmaintain the existing defences and use Property Level Protection and a ood warning/ emergency response plan (no Temporary Flood Barriers) to manage and reduceooding to residential properties at signicant risk. Use redevelopment opportunitiesto facilitate the raising / implementation of new strategic defences. In the long term(from 2055), if the funding can be secured, implement new defences such as seawallsor setback oodwalls to manage the increase in ood and erosion risk posed by sealevel rise.

Improve (now) – Replace and raise frontline defences to provide a 1 in 200 year (0.5% AEP) standard of protection.

SMZ 6b (W26-28, W30, W32) Potential Strategic Options

Medina Estuary (and East Cowes Outer Esplanade)Do Nothing – No active intervention. Baseline scenario.

Do Minimum – H&S and access.

Maintain – Maintenance of existing structures and refurbishment at end of design life. Accept standard of protection against ooding will fall over time due to sea level rise.

SMZ 6c (W29) Potential Strategic OptionsNewport Harbour


Do Minimum – Maintain H&S and access. Provide ood warning and emergencyresponse plan.

Maintain (and PLP) then Improve from 2055 (through redevelopment) – In theshort term recommend Property Level Protection to manage and reduce oodingto the few residential properties at very signicant risk. Maintain then refurbishexisting defences once they reach the end of their service life. In the long term useredevelopment opportunities to facilitate the raising / implementation of new strategicdefences to improve the standard of ood protection.

Maintain (and PLP) then Improve from 2055 (through a fro ntline scheme) – In theshort term recommend Property Level Protection to manage and reduce ooding tothe few residential properties at very signicant risk. Maintain then refurbish existingdefences once they reach the end of their service life. A new frontline scheme from2055 to improve the standard of ood protection.

Improve (now) – Raise / implement new frontline defences to manage longer termincrease in ood risk posed by sea level rise.

Strategic Option Appraisal

The next stage in the Strategy development process was to appraisethe strategic options to select the preferred option for each SMZ.This appraisal process included an economic appraisal (Benet :

Cost analysis), a number of environmental assessments, social andtechnical appraisals and a consideration of funding and affordability.This process was undertaken to ensure that the preferred options putforward are economically viable and deliverable, meet the Strategyobjectives and are technically robust, socially acceptable andenvironmentally sustainable.

Technical aspects

A primary consideration in the development of a Strategy is to knowis to know which proposals are technically viable. There is little pointin undertaking detailed economic and environmental appraisals, orrecommending an option, if the option in question cannot reasonablybe implemented on the ground.

Technical considerations include considerations include the defencetype in question, timing of works, space and height requirements,

all in the context of the specic location and present condition of thesite in question.

For example, for a currently undefended, open space location, thereare few technical issues and a wide range of options are likely to betechnically viable (e.g. revetments, seawalls, land raising, oodwalls,

earth bunds etc ) However for a more constrained site such as • Maintaining waterfront connectivity links to the sea and improving


46/168


earth bunds etc.). However, for a more constrained site, such asa dense urban environment where space may be very limited,signicant technical challenges may be present for many options

(e.g. land raising or earth bunds which require space) and may limitthe technically feasible options to those such as a oodwall which

require a smaller footprint to implement.

In order to be able to assess the technical feasibility of options a

sound appreciation of the coastline was therefore required.This was achieved through the baseline assessments undertaken.In addition, numerous site walkovers were carried out to assessthe practical and technical constraints offered along the coastline inrespect to the various local measures identied. This understanding

of the Strategy area, coupled with the project team’s extensiveengineering judgement, allowed the technical feasibility of optionsto be appraised.

Social aspects

Stakeholder engagement with key organisations was undertakenduring the development of the options. This included a bus tourof the frontage with key stakeholders and as well as dedicatedstakeholder workshops. There continues to be ongoing liaison withmany of the organisations along the frontage. The feedback andinformation received during Strategy development provided a clearunderstanding of stakeholder needs, desires and opportunitiesto deliver wider outcomes. A number of recurring and commonthemes and aspirations were raised by stakeholders for theStrategy to consider. These include (not in order of importance):

• Robust ood and erosion risk management – protecting keyassets and people

• Maintain critical infrastructure and the ferry links to the Island• Maintaining and improving coastal access (i.e. walking, cycling,

shing, nature watching and leisure pursuits)

• Maintaining waterfront connectivity, links to the sea and improvingharbour facilities

• Safeguarding cultural and natural heritage assets• Protecting, enhancing and creating environmentally important sites• Maintaining recreational space areas• Keeping natural areas unspoilt• Maintaining the Islands tourism economy• Linking new defences with redevelopment opportunities

The option appraisal process accounted for these aspirations and theintent of the preferred options is to support and facilitate these wherepossible.

Environmental aspects

With so many environmentally and culturally important areas anddesignations on the Island, key environmental considerations andobjectives helped shape the preferred strategic options. This wasachieved through a Strategic Environmental Assessment (SEA) which

was undertaken as an integral part of the option appraisal process(see Appendix G). The SEA appraised the potential impacts of eachshort listed strategic option against the following categories:

• Biodiversity• Climate• Cultural heritage• Human health• Landscape• Material assets

• Soil• Water

The interrelationship between each of the above categories wasalso considered.

The environmental appraisal information was included as part The costs of a strategic option were estimated based on the defence


47/168


The environmental appraisal information was included as partof the evidence for selecting the preferred option. Where possibleit is intended that the preferred options should not signic

Documents

West Wight Coastal Strategy March 2016