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Summary Report June 2012

South Devon Catchment Flood Management Plan

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June 2012

Environment Agency South Devon Catchment Flood Management Plan 1

Introduction

I am pleased to introduce our summary of the South Devon

Catchment Flood Management Plan (CFMP). This CFMP gives an

overview of the flood risk in the South Devon catchment and sets

out our preferred plan for sustainable flood risk management over

the next 50 to 100 years.

The South Devon CFMP is one of 77 CFMPs for Englandand Wales. Through the CFMPs, we have assessedinland flood risk across all of England and Wales for thefirst time. The CFMP considers all types of inlandflooding, from rivers, ground water, surface water andtidal flooding, but not flooding directly from the sea(coastal flooding), which is covered by ShorelineManagement Plans (SMPs). Our coverage of surfaceand ground water is however limited due to a lack ofavailable information.

The role of CFMPs is to establish flood risk managementpolicies which will deliver sustainable flood riskmanagement for the long term. This is essential if weare to make the right investment decisions for thefuture and to help prepare ourselves effectively for theimpact of climate change. We will use CFMPs to help ustarget our limited resources where the risks aregreatest.

This CFMP identifies flood risk management policies toassist all key decision makers in the catchment. It wasproduced through a wide consultation and appraisalprocess, however it is only the first step towards anintegrated approach to Flood Risk Management. As weall work together to achieve our objectives, we mustmonitor and listen to each others progress, discusswhat has been achieved and consider where we mayneed to review parts of the CFMP.

There are many sources of flood risk within the SouthDevon catchment. The main risk of flooding is fromrivers and is largely due to insufficient channel capacityand problems associated with culverts. Risks to people,property and infrastructure are concentrated mainly inNewton Abbot, Kingsteignton, Bovey Tracey,Buckfastleigh, Ashburton, Totnes, Ivybridge and Torbay.Surface water flooding is also a significant source offlood risk. There was widespread flooding across SouthDevon in 1979 and 2000.

We cannot reduce flood risk on our own, we willtherefore work closely with all our partners to improvethe co-ordination of flood risk activities and agree themost effective way to manage flood risk in the future.We have worked with others including: Devon CountyCouncil, Natural England, South West Water and theNational Farmers Union to develop this plan.

This is a summary of the main CFMP document, if youneed to see the full document an electronic version canbe obtained by emailing [email protected] or alternatively paper copies can be viewed at any ofour offices in South West Region.

Richard CresswellSouth West Regional Director

2 Environment Agency South Devon Catchment Flood Management Plan

The purpose of a CFMP in managing flood risk 3

Catchment overview 4

Current and future flood risk 6

Future direction for flood risk management 10

Sub-areas

1 Dartmoor sub-area 12

2 Avon Estuary sub-area 14

3 Torbay sub-area 16

4 Newton Abbot and Totnes sub-area 18

5 Dart, Teign and Kingsbridge Estuaries sub-area 20

6 Bovey Tracey and Ashburton sub-area 22

7 Buckfastleigh sub-area 24

8 Lower Erme sub-area 25

9 Rural Mid-Lower Teign, Dart and Avon sub-area 26

Map of CFMP policies 28

Contents


The purpose of a CFMP in managing flood riskCFMPs help us to understand thescale and extent of flooding now andin the future, and set policies formanaging flood risk within thecatchment. CFMPs should be used toinform planning and decisionmaking by key stakeholders such as:

• the Environment Agency, who willuse the plan to guide decisionson investment in further plans,projects or actions;

• Regional Assemblies and localauthorities who can use the planto inform spatial planningactivities and emergencyplanning;

• Internal Drainage Boards (IDB),water companies and otherutilities to help plan theiractivities in the wider context ofthe catchment;

• transportation planners;

• land owners, farmers and landmanagers that manage andoperate land for agriculture,conservation and amenitypurposes;

• the public and businesses toenhance their understanding offlood risk and how it will bemanaged.

Figure 1. The relationship between CFMPs, delivery plans, projects and actions

CFMPs aim to promote moresustainable approaches tomanaging flood risk. The policiesidentified in the CFMP will bedelivered through a combination ofdifferent approaches. Together withour partners, we will implementthese approaches through a rangeof delivery plans, projects andactions.

The relationship between the CFMP,delivery plans, strategies, projectsand actions is shown in Figure 1.

Policy planning• CFMPs and Shoreline Management Plans.

• Action plans define requirement for deliveryplans, projects and actions.

Note: Some plans may not be led by us – we may identify theneed and encourage their development.

Policy delivery plans (see note)• Influence spatial planning to reduce risk and

restore floodplains.

• Prepare for and manage floods (including localFlood Warning plans).

• Managing assets.

• Water level management plans.

• Land management and habitat creation.

• Surface water management plans.

Projects and actions• Make sure our spending delivers the best

possible outcomes.

• Focus on risk based targets, for example numbersof households at risk.


The South Devon CFMP covers thecatchments of the Rivers Teign, Dart,Erme and Avon, which flow east andsouth from Dartmoor into theestuaries and sea. It also includesseveral small watercourses drainingthe Torbay area. The area isenvironmentally rich, containingseveral important environmentalsites and a very high quality riversystem.

The South Devon CFMP covers anareas of some 1,500 squarekilometres (580 square miles).

The main physical characteristics ofthe catchments are steeply slopingwatercourses rising in the DartmoorNational Park, that then flow intowider, more permeable valleys in thelower reaches. Annual rainfall rangesfrom more than 2,300mm (90in) in

Catchment overview

upland areas to less than 1,000mm(39in) on the coast. The England andWales average is 920mm (36in).

Geology is divided betweenDartmoor’s impermeable granite tothe north and the mainly Devonianand Carboniferous deposits to thesouth. Impermeable rocks respondfaster to rainfall and generate higherflood peaks than more permeablerocks. Water levels in the largelyimpermeable upper catchment risefairly rapidly after rainfall. They reachtheir peak in a relatively short time –typically less than 12 hours – and fallquickly after the rain has stopped.Less severe gradients in the lowercatchment mean that rivers therereach their flood peak in typically 12to 24 hours.

There is a varied landscape acrossthe area, including the uplands ofDartmoor National Park andextensive estuaries to the south.Much of the countryside isrecognised for its environmental andcultural value including an Area ofOutstanding Natural Beauty (AONB)and 470 Scheduled Monuments.There are many other ecologically,socially and historically importantsites in the catchment and a networkof good quality river courses, withfour Special Areas of Conservation(SAC) and 74 Sites of SpecialScientific Interest (SSSI).

Urban development (about 7% of thecatchment) is mainly concentrated inthe lower reaches of the River Teign(at Newton Abbot and Kingsteignton)and in the Torbay area. Around 90%of the catchment is agricultural.

Water levels in the largelyimpermeable upper catchment risefairly rapidly after rainfall.


Map 1. Location and extent of the South Devon CFMP area

© Crown Copyright. Environment Agency 100026380.

Legend

South DevonCFMP

Urban areas

Main rivers

Railway

MotorwayTavistock

Plymouth

Okehampton

0 4 8 12 16Kilometres

Exeter

BoveyTracey

Ashburton

Dawlish

Teignmouth

Torquay

Brixham

Dartmouth

Kingsbridge

Ivybridge

NewtonAbbot

N

➜ A family wade through floods at Teigngrace in November 2000 Photo: Gareth Williams/Express and Echo


Current and future flood risk

There are many sources of flood riskwithin the South Devon catchment.The main risk of flooding is fromrivers and is largely due toinsufficient channel capacity andproblems associated with culverts.

Several SSSIs, SACs, ScheduledMonuments and National NatureReserves (NNRs) are at risk.

We spend more than £250,000 ayear on flood risk management inSouth Devon and local authoritiescarry out further management. Awarning system is in place for mosturban areas, with the exception ofTorbay, although there is sometimesless than two hours warning of animpending flood. There is no floodwarning for many locations next tosmaller watercourses.

Overview of the current flood risk

Some 8,200 properties areestimated to be at risk from the 1%annual probability flood, ignoring theeffect of defences. This represents5% of all property across the area.

Also at risk are Torre Abbey, the fourconservation areas of Torbay, andthe main rail line to Plymouth andPenzance. Other community assetsat risk include various schools,health centres, a hospital and awaste water treatment works.

Environmental assets that are withinthe floodplain and could be affectedby management activities includethe River Lowman Valley Woods SSSI,Buckfastleigh Caves SSSI, the RiverErme and the Salcombe andKingsbridge Estuary SSSIs.

What is at risk?

‘The River Dart rose higher onMonday night than ever knownduring summer months. A floodcame down from the Dartmoor hillswith unusual rapidity. Water roseabove 12 feet on the banks within afew minutes.’ 1848

Table 2. Critical infrastructure at risk:

25 electricity substations, 6 railway lines, 6 A roads, 1 hospital, 5 emergency services, 2 water treatment works


Map 2. Flood risk to property in a 1% annual probability river flood, ignoring current flood defences


Legend

Properties with a 1%chance of flooding

101 - 150

151 - 200

201 - 500

501 - 1,000

1, 1 - 1,500

South Devon CFMPMain rivers

Bovey Tracey

Ashburton

TorquayTotnes

Ivybridge

Newton Abbot

Kingsteignton

Kingskerswell


N

Table 1. Locations of towns and villages with 100 or more properties at risk in a 1% annual probability river flood

Number of properties at risk Locations

1,000 to 2,000 Newton Abbot

500 to 1,000 Torbay, Totnes

250 to 500 Kingsteignton

100 to 250 Kingskerswell, Ivybridge, Ashburton, Bovey Tracey


How we currently manage the risk

• Flood risk mapping – A major partof the programme is Flood ZoneImprovements and HazardMapping. This is focused onimproving the mapping at high-risk locations.

• Managing development – Ourdevelopment control teamsupports the planning process byensuring that new developmentshave the appropriate flood riskassessments and follow PPS25(Government Planning PolicyStatement on Development andFlood Risk).

• Flood warning – In some areasthere is currently no serviceprovided, in other areas such asBuckfastleigh and Harbertonfordthere is less than two hourswarning provided. Elsewhere inthe catchment, registeredproperties receive a directmessage via phone, email or fax.Major Incident Plans have been

developed for Newton Abbot,Kingsteignton, Totnes,Teignmouth, Shaldon andDartmouth.

• Flood defence schemes – Wehave flood defence schemes toalleviate river flooding atAshburton, Bovey Tracey,Buckfastleigh, Harbertonford,Kingsteignton and Newton Abbot,and tidal defences at Teignmouthand combined tidal and riverdefences at Totnes. In additionthere are a range of local authoritydefences in the catchment.

• Maintenance – We maintainchannels and defences, with localauthorities carrying out a largeamount of further work.

The distribution of potential floodrisk from rivers and tides isillustrated in Map 2 for a flood with a1% annual probability (0.5% fortides) of occurring or beingexceeded.

The greatest concentration ofproperties at risk of flooding is atNewton Abbot and Kingsteignton.Here some 1,650 properties are atrisk from river and tidal flooding.This is set to increase due to risingsea levels.

Torbay and Totnes then have thenext highest concentrations inproperty at risk with some 670 and610 properties at risk respectively.

In addition to these locations, thereare risks of surface water flooding,which can be deep and fast flowing,across much of the catchment.However, further studies followingon from the CFMP are needed by usand our partners to quantify thispotential risk.

Where is the risk?

➜

Cars in Newton Abbot are winchedfrom the River Lemon’s floodwatersin December 1979


The impact of climate change and future flood risk

It is widely accepted that our climateis changing and increasing peak riverflows and sea levels will have asignificant effect on flood risk. Landuse and management changes in thecatchment will also affect thefrequency and magnitude offlooding. We have combined thesefactors with different levels of floodrisk management to forecast floodrisk over the next 100 years.

Climate change is likely to be themain factor influencing futureincreases in flood risk in mostplaces. For the South Devon CFMPthe future scenario use was asfollows:

• 30% increase in peak flows and500mm sea level rise due toclimate change.

• additional 20 square kilometres ofdevelopment in urban areas.

• additional 5 square kilometres ofdevelopment in rural areas.

• 5% increase in peak flows due toland use and land management.

0

200

400

600

800

1000

1200

1400

1600

Newton Abbot Kingsteignton Torbay Totnes Ashburton Bovey Tracey Buckfastleigh Ivybridgeand Ermington

Kingskerswell

Num

ber o

f Pro

pert

ies

at F

lood

Ris

k

Current Future

Figure 2. Current and future (2100) flood risk to property from a 1% annualprobability river flood, ignoring current flood defences

The sensitivity testing undertaken forthe catchment has shown that, inaddition to climate change, changesin agricultural land use and landmanagement will have a significantimpact on peak flows. Urbandevelopment is unlikely to have alarge impact.

Newton Abbot and Torbay would seemost properties affected in the future(see Figure 2).


Approaches in each sub-area

We have divided the South Devon catchment into ninedistinct sub-areas which have similar physicalcharacteristics, sources of flooding and level of risk. Wehave identified the most appropriate approach tomanaging flood risk for each of the sub-areas andallocated one of six generic flood risk managementpolicies, shown in Table 2.

To select the most appropriate policy, the plan hasconsidered how social, economic and environmentalobjectives are affected by flood risk managementactivities under each policy option.

Map 3. South Devon sub-areas

Totnes

Exeter

Brixham

Shaldon

Saltash

Dawlish

Exmouth

Torquay

Salcombe

PaigntonPlympton

TorpointIvybridge

Plymstock

Dartmouth

Ashburton

West Hill

Callington

Launceston

Okehampton

Kingsbridge

Horrabridge

Bovey Tracey

NewtonAbbot

Kingsteignton

Kingskerswell

Newton Poppleford

Teignmouth

BudleighSalterton



N

LegendSouth Devon CFMP

Sub-area

Dartmoor (Policy 6)

Avon Estuary (Policy 6)

Torbay (Policy 5)

Newton Abbot and Totnes (Policy 5)

Dart, Teign and Kingsbridge Estauries (Policy 5)

Bovey Tracey and Ashburton (Policy 5)

Buckfastleigh (Policy 4)

Lower Erme (Policy 3)

Rural Mid and Lower Teign,Dart and Avon (Policy 2)

1

2

3

4

5

6

7

8

9

Future direction for flood risk management

➜ A flooded quay at Dartmouth in April 1985


Policy 1

Areas of little or no flood risk where we will continue to monitor and advise

This policy will tend to be applied in those areas where there are very few properties at risk of flooding. It reflects a commitment to work with the natural flood processes as far as possible.

Policy 2

Areas of low to moderate flood risk where we can generally reduce existing flood risk management actions

This policy will tend to be applied where the overall level of risk to people and property is low to moderate.It may no longer be value for money to focus on continuing current levels of maintenance of existing defencesif we can use resources to reduce risk where there are more people at higher risk. We would therefore reviewthe flood risk management actions being taken so that they are proportionate to the level of risk.

Policy 3

Areas of low to moderate flood risk where we are generally managing existing flood risk effectively

This policy will tend to be applied where the risks are currently appropriately managed and where the risk offlooding is not expected to increase significantly in the future. However, we keep our approach under review,looking for improvements and responding to new challenges or information as they emerge. We may reviewour approach to managing flood defences and other flood risk management actions, to ensure that we aremanaging efficiently and taking the best approach to managing flood risk in the longer term.

Policy 4

Areas of low, moderate or high flood risk where we are already managing the flood risk effectively but where wemay need to take further actions to keep pace with climate change

This policy will tend to be applied where the risks are currently deemed to be appropriately-managed, butwhere the risk of flooding is expected to significantly rise in the future. In this case we would need to do morein the future to contain what would otherwise be increasing risk. Taking further action to reduce risk will requirefurther appraisal to assess whether there are socially and environmentally sustainable, technically viable andeconomically justified options.

Policy 5

Areas of moderate to high flood risk where we can generally take further action to reduce flood risk

This policy will tend to be applied to those areas where the case for further action to reduce flood risk is mostcompelling, for example where there are many people at high risk, or where changes in the environment havealready increased risk. Taking further action to reduce risk will require additional appraisal to assess whetherthere are socially and environmentally sustainable, technically viable and economically justified options.

Policy 6

Areas of low to moderate flood risk where we will take action with others to store water or manage run-off inlocations that provide overall flood risk reduction or environmental benefits

This policy will tend to be applied where there may be opportunities in some locations to reduce flood risklocally or more widely in a catchment by storing water or managing run-off. The policy has been applied toan area (where the potential to apply the policy exists), but would only be implemented in specific locationswithin the area, after more detailed appraisal and consultation.

Table 3. Policy options


Dartmoor

Sub-area 1

The issues in this sub-area

The area of the Dartmoor NationalPark located within the CFMPincludes the sources of the Teign,Dart, Avon and Erme rivers. Thereare no major towns in this area,infrastructure is limited (with nodefence structures) and there arenegligible economic losses fromflooding.

There are approximately 60properties at risk from a 1% annualprobability flood event and this mayincrease to approximately 150properties in the future 1% annualprobability flood event.

Our key partners are:

Dartmoor National Park

Natural England

National Farmers Union (NFU)

Country Landowners Association

Land owners and farmers

The study’s assessment shows thata reduction in flows from uppercatchments could result in areduction in flood risk atdownstream urban areas whererisks to people and the economy arecurrently high (and expected toincrease in the future).

A number of designatedenvironmental sites experienceflooding, but natural river processesand sensitive flood riskmanagement generally benefitthese sites. These sites includeDartmoor SAC and South DartmoorWoods SAC. There are opportunitiesto maximise the naturalhydrological processes for thebenefit of Biodiversity Action Planhabitats and species. This presentsan opportunity to create andmanage ecologically functionalwetlands in which the naturalprocesses of peatlanderosion/accretion, soilconservation, and waterstorage/dissipation are optimised.Consultation with local farmers andthe NFU will be of key importance,with agreement needed to bereached with all interested partiesbefore any land can be used foradditional flooding.

The vision and preferred policy

Policy Option 6 - we will take actionwith others to store water ormanage run-off in locations thatprovide overall flood risk reductionor environmental benefits.

This supports all the environmentalobjectives apart from possibly thehistoric environment objective.However, without a more detailedassessment of the impacts on thehistoric environment it is notpossible to determine the impactson these features. Consultation withthe Dartmoor National ParkAuthority, English Heritage andNatural England will therefore beessential to the progression of thispolicy.

Whilst the policy involves a strategicincrease in flooding in allocatedareas, it is not intended to adverselyaffect the risk to individualcommunities and we will not putthese communities at increasedrisk. Depending on actions taken,the risk to these communities mayin fact reduce.

We will continue with our currentmaintenance activities where thereare significant numbers of peopleand properties at risk. Any newdevelopments in the area will stillbe expected to comply with PPS25and take into account this plan’spolicy for the area.


Proposed actions to implement the preferred policy

• We will develop a land management plan that identifies locations that would benefit fromincreased flooding, increased water levels. This will support existing studies such as theMire restoration project, culm restoration, Action for Wildlife, and Dartmoor High MoorlandVision 2030.

• We will work with the agricultural industry to seek opportunities where a change in landmanagement practices could reduce flood risk and improve water quality and habitats.

• We will work with partners to identify and reduce the impact of flood risk managementpractices on the historic environment including areas of palaeoenvironmental potential.

To support the policy, land use planners should designate all floodplain and wetland areas asfunctional floodplain to support their role in attenuating floodwaters and reducing risksdownstream.


Avon Estuary

Sub-area 2


The Avon Estuary sub-area extendsfrom the coast inland to AvetonGifford, which is situated at theupper tidal limit of the Avon Estuary.

A small private tidal defencescheme protects one property andfields from a 1% annual probabilityflood. However, approximately 10properties are still at risk from a 1%flood. There is only about one hoursflood warning to Aveton Gifford forflooding from the River Avon.

Future flood risk will mainly becaused by climate change(increased rainfall, peak flows andsea level rise). Approximately 20properties may be at risk by 2100.


South Hams District Council

Department for Environment, Foodand Rural Affairs (Defra)

Natural England

Landowners

Local farmers



Policy Option 6 - we will take actionwith others to store water managerun-off in locations that provideoverall flood risk reduction orenvironmental benefits.

As only a small number ofproperties are at risk and theassociated economic damages inthis rural area are minor, weconsider policies to maintain orincrease flood risk managementactions are inappropriate.

This supports environmentalobjectives and does not havesignificant negative implications foreconomic and social objectives. Thepolicy will support intertidalBiodiversity Action Plan habitats tobe created and help restore linkswith the floodplain.

The policy will involve identifyingspecific areas where additionalflooding may be appropriate, andagreement will need to be reachedwith all interested parties (such aslocal farmers). This is likely toinvolve looking at any impact onfarming business and possiblemechanisms for compensation.

As the area is rural there are fewpeople and properties at risk, anoverall increase in flooding in thisarea is acceptable, assuming therisk to individual properties inAveton Gifford is not increased. Amore detailed study may be neededto make sure that the chosen policydoes not significantly increase riskin the village.

Proposed actions to implement thepreferred policy

• We will look at ways ofreconnecting the river/estuary toits natural floodplain to utiliseflood storage, reduce risk topeople and enhance habitats.

• We will look at ways of improvingthe flood warning service inAveton Gifford.

To support the policy, land useplanners should designate allfloodplain and wetland areas asfunctional floodplain to supporttheir role in attenuating floodwatersand providing Biodiversity ActionPlan habitat.


➜ The tidal road to the south of Aveton Gifford


Torbay

Sub-area 3


Torbay has small watercourses thatflow eastwards through the urbanarea directly into the sea. Flood riskis from fluvial, tidal, sewer andsurface water.

Approximately 700 properties inTorquay, Paignton and Brixham (and1,000 across the whole area) are atrisk from flooding in 1% fluvial and0.5% tidal annual probabilityfloods. Our review suggests that120 properties are at risk fromsewer flooding and at least 400properties are affected by surfacewater run-off. Only 2% of ourflooding records relate togroundwater flooding.


Torbay Council

South West Water

No modelling was carried out forTorbay so the assessment of floodrisk to properties is based on ourFlood Map. We have assumed thatthe current 0.1% flood outline willapproximately represent the 1%flood outline by 2100. The numberof properties at risk is expected toincrease to well in excess of 1,000.

Schools and health centres are atrisk of flooding. Main roadsexperience frequent flooding.Landfill sites at Clennon Valley andPaignton Zoo are at risk fromflooding in extreme floods fromminor watercourses. The Barton Tipleachate lagoon is prone to floodingfrom surface water into theheadwaters of the Aller Brook.

There are numerous small schemesfor fluvial, tidal, surface water andsewer flooding in Torquay, Paigntonand Brixham, providing a range ofprotection.

Future flood risk will mainly be dueto climate change and urbandevelopment. Torquay is identifiedas a likely site for futuredevelopment in South Devon whichwould lead to increased surface run-off and pressure on seweragesystems. The number of propertiesat risk could increase due to thesefactors.


Policy Option 5 - we can generallytake further action to reduce floodrisk.

This is the only policy to meet all ofthe social and economic objectives.It will reduce the number of peopleand properties at risk and minimisedisruption to transport links in allbut the most extreme events. Itsupports the environmentalobjectives by increasing thestandard of protection for TorreAbbey, four conservation areas, aswell as improving water quality.



• System Asset Management plans and performance specifications will be produced for all our flood risksystems and major assets. These will assess flood risk maintenance with the aim to reduce flood risk inTorbay and will include environmental constraints and targets.

• Investigate causes of flooding, identify measures such as flood storage areas and implementrecommendations to reduce current risks including from combined fluvial and tidal conditions.

• We will examine possible options for providing a flood warning service in Torbay.

• We will examine ways to work with the local planning authority to improve flood risk in the future andensure that all development complies with PPS25.

• We will look at different options for opening up the floodplain through relocation strategies. We will alsoaim to secure, restore and keep an area free from development next to all watercourses in and aroundurban areas.

• Develop an Integrated Urban Drainage Strategy, with a review of watercourses and catchments, foul andsurface water sewerage, and the impact of climate change.

• Improve the way that flooding records are collated from different sources.

➜ Flooding at the lower end of Union Street, Torquay


Newton Abbot and Totnes

Sub-area 4


The urban area of Newton Abbot,including the town of Kingsteignton,is located at the confluence of therivers Teign and Lemon and at thehead of the Teign Estuary. Itencompasses the Aller Brookcatchment.

Development at Newton Abbot andKingsteignton has extended into thefloodplains and, without defences inplace, approximately 1,800properties would be at risk from a1% annual probability flood. TheRiver Lemon flood defence schemegives some protection to 1,000properties; the Kingsteignton flooddefence scheme to a further 300properties. A retention dam atHolbeam is designed to hold excessfloodwaters in events up to the 1%flood.


Devon County Council


Teignbridge District Council

Natural England

Teign Estuary Partnership

There may be risks to health centresand schools. Although flows are notfast, they can be deep, causing arisk to public safety. ThePaddington-Penzance railway line isat risk of flooding from the AllerBrook.

Totnes is located at the head of theDart Estuary. Previous developmentin the town has taken place withinthe floodplain. A flood alleviationscheme constructed in 1982 wasdesigned to protect approximately500 properties from a 3.3% annualprobability combined fluvial andtidal flood and from a 0.5% tidalflood. However, a more recent studyhas found that the standard ofprotection varies between 1.3% and10%.

There is still a risk of flooding frommore severe flood events.Approximately 600 properties are atrisk from a 1% flood and over 700properties from a 0.1% flood. Ahospital, four health centres and awaste water treatment worksimmediately upstream of the townare also at risk from combinedfluvial and tidal flooding. In additionto fluvial/tidal flood risks, there arealso surface water floodingproblems in Totnes.

Future flood risk will be causedmainly by climate change (increasedrainfall, peak flows and sea levelrise). Economic damages, disruptionto communications and the threat topublic health and safety areexpected to increase significantlywith climate change, especially inTotnes. Flows in the Aller Brook areparticularly sensitive to urbanisationand the whole area may be the focusfor future development in SouthDevon. Future flood risk changes inthe Teign catchment will be caused,to a lesser extent, by land use andmanagement.

In the future 1% annual probabilityflood 1,375 properties in NewtonAbbot are expected to be at risk,while 730 properties in Totnes areexpected to be at risk.



• System Asset Management plansand performance specificationsproduced for all our flood risksystems and major assets. Thesewill assess flood riskmaintenance to reduce flood riskin the urban areas and includeenvironmental constraints andtargets. These will assess thestandard of protection andstructural integrity of defences inNewton Abbot.

• Continue to improve floodmapping of areas benefiting fromdefences for the River Lemon inthe Newton Abbot area. Carry outmodelling to identify locations atrisk of flooding in Totnes; inparticular any culverts andchannels causing problems needto be identified. Theseassessments should includecombined tidal and fluvial orsurface water flooding.

• Look at options for reducingflooding including surface waterflooding problems and optionsfor flood routing away fromproperties and importantinfrastructure in Newton Abbotand relocating existingcommercial properties in Totnes.



The policy and actions would reducethe number of properties in NewtonAbbot that are at risk. The risk toinfrastructure would be reduced,and a significant number ofvulnerable people would beprotected.

In Totnes, reducing educing theflood risk would benefit ascheduled monument and Totnes’conservation area and would reducethe number of properties in NewtonAbbot that are at risk. It would alsohelp to improve water quality withinthe River Dart. In particular the riskof flooding to the waste watertreatment works upstream of Totnescould be reduced thus avoidingimpacts on water quality andenvironmental and public healthimplications.

We believe the policy is anenvironmentally acceptable option.However, the existing debrisclearance within the River LemonValley Woods SSSI is considered tobe adversely affecting the site. Thisshould not affect the policy and wewill work with Natural England tofind a solution.

• Apply new flood risk mapping tothe multi-agency flood warningresponse plan for Newton Abbotand Totnes. Review the floodwarning service for the RiverTeign at Kingsteignton andencourage the production ofcommunity flood action plans.Develop a new flood warningarea for the Aller Brook to provideflood warnings for Kingskerswelland Newton Abbot. Considerways of improving the floodwarning service for Totnes.

• Consider ways to compensate for‘coastal squeeze’ throughout theSouth Devon CFMP area, and inparticular in the Newton Abbotand Totnes areas. This shouldidentify locations for habitatcreation.


Dart, Teign and Kingsbridge Estuaries

Sub-area 5


Risks to people and the economyfrom tidal and fluvial flooding arecurrently high and are sensitive torising sea levels in the future.Numerous scattered settlementsadjacent to the estuaries are at riskfrom flooding.

For the Teign Estuary there areapproximately 850 properties withinthe current 1% annual probabilityflood extent (1% fluvial and 0.5%tidal). Approximately 1,300properties in the Teign estuary areestimated to be within the future 1%annual probability flood extent. Alsoat risk are numerous health centresin Teignmouth and Shaldon, several




Natural England

schools in Shaldon, and the mainlinerailway between Newton Abbot andTeignmouth at several locations.There are combined fluvial/ tidaldefences at Shaldon as well as tidaldefences at Teignmouth (constructedin 1991). Teignmouth is also affectedby wave action.

For the Kingsbridge Estuaryapproximately 350 properties andseveral health centres are within thecurrent 1% annual probability floodextent, and 450 properties are withinthe current 0.1% flood extent. 450properties are expected to be at riskwithin the future 1% annualprobability flood event.

For the Dart Estuary approximately350 properties are within the current1% annual probability flood extent(1% fluvial and 0.5% tidal). Severalhealth centres in Dartmouth are alsoat risk. Approximately 400properties in the Dart Estuary areestimated to be within the future 1%annual probability flood extent.Dartmouth is also affected by waveaction.



Future flood risk will mainly becaused by climate change, withpossible sea level rises increasingthe frequency and depth of futureflooding. The chosen policy isconsidered to be the only policy tomeet social and economic needs asa result of the large number ofproperties at risk and the potentialfor this to significantly increase inthe future.

Reducing flood risk overall willdepend on working with ShorelineManagement Plan policies andactions to reduce wave overtoppingas well as flooding from fluvial andtidal sources.



• System Asset Management plans and performance specifications will be produced for all our flood risksystems and major assets. These will assess flood risk maintenance with the aim to reduce flood risk inthe policy unit and will include environmental constraints and targets.

• We will investigate options to reduce flood risk to settlements around the estuaries. This should includehabitat creation or enhancement to contribute to Devon’s Biodiversity Action Plan targets.

• We will identify locations where tidelocking of tributaries is causing problems. We will investigate, andwhere appropriate implement solutions (for example at Bitton and Brimley Brooks in Teignmouth).

• Produce community flood action plans in Dartmouth and Kingsbridge to reduce flood risk throughengagement of the local community.

➜ Flooding from the River Teign at Teigngrace


Bovey Tracey and Ashburton

Sub-area 6


Bovey Tracey is situated on the RiverBovey, approximately 5 kmupstream of the confluence with theRiver Teign. Part of the town, built inthe 19th and 20th centuries, iswithin the floodplain, with floodingfrom the River Bovey, smallerwatercourses and surface water.Some 130 properties are at riskfrom a 1% annual probability flood.

A flood alleviation scheme wasconstructed in 1986 on the RiverBovey that protects approximately50 properties to a 1.7% annualprobability standard. There areother defences on the smallerwatercourses flowing into the RiverBovey. However, the flood warningservice provides less than one hourwarning due to the size ofcatchment and speed of responseto rain.



Devon County Council

Dartmoor National Park Authority

South West Water

Development within the Ashburtonarea has led to increased flood risk,and a flood alleviation scheme wasconstructed in 1989 to provideprotection to properties in floods upto a 2% flood annual probability.However, the scheme only coversthe River Ashburn and not theBalland Stream that flows just northof the A38. There is also still a riskfrom more severe events;approximately 150 properties andtwo health centres are at risk from a1% flood, increasing toapproximately 350 properties by2100.

There is no flood warning forAshburton and water levels can risequickly, with deep and fast flows.The present risk to people andproperties from flooding is high,and social vulnerability is also high.

Future flood risk will mainly becaused by climate change(increased rainfall and peak flows)but also, to a lesser extent, by landuse and management changes inthe upper Bovey catchment.



Bovey Tracey has been identifiedwithin a Strategic DevelopmentZone. This may enable largenumbers of extra houses andcommercial properties to be built.Additional flood risk managementaction may need to be secured,principally through the land useplanning system, to avoid theeffects of this urban development.

The chosen policy has beenproposed to take further action toreduce flood risk to existingresidential and commercial propertyin the future. This is not to enablenew development to take place inareas at risk.



• System Asset Management plans and performance specifications will be produced for all our Flood risksystems and major assets. These will assess flood risk maintenance with the aim to reduce flood risk andwill include environmental constraints and targets.

• We will take action to reduce the flood risk in Ashburton including the Balland Stream as well as the RiverAshburn. We will assess and improve where necessary the defences on the River Bovey and surroundingwatercourses.

• We will influence partners to improve highways drainage in Ashburton.

• Investigate a flood warning for the river Ashburn at Ashburton, and encourage the production ofcommunity action plans to reduce flood risk through engagement of the local community.

• Consider ways of improving the flood warning service to Bovey Tracey and encourage the production ofcommunity flood action plans to reduce flood risk through engagement of the local community.

• Produce a study to look at ways of creating flood storage areas. This should aim to reduce flood risks toproperty in Bovey Tracey and further downstream, but should also provide Biodiversity Action Plan habitatenhancement or creation opportunities.

➜ Flooding in Bovey Tracey


Buckfastleigh

Sub-area 7


The area covers the towns ofBuckfastleigh and Buckfast.Buckfastleigh is located at theconfluence of the River Ashburn,River Dart and River Mardle, withBuckfast lying just upstream on theRiver Dart.

There is a less than one hour floodwarning for Buckfastleigh as waterlevels can rise rapidly.

A flood alleviation scheme wasconstructed in Buckfastleigh in1988 and protects properties with adesign standard of protection of 2%annual probability. However, it ispossible that the standard ofprotection provided hassubsequently reduced. In addition,there is a risk from more severeevents, with 95 properties at riskfrom a 1% flood that is anticipatedto increase to over 200 propertiesby 2100. This includes properties atrisk from the River Dart, the RiverMardle and the Dean Burn whichflow into Buckfastleigh from thesouth east.

Greater horseshoe bat hibernationand maternity roost sites arelocated within the floodplain. Thereis a risk of potential flooding of theBuckfastleigh Caves SSSI (part ofSouth Hams SAC).



Future flood risk will mainly becaused by climate change(increased rainfall and peak flows)and, to a lesser extent, by land useand management changes in theupper Dart.


Policy Option 4 - we are alreadymanaging the flood risk effectively,but we may need to take furtheractions to keep pace with climatechange.

We believe the 2% standard ofprotection given by the defencescheme and maintenance issufficient at the moment. As suchthe policy to take further action tosustain the current scale of floodrisk into the future is appropriate forthe 200 properties at risk.

If land management changes onDartmoor identified in this CFMPhave a significant effect on reducingpeak flows, it may be possible inthe future to ‘downgrade’ futurerequirements at Buckfastleigh andBuckfast without increasing risks toproperty and life. Similarly, anyfuture alterations in flow regime forthe River Ashburn as a result ofimplementing the proposed policyin Ashburton will also need to betaken into account.


• System Asset Management plansand performance specificationswill be produced for all our floodrisk systems and major assets.These will assess flood riskmaintenance with the aim ofsustaining the current scale offlood risk in Buckfastleigh andwill include environmentalconstraints and targets.

• Consider ways of improving theflood warning service. This willinclude targeting communities atrisk in Buckfast and Buckfastleighand investigating improvementsto the River Mardle and DeanBurn at Buckfastleigh.


Lower Erme


The sub-area covers the River Ermefrom Ivybridge to the coast. It ispredominantly rural but does includethe towns of Ivybridge and Ermington.

Ivybridge is situated on the RiverErme where the river leavesDartmoor and enters the lower lyingSouth Hams area. Ermington islocated to the south, on the lowerreaches of the Erme.

There are no flood alleviation schemesand there is less than half an hourflood warning for the towns.Approximately 160 properties inIvybridge and Ermington are at risk offlooding from a 1% annual probabilityflood (the majority of these being inIvybridge), increasing to approximately250 properties by 2100. Approximately190 properties are currently at riskfrom a 0.1% flood (again, the majorityof these in Ivybridge).

25% of the Erme Estuary SSSI iswithin the 1% flood extent. Silt levelsare high in the lower catchment of the



Natural England

Local Farmers

National Farmers Union


River Erme, caused by soil erosion asa result of the steep-sided agriculturalfields adjacent to the river.


Policy Option 3 - we are generallymanaging existing flood riskeffectively.

As this is a predominantly ruralarea, with the two urban areasbeing fairly small, increasing thelevel of flood risk management isnot considered significant enoughto be justified. The chosen policy isconsidered most sustainable overthe next 100 years. Any increase inrisk is not significant and it meetsour social and economic objectives.


• System Asset Management plansand performance specificationswill be produced for all our floodrisk systems and major assets.These will include a review todetermine the appropriate level ofmaintenance consistent with thispolicy option and will includeenvironmental constraints andtargets. This action should includethe production of a System AssetManagement Plan for the ErmeEstuary which must support thefavourable condition of the SSSI.

• Investigate the flood risk inIvybridge, and reviewopportunities for reducing currentmaintenance activities ifappropriate.

• Consider ways of reconnecting theriver to its natural floodplain toutilise flood storage and enhancehabitats, in particular within andaround the Erme Estuary SSSI.Include a review of the likelychange in flood risk associatedwith this action.

• Encourage the production ofcommunity flood action plans inthe Lower Erme and Ivybridge toincrease the local communityawareness and engagement offlooding issues.

• With the agricultural industry,seek opportunities where achange in land managementpractices could reduce flood riskand improve water quality andhabitats.

We will look to land use planners toensure that no further developmentis allocated in areas at risk offlooding. Planners should aim toreduce flood risks to existingdeveloped areas by incorporatingresilience and resistance measuresand by changing uses to lessvulnerable types where possible.Furthermore, due to the shortwarning times, it is essential thatvulnerable development includessuitable warning and evacuationprocedures.

Sub-area 8


Sub-area 9

Rural Mid and Lower Teign,Dart and Avon


This mainly rural area covers the midand lower extents of the three majorwatercourses in the South DevonCFMP: the Teign, Dart and Avon. Thearea extends from the Dartmoorboundary to the estuaries, butexcludes the urban areas of BoveyTracey, Buckfastleigh, Buckfast,Ashburton, Newton Abbot andTotnes.





Natural England

Landowners



It is a large and varied area thatcontains a number of smaller villagesbut no major towns.

Scattered across the whole area, 500properties are at risk from a 1%annual probability flood, with 700properties, agricultural land and thepreserved railway at Staverton beingat risk from an extreme flood (with0.1% annual probability). Part of theA383 between Bovey Tracey andNewton Abbot is at risk from theRiver Lemon in a 0.1% flood. Theedge of the Heathfield South Landfillsite is also at risk from flooding withimplications for water quality in theRiver Teign.

Future flood risk will mainly becaused by climate change, but landuse and management changes willalso have an impact. Approximately700 properties may be at risk from a1% flood by 2100.

Harbertonford flood defence schemeon the River Harbourne was built in2002 and protects 50 propertiesfrom events up to the 2.5% flood.


Policy Option 2 - we can generallyreduce existing flood riskmanagement actions.

Due to the scattered nature ofproperties, the most appropriatepolicy is to generally reduce ourexisting flood risk managementactions but to continue ouractivities in certain key locations.

For instance, the risk to people andthe economy at Harbertonford(where social vulnerability is high)could increase significantly in thefuture if defences becomeineffective so we shall continue tomaintain these.



• Produce System Asset Management plans and performance specifications for our flood risk systems andmajor assets. These will aim to reduce actions where appropriate and include environmental constraintsand targets. We will continue with our current activities in certain key locations.

• With the agricultural industry seek opportunities where a change in land management practices couldreduce flood risk and improve water quality and habitats. Influence local, regional and nationalagricultural policies, and assess how they can be integrated into flood risk management practices.

• Consider ways of reconnecting the river to its natural floodplain to utilise flood storage, reduce risk topeople and enhance habitats. This should provide opportunities to enhance or create Biodiversity ActionPlan habitats.

• Develop a community flood warning area to provide a more targeted warning for Staverton. Consider waysof improving the flood warning service in Harbertonford.

• Encourage production of community flood action plans through engagement of the local community. Thisshould include at least the significant flood risk locations of Harberton, Harbertonford.

➜ Flooding from the River Harbourne at Harbertonford in December 1999. Fifty homes were affected andwater swept into the bar at the Maltsters Arms, where staff provided customers with rubber boots


Map of CFMP policies

Map of the policies in the South Devon catchment


Legend

Main rivers

Urban areas

Preferred approach

Policy 1

Policy 2

Policy 3

Policy 4

Policy 5

Policy 6

South Devon CFMP

Tavistock

Plymouth

Okehampton

Exeter

Bovey Tracey

Teignmouth

Torquay

Brixham

Dartmouth

Kingsbridge

TotnesIvybridge


1

2

3

4

4

5

5

5

6

6

7

89

9

N

1 Dartmoor

2 Avon Estuary

3 Torbay

4 Newton Abbot and Totnes

5 Dart, Teign and Kingsbridge Estuaries

6 Bovey Tracey and Ashburton

7 Buckfastleigh

8 Lower Erme

9 Rural Mid and Lower Teign, Dart and Avon

The sub-areas

GESW0612BWPU-E-E

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