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managing

flood risk

Summary Report June 2012

Tamar Catchment 

Flood Management Plan



We are the Environment Agency. It’s our job to look after your

environment and make it

a better place

– for you, and for

future generations. 

Your environment is the air you breathe, the water you drink

and the ground you walk on. Working with business,

Government and society as a whole, we are making your

environment cleaner and healthier.

The Environment Agency. Out there, making your environment

a better place.

Published by:

Environment Agency

Manley House

Kestrel Way

Exeter EX2 7LQ

Tel: 0870 8506506

Email: enquiries@environment-agency.gov.uk

www.environment-agency.gov.uk

© Environment Agency 

All rights reserved. This document may be reproduced 

with prior permission of the Environment Agency.

June 2012



Environment Agency

Tamar Catchment Flood Management Plan

1

Introduction



I am pleased to introduce our summary of the Tamar Catchment

Flood Management Plan (CFMP). This CFMP gives an overview of

the flood risk in the Tamar catchment and sets out our preferred

plan for sustainable flood risk management over the next 50 to 100

years.

The Tamar CFMP is one of 77 CFMPs for England and



Wales. Through the CFMPs, we have assessed inland

flood risk across all of England and Wales for the first

time. The CFMP considers all types of inland flooding,

from rivers, ground water, surface water and tidal

flooding, but not flooding directly from the sea (coastal

flooding), which is covered by Shoreline Management

Plans (SMPs). Our coverage of surface and ground

water is however limited due to a lack of available

information.

The role of CFMPs is to establish flood risk management

policies which will deliver sustainable flood risk

management for the long term. This is essential if we

are to make the right investment decisions for the

future and to help prepare ourselves effectively for the

impact of climate change. We will use CFMPs to help us

target our limited resources where the risks are

greatest.

This CFMP identifies flood risk management policies to

assist all key decision makers in the catchment. It was

produced through a wide consultation and appraisal

process, however it is only the first step towards an

integrated approach to Flood Risk Management. As we

all work together to achieve our objectives, we must

monitor and listen to each others progress, discuss

what has been achieved and consider where we may

need to review parts of the CFMP.

Flooding within the Tamar catchment can be attributed

to flooding from the rivers, estuaries, surface water run-

off and drainage systems. Previous incidents include

flooding in Launceston in December 1979, widespread

flooding in October 2000 and a dramatic event in

Canworthy Water in August 2004. While the numbers of

properties at risk across the Tamar catchment may be

relatively low compared with other areas of the country,

the risk to life, and community disruption caused by

flooding, can be just as significant.  

We cannot reduce flood risk on our own, we will

therefore work closely with all our partners to improve

the co-ordination of flood risk activities and agree the

most effective way to manage flood risk in the future.

We have worked with others including Plymouth City

Council, Natural England, South West Water and the

National Farmers Union to develop this plan. 

This is a summary of the main CFMP document, if you

need to see the full document an electronic version can

be obtained by emailing 

enquiries@environment-agency.gov.uk 

or alternatively paper copies can be viewed at any of

our offices in South West Region.

Richard Cresswell

South West Regional Director



2   

Environment Agency

Tamar 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

Upper Tamar sub-area



12

2

Tidal Central sub-area



13

3

Plymouth sub-area



14

4

East Tamar sub-area



16

5

Central Tamar sub-area



18

6

West Tamar sub-area



20

Map of CFMP policies 

21 

Contents



Environment Agency

Tamar Catchment Flood Management Plan

3

The purpose of a CFMP 



in managing flood risk

CFMPs help us to understand the

scale and extent of flooding now and

in the future, and set policies for

managing flood risk within the

catchment. CFMPs should be used to

inform planning and decision

making by key stakeholders such as:

• the Environment Agency, who will

use the plan to guide decisions

on investment in further plans,

projects or actions;

• Regional Assemblies and local

authorities who can use the plan

to inform spatial planning

activities and emergency

planning;

• Internal Drainage Boards (IDB),

water companies and other

utilities to help plan their

activities in the wider context of

the catchment;

• transportation planners;

• land owners, farmers and land

managers that manage and

operate land for agriculture,

conservation and amenity

purposes;

• the public and businesses to

enhance their understanding of

flood risk and how it will be

managed.


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

CFMPs aim to promote more

sustainable approaches to

managing flood risk. The policies

identified in the CFMP will be

delivered through a combination of

different approaches. Together with

our partners, we will implement

these approaches through a range

of delivery plans, projects and

actions. 

The relationship between the CFMP,

delivery plans, strategies, projects

and actions is shown in Figure 1. 

Policy planning

• CFMPs and Shoreline Management Plans.

• Action plans define requirement for delivery

plans, projects and actions.

Note: Some plans may not be led by us – we may identify the

need and encourage their development.

Policy delivery plans (see note)

• Influence spatial planning to reduce risk and

restore floodplains.

• Prepare for and manage floods (including local

Flood 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 numbers

of households at risk.




4   

Environment Agency

Tamar Catchment Flood Management Plan

The Tamar catchment lies between

the East Cornwall, North Devon and

South Devon CFMP areas. It drains

an area of 1,800 square kilometres

(700 square miles). The River Tamar

meets the sea at Plymouth Sound,

with the Tamar estuary extending

approximately 22km inland to

Gunnislake. 

The topography of the Tamar

catchment is varied.  The main

upland areas are west Dartmoor and

east Bodmin moor, from which the

Thrushel, Lyd, Tavy, Walkham, Plym,

Yealm, Ottery, Kensey and Inny rivers

spring. The remainder of the

catchment is made up of rolling

farmland, valleys and heaths. The

River Tamar itself originates from the

far northern part of the catchment, in

the hills close to the North Devon

coast. Annual rainfall ranges from

more than 2,000mm (80in) on the

edge of Dartmoor to less than

1,000mm (40in) on the coastal

Catchment overview 

lowlands. The England and Wales

average is 920mm (36in).

Granites make the upper catchment

relatively impervious which in turn

leads to the flashy nature of rivers

and their tributaries, often resulting

in water levels rising rapidly in a

short time. The lower areas have

sandstones and mudstones overlain

with alluvial silts and clays and

terrace deposits from rivers and sea.

The Tamar catchment is

environmentally rich with many

important environmental locations,

and some quality river systems.  The

area has a rich mining heritage with

the western edge of the catchment

included in the Cornish mining World

Heritage site. There are three Areas

of Outstanding Natural Beauty, five

Special Areas of Conservation (SAC),

one Special Protection Area (SPA), 61

Sites of Special Scientific Interest

(SSSIs) and 880 Scheduled

Monuments.

Most of the catchment is rural, with

only four per cent being urbanised.

However the principal urban centre is

Plymouth, which is the most

populous city in Devon and Cornwall.

Tavistock and Launceston are the

other major settlements within the

catchment, along with Saltash,

Plympton and Plymstock (which are

all within the housing market area of

Plymouth). Just over 341,000 people

live in the Tamar catchment. Over

250,000 of these are in the Plymouth

area.  


Granites make the upper catchment

relatively impervious which in turn

leads to the flashy nature of rivers

and their tributaries, often resulting

in water levels rising rapidly in a

short time.




Environment Agency

Tamar Catchment Flood Management Plan

5

Map 1. Location and extent of the Tamar CFMP area



© Crown Copyright. Environment Agency 100026380.

Legend


Tamar CFMP

Urban areas

Main rivers

Railway


Motorway

Camelford

Launceston

Tavistock

Bodmin

Callington



Horrabridge

Liskeard


Plymouth

Ivybridge

0 4 8 12 

16

Kilometres



Okehampton

Bude


Great

Torrington

N



Flooding from the River



Kensey at Newport in

Launceston in 1980  




6   

Environment Agency

Tamar Catchment Flood Management Plan

Current and future flood risk

There is a recorded history of

flooding within the Tamar catchment

that dates back to the 19th Century.

This is from a range of sources:

rivers, the estuaries, surface water

run-off and sewer systems.

More recent flooding incidents

include Launceston in December

1979, widespread flooding in

October 2000 and extreme flooding

in August 2004 at Canworthy Water.

The estuaries contribute to flood risk

in the Tamar catchment, making

flooding from the rivers worse when

high tides coincide with high

rainfall.  For example, in February

1974, very high tides in the Tamar

estuary caused areas of Calstock,

Cargreen, Morwellham, and

Millbrook to flood. 

While the numbers of properties at

risk across the Tamar catchment may

be relatively low compared with

other areas of the country, the risk to

life, and community disruption

caused by flooding can be just as

great. 

There are flood alleviation schemes



throughout the catchment that

reduce this flood risk. Over 90km of

defences provide varying levels of

protection.

Overview of the current flood risk

Today, this accounts for over 2,750

properties across the catchment at

potential risk of flooding from rivers

and the tide (excluding those behind

defences).

Also at risk are the police station at

Tavistock, the A30 and A374, the

mainline railway in at least three

locations, two schools, a nursery and

a health centre.

Furthermore, some designated

environmental sites are within the

floodplain or may be affected by

actions. These include Culm

Grasslands SAC and Dartmoor SAC,

and SSSIs such as Dunsdon Farm,

Otter Valley, Kernick and Ottery

Meadows, and Grimscott and

Lymsworthy Meadows.

What is at risk?

‘… More than three-quarters

being the heaviest shower I have

ever witnessed; the whole of the

lower part of the town

(Plymouth) was flooded.’ 

1871



Table 2. Critical infrastructure at risk:

7 electricity substations, 14 railway lines, 17 A roads, 1 water treatment works

Number of properties at risk

Locations

>1,000

Plymouth


500 to 1,000

None


100 to 500

Plympton, Tavistock, Launceston                          

50 to 100

None


25 to 50

Plymstock, Bridestowe, Saltash

Environment Agency

Tamar Catchment Flood Management Plan

7

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



© Crown Copyright. Environment Agency 100026380.

Legend


Properties with a 1%

chance of flooding

25 - 50

51 - 100


101 - 500

501 - 1,000

1,001 - 1,500

Tamar CFMP

Main rivers

Launceston

Tavistock

Plymouth


Plympton

0 4 8 12 

16

Kilometres



Plymstock

Bridestowe

Saltash

N

Table 1. Locations of towns and villages with 25 or more properties at risk in a 1% annual probability flood




8   

Environment Agency

Tamar Catchment Flood Management Plan

How we currently manage the risk

• Flood risk mapping – A major part

of the programme is Flood Zone

Improvements and Hazard

Mapping. This is focused on

improving the mapping at high-

risk locations.

• Managing development – Our

development control team

supports the planning process by

ensuring that new developments

have the appropriate flood risk

assessments and follow PPS25

(Government Planning Policy

Statement on Flood Risk).

• Flood warning – a multi-media

warning service called Floodline

Warnings Direct provides targeted

warnings to people via different

media methods, including

telephone, email and SMS text

messaging. We also provide a

public access telephone service

called Floodline that people can

ring to check if there is a flood

warning for their area. Major

Incident Plans are in place for

Launceston and Plympton and for

tidal flooding at the Barbican,

Plymouth.

• Flood defence schemes – We

have flood defence schemes at

Canworthy Water, Cawsand,

Gunnislake and Calstock,

Launceston, Notter Bridge,

Bathpool, Millbrook, Plympton,

Plymouth, Tavistock, Horrabridge,

Walkhampton, Yealmbridge and

Yealmpton.

• Maintenance – We maintain

channels and defences.

The distribution of potential flood

risk from rivers and tides is

illustrated in Map 2 for a flood with a

1% annual probability (0.5% for

tides) of occurring or being

exceeded.

The greatest concentration of

properties at risk of flooding is at

Plymouth and Plympton. Here some

1,510 properties are at risk from

river and tidal flooding. This is set to

increase due to rising sea levels.

Tavistock and Launceston have the

next highest concentrations in

property at risk with some 270 and

110 properties at risk respectively.

In addition to these locations, there

are risks of surface water flooding,

which can be deep and fast flowing,

across much of the catchment.

However, further studies following

on from the CFMP are needed by us

and our partners to quantify this

potential risk.

Where is the risk?

Minor roads near Launceston



impassable due to flooding


Environment Agency

Tamar Catchment Flood Management Plan

9

The impact of climate change and future flood risk



We have considered a range of

factors that could influence flood risk

over the next 100 years to find out

how flood risks could change in the

Tamar catchment.  We have found

that climate change has the greatest

influence on future flood risk,

increasing flooding from rivers and

the sea, as well as from sewers.

Land management also contributes,

because of the rural nature of the

catchment.

Urban development could affect

flood risk in a small number of

locations, including Plymouth,

Tavistock and Launceston.

Development in Plymouth in

particular may be significant with

investment and re-generation efforts

in existing waterfront areas. In

addition, a new town is planned at

Sherford, to the north-east of

Plymstock.  As with all new

development, the new town of

Sherford will need to be

implemented in accordance with

PPS25 to ensure that flood risks are

not increased.  

The following future scenario has

been used in the Tamar CFMP. 

• 20% increase in peak flow in all

watercourses due to climate

change.

• a total sea level rise of 900mm by



2100 due to climate change.

• 7% increase in river flows due to

land use change.

• 4% increase in river flows in

certain locations due to urban

development. 

0

500


1000

1500


2000

2500


Plymouth

Plympton


Tavistock

Launceston

Plymstock

Bridestowe

Current

Future


Number of

 Pr


oper

tie


s

 at


 Flood Ri

sk

Figure 2. Current and future (2100) flood risk to property from a 1% annual



probability river flood, ignoring current flood defences

In the future we expect flood extents

to increase slightly but this is limited

in most places by the topography of

the catchment. However flood

depths are likely to increase. This

means that more people and

property will be affected more

frequently by flooding in the future.

Plymouth is expected to see the

greatest flood risk in the future (see

Figure 2). 




10   

Environment Agency

Tamar Catchment Flood Management Plan

Approaches in each sub-area

We have divided the Tamar catchment into six distinct

sub-areas which have similar physical characteristics,

sources of flooding and level of  risk. We have identified

the most appropriate approach to managing flood risk for

each of the sub-areas and allocated one of six generic

flood risk management policies, shown in Table 2.

To select the most appropriate policy, the plan has

considered how social, economic and environmental

objectives are affected by flood risk management

activities under each policy option.

Map 3. Tamar sub-areas

Bude


Fowey

Bodmin


Totnes

Saltash


Plympton

Plymouth


Liskeard

Polzeath


Delabole

Torpoint


Ivybridge

Camelford

Plymstock

St Blazey

Tavistock

Ashburton

Callington

St Austell

Launceston

Okehampton

Mevagissey

Wadebridge

Kingsbridge

Horrabridge

Lostwithiel

St Columb Road

Great Torrington

Gunnislake

Tywardreath

© Crown Copyright. Environment Agency  100026380. 

0

4

8



12

16

Kilometres



N

Legend


Tamar CFMP

Sub-area

Upper Tamar (Policy 6)

Tidal Central (Policy 6)

Plymouth Area (Policy 5)

East Tamar (Policy 4)

Central Tamar (Policy 3)

West Tamar (Policy 3)

1

2

3

4

5

6

7

8

9

Future direction for 

flood risk management

A farmer tries to reach a bullock in floods at Polson Bridge,



Launceston in October 2000


Environment Agency

Tamar Catchment Flood Management Plan

11

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 defences

if we can use resources to reduce risk where there are more people at higher risk. We would therefore review

the 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 of

flooding 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 review

our approach to managing flood defences and other flood risk management actions, to ensure that we are

managing 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 we

may 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, but

where the risk of flooding is expected to significantly rise in the future. In this case we would need to do more

in the future to contain what would otherwise be increasing risk. Taking further action to reduce risk will require

further appraisal to assess whether there are socially and environmentally sustainable, technically viable and

economically 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 most

compelling, for example where there are many people at high risk, or where changes in the environment have

already increased risk. Taking further action to reduce risk will require additional appraisal to assess whether

there 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 in

locations 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 risk

locally or more widely in a catchment by storing water or managing run-off. The policy has been applied to

an area (where the potential to apply the policy exists), but would only be implemented in specific locations

within the area, after more detailed appraisal and consultation.

Table 3. Policy options 




12   

Environment Agency

Tamar Catchment Flood Management Plan

Upper Tamar

Sub-area 1

The issues in this 

sub-area 

The steeper rivers in this area react

fast to localised rainfall and

produce rapid increases in river

flows. This affects the  settlements

of Holsworthy, Bridgerule,

Bridestowe, Northcott Hamlet and

Canworthy Water. When combined

with areas of restricted natural

floodplain, fast flows build up at

these constrictions and cause

severe localised flooding.

The 1% annual probability flood

affects approximately 90 properties,

a church and limited areas of

environmental importance. It is

estimated that in the future, by

2100, an additional 20 properties

could lie within the 1% annual

probability flood extent. This is

mainly due to the impacts of

climate change.

Our key partners are:

West Devon District Council

Torridge District Council

Devon County Council

Cornwall Council

Dartmoor National Park

National Farmers Union

South West Forestry

The vision and 

preferred policy 



Policy Option 6 - we will take action

with others to store water or

manage run-off in locations that

provide overall flood risk reduction

or environmental benefits. 

This will reduce flood risk in

settlements and reduce the level of

risk in downstream areas. In

addition, this policy would benefit

the geomorphological processes of

the catchment and the natural

environment.  Care must be taken to

ensure that actions do not result in

the disturbance to various SSSI and

SAC habitats and features. 

Actions should concentrate on

floodplain attenuation

(connectivity) measures to benefit

the catchment downstream.  Land

management measures to minimise

run-off should also be targeted.

Proposed actions 

to implement the

preferred policy 

• Complete Systems Asset

Management Plans for existing

defences at the Tamar, Deer and

Claw confluence.  Consider the

potential to re-establish

floodplain and create wetland

habitat to reduce peak flows

downstream. Explore the

possibilities for flood attenuation

at Roadford Reservoir to reduce

peak flows at Lifton and Tinhay.

• Continue with work to identify

rapid response catchments. 

• Increase awareness of landowner

responsibility regarding land

ownership, maintenance and

surface water flooding across the

dispersed, isolated communities.

• Investigate the potential for

creating wetland habitat and

flood storage in existing

floodplains. For instance,

upstream of Canworthy Water.

• Increase woodland and forest

cover by diversifying farming and

involving the community in

promoting the development of

woodland on upper catchment

slopes.

Land use planners should designate



floodplains and wetland areas as

functional floodplain in order to

maximise their storage potential

and reduce risks downstream. This

will also avoid introduction of

further constrictions to flood flows.




Environment Agency

Tamar Catchment Flood Management Plan

13

Our key partners are:



West Devon District Council

South Hams District Council

Cornwall Council

Devon County Council

Natural England

South West Forestry

Landowners

National Farmers Union

Tidal Central

The issues in this 

sub-area 

Tidal Central covers the lower

section of the River Tamar. It

includes the villages of Calstock,

Morwellham and Bere Ferrers, as

well as part of Gunnislake.

At Morwellham flooding is largely a

result of high flows in the River

Tamar.  At Calstock it is due to a

combination of heavy rainfall and

high tides.  Above Gunnislake the

River Tamar flows within an incised

valley that naturally limits

floodplain storage and confines the

flow of floodwater.  Inundation can

also occur at periods of very high

spring tides.

There are several incidents of

surface water flooding recorded

across the area.

The 1% annual probability fluvial

flood (and 0.5% tidal) affects

approximately 50 properties. There

is one electricity substation at risk.

The number of properties at risk in

the future, as a result of the impact

of climate change has not yet been

assessed.  

The vision and 

preferred policy 



Policy Option 6 - we will take action

with others to store water or

manage run-off in locations that

provide overall flood risk reduction

or environmental benefits. 

The chosen policy  will play an

important role in absorbing the

impacts of sea level rise.

We would intend to review the

capabilities of existing defences at

locations such as Morwellham and

Calstock, to ensure we can maintain

flood risk at an acceptable level.

The policy can also support the

improvement and expansion of

existing wetland areas and

designated sites.

Proposed actions 

to implement the

preferred policy 

• Develop System Asset

Management Plans that will

reduce our level of maintenance

and will utilise the floodplains

more effectively.

• Investigate the possibility of

creating flood storage areas for

fluvial waters linking existing

limited floodplains within the

estuary.  

• Investigate potential for wetland

habitat creation through the

expansion of existing SSSI areas

and other appropriate wetland

areas within the Tamar estuary.

• Produce detailed studies for

Morwellham, Gunnislake and

Calstock to review capabilities of

current defences to cope with

combined high fluvial flow and

spring tides. 

• Review urban drainage capacity

at Metherell and look at

improving conveyance at times of

high flows to reduce and prevent

out of bank flows. 

Land use planners should designate

floodplains and wetland areas as

functional floodplain to protect and

enhance their storage potential.

Sub-area 2



14   

Environment Agency

Tamar Catchment Flood Management Plan

Plymouth Area

Sub-area 3

The issues in this 

sub-area 

The Plymouth Area covers sections

of the Plymouth Sound, Tamar and

Plym estuaries, and includes the

City of Plymouth. 

The City of Plymouth contains by far

the largest number of properties

within the Tamar catchment. The

city forms an important part of the

South West’s Regional Spatial

Strategy in providing new homes in

the future. Much of this

development may be around, or

adjacent to, the waterside areas.

Some of these areas of the city are

in the floodplain of the Tamar and

Plym estuaries. Infrastructure

around the city such as the A374

and mainline railway is also at risk.

Our key partners are:

Plymouth City Council

Cornwall Council

South Hams District Council

Devon County Council 

South West Water

Network Rail

Natural England

It is estimated that, for the sub-area

as a whole, 1,600 properties are at

risk of flooding within the fluvial 1%

(and tidal 0.5%) annual probability

flood area. The defences at these

and other areas affected by flooding

are regularly maintained and are in

good condition although a residual

flood risk remains. Approximately

500 properties are protected by

defence schemes at the Barbican

and Plympton.  

Surface water and sewer flooding

occurs due to surface water volumes

exceeding urban drainage system

capacity.

The number of properties at risk is

expected to increase to 2,800 by

2100 as a result of the impacts of

climate change and proposed

development planned within the

catchment.

The vision and 

preferred policy 

Policy Option 5 - we can generally

take further action to reduce flood

risk. 

This policy will support



sustainability objectives by

reducing the future increase in flood

risks to the urban environment

whilst avoiding significant adverse

impacts on the environment. The

benefits are most significant in

relation to the economy of the

urban centres.

Objectives relating to

geomorphology, biodiversity, and

landscape may be met, but this

depends on the response used to

manage flood risk.  However, it is

envisaged that sensitive and

appropriate approaches to

managing flood risk (through

incorporation of environmental

constraints during detailed

appraisal and design) could be

developed that do not cause

adverse impacts in the long term. 



Environment Agency

Tamar Catchment Flood Management Plan

15

Proposed actions to implement the preferred policy 



• Develop System Asset Management Plans to help reduce flood risk and investigate the need for, and

where necessary implement, Surface Water Management Plans for problem areas in Plymouth and

Plympton. 

• Produce detailed studies for Plymouth, Plympton, Plymstock, Tamerton Foliot, Saltash and Turnchapel to

review flow capacities, obstructions to high flows and to investigate upstream attenuation. 

• Use programmes to raise and maintain awareness of flood risk and self-help measures.

• Ensure development conforms to PPS25 and identify opportunities through the implementation of PPS25

to work with developers to reduce flood risk elsewhere in Plymouth area.  

• Investigate adaptation measures for the mainline railway and the A374 road against increased flooding

due to climate change. 

• Investigate opportunities to create green corridors alongside the rivers.

• Investigate opportunities for managed realignment to restore intertidal habitat along Plymouth waterfront

and estuaries.  

• Continue with work to identify rapid response catchments. 

• Review urban drainage capacity within Plymouth, Plympton and other major urban areas. Implement

findings and provide recommendations. 

• Implement strategies for flood risk management of the mine site identified at Plympton to assess the

potential pollution risk from flooding.




16   

Environment Agency

Tamar Catchment Flood Management Plan

East Tamar 

Sub-area 4

The issues in this 

sub-area 

The steeper rivers in this sub-area

react quickly to localised rainfall,

producing rapid increases in flows

that affects settlements such as

Tavistock, Horrabridge,

Walkhampton and Dousland.

Exposed estuarine locations (Newton

Ferrers/Noss Mayo) can be subject to

tidal flooding when high tides

coincide with heavy rainfall. There is

also a history of surface water

flooding in Tavistock due to the

inadequacy of urban drainage

systems.  

Our key partners are:

Devon County Council

West Devon District Council

South Hams District Council

Dartmoor National Park

Natural England

South West Water

It is estimated that 500 residential

properties, 3 electricity substations,

and a police station (in Tavistock) are

at risk of flooding from the 1%

annual probability flood.

Approximately 100 properties are

protected by defence schemes at

Dousland, Tavistock and

Walkhampton. The defences at these

settlements are regularly maintained

and are in good condition, although

a residual flood risk remains during

severe events.

In the future, Tavistock is expected to

see the greatest increase in the

number of properties at risk, with the

number increasing from 270 to 390. 

The vision and 

preferred policy 

Policy Option 4 - we are already

managing the flood risk effectively,

but we may need to take further

actions to keep pace with climate

change. 

The chosen policy was selected to

minimise potential social and

economic impacts from increased

flood risk in the future, whilst

avoiding potentially significant

environmental impacts.

Actions should concentrate on the

existing key settlements, but should

also include floodplain attenuation

(connectivity) measures to benefit

downstream areas.

Land management measures to

minimise run-off should also be

targeted.



Environment Agency

Tamar Catchment Flood Management Plan

17

Proposed actions to implement the preferred policy 



• Develop System Asset Management Plans to help reduce flood risk.

• Undertake studies for flood risk problem areas such as Tavistock, Horrabridge, Walkhampton, Milton

Combe, Yealmpton, Wembury and Newton Ferrers to review flow capacities, possible obstructions to high

flows, and to investigate upstream attenuation. 

• Continue with work to identify rapid response catchments.

• Support Local Authorities in the preparation of Local Development Framework Plans and associated

Strategic Flood Risk Assessments.

• Review urban drainage capacity within Tavistock particularly with regard to infill and new development to

find out where improvements can be made. 

• Investigate the potential for creating flood storage areas in the upper parts of the catchment by creating

wetland habitat that are linked to existing floodplains, providing benefits to the lower parts of the

catchment including Tavistock. 

• Review the possibility of more woodland and forest cover by diversifying farming and involving the

community in promoting the development of woodland. 

• Raise and maintain awareness of flood risk and self-help measures.

• Increase awareness of landowner responsibility regarding maintenance and surface water flooding across

the dispersed and possibly isolated communities.

The flooded River Yealm at Yeolmbridge in 1999




18   

Environment Agency

Tamar Catchment Flood Management Plan

Central Tamar

Sub-area 5

The issues in this 

sub-area 

Central Tamar covers sections of the

Rivers Kensey, Ottery, Carey,

Thrushel, Lyd and Tamar. It includes

the town of Launceston which is

situated within the flood plain of the

River Kensey upstream of the

confluences of the Rivers Kensey and

Tamar.  

Our key partners are:

Torridge District Council

West Devon District Council

Cornwall Council

Devon County Council

South West Water

Highways Agency

It is estimated that 140 properties

are at risk from the 1% annual

probability flood, with 100 of these

located in Launceston (as well as

other major infrastructure in the town

such as the A388) and 10 properties

in the villages of Lifton and Tinhay.

Flood defences reduce risks to 130

properties at Lifton/Tinhay, Luckett,

and Launceston (from both the River

Kensey and the Wooda Stream).  The

defences at these settlements are

regularly maintained and are in good

condition though a residual flood

risk remains during severe events. 

The number of properties at risk in

Launceston by 2100 will be in the

order of 125 as a result of the

impacts of climate change and

limited further development planned

within the catchment.

The vision and 

preferred policy 

Policy Option 3 - we are generally

managing existing flood risk

effectively. 

There are a limited number of

economic and social assets at risk

of infrequent flooding in the long-

term.  Whilst this policy will result in

the flood risk to these assets

increasing, the increased risk is not

considered to be significantly large

to justify increased levels of flood

risk management.

Actions in the Upper Tamar area

have the potential to reduce flood

risks in this area, which represents

a more effective response to flood

risk management as a whole.

The impacts of new development in

Launceston should be mitigated,

and overall flood risks reduced,

through the application of Planning

Policy Statement 25.




Environment Agency

Tamar Catchment Flood Management Plan

19

Proposed actions to implement the preferred policy 



• Review existing channel maintenance and defences, and deliver System Asset Management Plans. In the

long term, review the effectiveness of existing flood risk management at Lifton, Tinhay and Gunnislake,

through the production of the plans.

• Investigate potential for creating wetland habitat by creating flood storage areas linked to existing

floodplains in the northern half of the area. This could be beneficial in reducing peak flows in this area

and downstream.

• Continue with programmes to raise and maintain awareness of flood risk and self-help measures.

• Continue with work to identify rapid response catchments. 

• Support Local Authorities in the preparation of Local Development Framework Plans and associated

Strategic Flood Risk Assessments, including at least a level 2 assessment  for development in

Launceston. Consider possible land use changes to less sensitive uses.

• Review existing flood risk in Launceston particularly with regard to infill and new development.

• Promote opportunities for the Environment Agency and the Highways Agency to work together to

implement Sustainable Drainage Systems.




20   

Environment Agency

Tamar Catchment Flood Management Plan

West Tamar

Sub-area 6

The issues in this 

sub-area 

West Tamar covers the Rivers Inny

and Lynher and smaller rivers

draining to the Tamar. Flooding is

due to river, surface water, tidal and

tidal/wave action. 

• River flooding is experienced

throughout the area with

overtopping of defences and

structure blockage leading to

excessive surface water flow.

This flooding can occur rapidly

and is often very localised. 

• Exposed coastal locations

(Kingsand and Cawsand) and

estuarine locations (such as

Polbathic) experience tidal

flooding particularly at high

spring tides and have relatively

low standards of defence.

There are more than 270 properties

and one electricity substation at risk

of flooding. Of these, 16 properties

are defended by a scheme at

Millbrook. A section of the A374

between Polbathic and Sheviock is

also affected.

Our key partners are:

Cornwall Council 

South West Water

The number of properties at risk is

not expected to increase by 2100.

The expected annual damages are

predicted to change very little by

2100 as a result of the impacts of

climate change and limited further

development planned within the

catchment.

The vision and 

preferred policy



Policy Option 3 - we are generally

managing existing flood risk

effectively. 

The chosen policy allows us to

undertake work such as System

Asset Management Plans to review

the existing defence regimes.  It will

allow us to continue to manage the

flood risk into the future at locations

such as Altarnun and Millbrook -

accepting that there may be a slight

increase in flood risk in the longer

term but not committing large

expenditure to the development or

improvement of new flood defence

schemes.


This should provide benefits to

Plymouth by allowing more

resources to be concentrated in the

area of greater residential and

commercial development.

Additionally, the policy should avoid

adverse impacts upon

environmentally designated sites.

Proposed actions 

to implement the

preferred policy 

• Deliver System Asset

Management Plans based on

existing or alternative actions.

• Review flow capacities and

possible obstructions to high

flows at St Germans, Tideford,

and Polbathic. 

• Continue to use programmes to

raise and maintain awareness of

flood risk and self-help

measures.

• Increase awareness of landowner

responsibility regarding

maintenance and surface water

flooding across the dispersed,

isolated communities within this

policy area.

• Continue with work to identify

rapid response catchments.




Environment Agency

Tamar Catchment Flood Management Plan

21

Map of CFMP policies



Map of the policies in the Tamar catchment

© Crown Copyright. Environment Agency 100026380.

Legend

Tamar CFMP



Main rivers

Urban areas



Preferred approach

Policy 1


Policy 2

Policy 3


Policy 4

Policy 5


Policy 6

Lostwithiel

Camelford

Launceston

Tavistock

Bodmin


Callington

Horrabridge

Liskeard

Plymouth


Ivybridge

Okehampton

Bude

Great


Torrington

0 4 8 12 

16

Kilometres



Plympton

Plymstock

1

2

3



4

5

6



N

1

Upper Tamar 



2

Tidal Central  

3

Plymouth 



4

East Tamar 

5

Central Tamar



6

West  Tamar

The sub-areas



GESW0612BWPV-E-E

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