OCTOBER 2009

This Biodiversity Action Plan has been prepared by the Mildenhall Internal Drainage Board in accordance with the commitment in the Implementation Plan of the DEFRA Internal Drainage Board Review for IDBs to produce their own Biodiversity Action Plans by April, 2010.

It also demonstrates the Board’s commitment to fulfilling its duty as a public body under the Natural Environmental and Rural Communities Act 2006 to conserve biodiversity.

Many of the Board’s activities have benefits for biodiversity, not least its water level management and ditch maintenance work.  It is hoped that this Biodiversity Action Plan will help the Board to maximise the biodiversity benefits from its activities and demonstrate its contribution to the Government’s UK Biodiversity Action Plan targets.

The Board has adopted the Biodiversity Action Plan as one of its policies and is committed to its implementation.  It will review the plan periodically and update it as appropriate.

……………………………………………………………..             Date ………………………………………………..

C J Butcher
Chairman of the Board

This Biodiversity Action Plan is a public statement by the Board of its biodiversity objectives and the methods by which it intends to achieve them.

We would welcome appropriate involvement in the delivery of the Plan from interested organisations, companies and individuals.

You can contact us about this Biodiversity Action Plan by writing to the following address:

Mildenhall Internal Drainage Board
The Drainage Office
Main Street
Prickwillow
Ely
Suffolk
CB7 4UN

or by e-mail: jean@elydrainageboards.co.uk

CONTENTS

1                 IDB BIODIVERSITY – AN INTRODUCTION

1.1     Introduction
1.2     What is Biodiversity
1.3     The Importance of Conserving Biodiversity
1.4     The Biodiversity Action Planning Framework
1.5     Biodiversity – The International Context
1.6     Biodiversity – The National Context
1.7     Local Biodiversity Action Plans
1.8     Internal Drainage Boards and Biodiversity
1.9     The Aims of the IDB Biodiversity Action Plan

2                 THE IDB BAP PROCESS

2.1     The Biodiversity Audit
2.2     Evaluating and Prioritising Habitats and Species
2.3     Setting Objectives, Targets and Indicators
2.4     Implementation
2.5     Monitoring
2.6     Reporting and Reviewing Progress

3                 THE BIODIVERSITY AUDIT

3.1     Introduction
3.2     Local Biodiversity Action Plans
3.3     IDB Biodiversity Audit Boundary
3.4     Sources of Data – Habitats
3.5     Sources of Data – Species

4                 NATURE CONSERVATION SITES

4.1     The Drainage District
4.2     Geology
4.3     Landscape
4.4     Statutory Nature Conservation Sites
4.5     Non-statutory Local Sites

5                 HABITAT AUDIT

5.1     Habitat Audit Summary
5.2     Habitats of Importance for the IDB

6                 SPECIES AUDIT

6.1     Species Audit Summary
6.2     Species of Importance for the IDB

7                 HABITAT AND SPECIES ACTION PLANS

7.1     Habitat and Species Action Plans

8-13             HABITAT ACTION PLANS

14-16           SPECIES ACTION PLANS

17                PROCEDURAL ACTION PLAN

18                IMPLEMENTATION

18.1   Implementation
19.1   Monitoring

19               MONITORING

20               REVIEWING AND REPORTING PROGRESS

20.1   Reviewing and Reporting Progress

21                APPENDIX A

Table of BAP Priority Species

 

1          IDB BIODIVERSITY – AN INTRODUCTION

1.1     Introduction

The IDB has conducted a biodiversity audit of its district and identified those habitats and species that would benefit from particular management or actions by the IDB.  Using this information, which is presented in later sections, the IDB’s Biodiversity Action Plan has been developed.  The Plan identifies objectives for the conservation and enhancement of biodiversity within the drainage district, and goes on to describe targets and actions that will hopefully deliver these objectives.  The intention is to integrate, as appropriate, biodiversity into the Board’s activities, such as annual maintenance programmes and capital works projects.

The action plan will help to safeguard the biodiversity of the drainage district now and for future generations.  In particular, it is hoped that implementing the plan will contribute to the achievement of local and national targets for UK BAP priority species and habitats.  Species and habitats which are not listed in the UK BAP but may be locally significant for a variety of reasons have also been considered.

The Plan is an evolving document that will be reviewed and updated on a regular basis.  It covers the entire drainage district for the IDB, as shown on page 5.

 

Map of Mildenhall IDB

 

1.2     What is Biodiversity?

The Convention on Biodiversity agreed at the Earth Summit in Rio de Janeiro in 1992 defined biodiversity as:

“The variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems”.

Biodiversity can be defined simply as “the variety of life” and encompasses the whole spectrum of living organisms, including plants, birds, mammals and insects.  It includes both common and rare species, as well as the genetic diversity within species.  Biodiversity also refers to the habitats and ecosystems that support these species.

1.3     The Importance of Conserving Biodiversity

Biodiversity is a vital resource and it is essential to acknowledge its importance to our lives along with the range of benefits that it produces:

• Supply of ecosystem services – water, nutrients, climate change mitigation, pollination
• Life resources – food, medicine, energy and raw materials
• Improved health and well-being
• Landscape and cultural distinctiveness
• Direct economic benefits from biodiversity resources and ‘added value’ through local economic activity and tourism
• Educational, recreational and amenity resources

1.4     The Biodiversity Action Planning Framework

This IDB Biodiversity Action Plan is part of a much larger biodiversity framework that encompasses international, national and local levels of biodiversity action planning and conservation.

1.5     Biodiversity – The International Context

The international commitment to halt the worldwide loss of habitats and species and their genetic resources was agreed in 1992 at the United Nations Conference on the Environment and Development, commonly known as the Rio Earth Summit.  Over 150 countries, including the United Kingdom, signed the Convention on Biological Diversity, pledging to contribute to the conservation of biodiversity at the global level.  These states made a commitment to draw up national strategies to address the losses to global biodiversity and to resolve how economic development could go hand in hand with the maintenance of biodiversity.

The Rio Convention includes a global commitment to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level.  The 2002 World Summit in Johannesburg on Sustainable Development subsequently endorsed this target.

1.6     Biodiversity – The National Context

The UK Biodiversity Action Plan (UK BAP) is the UK commitment to Article 6A of the Rio Convention on Biological Diversity.  It describes the UK’s priority species and habitats, and seeks to benefit 65 priority habitats and 1149 species in total.  It identifies other key areas for action such as the building of partnerships for conserving biodiversity and gathering vital biodiversity data.

In England, Working with the Grain of Nature sets out the Government’s strategy for conserving and enhancing biological diversity, and establishes programmes of action for integrating biodiversity into policy and planning for key sectors, together with appropriate targets and indicators.  The Strategy has a Water and Wetlands Group and an associated programme of action that includes:

• Integrating biodiversity into whole-catchment management.
• Achieving net gain in water and wetland BAP priority habitats through Water Level Management Plans, Catchment Flood Management Plans, and sustainable flood management approaches.

1.7     Local Biodiversity Action Plans

For the UK Biodiversity Action Plan to be implemented successfully it requires some means of ensuring that the national strategy is translated into effective action at the local level.  The UK targets for the management, enhancement, restoration, and creation of habitats and species populations have therefore been translated into targets in Local Biodiversity Action Plans (LBAPs), which tend to operate at the county level.

1.8     Internal Drainage Boards and Biodiversity

The Natural Environment and Rural Communities Act 2006 places a duty on IDBs to conserve biodiversity.  As a public body, every IDB must have regard in exercising its functions, so far as is consistent with the proper exercise of those functions, to the purpose of conserving biodiversity.

The Act states that conserving biodiversity includes restoring or enhancing a population or habitat.  In so doing, an IDB should have regard to the list published by the Secretary of State of living organisms and types of habitat that are of principle importance for the purpose of conserving biodiversity.  In effect, this list comprises the Biodiversity Action Plan priority species and habitats for England.

In 2007, the Government’s IDB Review Implementation Plan established a commitment that IDBs should produce their own Biodiversity Action Plans.

This IDB Biodiversity Action Plan has been produced to help fulfil these requirements and seeks to set out targets and actions that complement the UK Biodiversity Action Plan and Local Biodiversity Action Plans.

1.9     The Aims of the IDB Biodiversity Action Plan

The aims of this IDB BAP are:

• To ensure that habitat and species targets from the UK Biodiversity Action Plan and the local LBAP are translated into effective action within the drainage district.
• To identify targets for other habitats and species of local importance within the drainage district.
• To develop effective local partnerships to ensure that programs for biodiversity conservation are maintained in the long term.
• To raise awareness within the IDB and locally of the need for biodiversity conservation, and to provide guidance to landowners, occupiers and their representatives on biodiversity and inland water management.
• To ensure that opportunities for conservation and enhancement of biodiversity are fully considered throughout the IDB’s operations, and
• To monitor and report on progress in biodiversity conservation.

2          THE IDB BAP PROCESS

2.1     The Biodiversity Audit

To produce this IDB Biodiversity Action Plan, information on the habitats and species present in the catchment was first obtained.  This “Biodiversity Audit” involved the collation of existing data held by the IDB and by other biodiversity partners.

2.2     Evaluating and Prioritising Habitats and Species

The Biodiversity Audit identified those priority habitats and species in the UK Biodiversity Action Plan and the Local Biodiversity Action Plan that can be found in the drainage district.  Additional non-BAP habitats and species deemed to be important within the drainage district were also identified.

Further habitats and species, together with additional targets and actions, may be added in the future, as knowledge is improved and delivery of the IDB BAP is reviewed.

A range of criteria was then used to select those species and habitats that are of particular importance to the IDB – that is to say, those habitats and species that could benefit from IDB actions.  The criteria used included their national and local status, the opportunities for effective IDB action and the resources available.

2.3     Setting Objectives, Targets and Indicators

For each habitat and species identified as being important to the IDB, conservation objectives and targets have been drawn up and set out in the Plan.  The objectives express the IDB’s broad aims for benefitting a particular habitat or species.  The related targets have been set to focus IDB programmes of action and to identify outcomes that can be monitored to measure achievement.  For each target an indicator has been set – a measurable feature of the target that, when monitored over time, allows delivery to be assessed.

In order for this BAP to be as effective as possible the targets and actions have been devised to be SMART (Specific, Measurable, Achievable, Relevant and Time-limited).  The targets are ambitious, but are also considered to be proportionate and practicable given the resources available.

Procedural targets and actions have also been considered.  These are targets that the Board will use to measure the way in which it considers and incorporates biodiversity across the whole range of its operations.  These may involve changes to administrative, management and operating procedures.

2.4     Implementation

Once targets have been set for habitats and species, it is important that the actions to deliver the Biodiversity Action Plan are described.  The Plan sets out how the Board intends to implement the actions in the plan, often in partnership with other organisations or individuals.

2.5     Monitoring

Achievement of the Plan targets will be measured by a programme of monitoring which the Board will undertake, in some instances with assistance from its partners, and the methods to be used are described in the Plan.

2.6     Reporting and Reviewing Progress

It is important to review the implementation of the BAP, assess changes in the status of habitats and species and the overall feasibility of objectives and targets.  In addition, it is vital that the successful achievement of targets is recorded and the gains for biodiversity registered in the public domain.

The Plan sets out the methods the IDB will be using to review the delivery of targets and to communicate progress to partner organisations and the public.

3          THE BIODIVERSITY AUDIT

3.1     Introduction

The following Sections 4, 5 and 6 summarise the results of the Biodiversity Audit, undertaken in 2009.  Section 4 provides information about the drainage district and a list of the nature conservation sites that occur within or bordering its boundaries.  Sections 5 and 6 list respectively the habitats and species occurring within the district that are of potential importance to the IDB.

3.2     Local Biodiversity Action Plans

The following Local Biodiversity Action Plan covers the IDB’s Drainage District:

• Suffolk Local Biodiversity Action Plan.

3.3     IDB Biodiversity Audit Boundary

The Biodiversity Audit covers the entire district of the IDB, as shown on page 5.  Where data has been obtained that shows a record of a species in a 1km square or 10km square which the district wholly or partially covers, this has been included in the area of the audit.

3.4     Sources of Data – Habitats

Information on habitats of relevance occurring within the drainage district was obtained from the following sources:

• UK list of Priority Habitats from http://www.ukbap.org.uk
• Protected and other species surveys of the drainage district undertaken by the Board.
• Suffolk Wildlife Trust – http://wildlifebcnp.org
• Suffolk Biological Records Centre

3.5     Sources of Data – Species

• Information on species of relevance occurring within the drainage district was obtained from the following sources:
• Protected and other species surveys of the drainage district undertaken by the Board.
• National Biodiversity Network (NBN) Gateway – http://www.searchbnp.net/
• Suffolk Wildlife Trust – http://www.wildlifebcnp.org
• Suffolk Biological Records Centre

Back to top

4          NATURE CONSERVATION SITES

4.1     The Drainage District

The Drainage District covers an area of 3,455 hectares and contains 53.4km of IDB maintained watercourses.  It is located in Suffolk and forms part of the “South Level Fens”.

4.2     Geology

The Pumping Station Basin consists of bodied black peat over silty clay.  As you move towards the edge of the Fen, topsoils of sandy drift and loamy chalk drift over the sand and chalk to the north and west at the District Boundary.

4.3     Landscape

4.3.1  Landscape Designations

There are no National Parks of Areas of Outstanding Natural Beauty (AONBs) within the Mildenhall Internal Drainage District.

4.3.2  Landscape Character

Natural England has divided the whole of England into a number of Joint Character Areas (JCA) based on characteristic landforms, wildlife and land use.  They are not designations and are not confined by traditional administrative boundaries.  For each JCA, Natural England has prepared a profile that characterises the wildlife and natural features, identifies the influences that act upon those features and set objectives for nature conservation.

The Mildenhall Internal Drainage District falls partly within the Fens JCA and partly within the Breckland JCA.

The Fens

The Fens JCA is a large-scale, flat, open landscape with extensive vistas to level horizons and huge skies.  A hierarchy of rivers, drains and ditches provides a strong influence throughout the area.  Embanked rivers and roddens create local enclosure and elevation.  Banks provide good grazing and grassland habitats.  Modestly elevated ‘islands’ within the Fens provide higher ground for most settlement.  A higher proportion of grassland, tree cover and hedgerows are associated with these areas.  Peaty Fens drained in the 17th century comprise of large rectilinear fields of black soil.  There is a geometric road and drainage pattern with major high-level drains, washes and associated pumping stations with road and rail links often on elevated banks.  Fragments of relic wet fen areas are situated at Wicken, Woodwalton and Holme. Marshes directly adjacent to the Wash exhibit an exceptionally open aspect, broken only by a series of sea walls with associated river outfall structures, tidal saltmarshes and mudflats.  Bronze Age, Iron Age and Roman landscapes are emerging from below the falling peat.  Very rich archaeology especially on fen margins.

Breckland

The Breckland JCA is a unique combination of underlying rocks, soils and semi-continental climate, with slightly undulating dry terrain contrasting with shallow, wooded river valleys.  It is a distinctive large-scale landscape of pale-coloured arable fields or open heath contrasting with vertical elements of pine lines, belts or forest with a strong geometry of large regular fields clearly defined by pine rows or neat thorn hedges, sometimes indicative of the continuity of large estates and long straight undulating roads.  There is a long history of settlement but is now very sparsely populated, with nucleated villages in river valleys and post-war London overspill development (Thetford, Brandon and Mildenhall).

4.4     Statutory Nature Conservation Sites

4.4.1  International Sites

The following internationally-designated conservation sites are found within the District:

Table 1.  International Designations

Site name	Designation	Features Relevant to IDB
Breckland	SPA/SAC	Rivers, ditches, water level management, wildlife and plants
Fenland	SAC	Rivers, ditches, water level management, wildlife and plants

4.4.2  National Sites

The following nationally-designated conservation sites are found within the District:

Table 2.  National Designations

Site name	Designation	Features Relevant to IDB
Wilde Street Meadows	SSSI	Rivers, ditches, water level management, wildlife and plants

4.4.3  Local Nature Reserves

There are no Local Nature Reserves designated by local authorities under Section 21 of the National Parks and Access to Countryside Act 1949 within the Mildenhall Drainage District.

4.5     Non-statutory Local Sites

A number of sites have been identified locally as being important for wildlife.  Whilst these designations do not have statutory status, the sites themselves are important for their contribution to biodiversity and planning policy requires that they are given consideration.  The following local sites are to be found within or bordering the Drainage District:

Table 4.  Non-statutory Designations

Site name	Designation	Features Relevant to IDB
Beck Row Golf Course	CWS	–
Aspal Park	CWS	–
Beck Row Churchyard	CWS	–

5          HABITAT AUDIT

5.1     Habitat Audit Summary

This habitat audit summary lists the broad habitat types and UK BAP priority habitats that occur within the Drainage District as identified by the information gathering exercise.  Also listed are habitats deemed to be of local importance and/or featured in the county Local Biodiversity Action Plan that occur in the Drainage District.  Habitats that are of potential importance for the IDB, where water level management or other IDB activities may be of benefit, are identified.  Finally, brief notes are included on the potential for the IDB to maintain, restore or expand its important habitats.

Table 5.  Habitat Audit Summary

Broad Habitat Types	UK BAP Priority Habitat	Local Biodiversity Action Plan Habitat	Habitat of Importance for IDB	IDB Potential for Maintaining, Restoring or Expanding Habitat
Arable Land	Arable Field Margins	Farmland: Arable farmland, arable field margins and improved grassland	Farmland Habitats	Encourage land managers to leave arable field margins.
N/A	N/A	Drainage ditches	Drainage ditches	Opportunities for improvements via changes in management regimes.
Rivers & streams	Rivers & streams	Rivers & streams	Rivers	Improvement to drainage ditch habitat.
Fen, marsh & swamp	Reedbed	Reedbed	Reedbed	Appropriate cutting and water level management.
Standing open waters	Eutropic standing waters	Ponds, lakes & reservoirs	Open water (Gravel pits, farm reservoirs)	Improvement to drainage ditch habitat.  Associated wildlife will use both open water and drainage ditches.
N/A	N/A	N/A	Scrub	Provision and maintenance of small areas of scrub near watercourse.

5.2     Habitats of Importance for the IDB

The following section provides more information on the status and location of the habitats within the Drainage District that are of importance for the IDB and may benefit from water level management or other IDB activities.

5.2.1  Farmland Habitats

Description:
The farmland countryside is important for biodiversity, providing nesting and feeding areas for game birds and passerines and habitats for arable flowers, butterflies and other invertebrates.  However, many species, particularly annual arable wildflowers and farmland birds, have declined over recent years and are now the focus of UK BAP Species Action Plans.  This decline in biological value has largely been due to production-orientated agricultural policies and technological advances.
However, certain habitats within the farmed landscape can still provide important refuges and corridors for wildlife.
Increasingly, many farmers are managing their land to create conditions which benefit key farmland species, without having serious detrimental effects on farm production.  Agri-environmental schemes help farmers deliver biodiversity conservation, for example, through set-aside areas, the retention of winters stubble and the use of buffer strips.
National status and local county status:
Agriculture occupies around 70% of land area in England.  However, its relative importance to the UK economy has been declining as a result of relatively slow growth in demand and improvements in productivity due to technical change.  Over recent years the area of farmland managed with wildlife in mind has increased due to the introduction of a range of agri-environmental schemes.
Arable field margins and ponds both have habitat action plans within the UK BAP.
Status and locations within the IDB District:
Arable farmland dominates the Mildenhall IDB Drainage District.  The majority of the District is under intensive arable cultivation, being dominated by large cultivated fields which are of relatively good quality.
Some areas adjacent to IDB drains have both Entry Level and Higher Level Environmental Stewardship Agreements.  Environmental Stewardship strips and grass strips can also be found in many places, acting as a buffer to activities within the fields.
Potential improvements:
Encourage land managers to maintain/leave arable field margins.

5.2.2  Drainage Ditches

Description:
Drainage ditches can vary in size from small roadside cuts to 30m wide agricultural drains which, connected together, comprise a large linear, mainly freshwater system.  The flow of water in Fenland Landscape Area ditches is typically slow moving and is artificially regulated.  However, some smaller drains can be dry, especially in summer.
National status and local county status:
Although an artificial habitat, drainage ditches and their associated banks are of high value for a broad range of wildlife.  Plants associated with ditches include emergent species such as arrow head Sagittaria sagittifolia and flowering rush Butomus umbellatus, submerged species such as the hornwart Ceratophyllum demersum and floating species such as frog-bit Hydrocharis morsus-ranae.  Ditches and their banks can also shelter many plant and animal species, including water vole, breeding birds, grass snake and a wide variety of invertebrates, some specific to drainage ditches.
Rare species associated with drainage ditches include the Nationally Scarce species Marsh sow-thistle Sonchus palustris, Fen pondweed Potamogeton coloratus, Fen ragwort Senecio paludosus (Red list: Critically Endangered), Hair-like pondweed Potamogeton trichoides, Whorled water-milfoil Myriophyllum verticillatum, Fringed water-lily Nymphoides peltata, Greater water-parsnip Sium latifolium, the stoneworts Nitella tenuissima (Red List: Endangered) and Tolypella prolifera (Red List: Vunerable), the snails Pseudanodonata complanata, Pisidium pseudosphaerium (Red List: Rare) and Valvata macrostoma (Red List: Vunerable), the hairy dragonfly Brachytron pratense, the aquatic beetle Donacia dentata, the weevil Bagous subcarinatus, the relic fen diving beetle Agabus undulates and the spined loach Cobitis taenia.
Status and locations within the IDB District:
This is the key habitat influenced by the Mildenhall IDB.  Within the area covered by this BAP, the smallest drainage ditches are managed by private landowners, many of whom will be known to the IDB, and the rest are directly managed by an IDB.
Potential improvements:
Improvements to species diversity must be made without compromising the drainage function of the ditch system.  There are opportunities for improvements via changes in management regimes as well as actions to benefit specific species.  The drainage ditches form an inter-connected wetland habitat network with the potential to support a wide range of threatened and common species and to provide habitat connections between important wetland habitats.

5.2.3  Rivers

Description:
In their natural state rivers are dynamic systems, continually modifying their form.  However in many cases their ability to rejuvenate and create new habitat has been reduced or arrested by flood defence structures and impoundments.  Rivers and streams often provide a wildlife corridor link between fragmented habitats in intensively farmed areas.
National status and local county status:
Rivers and streams are one of the most intensively used semi-natural habitats in the UK.  They convey floodwaters, accept discharges from roads, sewage treatment works and industry; provide water for human consumption, agricultural and industrial use; and are used as a recreational resource for popular activities such as angling, boating and walking.  The plant and animal assemblages of rivers and streams vary according to their geographical area, underlying geology and water quality.  Lowland, nutrient rich systems as found in Suffolk are dominated by higher plants, and coarse fish such as chub, dace and roach.
Status and location within the IDB District:
The major rivers adjacent to the District (managed by the Environment Agency) are the River Lark and Cut-Off Channel.
Potential improvements:
While main rivers are managed by the Environment Agency, watercourses managed by Mildenhall IDB are pumped into main rivers and so have an impact on river habitat.  Improvements to drainage ditch habitat are likely to contribute to improvements in biodiversity on main rivers.

5.2.4  Reedbed

Description:
Reedbeds are wetlands dominated by stands of the reed Phragmites australis, where the water table is at or above ground level for most of the year.
National status and local county status:
Reedbed is one of the rarest habitat types in Britain, with a total area of only about 6,500ha, most of which is highly fragmented.  Reedbeds support a diverse fauna, including 6 nationally rare Red Data Book bird species (including Bittern, bearded tit and marsh harrier).  5GB Red Data Book invertebrates are closely tied to this habitat (including reed leopard moth and swallowtail butterfly).  Reedbeds are often associated with other habitats such as open water, grazing marsh and carr woodland.
Many of the UK’s most important weedbed sites are on the coast where they are at threat from loss through coastal erosion and deterioration through saline incursion.  Suffolk already holds areas of weedbeds, and has significant potential for expanding these or creating new reedbeds, so the county may become very important for the proportion of the national resource in future years.  Species that depend on the coastal lying reedbeds such as bitterns, need to find feeding and breeding habitat further inland to ensure their survival.
Status and location within the IDB District:
Drainage ditches hold an unknown amount of this habitat.  The importance of linear reedbeds is often understated.
Potential improvements:
Reedbeds require appropriate cutting and water level management.  The Mildenhall IDB are responsible for reed areas in drainage ditches and are also key partners in water level management for reedbeds in other ditches.

5.2.5  Open Water

Description:
Eutrophic open water is characterised by having dense populations of algae in mid-summer and beds covered by dark anaerobic mud, rich in organic matter.  The water column contains concentrations of phosphorus and nitrates, often in excessive quantities when the water-body is said to be hyper-eutrophic.  The LBAP covers water bodies of all sizes, from ephemeral ponds to large lakes.
National status and local county status:
There is currently limited information available about open water sites in Suffolk in terms of their conservation status, water quality and importance for biodiversity.  Very little survey of the deep water areas has been carried out, and it is possible that the deep waters of lakes contain populations of rare stoneworts.  Collecting further information is the key action for this habitat.  Open water is an important habitat for water birds, which may be supported in nationally important numbers, especially where there are many water bodies close together.
Status and location with the IDB District:
IDB Designated Main Drains have large areas of open water.  Less is known about the status and distribution of ponds.  A network of nearby ponds and lakes will support a greater diversity of wildlife than an isolated pond.
Potential improvements:
Even if a lake is not within the control of a drainage board, the associated wildlife will also use nearby drainage ditches, which must be taken into account during ditch management.

5.2.6  Scrub

Description:
The term ‘scrub’ encompasses a variety of habitats.  These habitats are often divided into ‘scattered’ and ‘continuous/dense’ scrub, the former characterised by hawthorn, blackthorn or bramble and the latter by a wide range of woody species.  Often it is important to control scrub where it spreads onto high quality habitats such as lowland meadows.  However, scrub is very important as a transitional habitat and as part of habitat mosaics given that it supports large numbers of species of animals listed in the UK Biodiversity Action Plan.  Many birds feed in the open, but near enough to scrub to be able to find refuge if danger threatens.  In addition, scattered scrub in open sites is often very significant for nest sites and song-posts.
National status and local county status:
Scrub is not a BAP habitat and has not been thoroughly recorded nationally or locally.  It is a key habitat for many species and forms an essential part of habitat mosaics.
Status and locations within the IDB District:
Scrub is vital for nesting birds such as yellowhammer, linnet and corn bunting.  Larger areas may support cuckoo and turtle dove.  Scrub also supports a range of insects and small mammals, providing hunting grounds for birds of prey.  Even small areas of dense scrub can provide lying up sites for otter.
Potential improvements
Provision and maintenance of small areas of scrub near watercourses, with varying age structures, significantly benefits the biodiversity of the watercourse.

6          SPECIES AUDIT

6.1     Species Audit Summary

Appendix A lists all the BAP priority species that occur within the Mildenhall IDB District as identified by the information gathering exercise.  Also listed are species deemed to be of local importance and/or identified in the county Local Biodiversity Action Plan that occur in the Mildenhall IDB District.  This species audit summary lists species that are of potential importance for the Mildenhall IDB, where water level management or other IDB activities may be of benefit.  Finally, brief notes are included on the potential for the Mildenhall IDB to maintain or increase the population or range of species of importance.

Table 6.  Species Audit Summary

Common Name	Group	Order	Scientific Name	UK BAP Priority Species	Local Biodiversity Action Plan(s) Species (S) Suffolk	Non-BAP Species but important in Mildenhall District	Reason for importance to Mildenhall District
Water vole	Terrestrial Mammals	Terrestrial Mammal	Arvicola terrestris	Yes	Yes (S)	–	Lives largely along ditch banks; ditch management has significant impact on local populations.
Otter	Terrestrial Mammals	Terrestrial mammal	Lutra lutra	Yes	Yes (S)	–	Potential to improve habitat to benefit otters, for example by putting in holts and bridge ledges.
Barn Owl	Birds	Bird	Tyto alba	No	No (S)	Yes	Barn owls have extensive foraging habitat but limited opportunity for nesting.  Potential for putting up and monitoring nest boxes.

6.2     Species of Importance for the IDB

The following section provides more information on the status and location of the species within the Drainage District that are of importance for the IDB and may benefit from water level management or other IDB activities.

6.2.1  Water vole

Description:
As of 2008, the water vole is protected under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended).  It is illegal to kill, injure or take water voles or to damage or destroy their resting place.
National status and local status:
The water vole is found throughout Britain but is confined mainly to lowland areas near water.  Once common and widespread, this species has suffered a significant decline in numbers and distribution.  A recent population estimated based on the number of latrines found suggested a total GB pre-breeding population of 1,200,000 animals.
Status and locations with the Mildenhall District:
A large proportion of drainage ditches within the Mildenhall District support populations of water vole.  Where intensive studies have been undertaken, water voles have been recorded in approximately 58% of ditches surveyed.  (A total of 89% of the Board’s drains have been surveyed to date).  The area as a whole forms a significant regional (and possibly national) stronghold for this threatened species.  Mink predation is a threat but it may be that the amount of habitat and the complex connections within the ditch system has allowed water voles to survive.
Potential improvements:
Most of the water vole habitat is under the management of Mildenhall IDB or local landowners.  Ditch management may have a major impact on water vole populations and require care and following good practice to conserve and encourage populations as well as to stay within the law.  Water vole is probably the most important species to be considered by Mildenhall IDB.  Controlling mink will also encourage populations to thrive.

6.2.2  Otter

Description:
The otter is listed on Appendix 1 of CITES, Appendix II of the Bern Convention and Annexes II and IV of the Habitats Directive.  It is protected under Schedule 5 of the Wildlife and Countryside Act 1981.  It is illegal to kill, injure or take otters or to damage or destroy their resting place.
National status and local status:
Formerly widespread throughout the UK, the otter underwent a rapid decline in numbers from the 1950s to 1970s and was effectively lost from midland and south-eastern counties of England by the 1980s.  The decline now appears to have halted and sightings are being reported in former habitats.  Otters now use all major watercourses in Suffolk and populations appear to be recovering.
Status and locations with the Mildenhall District:
Unknown.
Potential improvements:
Providing holts and lying-up habitats is likely to be of great benefit to otters.  Ledges under bridges will make monitoring easier and may also encourage otters to use the waterways at times of high flow.

6.2.3  Barn Owl

Description:
Barn owls are protected under Schedule 1 of the Wildlife and Countryside Act 1981.  It is an offence to take, injure or kill a barn owl or to take, damage or destroy its nest, eggs or young.
National status and local status:
Widely distributed across the UK, and indeed the world, barn owl has suffered declines over the past fifty years as intensive agricultural practices cause degradation of once prey-rich habitats.  This decline, fortunately, has halted in many areas and the population may now be increasing.
Status and locations within the Mildenhall District:
The Mildenhall District supports a significant population of barn owls, which use ditch banks for foraging.  The population may be limited by lack of nest sites.
Potential improvements:
Provide nest boxes and improve foraging habitat in the area of nest box sites.

7          HABITAT AND SPECIES ACTION PLANS

7.1     Habitat and Species Action Plans

The following sections contain action plans for each of the habitats and species that have been prioritised for action by the IDB.  The plans set out the objectives, targets and actions that the IDB believes are appropriate for each.  These plans will be reviewed and updated periodically.

7.2     Action Plans for the Mildenhall IDB

7.2.1  Habitat Action Plans

The following Habitat Action Plans are included for Mildenhall Drainage District:

• Farmland Habitats
• Drainage Ditches
• Rivers
• Reedbed
• Open Water
• Scrub

7.2.2  Species Action Plans

The following Species Action Plans are included for Mildenhall Drainage District:

• Water vole
• Otter
• Barn owl

7.2.3  Procedural Action Plans

• Promote best practice in all water level management works.
• Control of culverting.
• Training of plant operatives in appropriate ditch/habitat management.

8          HABITAT ACTION PLAN – FARMLAND HABITATS

8.1   Introduction

The farmland countryside is important for biodiversity, providing nesting and feeding areas for game birds and passerines and habitats for arable flowers, butterflies and other invertebrates.  However, many species, particularly annual arable wildflowers and farmland birds, have declined over recent years and are now the focus of UK BAP Species Action Plans.  This decline in biological value has largely been due to production-orientated agricultural policies and technological advances.
However, certain habitats within the farmed landscape can still provide important refuges and corridors for wildlife.
Increasingly, many farmers are managing their land to create conditions which benefit key farmland species, without having serious detrimental effects on farm production.  Agri-environmental schemes help farmers deliver biodiversity conservation, for example, through set-aside areas, the retention of winters stubble and the use of buffer strips.

8.2   UK Status and Regional Status

Agriculture occupies around 70% of land area in England.  However, its relative importance to the UK economy has been declining as a result of relatively slow growth in demand and improvements in productivity due to technical change.  Over recent years the area of farmland managed with wildlife in mind has increased due to the introduction of a range of agri-environmental schemes.
Arable field margins and ponds both have habitat action plans within the UK BAP.

8.3   Local Status

Arable farmland dominates the Mildenhall IDB Drainage District.  The majority of the District is under intensive arable cultivation, being dominated by large cultivated fields which are of relatively good quality.
Some areas adjacent to IDB drains have both Entry Level and Higher Level Environmental Stewardship Agreements.  Environmental Stewardship strips and grass strips can also be found in many places, acting as a buffer to activities within the fields.

8.4   Current Factors Causing Loss and Decline

The current threats to farmland habitats in the Mildenhall Drainage District can include:-

• Intensification of cereal production, including the use of herbicides to ensure a weed free monoculture and summer use of insecticides.
• The shift to winter cropping and the associated loss of winter stubbles.
• The reduction in rotation of cereal crops with other land covers (including grass leys and fallows).
• The reduction in the undersown area associated with the shift to winter cropping.  Undersown cereal crops are important for over-wintering sawflies.
• The influence of European Agricultural policy through the Common Agricultural Policy (CAP) which directs how farmers can work the land.
• Land drainage and flood defence operations, specifically deposition of cut vegetation and silts on field margins.
• Neglect and poor management.
• Nutrient enrichment from agricultural run-off.

8.5   Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1	Manage water levels and flood risk to the benefit of agricultural land within the Drainage District	1.2	Consider changes in water level regime upon specific requests from landowners	All occupiers within the district	Ongoing throughout life of plan	Plan production	When required
2	Encourage the enhancement of the farmland habitats for the benefit of wildlife	2.1	Encourage the use of buffer strips adjacent to watercourses in the Drainage District	All occupiers within the district	Ongoing	Length of new growth (m)	Annually
		2.2	Promote the uptake of Environmental Stewardship schemes within the Drainage District	All occupiers within the district	Ongoing	Report number	Annually
		2.3	Investigate the possibility of managing any land currently out of production	All occupiers within the district	Ongoing	Report number	Upon completion
		2.4	Identify any potential areas in the Drainage District that offer significant biodiversity value	All occupiers within the district	Ongoing	Report number	Annually

8.6   Associated Species

Key species associated with the habitat action plan for farmland habitats include:

• Farmland birds
• Woodland birds

9          HABITAT ACTION PLAN – DRAINAGE DITCHES

9.1   Introduction

Drainage ditches can vary in size from small roadside cuts to 30m wide agricultural drains which, connected together, comprise a large linear, mainly freshwater system.  The flow of water in Fenland Landscape Area ditches is typically slow moving and is artificially regulated.  However, some smaller drains can be dry, especially in summer.

9.2   UK Status and Regional Status

Although an artificial habitat, drainage ditches and their associated banks are of high value for a broad range of wildlife.  Plants associated with ditches include emergent species such as arrow head Sagittaria sagittifolia and flowering rush Butomus umbellatus, submerged species such as the hornwart Ceratophyllum demersum and floating species such as frog-bit Hydrocharis morsus-ranae.  Ditches and their banks can also shelter many plant and animal species, including water vole, breeding birds, grass snake and a wide variety of invertebrates, some specific to drainage ditches.
Rare species associated with drainage ditches include the Nationally Scarce species Marsh sow-thistle Sonchus palustris, Fen pondweed Potamogeton coloratus, Fen ragwort Senecio paludosus (Red list: Critically Endangered), Hair-like pondweed Potamogeton trichoides, Whorled water-milfoil Myriophyllum verticillatum, Fringed water-lily Nymphoides peltata, Greater water-parsnip Sium latifolium, the stoneworts Nitella tenuissima (Red List: Endangered) and Tolypella prolifera (Red List: Vunerable), the snails Pseudanodonata complanata, Pisidium pseudosphaerium (Red List: Rare) and Valvata macrostoma (Red List: Vunerable), the hairy dragonfly Brachytron pratense, the aquatic beetle Donacia dentata, the weevil Bagous subcarinatus, the relic fen diving beetle Agabus undulates and the spined loach Cobitis taenia.

9.3   Local Status

This is the key habitat influenced by the Mildenhall IDB.  Within the area covered by this BAP, a few large watercourses are managed by the Environment Agency, the smallest drainage ditches are managed by private landowners, many of whom will be known to the IDB, and the rest are directly managed by an IDB.

9.4   Current Factors Causing Loss and Decline

Mildenhall Drainage District drainage ditch habitat loss and decline can be brought about by:-

• Agricultural intensification of surrounding land, particularly use of fertilizers, herbicides and insecticides.  These can leach into the watercourse.
• Inappropriate cleaning and unsympathetic profiling of ditches and cutting of bank side vegetation.
• Filling in of ditches for agricultural land gain.
• Water abstraction, particularly for summer irrigation.
• Inappropriate regulation of water flow within the ditch system.
• In some cases, overgrowth of willow scrub or reed can reduce the overall wildlife value of a ditch although these successional habitats are of notable value for some invertebrates and birds such as the reed bunting.
• Lowering of the summer water table through abstraction and climatic change.
• In some cases, loss of traditional bank side cattle grazing and puddling has lowered the value of some drainage ditches for specialist invertebrates.
• New housing at settlement edges can result in the loss of local watercourses (through culverting etc).
• Uniformity of management over large areas simultaneously can reduce habitat diversity.
• Threats from introduced species (i.e. mink, Elodea species and Crassula helmsii).

9.5   Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1	Maintain and enhance the existing habitat and species diversity of the Drainage District, including the fish population	1.1	Prepare a list of habitat quality ‘indictor’ species to assess the health of the watercourses	Wildlife Trust	2009	List production	Upon completion
		1.2	Set up a survey and monitoring programme for key ‘indicator’ species	Wildlife Trust	Ongoing	Length (m) of channel surveyed	Annually
		1.3	Identify and assess potential impacts of all new discharges into watercourses	–	Ongoing	Number of consents issued	Annually
2	Enhance the habitat of other watercourses within the Drainage District	2.1	Produce guidance and provide advice to riparian owners within the Drainage District	Wildlife Trust	Ongoing	Number of owners advised	Annually
		2.2	Ensure any IDB consents cause minimum environmental damage to the aquatic habitat	–	Ongoing	Number of consents issued	Annually
3	Control non-native invasive species along watercourses	3.1	Record and monitor non-native invasive plants and animals	Environment Agency	2010	Length (m) of channel surveyed	Annually
		3.2	Control stands of invasive plants annually, as recorded	Environment Agency	As required	Area treated (m²)	When required
		3.3	Undertake control of non-native animals as required (e.g. Mink)	Landowners	As required	Number controlled	When required

9.6   Associated Species

Key species associated with the habitat action plan for drainage ditches include:

• Water Vole Arvicola terrestris (Species Action Plan)
• Otter Lutra lutra (Species Action Plan)
• Kingfisher Alcedo atthis
  • European Eeel Anguilla Anguilla

Back to top

10           HABITAT ACTION PLAN – RIVERS

10.1 Introduction

In their natural state rivers are dynamic systems, continually modifying their form.  However in many cases their ability to rejuvenate and create new habitat has been reduced or arrested by flood defence structures and impoundments.  Rivers and streams often provide a wildlife corridor link between fragmented habitats in intensively farmed areas.

10.2 UK Status and Regional Status

Rivers and streams are one of the most intensively used semi-natural habitats in the UK.  They convey floodwaters, accept discharges from roads, sewage treatment works and industry; provide water for human consumption, agricultural and industrial use; and are used as a recreational resource for popular activities such as angling, boating and walking.  The plant and animal assemblages of rivers and streams vary according to their geographical area, underlying geology and water quality.  Lowland, nutrient rich systems as found in Suffolk are dominated by higher plants, and coarse fish such as chub, dace and roach.

10.3 Local Status

The major rivers adjacent to the District (managed by the Environment Agency) are the River Lark and Cut-Off Channel.

10.4 Current Factors Causing Loss and Decline

Mildenhall Drainage District river habitat loss and decline can be brought about by:-

• Pollution including eutrophiation and acidification.
• Excessive ground water and surface water abstraction.
• Construction of dams and reservoirs.
• Water transfer schemes between rivers.
• Land drainage and flood defence works which if not sensitively carried out, can reduce stream habitat and isolate streams from their floodplains.
• Inappropriate bank management, including overgrazing.
• Introduction of invasive plant species and animal species.

10.5 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1.	Maintain water quality within river system	1.1	Inspect outfall for water quality, siltation and flow	Environment Agency	Ongoing	Number of inspections	Annually

10.6 Associated Species

Key species associated with the habitat action plan for rivers include:

• Water Vole Arvicola terrestris (Species Action Plan)
• Otter Lutra lutra (Species Action Plan)
• Kingfisher Alcedo atthis
• European Eel Anguilla anguilla

Back to top

11         HABITAT ACTION PLAN – REEDBED

11.1 Introduction

Reedbeds are wetlands dominated by stands of the reed Phragmites australis, where the water table is at or above ground level for most of the year.

11.2 UK Status and Regional Status

Reedbed is one of the rarest habitat types in Britain, with a total area of only about 6,500ha, most of which is highly fragmented.  Reedbeds support a diverse fauna, including 6 nationally rare Red Data Book bird species (including Bittern, bearded tit and marsh harrier).  5GB Red Data Book invertebrates are closely tied to this habitat (including reed leopard moth and swallowtail butterfly).  Reedbeds are often associated with other habitats such as open water, grazing marsh and carr woodland.
Many of the UK’s most important weedbed sites are on the coast where they are at threat from loss through coastal erosion and deterioration through saline incursion.  Suffolk already holds areas of weedbeds, and has significant potential for expanding these or creating new reedbeds, so the county may become very important for the proportion of the national resource in future years.  Species that depend on the coastal lying reedbeds such as bitterns, need to find feeding and breeding habitat further inland to ensure their survival.

11.3 Local Status

Drainage ditches hold an unknown amount of this habitat.  The importance of linear reedbeds is often understated.

11.4 Current Factors Causing Loss and Decline

Mildenhall Drainage District reedbed habitat loss and decline can be brought about by:-

• Small total area of habitat and critically small population sizes of several key species dependent on the habitat.
• Loss of area by excessive water extraction and in the past, land drainage and conversion to intensive agriculture.
• Lack of or inappropriate management of existing reedbeds leading to drying, scrub encroachment and succession to woodland.
• Pollution of water supplies to the reedbed: siltation may lead to drying; toxic chemicals may lead to loss of fish and amphibian prey for key species; accumulation of poisons in the food chain and eutrophication may cause reed death.

11.5 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1.	Promote the creation of reedbeds and promote the creation of large reedbeds on other suitable land.	1.1	Support the enlargement of existing reedbeds and seek sites suitable for the creation of further reedbeds.	Wildlife Trust	Ongoing	Area (m²) of new habitat created	Annually
2.	Monitor and record key species for these habitats in the county.	2.1	Identify key species and their locations.	Landowners Wildlife Trust	Ongoing	Number of inspections	Annually
3.	Ensure that advice on habitat creation is available and is promoted to landowners.	3.1	Produce and promote literature/information.	Wildlife Trust	Ongoing	Number of landowners informed	Annually
4.	Increase public awareness of the importance of and threats to this habitat.	4.1	Promote and produce literature to encourage the conservation and sensitive management of this habitat.	Wildlife Trust	Ongoing	Amount of public informed	Annually

11.6 Associated Species

Key species associated with the habitat action plan for reedbed include:

• Farmland birds

12         HABITAT ACTION PLAN – OPEN WATER

12.1 Introduction

Eutrophic open water is characterised by having dense populations of algae in mid-summer and beds covered by dark anaerobic mud, rich in organic matter.  The water column contains concentrations of phosphorus and nitrates, often in excessive quantities when the water-body is said to be hyper-eutrophic.  The LBAP covers water bodies of all sizes, from ephemeral ponds to large lakes.

12.2 UK Status and Regional Status

There is currently limited information available about open water sites in Suffolk in terms of their conservation status, water quality and importance for biodiversity.  Very little survey of the deep water areas has been carried out, and it is possible that the deep waters of lakes contain populations of rare stoneworts.  Collecting further information is the key action for this habitat.  Open water is an important habitat for water birds, which may be supported in nationally important numbers, especially where there are many water bodies close together.

12.3 Local Status

IDB Designated Main Drains have large areas of open water.  Less is known about the status and distribution of ponds.  A network of nearby ponds and lakes will support a greater diversity of wildlife than an isolated pond.

12.4 Current Factors Causing Loss and Decline

Mildenhall Drainage District open water habitat loss and decline can be brought about by:-

• Weedgrowth.
• Siltation.
• Reduction in water levels.
• Drought.

12.5 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1.	Maintain and enhance water quality throughout the Drainage District.	1.1	Set appropriate water quality standards, monitor and enforce.	–	Ongoing	Number of inspections	Annually
2.	Restoration of water bodies lost as a result of development.  The nature conservation value of water bodies should not be diminished as a result of development.	2.1	Ensure developers are made aware of the importance of ponds.  Discuss protection, mitigation and conservation of ponds on development sites at planning application stage.	East Cambs. District Council Planning Dept. Developers	Ongoing	Number of developers informed	Annually
3.	Gain a good understanding of extent, status and distribution of all open water bodies in the Drainage District.	3.1	Collate and interpret current data.  Identify gaps in current knowledge and commission surveys as appropriate.	–	Ongoing	Amount of information collected	Annually

12.6 Associated Species

Key species associated with the habitat action plan for open water include:

• Water Vole Arvicola terrestris (Species Action Plan)
• Otter Lutra lutra (Species Action Plan)
• Kingfisher Alcedo atthis

Back to top

13         HABITAT ACTION PLAN – SCRUB

13.1 Introduction

The term ‘scrub’ encompasses a variety of habitats.  These habitats are often divided into ‘scattered’ and ‘continuous/dense’ scrub, the former characterised by hawthorn, blackthorn or bramble and the latter by a wide range of woody species.  Often it is important to control scrub where it spreads onto high quality habitats such as lowland meadows.  However, scrub is very important as a transitional habitat and as part of habitat mosaics given that it supports large numbers of species of animals listed in the UK Biodiversity Action Plan.  Many birds feed in the open, but near enough to scrub to be able to find refuge if danger threatens.  In addition, scattered scrub in open sites is often very significant for nest sites and song-posts.

13.2 UK Status and Regional Status

Scrub is not a BAP habitat and has not been thoroughly recorded nationally or locally.  It is a key habitat for many species and forms an essential part of habitat mosaics.

13.3 Local Status

Scrub is vital for nesting birds such as yellowhammer, linnet and corn bunting.  Larger areas may support cuckoo and turtle dove.  Scrub also supports a range of insects and small mammals, providing hunting grounds for birds of prey.  Even small areas of dense scrub can provide lying up sites for otter.

13.4 Current Factors Causing Loss and Decline

Mildenhall Drainage District scrub habitat loss and decline is brought about by:-

• Development pressure.
• Not managed appropriately – either over-managed or neglected.
• Excessive clearance.
• Fires/arson.
• Change to nutrient levels, leading to changing plant community dynamics.
• Public awareness of scrub areas as ‘wastelands’.
• Need for time and space for succession to develop.

13.5 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1.	Undertake survey of scrub habitat and evaluate to establish area, age, range, succession and management.	1.2.	Undertake survey as to extent of resource (area, age range, succession and management).	–	Ongoing	Amount of information gathered	Annually
2.	Identify key sites for positive appropriate management.	2.1	Encourage development of strategies to promote positive management of scrub.	–	Ongoing	Number of strategies produced	Annually
3.	Promote awareness and positive perception of scrub as a habitat.	3.1	Promote awareness and positive perception of scrub.	–	Ongoing	Number of people informed	Annually

13.6 Associated Species

Key species associated with the habitat action plan for scrub include:

• Water Vole Arvicola terrestris (Species Action Plan)
• Otter Lutra lutra (Species Action Plan)

 

Back to top

14         SPECIES ACTION PLAN – WATER VOLE

14.1 Introduction

The water vole is an agile swimmer living in a complex system of waterside burrows. Favoured habitats include well-vegetated banks of ditches, streams, rivers and ponds, with recent work showing them to be more numerous in upland moorland and moorland fringe habitats than formerly thought. They are herbivores, primarily feeding on lush waterside vegetation, which they also use as cover from their many predators. Water voles live in colonies and are territorial during a breeding season which lasts from March to October. A female may produce two to five litters each of five to eight young. As food supplies diminish during wintertime, they are less active, spending the majority of time underground.
Once common and widespread across Britain, the water vole has suffered a long-term decline in both numbers and distribution since the Industrial Revolution. The decline has accelerated dramatically in the last two decades.p

14.2 Legal Status

As of 2008, the water vole is protected under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended).  It is illegal to kill, injure or take water voles or to damage or destroy their resting place.

14.3 UK Status and Regional Status

The water vole is found throughout Britain but is confined mainly to lowland areas near water.  Once common and widespread, this species has suffered a significant decline in numbers and distribution.  A recent population estimated based on the number of latrines found suggested a total GB pre-breeding population of 1,200,000 animals.

14.4 Local Status

A large proportion of drainage ditches within the Mildenhall District support populations of water vole.  Where intensive studies have been undertaken, water voles have been recorded in approximately 58% of ditches surveyed.  (A total of 89% of the Board’s drains have been surveyed to date).  The area as a whole forms a significant regional (and possibly national) stronghold for this threatened species.  Mink predation is a threat but it may be that the amount of habitat and the complex connections within the ditch system has allowed water voles to survive.

14.5 Threats

The main threats to water vole in the Mildenhall Drainage District can include:

• Habitat degradation and loss.
• River engineering, bank protection and maintenance works, which result in loss of habitat and site degradation.
• Bank protection such as hard edging and sheet piling, which leads to destruction of habitat.
• Lack of appropriate riparian management, which results in replacement of suitable vegetation to form dense scrub on the bank.
• Silting up and drying of the wetland.
• Population fragmentation.  Localised populations become more vulnerable to environment change.  Colonies isolated from other populations are vulnerable to extinction.  Stretches of watercourse or canal without bankside vegetation effectively act as a barrier to free movement.  These colonies are trapped and habitat degradation within their local area denies them feeding and breeding opportunities.
• Adverse events such as pollution incidents can lead to further losses in a local population.  The variable reproductive capacity of water voles affect the capacity of the species to recover from such adverse events.  Insufficient interaction between colonies may weaken the genetic pool.
• Predation from cats, red foxes, brown rats, stoats, weasels, herons, owls and pike.  The American mink is uncommon in urban areas.
• Pollution.  Poisoning by rodenticides is a particular threat in urban areas.  Contaminants affecting water voles include organochlorine pesticides, PCB’s, heavy metals and organic pollution from agriculture and sewage.
• Fluctuations of water levels.  Access by water voles to food, cover and burrows along river banks and in pools will be affected by fluctuations in water levels.

14.6 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1	Increase knowledge of the status, distribution and ecology of water voles	1.1	Carry out survey work to monitor population changes to establish conservation changes.	Wildlife Trust	Ongoing	Number of surveys produced	Annually
2	Restore water vole populations to a sustainable level by protecting, maintaining and enhancing the features required by the species	2.1	Enhance habitat through the restoration of bankside vegetation to link fragmented populations.  Restore degraded habitat.	All ditch managers	Ongoing	Length (m) of bankside vegetation restored	Annually
		2.2	Identify sites used by water voles and ensure the information is made available to LPAs so that sites can be protected and managed.	Wildlife Trust All ditch managers	Ongoing	Number of inspections	Annually
3	Raise awareness of water voles conservation issues	3.1	Raise awareness of water voles and encourage a sympathetic proactive response to their conservation and management.	Wildlife Trust All occupies within the District	Ongoing	Number of people informed	Annually

 

Back to top

15         SPECIES ACTION PLAN – OTTER

15.1 Introduction

The otter is a long slender bodied mammal with brown fur, which is quite often pale on the underside. The head to body length can be up to 120cm. The tail makes up approximately a third of the body length. Otters have small ears and webbed feet. To compensate for the lack of a fat layer they have a double layer of fur to trap air and keep them warm in the water. The average weight for males is 10.1kg, and around 7kg for females.
Otters may inhabit any unpolluted body of freshwater, including lakes, streams, rivers, and ponds, as long as there is good supply of food. Otters may also live along the coast, in salt water, but require regular access to freshwater to clean their fur.
An otter’s diet mainly consists of fish but can also include birds, insects, frogs, crustaceans and sometimes small mammals.

15.2 Legal Status

The otter is listed on Appendix 1 of CITES, Appendix II of the Bern Convention and Annexes II and IV of the Habitats Directive.  It is protected under Schedule 5 of the Wildlife and Countryside Act 1981.  It is illegal to kill, injure or take otters or to damage or destroy their resting place.

15.3 UK Status and Regional Status

Formerly widespread throughout the UK, the otter underwent a rapid decline in numbers from the 1950s to 1970s and was effectively lost from midland and south-eastern counties of England by the 1980s.  The decline now appears to have halted and sightings are being reported in former habitats.  Otters now use all major watercourses in Suffolk and populations appear to be recovering.

15.4 Local Status

Unknown.

15.5 Threats

The main threats to water vole in the Mildenhall Drainage District can include:

• Lack of suitable lying up sites such as hollows in large riverside tree roots, scrub patches, reedbeds etc.
• Loss of wetlands within the floodplain.
• Lack of large undisturbed areas suitable for breeding.
• Lack of sustainable fish stocks limiting food availability to otters.
• Accidental mortality, e.g. road casualties.
• Non-installation of otter guards on eel nets.
• Direct effect of contaminants, e.g. PCBs and heavy metals.

15.6 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1	Restore otter populations to a sustainable level by protecting, maintaining and enhancing the features required by the species	1.1	Protect and enhance the remaining areas of semi-natural habitat and riverine features of value to otters.	All ditch managers	Ongoing	Area (m) of habitat protected	Annually
		1.2	Promote the establishment of otter havens through contacts with local landowners and schemes such as Countryside Stewardship.	All occupiers All land managers	Ongoing	Number of landowners informed	Annually

 

Back to top

16         SPECIES ACTION PLAN – BARN OWL

16.1 Introduction

With heart shaped face, buff back and wings and pure white under parts the barn owl is a distinctive and much loved countryside bird. Widely distributed across the UK, and indeed the world.  It can be seen in open country, along field edges, riverbanks and roadside verges.  You can see them all year round, during the day, but best at dusk.

16.2 Legal Status

Barn owls are protected under Schedule 1 of the Wildlife and Countryside Act 1981.  It is an offence to take, injure or kill a barn owl or to take, damage or destroy its nest, eggs or young.

16.3 UK Status and Regional Status

Widely distributed across the UK, and indeed the world, barn owl has suffered declines over the past fifty years as intensive agricultural practices cause degradation of once prey-rich habitats.  This decline, fortunately, has halted in many areas and the population may now be increasing.

16.4 Local Status

The Mildenhall District supports a significant population of barn owls, which use ditch banks for foraging.  The population may be limited by lack of nest sites.

16.5 Threats

The main threats to the barn owl in the Mildenhall Drainage District can include:

• Habitat loss, especially rough grassland, resulting in a reduction of small mammals which are the main food supply of barn owls.
• Loss of nesting sites such as old buildings and mature/dead trees.
• Changing climate, especially the effects of the harsher winters, which diminish food reserves.
• Increasing or changing use of pesticides, especially rodenticides, as barn owls may indirectly consume these by eating contaminated small mammals.
• Road mortalities.
• Water trough facilities – a number of owls drown in these drinking troughs.

16.6 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Action	Partners	Date	Indicators	Reporting
1.	Ensure the protection of the species through the Wildlife and Countryside 1981.	1.1	Use the Wildlife and Countryside Act 1981 to protect both the bird and known breeding sites.	Wildlife Trust	Ongoing	Number of birds/breeding sites in district	Annually
2.	Maintain habitats suitable for barn owls.	2.1	Encourage land management suitable for barn owls through the District especially between breeding sites and along river corridors.	Landowners	Ongoing	Amount of land managed	Annually
3.	Enhance the countryside in a manner beneficial to providing both nest sites and hunting grounds for barn owls, with the aim of extending their range.	3.1	Use best practice to ensure that design and management of river corridors and roadside habitats take barn owls into consideration.	–	Ongoing	Amount of land managed	Annually
		3.2	Establish, maintain and make available to conservation organisations a breeding and roosting site database, including the location of all nest boxes.	Hawk and Owl Trust	Ongoing	Amount of information collected	Annually
4.	Protect barn owls with the aim of increasing numbers and expanding their range.	4.1	Increase the barn owl population by 20%	Hawk and Owl Trust Wildlife Trust	Ongoing	Number of owls in district	Annually
		4.2	Increase the number of nest boxes, especially along waterways.  Ensure the boxes are not erected near any major roads.	Hawk and Owl Trust Wildlife Trust	Ongoing	Number of owl boxes erected	Annually
5.	Provide advice and information connected to the preservation of sites and feeding habitats which are preferred by barn owls.	5.1	Landowners to be advised on land management for barn owls.	Landowners	Ongoing	Number of landowners advised	Annually

 

17         PROCEDURAL ACTION PLAN

17.1 Introduction

A number of procedural targets and actions have been established within this Procedural Action Plan.  These are intended to integrate biodiversity considerations into IDB practices and procedures.

17.2 Objectives and Targets

Target Ref.	Target	Action Ref.	IDB Actions	Partners	Date	Indicators	Reporting
1	Promote best practice in all drainage works	1.1	Advise land managers of best environmental practice in relation to ditch management	All occupiers within the district	Ongoing	Number of land managers advised	Annually
		1.2	Require developers to follow best environmental practice	All occupiers within the district	Ongoing	Number of developers advised	Annually
		1.3	Publicise examples of best environmental practice by Board on website	All occupiers within the district	Ongoing	Amount of information available on website	Annually
		1.4	Make available environmental information to interested parties	All occupiers within the district	Ongoing	Amount of information available	Annually
2	Control of culverting of watercourses	2.1	Review of land drainage consents to only allow necessary culverting	All occupiers within the district	Ongoing	Number of consents issued	Annually
3	Training of operatives	3.1	Training of all staff / operatives in recognition of target species	All staff / occupiers within the district	Ongoing	Number of staff trained	Annually
		3.2	Training of all operatives in appropriate use of plant / habitat management	All operatives	Ongoing	Number of operatives trained	Annually

 

Back to top

18         IMPLEMENTATION

18.1   Implementation

The actions detailed in the habitat and species action plans in previous chapters will be implemented predominantly through minor changes to IDB management and maintenance methods.

To compliment this BAP a maintenance programme will be devised by the Board, through which many of the actions will be implemented.  Any capital works undertaken by the Board will also allow implementation of BAP actions.

Partnership working with other members of the Working Group will allow several actions to be implemented, for example, data collection and the provision of advice.

 

19         MONITORING

19.1   Monitoring

Monitoring of the Mildenhall BAP will be required to ensure that the actions detailed in the habitat and species action plans are being implemented.

Monitoring of the indicators detailed in the action plans will be undertaken and recorded, generally on an annual basis.

Species and habitats vary naturally over time.  Monitoring will result in new information, such as the presence of species missed during earlier surveys.  Any new information will be incorporated into the IDB BAP as appropriate.

 

20         REVIEWING AND REPORTING PROGRESS

20.1   Reviewing and Reporting Progress

Progression of the BAP requires monitoring and reporting to the public, BAP Working Group and also to the UK BAP.

Progress towards each of the targets is likely to be assessed annually and it is anticipated that the Mildenhall IDB BAP will be fully reviewed after five years.  However, the production and long-term development of the BAP is a flexible process.

Annual reporting will be done through meetings of the Mildenhall Internal Drainage Board and through the national Biodiversity Action Reporting System (BARS).  Targets and actions for the individual action plans have been written so that they fit the national BARS, which is the approved system for reporting.  Using BARS annual progress reports will be produced and made available.

 

21.   APPENDIX A – TABLE OF BAP PRIORITY SPECIES

Common Name	Taxon Group	Scientific Name
Common Toad	Amphibian	Bufo bufo
Barn Owl	Bird	Tyto alba
Bewick’s Swan	Bird	Cygnus columbianus
Corn Bunting	Bird	Miliaria calandra
Lesser Spotted Woodpecker	Bird	Dendrocopos minor
Linnet	Bird	Carduelis cannabina
Merlin	Bird	Falco columbarius
Quail	Bird	Coturnix coturnix
Red Kite	Bird	Milvus milvus
Redshank	Bird	Tringa totanus
Rock Dove	Bird	Columba livia
Skylark	Bird	Alauda arvensis
Stone-curlew	Bird	Burhinus oedicnemus
Turtle Dove	Bird	Streptopelia turtur
Yellow Wagtail	Bird	Motacilla flava
European Eel	Bony Fish	Anguilla anguilla
Annual Knawel	Flowering Plant	Scleranthus annuus
Black Poplar	Flowering Plant	Populus nigra betulifolia
Brookweed	Flowering Plant	Samolus valerandi
Bur Medick	Flowering Plant	Medicago minima
Common Milkwort	Flowering Plant	Polygala vulgaris
Common Rock-rose	Flowering Plant	Helianthemum nummularium
Corn Spurry	Flowering Plant	Spergula arvensis
Dense-flowered Fumitory	Flowering Plant	Fumaria densiflora
Dittander	Flowering Plant	Lepidium latifolium
Divided Sedge	Flowering Plant	Carex divisa
Dropwort	Flowering Plant	Filipendula vulgaris
Dwarf Spurge	Flowering Plant	Euphorbia exigua
Fen Orchid	Flowering Plant	Liparis loeselli
Few-flowered Fumitory	Flowering Plant	Fumaria muralis boraei
Field Gromwell	Flowering Plant	Lithospermum arvense
Fine-leaved Fumitory	Flowering Plant	Fumaria parviflora
Fine-leaved Water-dropwort	Flowering Plant	Oenanthe aquatic
Grass-wrack Pondweed	Flowering Plant	Potamogeton compressus
Great Water Parsnip	Flowering Plant	Sium latifolium
Greater Spearwort	Flowering Plant	Ranunculus lingua
Green-winged Orchid	Flowering Plant	Orchis morio
Hoary Cinquefoil	Flowering Plant	Potentilla argentea
Hound’s Tongue	Flowering Plant	Cynoglossum officinale
Large-flowered Hemp-nettle	Flowering Plant	Galeopsis speciosa
Loose Silky-bent	Flowering Plant	Apera spica-venti
Marsh Dock	Flowering Plant	Rumex palustris
Marsh Speedwell	Flowering Plant	Veronica scutellata
Marsh Stitchwort	Flowering Plant	Stellaria palustris
Marsh Willowherb	Flowering Plant	Epilobium palustre
Narrow Small-reed	Flowering Plant	Calamagrostis stricta
Night-flowered Catchfly	Flowering Plant	Silene noctiflora
Opposite-leaved Pondweed	Flowering Plant	Groenlandia densa
Prickly Poppy	Flowering Plant	Papaver argemone
Purple Fescue	Flowering Plant	Vulpia ciliate ambigua
Rough Poppy	Flowering Plant	Papaver hybridum
Sand Catchfly	Flowering Plant	Silene conica
Shepherd’s Cress	Flowering Plant	Teesdalia nudicaulis
Sickle Medick	Flowering Plant	Medicago sativa falcata
Small Pondweed	Flowering Plant	Potamogeton berchtoldii
Small Scabious	Flowering Plant	Scabiosa columbaria
Smooth Cat’s-ear	Flowering Plant	Hypochaeris glabra
Smooth Rupture-Wort	Flowering Plant	Herniaria glabra
Common Name	Taxon Group	Scientific Name
Sneezewort	Flowering Plant	Achillea ptarmica
Spanish Catchfly	Flowering Plant	Silene otites
Tubular Water-dropwort	Flowering Platn	Oenanthe fistulosa
Tufted Sedge	Flowering Plant	Carex elata
Violet	Flowering Plant	Viola x contempta
Water Purslane	Flowering Plant	Lythrum portula
Wild Pansy	Flowering Plant	Viola tricolor
Five-banded Tailed Digger Wasp	Flowering Plant	Cerceris quinquefasciata
Pashford Pot Beetle	Insect – beetle	Cryptocephalus exiquus
Large Garden Bumble Bee	Insect – hymenopteran	Bombus (megabombus) ruderatus
Solitary Wasp	Insect – hymenopteran	Stigmus pendulus
Spider Hunting Wasp	Insect – hymenopteran	Arachnospila consobrina
Desmoulin’s Whorl Snail	Mollusc	Vertigo (vertigo) moulinsiana
The Shining Ram’s-horn	Mollusc	Segmentia nitida
Grass Snake	Reptile	Natrix natrix
Viviparous Lizard	Reptile	Lacerta vivipara
Badger	Terrestrial Mammal	Meles meles
Brown Hare	Terrestrial Mammal	Lepus capensis
Harvest Mouse	Terrestrial Mammal	Micromys minutus
Hedgehog	Terrestrial Mammal	Erinaceus europaeus
Otter	Terrestrial Mammal	Lutra lutra
Water Shrew	Terrestrial Mammal	Neomys fodiens
Water Vole	Terrestrial Mammal	Arvicola terrestris