Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
ENVIRONMENT AGENCY HAMPSHIRE AND ISLE OF WIGHT AREA
HABITATS REGULATIONS (REG. 50) REVIEW OF CONSENTS STAGE 3 APPROPRIATE ASSESSMENT RIVER ITCHEN cSAC
Final version February 2005 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
EXECUTIVE SUMMARY
OVERVIEW OF APPROACH. The Agency has adopted a staged approach to the Review of Consents (RoC) required in accordance with the Habitats Regulations and described in the Agency’s EU Habitat and Birds Directives – Handbook for Agency Permissions and Activities.
Stage 1 involved the identification of all relevant permissions and has been completed. The following Agency consents are relevant: Abstraction licences, Discharge consents, PIR/IPPC/RAS authorisations and Waste Management licences.
In Stage 2, all relevant permissions identified in Stage 1 were subject to further assessment to identify ‘likely significant effect’. Those that failed the test passed into Stage 3. Relevant consents were Abstraction licences, Discharge consents and PIR/IPPC/RAS authorisations.
The purpose of this Stage 3 appropriate assessment is to ascertain that the Agency permissions are not having an adverse effect upon the integrity of the site. Each Agency permission is assessed both alone and in-combination with one another and with other plans and projects and prevailing conditions.
There are two possible conclusions to this assessment noted as follows:
The permission can be shown to have no adverse effect on the integrity of the site; OR The permission cannot be shown to have no adverse effect on the integrity of the site.
The published Conservation Objectives for the River Itchen cSAC underpinned the Stage 3 appropriate assessment. It is a scientific assessment, based upon the best available information including familiarity with the site, bases decisions upon reasonably foreseeable risk and draws upon professional judgement. It is also precautionary.
The River Itchen Sustainability Study. It is considered helpful to clarify the relationship between this appropriate assessment and the River Itchen Sustainability Study (hereafter referred to as RISS, or the Study).
The RISS was an AMP3 funded investigation which was carried out during the period 2000 to 2004. The Study was a collaborative project, managed by a steering group which included the Environment Agency, English Nature, water companies, local authorities and other key stakeholders and was project managed by Halcrow consultants.
The Study sought to collate existing local data and to generate new data about the abiotic and biotic attributes of the Itchen catchment over an ecological and hydrological assessment period – 30 years from 1970 to 2000, in order to inform the RoC Stage 3 process. In some cases the new data involved innovative and ground-breaking work. It drew upon local experts with long standing familiarity with the catchment. Hence the supporting information includes a combination of field surveys, professional expertise, DNA work, laboratory analyses in relation to eco-toxicological assessments/water quality determinands, mathematical modelling and data analysis. Assessments were carried out for the River Itchen system as a whole and for the key interest features, including those for which the cSAC/SSSI was designated. Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Assessment methods were based on ‘best science’ and involved leading academics and consultants who are acknowledged experts in their fields both in the UK and internationally. Ecological models were used for salmon, trout and invertebrate assessments, but for the other interest features adequate data were lacking to make any modelling exercise meaningful.
The RISS had two chief products. A large volume of site-specific data; and a DRAFT Strategy for the Itchen catchment.
The RISS DRAFT Sustainable Management Strategy is not part of the Agency’s review of consents Stage 3 appropriate assessment. They are two separate and distinct documents.
The appropriate assessment is the Agency’s and the decisions therein are the Agency’s alone.
The data generated by the RISS is common to both the DRAFT Sustainable Management Strategy and to the Agency’s RoC Stage 3 appropriate assessment.
CONCLUSIONS.
The final number of permissions from the assessments is given in Table A.
Table A: Stage 3 Appropriate Assessment – Final Number of Permissions & Conclusions. Total No. of Total No. of No adverse No adverse Others Agency Agency No adverse effect on site effect on site permissions permissions effect on site integrity integrity Function assessed in assessed in integrity can cannot be cannot be Stages 1 & Stage 3. be shown shown alone shown in- 2. combination 6172 115 15 53 0 Water Quality 62 128 48 9341 1 Water Resources 13 17 0 000 Waste 0 Process Industry 33 26 3316 2 7 Regulation Radioactive 0 3 21 000 Substances 21 Regulation Groundwater 00 0 0 0 0 Authorisations 1 See Part B.2. for explanation. 2 Revoked, repermitted under Reg. 48 or within 12 months of repermitting under Reg.48 3 No. unknown at time of Stages 1&2.
The Appropriate Assessments concludes that the existing Agency permissions are a combination of those which can be shown to have no adverse effect on site integrity and those which cannot.
For those which the Agency determines it cannot show no adverse effect on integrity of the Itchen cSAC, the range of reasons include the following :- Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Abstraction licences: The assessment concluded that, during a dry year, abstraction could cause flows in Candover Stream and in the main River Itchen south of Winchester, to fall to about 35% below naturalised flow in September.
Public water supply abstraction may impact on the 7 kilometres of river channel between the Otterbourne surface water abstraction intake and the Chickenhall sewage treatment works outfall. The Chickenhall sewage treatment works effluent discharge probably ensures that the Gaters Mill abstraction does not cause a fall in river flows to levels below 35% of the September naturalised flow.
A number of abstraction licenses in the upper catchment cannot be shown not to adversely effect site integrity due to their localised impacts. Low flows between the abstraction point and the associated discharge is a point of concern.
The assessment concludes that it cannot be shown that the Agency’s Candover augmentation licence will not adversely affect site integrity.
A number of licences also cause concern for their lack of fish screens representing a potential threat to fish through entrainment.
Discharge Consents: English Nature and the Environment Agency have agreed soluble phosphorus standards for the Itchen system. These standards are currently marginally exceeded in the River Arle, the upper tributary of the Itchen to the east, the middle Itchen to Easton, and significantly exceeded downstream of Easton, due to Harestock and Chickenhall sewage treatment works discharges. A number of discharges cannot be shown not to adversely effect site integrity as a result of the release of phosphates.
Sewage treatment works discharges had the potential to impact upon site integrity by reducing the ability of the river to meet River Ecosystem Class 1 for salmon. Although River Ecosystem Class 1 is achieved in the majority of the catchment, this is marginal in the lower Itchen downstream of Chickenhall STW outfall. For determinands in the River Ecosystem classification, discharges were deemed cannot show not adverse effect on site integrity on the basis of their maximum consented load discharge of ammonia, BOD, soluble reactive phosphorus and/or suspended solids.
‘Off-site’ impacts, or the effects of Agency permissions on ecological interest features whilst they are outside the River Itchen catchment, were also considered by this Assessment. The assessment considered Agency permissions in Southampton Water including the Itchen estuary. The discharge from Portswood sewage treatment works to the upper Itchen estuary is thought to potentially impact migratory salmonids through high ammonia levels and BOD.
PIR and RSR: The assessment concludes that there are no PIR or RSR permissions within the site that are adversely effecting site integrity. However, the assessment concludes that it cannot be shown that a number of thermal discharges from waterside industry in Southampton Water are not adversely effecting salmon. Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
The Interest features:
The Salmon population and supporting habitats. Salmon is potentially the most heavily impacted of the interest features by Agency regulated permissions. The salmon population is in a critical condition, numbers being significantly reduced over the last decade. Due to the life-cycle of this species the population is also slow to recover from Agency-related impacts. Factors thought to be significant in the riverine habitat with respect to salmon movement and survival are diffuse pollution - siltation of the salmon redds, summer low flow with respect to habitat suitability and entry to the river and eutrophication effects.
The passage of salmon through the estuary, particularly landwards, is thought to be influenced by river flow and water quality.
Macrophytes and the wider chalkstream biotope. The macrophyte community and invertebrate community have been shown to be impacted by the low flow period 1989 to 1992. The invertebrate community changed markedly in the dry years with some species (for example several mayfly species) showing a significant reduction in abundance. The flow impacts on invertebrates are usually short lived with recovery being rapid once higher flows return. However, the reduction in numbers could have an impact over several years for species higher up the food chain, for example salmon.
Nutrient enrichment from point or diffuse sources is also suspected of causing considerable change in the macrophyte community.
Background/prevailing conditions/unregulated activities: The assessment considers Agency regulated permissions in the context of background and prevailing conditions, including unregulated activities. The Assessment concludes that there are a number of fundamentally important factors having profound impacts upon a number of the interest features and their supporting habitats, irrespective of Agency permissions. Such influences, often specific to individual species and associated habitats, include, for example,:- obstructions to movement and diffuse pollution - sediment in spawning gravel (salmon); and disease (crayfish).
Site management, including river and fisheries management, grazing regime of riparian meadows, and water level management are all major influencing factor. The assessment considers these impacts in-combination with Agency permissions.
This appropriate assessment concludes Stage 3.
Stage 4 is the final element of the RoC process. The Agency will assess options to determine whether to affirm, modify or revoke those permissions in Stage 3. That process must be concluded by 31st March 2006. Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
CONTENTS
EXECUTIVE SUMMARY ii
CONTENTS 8
PART A - SITE DETAILS 13
1Site Details 13 1.1 Site Details 13 1.2 General Development of the Site 13 1.3 English Nature’s Condition Assessment of SSSI Units 14 1.4 Component Habitats and the cSAC Designated Interest Features 15 1.5 Summary Table of the Number of Permissions Going to Stage 3 16 1.6 The River Itchen Sustainability Study. 17 1.7 Review of Consents Group Members 18 1.8 Approach and Documentation 19 1.9 Summary of Main Issues, Perceived Risks and Responsibilities 20
PART B – FUNCTIONAL ASSESSMENTS 24
2 Introduction 24 2.1 The In-Combination Test: Triviality 24 2.2 Interest feature species and their supporting habitats. 25 2.3 Typical Species. 27 2.4 Off Site Impacts 28 2.4.1 Introduction 28 2.4.2 Otters 28 2.4.3 Atlantic Salmon 30 2.5 Integrity tables. 31
PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT 36
3 Water Quality Assessment 36 3.1 Summary of Outcomes 36 3.2 Identification of ‘likely significant effect’ permissions 36 3.3 Water Quality related Hazards and Sensitivities 40 3.4 Key determinands and standards 43 3.5 Site characterisation 46 3.5.1 Toxic contamination 46 3.5.2 Nutrient enrichment 48 3.5.3 pH 49 3.5.4 Salinity 49 3.5.5 Thermal regime 50 3.5.6 Turbidity and siltation 50 3.6 Assessment methods 50
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3.6.1 Introduction 50 3.6.2 Assessment methodology and assumptions 51 3.6.3 Assessment rules 53 3.6.4 Assessment of discharges to non-cSAC tributaries 56 3.7 Discussion of permissions 75 3.7.1 Application of Water Quality Rule 1 75 3.7.2 Application of Water Quality Rule 2 75 3.7.3 Application of Water Quality Rule 3 75 3.7.4 Application of Water Quality Rule 4 76 3.7.5 Application of Water Quality Rule 5 76 3.7.6 Summary of results by discharge type 77 3.8 Off-site impacts 79 3.9 Conclusion 80
PART B.2 WATER RESOURCES FUNCTIONAL ASSESSMENT. 86
4 Water Resources Assessment 86 4.1 Summary of Outcomes 86 4.2 Stage 1 and 2 Criteria 87 4.3 Hazards and Sensitivities for Permission Types 89 4.3.1 Change in water levels or table 89 4.3.2 Change in flow or velocity regime and reduced dilution capacity 90 4.3.3 Change in freshwater flow to estuary 90 4.3.4 Habitat loss 90 4.3.5 Entrapment 90 4.4 Characteristic Hydrology 90 4.5 Derivation of Target Flow Regime 92 4.5.1 Salmon Migration Model 92 4.5.2 PHABSIM Modelling 93 4.5.3 Macro-invertebrate six monthly mean flow thresholds 95 4.5.4 Use of Available Information to Derive Target Flow Regime 97 4.6 Use of the CAMS Ledger 101 4.7 Assessment Rules 104 4.8 Application of the Rules 119 4.8.1 Application of Water Resources Rule 1 to Abstraction Licences 119 4.8.2 Application of Water Resources Rule 2 to Abstraction Licences 119 4.8.3 Application of Water Resources Rule 3 to Abstraction Licences 120 4.8.4 Application of Water Resources Rule 4 to Abstraction Licences 120 4.9 Maps Showing Water Resource Permissions 134 4.10 Discussion of Permissions 134 4.11 Summary Conclusion – Water Resource Assessments 141 4.12 Conclusion 141 4.13 Robustness of Decision Making 142 4.14 Off Site Impacts – Water Resource Assessments 142
PART B.3 WASTE FUNCTIONAL ASSESSMENT. 144
5 Waste Licensing Assessment 144
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PART B.4 PIR FUNCTIONAL ASSESSMENT. 145
6 PIR Appropriate Assessment 145 6.1 Summary of Outcomes 145 6.2 Introduction 146 6.3 Assessment Tools 147 6.4 Assessment Criteria 148 6.5 Maps Showing PIR Permissions 151 6.6 List of Features Sensitive to PIR Permissions 153 6.7 Off Site Impacts – PIR Assessments 155 6.8 Discussion of Permissions 162 6.9 Off-Site Impacts 164 6.9.1 Summary conclusions – Off-site Impacts 166
PART B.5 RSR FUNCTIONAL ASSESSMENT. 167
7 RSR (Radioactive Substances Regulation) Appropriate Assessment 167 7.1 Summary of Outcomes 167 7.2 Introduction 167 7.3 Assessment Tools 168 7.4 List of Features Sensitive to RSR Permissions 170 7.5 Discussion of Permissions 170 7.5.1 Aqueous discharges 170 7.5.2 Aerial releases 170 7.6 Summary Conclusions – RSR Assessments 171
PART B.6 GROUNDWATER REGULATIONS ASSESSMENT. 173
8 Groundwater Regulations Authorisations Assessment 173
PART C (1) - MULTI-FUNCTIONAL IN-COMBINATION ASSESSMENT OF AGENCY PERMISSIONS 174
9 Multi Functional In Combination Assessments 174 9.1 SUMMARY 174 9.2 INTRODUCTION 174 9.3 DISCUSSION OF BETWEEN FUNCTION IMPACT TYPES 177 9.4 ASSESSMENT OF WATER DISCHARGE AND WATER ABSTRACTION PERMISSIONS. 178 9.4.1 Assessment Rules 178 9.4.2 RESULTS 179 9.5 DISCUSSION OF OUTCOMES 180 9.6 CONCLUSIONS - PART C.1 MULTI-FINCTIONAL IN- COMBINATION ASSESSMENT. 180
PART C (2) – EXTERNAL IN-COMBINATION ASSESSMENTS 184
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10 External Plans and Projects 184 10.1 INTRODUCTION. 184 10.2 Consultation with Competent Authorities 184 10.3 External Plans and Projects 185 10.4 CONCLUSIONS PART C.2 IN-COMBINATION ASSESSMENT – EXTERNAL PLANS AND PROJECTS. 187
11 Background/prevailing conditions including off-site impacts. 188 11.1 INTRODUCTION 188 11.1.1 Generic Factors Considered Through the In-Combination Assessments 188 11.1.2 Other Factors Identified Through the Study 190 11.2 DISCUSSION OF INFLUENCES AND THEIR RELATIVE IMPACTS.190 11.2.1 GENERAL ISSUES. 190 11.2.2 DISCUSSION OF FEATURES AND THEIR SUPPORTING HABITATS. 193 11.3 DISCUSSION OF AGENCY PERMISSIONS IN-COMBINATION WITH NON-AGENCY REGULATED INFLUENCES ON THE SALMON POPULATION AND ITS SUPPORTING HABITATS. 202 11.4 LONGER TERM INFLEUNCES. 209 11.5 PART C.2 IN-COMBINATION ASSESSMENT - BACKGROUND/PREVAILING CONDITIONS INCLUDING OFF SITE IMPACTS. 209 11.6 OVERARCHING Conclusions TO PART C.2 212
PART D - OVERALL CONCLUSIONS 213
12 Overall Conclusions 213 12.1 Overview 213 12.2 Water Quality Conclusions with Reference to Interest Features 213 12.3 Water Resources Conclusions with Reference to Interest Features 214 12.4 PIR Conclusions with Reference to Interest Features 215 12.5 RSR Conclusions with Reference to Interest Features 215 12.6 Final Number Permissions and Decision 215 12.6.1 Overview 215 12.6.2 No Adverse Effect on Site Integrity Cannot be Shown 215 12.6.3 No Adverse Effect on Site Integrity Can be Shown 216
PART E – FINAL APPROPRIATE ASSESSMENT RECORD 217
13 Final Appropriate Assessment Record 217 13.1 Summary Table of All Permissions 217 13.2 Conclusion 222
References. 224
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Appendices
Draft SSSI and the cSAC conservation objectives are given in Appendix A.
Appendix B contains information on EN condition assessment of the River Itchen SSSI units.
Status assessment sheets for the designated interest features are given in Appendix C.
Spreadsheet Databases for Completion of Appendix 21 Pro Forma are given in Appendix D.
Appendix E contains some of the PIR appropriate assessment information referenced in the text.
Appendix F contains the complete list of references from the River Itchen Sustainability Study (the Study).
Appendix G is further explanation of the WQ functional approach and supporting documentation.
Appendix H is further explanation of the WR functional approach.
Appendix I is further ecological information.
Appendix J is further discussion on the Agency’s methods in assessing ecological impacts of water quality and abstraction.
Appendix K gives a summary of the River Itchen Sustainability Study.
Appendix L presents the Stages 1 & 2 proformas.
Appendix M contains the Agency’s assessment with regards to endocrine disruptors.
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PART A - SITE DETAILS
1 SITE DETAILS
1.1 SITE DETAILS The name of the European site/composite SSSI for which this appropriate assessment document refers is given in Table 1.1.
Table 1.1 Name, Legal Status, and Priority of the European Site
Name River Itchen cSAC Legal Status candidate Special Area of Conservation; and Composite SSSIs HD RoC Priority of the European site High Priority Site Site area: 309.26 hectares
Site length: 40 km
The draft SSSI and the cSAC conservation objectives for the site are given in Appendix A.
Whilst acknowledging that the site is a continuum, the river system has been divided into six management units/reaches so that assessments could be carried out for contrasting reaches and for the river as a whole. The convention adopted was: Cheriton stream/Tichbourne (Management Unit 1 or MU1), River Arle (Management Unit 2 or MU2), Candover stream (Management Unit 3 or MU3), upper Itchen to Easton (Management Unit 4 or MU4), middle Itchen from Easton to Highbridge (Management Unit 5 or MU5), and lower Itchen from Highbridge to the tidal limit at Riverside Park (Management Unit 6 or MU6). Smaller divisions were defined as subdivisions of the main units e.g. 5a, 5b etc. and flood plain areas are indicated with a capital letter suffix e.g. 5F.
The relevant permissions, which are the subject of the Stage 3 appropriate assessment, are organised into the following broad categories.
Discharge Consents Abstraction Licences RSR Permissions Process Industry Regulation (IPC) Authorisations
The Area identified no permissions under the Groundwater Regulations and no Waste Management Licences in Stages 1 and 2 of the Review of Consents (RoC) process.
1.2 GENERAL DEVELOPMENT OF THE SITE The history of development of the river and its catchment are important to the appropriate assessment as they have a fundamental impact upon the aquatic environment. Although considered a most attractive scenery, the classic Chalk stream surrounded by Chalk downland
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is in fact a highly-managed environment. People first appeared in this area about 700,000 BP; Palaeolithic artefacts dating from around this time have been found in the Itchen valley (Hughes 1984). However, our ancestors probably made little impression on the scenery until Neolithic times (4500 to 2600 BC) when the hunter-gatherer lifestyle began to give way to agriculture.
Fields were cleared in the natural forest of oak, elm, lime, ash, field maple hazel and alder. However, limited tools meant that this process was slow until the Iron Age (750 BC to 43AD). The Romans introduced towns to the landscape and virtually completed the clearance of the natural woodland; however, some remnants of woodland remained and were managed for production of fuel and building materials. Since that time the whole catchment has been managed for agriculture, urban development, transport etc., with associated environmental impacts, and hardly a vestige of the pre-historic natural environment remains.
The River Itchen cSAC was selected as a SSSI because it is one of the finest examples of Chalk stream habitat anywhere in the world. As such it is a complex of dynamic processes partly shaped by a management regime that has changed and developed over millennia.
1.3 ENGLISH NATURE’S CONDITION ASSESSMENT OF SSSI UNITS Information on English Nature (EN)’s condition assessment of the River Itchen SSSI units was obtained from the EN’s web site at the following address: http://www.english- nature.org.uk/special/sssi/reportAction.cfm?report=sdrt13&category=S&reference=2000227.
Details of the condition assessment, compiled by EN on 1 February 2004, are given in Appendix B. The condition assessment information was combined with the assessment’s management units to produce Table 1.2. Table 1.2 summarises the number of SSSI units by reporting categories and by management units.
Table 1.2 Summary of Number of SSSI Units and EN Reporting Categories by Management Units EN Reporting Categories (No of SSSI Units) Total No Management Destroyed, Part- of SSSI Unit Unfavourable Unfavourable destroyed, Favourable Units and Recovering and Maintained Unfavourable and Declining MU 1740415 MU 200145 MU 3521210 MU 4754622 MU 5 11 11 3 14 39 MU 6225817 TOTALS32241438108
In Table 1.2, it can be seen that of the 108 SSSI units, 32 are in ‘favourable’ condition and 38 are ‘unfavourable and declining, destroyed, part destroyed’. The highest number of units under the latter category can be found in Management Unit 5. Management Units 5 and 6 have the highest number of units in ‘unfavourable’ condition.
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Expression of the condition assessment information also exists in terms of area of site in hectares at the following web address. http://www.natureonthemap.org.uk/map.aspx?m=sssi
Condition assessment information in terms of area of site is summarised in Table 1.3 in a similar fashion to the summary presented in Table 1.2 by reporting categories and by management units.
Table 1.3 EN Condition Assessment and Percentage Area in Favourable Condition EN Reporting Categories (Area of SSSI Units, Ha) Area of Management Destroyed, SSSI Units, Unit Unfavourable Unfavourable Part-destroyed, Favourable % and Recovering and Maintained Unfavourable and Declining MU 12218056%
MU 200392%
MU 3 6 21 4 16 7%
MU 42811172712%
MU 5 93 136 12 78 45%
MU 6 7 29 148 16 28% TOTAL % Area of 22% 30% 26% 21% 100% Units
In Table 1.3, it can be seen that the highest area of the site under the ‘unfavourable and declining’ category can be associated with Management Unit 5. Management Units 5 and 6 have the highest area of land in unfavourable condition.
1.4 COMPONENT HABITATS AND THE cSAC DESIGNATED INTEREST FEATURES Component habitats of the site and percentage coverage are given in Table 1.4.
Table 1.4 Site Component Habitats and % Coverage Site Name Component Habitats % Coverage
River Itchen cSAC Inland water bodies (standing water, running water) 40 Bogs. Marshes. Water fringed vegetation. Fens 27 Humid grassland. Mesophile grassland 19 Improved grassland 1 Broad-leaved deciduous woodland 10 Mixed woodland 2 Non-forest areas cultivated with woody plants 1 (including orchards, groves, vineyards
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An overview of the cSAC interest features for the site is given in Table 1.5.
Table 1.5 cSAC Interest Features 1.1 Riverine Habitats (can be associated with the Annex 1 habitat type ‘Floating vegetation of Ranunculus of plain and sub-mountainous rivers’ for which the cSAC has been selected.) 1.2 Southern Damselfly 1.3 Bullhead 1.4 Atlantic Salmon 1.5 Otter 1.6 Brook Lamprey 1.7 Native Crayfish
The basis for the interest features is elaborated upon as follows.
Annex I habitats that are a primary reason for selection of this site:
Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho- Batrachion vegetation
Annex II species that are a primary reason for site selection:
Southern Damselfly (Coenagrion mercuriale)
Bullhead (Cottus gobio)
Annex II species present as a qualifying feature, but not a primary reason for site selection:
White-clawed Crayfish (Austropotamobius pallipes) Brook lamprey (Lampetra planeri) Atlantic Salmon (Salmo salar) Otter (Lutra lutra)
This assessment does not simply focus upon these species above, per se. The assessment recognises the importance of the habitats that support the species. Hence in assessing the impacts of Agency permissions upon these interest features consideration is given to both directly affects upon the species populations as well as indirect affects upon their supporting habitats (see Table 1.4). This approach is discussed further in the Introduction to Part B.
1.5 SUMMARY TABLE OF THE NUMBER OF PERMISSIONS GOING TO STAGE 3 A summary of permissions going to Stage 3, obtained from the Pro Forma for Stages 1 and 2 of the Review of Consents under the Habitat Regulations, is given in Table 1.6.
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Table 1.6 Summary of Permissions Going to Stage 3 Function Stage 1 Stage 2 Water Quality 6172 114 Water Resources 128 412 Radioactive Substances 01 21 Regulation Process Industry 33 26 Regulation Waste 17 0 Groundwater Authorised discharges to groundwater issued under the Authorisations Groundwater Regulations. None were identified in Stages 1 and 2 of the RoC process
Notes to Table 1.6: 1Number of RSR Stage 1 permissions is unknown. Hence, the explanation in the introduction of the Functional Assessment – Chapter 7, Part B. 5.
2There were 41 water resources permissions deemed to have likely significant effect after stage 2. There were 45 licences within the catchment assessed in stage 3. The reasons for the mismatch are explained in Part B.2. Additionally three other abstraction licences in Southampton Water were also assessed.
1.6 THE RIVER ITCHEN SUSTAINABILITY STUDY.
It is considered helpful to clarify the relationship between this appropriate assessment and the River Itchen Sustainability Study (hereafter referred to as RISS, or the Study).
The Agency conducted Stage 3 of the review of consents process through the RISS. The RISS was an AMP3 funded investigation which was carried out during the period 2000 to 2004. The Study was a collaborative project, managed by a steering group which included the Environment Agency, English Nature, water companies, local authorities and other key stakeholders and was project managed by Halcrow consultants.
The Study sought to collate existing local data and to generate new data about the abiotic and biotic attributes of the Itchen catchment in order to inform the RoC Stage 3 process. In some cases the new data involved innovative and ground-breaking work. It drew upon local experts with long standing familiarity with the catchment. Hence the supporting information includes a combination of field surveys, professional expertise, DNA work (southern damselfly and otters), laboratory analyses in relation to eco-toxicological assessments/water quality determinands, mathematical modelling and data analysis in a holistic manner.
Assessments were carried out for the River Itchen system as a whole and for the key interest features, including those for which the cSAC/SSSI was designated. Assessment methods were based on ‘best science’ and involved leading academics and consultants who are acknowledged experts in their fields both in the UK and internationally. Ecological models were used for salmon, trout and invertebrate assessments, but for the other interest features adequate data were lacking to make any modelling exercise meaningful.
The RISS had two chief products. Apart from generating a considerable amount of data it produced a DRAFT Strategy for the Itchen catchment, which aspires to provide a framework to guide long term sustainable management of the catchment as a whole. It will be moved forwards by the RISS Steering Group.
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The RISS DRAFT Sustainable Management Strategy is not part of the Agency’s review of consents Stage 3 appropriate assessment. They are two separate and distinct documents. The appropriate assessment is the Agency’s, and the decisions therein are the Agency’s alone.
However, the large volume of data and information collated by the RISS is common to both the RISS Strategy and to the appropriate assessment. The appropriate assessment draws upon this supporting information and refers to it in the assessment. Therefore, when considering this assessment, the reader if referred to both the attached supporting documentation and to the RISS Technical Appendices.
There are three RISS Technical Appendices:-
Ecology and Fisheries Technical Appendix Water Resources and Flow Technical Appendix Water Quality and Land Management Technical Appendix
A summary of the Study can be found at Appendix K.
1.7 REVIEW OF CONSENTS GROUP MEMBERS
A number of Agency and EN staff, local and national experts and consultants have been involved in writing this appropriate assessment. A list of those people directly involved is given in Table 1.7.
Table 1.7: Review of Consents Group Members (Names in brackets refer to Agency staff involved in Stages 1 and 2 only) Water Quality Emma Pattullo, Dave Lowthion (Paul Salmon) Water Resources Rod Murchie, Alison Rennie, Catherine Waite (Rob Waite) RSR (Peter Brember) PIR John Massie, Sam Rouse, (Barry Keyworth) Waste Licensing (Sara O’Hara, Paul Eden) FRB Kevin Exley, Adrian Fewings, Andy Thomas, Tim Sykes, Kate Blazeby, Area Habitats Directive Tim Sykes Co-ordinator Regional Habitats Directive Steve Cook, Jo Simmons EN RoC Officer Caroline Chapman and Zoe Masters EN Conservation Officer(s) Alison Graham-Smith Note: EN conservation officers who also contributed to Stages 1, 2, and 3 (before Alison Graham-Smith) are: Ian Davidson-Watts and Amanda Newsome. EN National Specialists Johan Schutten and Chris Mainstone Consultants John West, Peter Burgon, Alex Neculae, Kunle Akande. Jon Cox
In addition to those above, a large number of individuals were involved in generating the supporting documentation to this assessment, much of that through the RISS. This included local, nationally and internationally recognised experts, and consultants as well as Agency staff. For example (not an exhaustive list):-
Nigel Holmes (consultant) – macrophytes and invertebrate ecology; David Solomon (consultant) – fish ecology, fisheries management and angling;
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Derek Gent (Agency) – fisheries. Adrian Hutchings (consultant) – crayfish ecology; Paul Chanin (consultant) and Graham Roberts (HWT):- otter ecology; Richard Shore (CEH) – otter and eel tissue ecotoxicology; Dave Thompson and Ali Strange – Southern Damselfly; Adam Fulton (Ecologist) and Jim Rouquette (student) – Southern damselfly; Richard Collingridge (consultant) & David Gowing – wet grassland hydroecology; Andrew Johnson (CEH) – endocrine disruption; Elaine Fisher and Nicky Cunningham (Agency) – endocrine disruptors; Cath Charles (Agency) – Water Resources; Tony Burch (Flood Defence) - assisted with ground water modelling etc.
1.8 APPROACH AND DOCUMENTATION
1.8.1 Introduction The purpose of the Stage 3 appropriate assessment is to ascertain that the Agency permissions are not having an adverse effect upon the integrity of the site. Each Agency permission is assessed both alone and in-combination with one another and with other plans and projects. There are two possible conclusions to this assessment noted as follows:
1. The permission can be shown to have no adverse effect on the integrity of the site and will be affirmed in Stage 4 of the Agency’s Review of Consents (RoC) process OR
2. The permission cannot be shown to have no adverse effect on the integrity of the site.
The Stage 3 appropriate assessment developed a set of rules which guides the decisions made about adverse effects, for the assessment of permissions associated with the following Agency functions
Water Quality Water Resources These guiding rules and criteria are informed by and linked to by the supporting information. The rules and criteria follow the principles of the assessment criteria contained within the Agency Work Instructions for Stage 3 appropriate assessments, the specific features of the River Itchen cSAC, and are consistent with the Study’s mathematical modelling and data analysis outputs.
1.8.2 Spreadsheets for Completion of the Appendix 21 Pro Forma
For convenience, all information relating to the individual permissions, with respect to the Water Quality and Water Resources functional assessments are contained in the following Excel files.
1. Excel spreadsheet on file as: Water Quality Functional Assessments.xls 2. Excel spreadsheet on file as: Water Resources Functional Assessments.xls The Excel files are part of this document as Appendix D.
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Separate spreadsheets were not developed for the PIR and RSR permissions as these permissions are incorporated into their associated functional assessment tools.
1.8.3 Format of Report
In accordance with the requirements of the Habitat Regulations Review of Consents Stage 3 appropriate assessment work instruction, the format and content of this document follows the recommendations of the Appendix 21 Pro Forma. Consequently, we have organised this document into five parts namely:
Part A Site Details
Part B Functional Assessments
Part C (1) Multi Functional In-Combination Assessment of Agency Permissions
Part C (2) External In-Combination Assessments
Part D Overall Conclusions
Part E Final Appropriate Assessment Record
Appendices A to M are attached.
The reader is also referred to the three RISS Technical Appendices:-
Ecology and Fisheries Technical Appendix Water Resources and Flow Technical Appendix Water Quality and Land Management Technical Appendix
1.9 SUMMARY OF MAIN ISSUES, PERCEIVED RISKS AND RESPONSIBILITIES A summary of the main issues, perceived risks and responsibilities for the site are given in Table 1.8. The summary of site issues given in Table 1.8 can be related to the condition of the habitats types that make-up the cSAC/SSSI. The appropriate assessment has involved the evaluation of the impacts upon the habitats that support the characteristic species, including those for which the cSAC/SSSI was designated. Notes on assessments of the ability of the river to support characteristic species and habitats are given in Appendix J.
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Table 1.8: Summary of Main Issues, Perceived Risks and Responsibilities
Issue Features Responsibilities 1. Air quality All features Agency permits – PIR/IPPC/IPC Industrial discharges to air causing acidification, Local Councils – Part B processes nitrogen loading and VOCs, NOx and SO2.
2. Toxic Contamination All features Agency – Discharge consents/Waste/ PIR/IPPC/IPC From effluent discharges and aerial deposition Local Councils – Part B processes CEFAS DEFRA
Risk of exposure from fish farms and watercress farms Farming and Agriculture Sewage discharge from urban area and farms Industry in lower reaches of the site
3. Water quality All features Agency – Discharge consents; PIR/IPPC/IPC Floodwater Atlantic Salmon DEFRA Nutrient enrichment/ sediment toxicity/ siltation/ pH/ Ranunculus Community turbidity/smothering/oxygen demand/ changes in Southern Damselfly High sensitivity, exposure from fish farms and watercress thermal regime Otter farms, and industry in lower reaches of the site. Farming and agriculture. Phosphorus levels exceed those Soluble reactive phosphorus and suspended solids in conservation objectives. concentrations, BOD and Ammonia Sewage discharge from urban area and farms Unquantifiable impact of water quality upon loss of salmon at low freshwater flows. Siltation of gravel lowering incubation success rates Thermal plumes from e.g. Marchwood might adversely affect migration behaviour
Water quality issues of lower Itchen tributaries Agency – Environment Management
4. Water Resources All features Agency Development Control/ Fisheries Changes in water levels/table Atlantic Salmon Abstraction licences/ Discharge consents/Land Drainage Changes in freshwater flows to estuary/velocity Brook Lamprey Consents/ Water Level Management Plan might not regime address issues/ PIR/IPPC/IPC Changes in surface flooding English Nature – SSSI
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Issue Features Responsibilities Changes in salinity regime Reduced dilution capacity Abstraction reducing flow can slow migration and lower Land drainage water quality in lower reaches. Abstraction can also cause Entrapment entrapment of smolts. Abstraction outside of site may Drought period water abstractions, local impacts on affect interest features. riverine habitats Low flows caused by abstraction can cause sedimentation of gravel and may affect spawning and nursery areas, exacerbating potential effects of natural drought
5. Land Use (catchment/off site land use) All features Agency – Development Control, discharge consents, land drainage
Intensive agriculture impacts on water quality and hydrology Development pressure
6. Site management All features Agency – Fisheries, Flood Defence (bankside/channel management, weed cutting). Also involving the terrestrial parts of the cSAC e.g. bankside vegetation management.
7. Fisheries management Atlantic Salmon Agency – Fisheries /FRB/ fisheries owners Bullhead Brook Lamprey Fisheries management operations, control of poaching – Southern Damselfly result of activities related to salmon fishing interests Fisheries management contrasts with requirements of Southern Damselfly
Note that most of the interest features need different habitats. 8. Barriers to movement Agency – Fisheries/FRB/Flood Defence
Obstructions to migration Atlantic Salmon Road crossings, safe access through system Otter Entrapment
9. Flood and Coastal Defence All features Agency – Flood Defence operations
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Issue Features Responsibilities Weed-cutting, Water level management 10. Non-physical disturbance noise/recreation) Otters Agency – Development Control
Shooting/noise
1. Physical damage (e.g. dredging/trampling) All features Agency – Development Control, FRB
Brook Lamprey Recreation, fishing, Country Parks, damage prevention by Atlantic Salmon fencing Bullhead Damage to channel morphology Ranunculus Community
2. Biological Disturbance (e.g. non-natives, extraction) All features Agency - FRB White-clawed Crayfish Major threats from Signal Crayfish (e.g. “Plague”), other non-native species and invasive plants
3. Habitat fragmentation/barriers to migration Southern Damselfly Agency - FRB
Habitat loss and entrapment of fish Atlantic Salmon Agency – Fisheries/FRB, Development Control
Impoundments – fish migration, development and proposed road crossings Large scale sea water abstractions could cause entrapment of fish
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PART B – FUNCTIONAL ASSESSMENTS
2 INTRODUCTION
This section introduces four overarching issues that are applicable to the functional assessments in Part B, (and to Part C):
in-combination, including judgements of triviality;
Interest feature species and their supporting habitats;
typical species;
off-site impacts; and
a description of how the Agency has developed and used ‘Integrity Tables’ in applying the Integrity test.
2.1 THE IN-COMBINATION TEST: TRIVIALITY Appendix 21 (Version 2) of the Agency’s guidance outlines that if the Agency determines that it cannot be shown that an Agency permission, on its own (alone) will not adversely affect the integrity of a site, then automatically all other permissions that add to that effect on the same interest feature of the same European site must, in-combination, also be deemed to contribute to the adverse effect on site integrity.
The only way such combined effects should not be deemed to be contributing to such a conclusion is where their combined contribution is ‘trivial’ as a proportion of the overall adverse effect upon site integrity.
The guidance specifically states that what constitutes trivial will necessarily be made on a case by case basis by the Areas, reflecting to the specifics of each individual site in question.
The Area defines triviality as follows: a) a trivial effect is one where, due to the scale, nature and duration of the consents considered and their associated environmental influences, it is not reasonably foreseeable that their contribution, alone or in-combination, to the effects on the site will result in any measurable change to the structure and/or function of the site; and b) there is no realistic mechanism by which they could act together 'in-combination’.
The determination of triviality is separate to, and comes before the conclusion of no adverse effect or cannot be shown to have no adverse effect on site integrity in-combination.
The Area has complied with Agency guidance (Appendix 21, Version 2; and an In- combination advice note, 5th February 2004). The Area has applied this definition of triviality throughout Parts B and Part C, when considering the in-combination test.
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2.2 INTEREST FEATURE SPECIES AND THEIR SUPPORTING HABITATS.
Clearly not all of the habitats within the cSAC boundary are Annex I habitat, in the same way as the Macrophyte community is, but rather they are included within the site for the supporting role they play to the interest features of the cSAC.
In considering impacts upon the species interest features the Agency has applied the following tests:-
Population data indicate that the species is maintaining itself on a long-term basis as a viable component of its natural habitats.
The species’ natural range is neither being reduced nor is likely to be reduced for the foreseeable future.
There is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.
Hence in assessing the impacts of Agency permissions upon these interest features consideration is given to both indirect effects upon their supporting habitats as well as directly effects upon the species populations. This is the case throughout the assessment.
The Agency collated and generated a great deal of Itchen-specific data on the listed interest features and their supporting habitats. This is all presented in the Ecology and Fisheries Technical Appendices.
Table showing which habitats within the Itchen cSAC are most utilised by which species interest feature.
Component habitat % coverage Salmon Bullhead Lamprey Southern Crayfish Otter of cSAC Damselfly Inland water bodies 40 (standing water, running water) Bogs. Marshes. Water 27 fringed vegetation. Fens Humid grassland. 19 Mesophile grassland Improved grassland 1 Broad-leaved deciduous 10 woodland Mixed woodland 2 Non-forest areas 1 cultivated with woody plants (including orchards, groves, vineyards Total 100%
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The Agency’s approach in this assessment for the interest features is described further below. The assessment discusses issues that affect the condition of these habitats, such as site management, in Part C.2.
Fish and Crayfish. The assessment considers the impacts of Agency permissions upon the fish species populations and upon their supporting habitat. In terms of habitats the assessment has focussed upon the aquatic habitats that include the main river, tributaries to the main river, and the Itchen estuary.
The crayfish interest feature is currently found only in MUs 2&3. Historical evidence suggests that crayfish once occupied the whole system. The assessment has considered the impacts upon the species itself and the habitats that support the species, irrespective of whether or not the interest feature is currently there or not. The assessment has focussed upon the aquatic habitats that include the main river and its tributaries.
Southern Damselfly. The assessment has considered impacts on a number of habitats thought to play a supporting role to this species. Clearly the riverine environment is a key one as the species occurs on the main river. Other habitats are characterised by ditches flowing through old water meadows, which themselves fall into the category of wet grassland and, where undermanaged, fen. In these habitats there are two key elements that sustain the species. The nature of the ditches is critical, and that includes many abiotic attributes such as water level, water velocity, and water chemistry, and biotic factors such as the structure and composition of emergent and marginal vegetation.
The water supply to these ditches comes directly from the main river via control structures, so Agency permissions have the potential to impact upon these habitats via affecting the river or by directly affecting the non-river habitats. The terrestrial nature of these habitats also sustains the species both directly during their adult stage and indirectly by affecting the ditch, it’s physical structure and the water therein.
The approach adopted by the Agency in this assessment has been to focus especially upon the impact of Agency permissions on the water in the ditch networks within these habitats and in the main river that supplies the water to these ditches. Reference to the species in the assessment hereafter should be taken as always referring to impacts upon the species populations and/or it’s supporting habitats including these non-riverine, non-Annex I habitats.
Otter. The otter is a landscape scale species in terms of its mobility and typical home range. Transient otters will also likewise cover large areas sometimes in short periods of time, and hence come into contact with a diverse range of habitat types. Some of these might not obviously support the population as a whole, but even small ditches and hedgerows, some remote from a river or wetland, may provide corridors for the movement of otters between catchments. Hence to be precautionary it is reasonable to presume that in the case of the Itchen the otter population is reliant at least for some time upon all of the habitat types that exist within the cSAC boundary.
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The most important element will be the aquatic environment, the river, it’s tributaries, ponds and the wetland habitats. The other habitats might be regarded as a landscape matrix within which these key habitats occur and provide linkages between them all.
In that respect the assessment has focused especially upon the impact of Agency permissions on the water environment in the river and it’s tributaries and the same ditches that support the southern damselfly. The assessment has not considered every pond or wetland within the catchment, as it is considered not practical to work at the micro-habitat level. Nor is it considered necessary, as the otter population will not be affected by impacts upon individual small ponds within the wider landscape context.
Reference to the species in the assessment hereafter should be taken as always referring to impacts upon the species population and/or it’s supporting habitats including these non- riverine, non-Annex I habitats.
The assessment discusses issues that affect the condition of these habitats, such as site management, in Part C.2.
2.3 TYPICAL SPECIES. Article 1 of the Habitats Directive defines the status of natural habitats as partly defined by characteristic, or typical, species. This is discussed further in guidance produced by the EC on Article 6 of the Directive (“Managing Natura 2000 sites – the provisions of Article 6 of the ‘Habitats’ Directive 92/43/EEC”, EC, April 2000). English Nature recognise the importance of considering typical species when applying the ‘integrity test’, as set out in their guidance note : Site Integrity, February 2004.
In undertaking this appropriate assessment, and determining conclusions relating to effect on site integrity, the Agency has considered typical species associated with the interest feature : Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho- Batrachion vegetation – a riverine habitat type. The assessment does not present a conclusion against each and every one of the typical species but, in a more general approach, in reaching each conclusion the Agency has considered these species. That is particularly an element of the Agency’s considerations as expressed through the ‘Integrity tables’.
A useful discussion of the ecological interests of chalkstreams including typical species is presented in the EN publication “ChalkRivers – nature conservation and management, C.P.Mainstone, 1999.”
Where particularly relevant, impacts upon one or more of the typical species/communities is discussed in the assessment in Part B.
On that basis, the conclusions set out in Parts B (and Part C) all consider the following typical species:
Invertebrate communities;
Water vole;
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Brown trout (wild);
Communities of coarse fish associated with the river (e.g. eel, roach brown trout);
Riverine bird species (e.g. kingfisher, little grebe, grey wagtail, gadwall);
Wildfowl, Waders and Breeding Passerines;
Aquatic plants include:- pond water-crowfoot Ranunculus peltatus, stream water-crowfoot R. penicillatus ssp. Pseudofluitans, Starworts Callitriche obtusangula and C. platycarpa, lesser water-parsnip Berula erecta, aquatic moss Fontinalis antipyretica.
Typical species and habitats are discussed further in Appendix J and the RISS Ecology and Fisheries Technical Appendix.
2.4 OFF SITE IMPACTS 2.4.1 Introduction Stages 1 and 2 considered permissions that are inside or outside of the boundary of Natura 2000 sites, but which might affect the site. A good example is groundwater abstractions that although possibly a long distance outside of the River Itchen cSAC boundary, abstract from the same aquifer and thus being in hydrological continuity with the site, have the potential to affect it. The RoC Stage 3 process addresses Agency permissions likely to significantly effect the site irrespective of whether the permissions are located within or outwith the site.
Another type of impact is where the interest features of the site leave the site boundary and come within the zone of influence of a permission that is outside the site. This type of impact is specifically addressed in sections of the appropriate assessment headed “Off-site Impacts”.
Of the interest features identified in Section 1.4, it is thought that only Otter and Atlantic Salmon are potentially vulnerable to being exposed to off site impacts in so much as they are known to leave the Itchen catchment as part of their natural behaviour. However, as discussed below the Agency believes that it is unreasonable to consider the impact of Agency permissions on the otter outside of the catchment. We do consider it reasonable to apply the off-site impacts assessment to salmon, as described below. Consequently the discussion of off-site impacts in the following functional assessments is focussed on the salmon interest feature.
2.4.2 Otters It is impossible to define the River Itchen cSAC ‘otter population’ in terms of its geographical extent. Otters are a wide-ranging species and individuals can occupy very large home ranges that may span more than one catchment. In addition to resident otters, whose ranges may cover tens of kilometres, otter populations include transient animals that move over much greater distances within and between catchments. The DNA fingerprinting, carried out as part of the Study (Technical ref E (S) 01 of the Ecology/Fisheries Technical Appendix), showed that otters probably move readily between the Itchen and Hamble catchments and otters from the Test have been found on the Itchen. Of the 13 individual otters identified through the DNA work, no more than six were ever recorded within the catchment at any one time.
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Accepting the weaknesses inherent in this new science, it can be said that there is practical evidence of extensive movements of the otters that comprise the Itchen population, into and out of the Itchen catchment.
On that basis the Agency determines that it is beyond the scope of this appropriate assessment to reasonably investigate every Agency permission through Stages 1 to 3, over an indefinable geographic area that might be visited by individual otters that form part of what can loosely be called the ‘Itchen cSAC otter population’. This determination is based on the fact that the:
area that might be visited by otters is indefinable; and
the risks to otters over a wider area than beyond the Itchen catchment are considered below.
The Agency has not undertaken site-specific investigations into permissions and prevailing conditions in adjacent catchments even though these may potentially affect the Itchen otter population. Instead the Agency has adopted a risk-based approach and considered the risks posed by Agency permissions, over a wider area than just the Itchen catchment.
The investigation into otters within the Itchen catchment is unique in its breadth and scope – see Technical ref E(S) 01a-b of the Ecology/Fisheries Technical Appendix. These studies include DNA fingerprinting studies, ecotoxicological examination of both otter tissues and otter prey (eels), and post mortem examinations of dead otters. The investigations conclude that the otter population is in favourable condition. The eel tissue analysis covers a 10-year period and the otter tissue analysis a 5-year period. The otter tissue work also includes dead otters recovered from adjacent catchments.
Abstraction licences, discharge consents (and impacts on water quality from lower Itchen tributaries such as Bow Lake stream – an important corridor linking the Itchen and Hamble catchments), and PIR/RSR consents are not directly implicated as key factors influencing the condition of the interest feature at present. On that basis the Agency concludes that the risk of adverse impacts on otters from Agency permissions is low both within the Itchen catchment and in neighbouring catchments.
In reaching this determination, the Agency has considered a wider geographical area. It is reasonable to assume that the main threats to the population in the Itchen are applicable in adjacent catchments, although the nature and scale of these is unknown. However, locally, there is evidence that otters have re-colonised the Test and Hamble catchments within recent years. It is safe to assume that environmental conditions are not preventing the recovery of the population locally.
On a wider regional scale, evidence of otters has also increased in the large geographic area spanning the gap between the Itchen cSAC and the nearest other cSAC where the otter is also an interest feature, the River Avon. Moreover the intervening area supports extensive areas of high quality habitats suitable for otters including the Solent Maritime cSAC, Solent and Southampton Water SPA and Ramsar, the New Forest cSAC, SPA/Ramsar, the River Lymington SSSI; and the River Test SSSI.
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The Agency concludes that the habitats available in the areas surrounding the Itchen catchment are of sufficient variety, quality and extent to ensure the long term viability and integrity of the Itchen cSAC otter population.
On this basis the Agency concludes that the integrity of the Itchen cSAC otter population is currently and reasonably foreseeably not adversely affected by off-site Agency permissions at present, or likely to be in the future. On that basis otters are not considered further in this assessment in terms of off-site impacts.
In reaching this determination, the Agency has consulted with Paul Chanin (internationally known mammal ecologist); Graham Roberts, Otters and Rivers Project Officer, Hampshire and Isle of Wight Wildlife Trust; and Tim Sykes, Biodiversity Technical Specialist, Agency, Hampshire and Isle of Wight Area.
2.4.3 Atlantic Salmon The Agency considers it appropriate to review permissions in Southampton Water with regards to impacts upon the Itchen salmon population, an interest feature of the Itchen cSAC.
The Itchen salmon population passes through Southampton Water on its migration to and from the River Itchen cSAC. Such a well-defined migration route brings the species into the direct influence from identifiable hazards associated with specific Agency permissions, with potential to affect the interest feature on a population scale. For this reason the Agency has reviewed abstraction licences and discharges in Southampton Water through the functional assessments.
The appropriate assessment does not extend this approach beyond Southampton Water. The Agency considers it outwith the scope of this appropriate assessment to review Agency permissions for their impacts upon the integrity of the Itchen cSAC salmon interest feature, when the migration route passes beyond Southampton Water. Other factors affecting the habitat of migrant salmonids in other countries or other parts of the UK may be the subject of other Agency permissions or external plans or projects in the future. However, it is considered beyond the scope of this appropriate assessment to take such Agency permissions and external plans or projects into account.
If it is imagined that Agency permissions associated with the site might affect salmon from the Itchen once they migrate beyond Southampton Water, then the reasonably foreseeable risks to the population from Agency permissions are greatly reduced by the buffering effects of the oceanic influence – the influence of natural marine factors (which are discussed further in Part C), will have an influence upon Agency related impacts.
The concept of an Itchen cSAC salmon population becomes impossible to define once the species enters the marine environment, where it shares its migration route with salmon from many other rivers. Once the ‘Itchen’ salmon leave Southampton Water they mix with salmon from other rivers, and that ‘mixed-stock’ population becomes too heterogeneous for the Agency to be able to apply Regulation 50 with any certainty to permissions or to properly assess factors, which might affect the integrity of the Itchen salmon.
Under normal circumstances, it would be beyond the ability of the Agency to undertake an ‘in combination’ assessment of all plans and projects affecting habitats used by migrant species
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anywhere within their natural range. This could involve considering plans and projects within other Member states of the European Community, or other regions of the UK. It seems unlikely that it was the intention of the Habitats Regulations for such a wide-ranging ‘in combination’ assessment exercise. Furthermore, the Agency’s Area-led approach to the RoC process does not lend itself to such Regional, UK-wide or international assessment. In addition, there is insufficient scientific information to link the populations of migrant species within the Solent with other sites within the UK, other Member States or more widely within the salmon’s natural range.
The effects of abstractions and associated discharges have been investigated and reported through Technical ref W (DD) 03 and W (DD) 04 of the Water Quality Technical Appendix. The “off-site” impacts from these abstractions and discharges (including heated outfalls) are taken into account through the functional (Parts B.1, B.2 and B. 4) and the multi functional in- combination assessments (Part C.1).
2.5 INTEGRITY TABLES. The Area has developed a mechanism to assist in the process of applying the integrity test. This tabular framework is based upon the definition of integrity set out in English Nature’s ‘Integrity paper’, (February 2004).
The Integrity tables are a decision making tool. They come in two parts: -
Part 1 table asks the five questions from English Nature’s Integrity paper but also includes reference to typical species and species range. Where the answer is ‘Yes’ to a question then the permission(s) is not adverse effect on integrity. Where the answer is ‘No’ then the conclusion is cannot show not adverse.
The 2nd table answers key site specific factors in relation to each question answered ‘No’ in the first table.
The Integrity tables enhance the whole assessment process by clearly demonstrating which Agency permission is effecting different elements of site integrity for each interest feature and in what way. It is possible to follow each permission through the process as every licence in Stage 3 goes through the tables.
However, the tables are not stand-alone. The assessment discusses a great deal of technical information and that must be read in conjunction with the tables.
Furthermore, to avoid repetition the specific licences that are concluded as cannot show adverse are listed in the tables, those for which the answers are ‘Yes’ , are not listed.
This approach was discussed with the EN Local Team and Zoe Masters and as a result of that consultation modifications have been made to the integrity tables to reflect EN comments. This approach is now agreed with EN.
Certain ‘rules’ apply to how the tables are completed as described above and in the following examples for the Solent Maritime cSAC.
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Example 1 : Part 1 table: Solent Maritime cSAC ANSWER ‘YES’ OR ‘NO’ IN EACH APPROPRIATE BOX FOR ALL PERMISSIONS. LIST PERMISSIONS THAT RECEIVE ‘NO’ ANSWERS IN THE BOXES CONCERNED. Integrity of site check list with respect to organic enrichment
Has the appropriate assessment shown that?
Assessment of habitats Assessment of habitat and species Assessment of species populations populations
Features for which the cSAC has 1) The area of annex 2) There will be no 3) The 4) There will be no 5) There will be no 6) The natural 7) There will be no been selected 1 habitats (or changes to the conservation interruption or direct effect on the range of the indirect effects on composite features) degradation of the will not be reduced? composition of the status of the site’s physical, chemical or population of the species within the the populations of habitats for which typical species is biological processes that species for which site is neither species for which the site was favourable (as support habitats and the site was being reduced nor the site was designated (e.g. defined in 5 – 7) species for which the site designated or is likely to be designated or was designated or reduction in species classified classified reduced for the classified due to structure, foreseeable future loss or degradation abundance or of their habitat diversity that (quantity/quality) comprises the habitat over time Estuaries Yes No (permission(s) No (permission(s) No (permission(s)
Atlantic saltmeadow Yes Yes Yes Yes Spartina swards Yes Yes Yes Yes
Sandbanks that are slightly covered Yes by sea water all the time Yes Yes Yes
Mudflats and sand flats not covered by sea water at low tide Yes No (permission(s) No (permission(s) No (permission(s)
Saline lagoons Yes Yes Yes Yes
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Annual vegetation of drift lines Yes Yes Yes Yes Perennial vegetation of stony banks Yes Yes Yes Yes Salicornia and other annuals colonising mud and sand Yes Yes Yes Yes
Shifting dunes along the shoreline with Ammophila arenaria (white Yes Yes Yes Yes dunes)
Desmoulin’s whorl-snail Vertigo moulinsiana Yes Yes Yes Yes
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Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Part 2 table: Example for Consideration of impacts against site integrity bullet points (‘key site specific factors’)
Habitats or Populations with ‘No’ answers in Stage 1 table1
Site Specific Integrity Estuaries, Factors Mudflats and sand flats not covered by sea water at low tide
Scale of impact Benthic invertebrate community impacted over an area of 48 ha2 of cSAC habitats; this is considered an adverse effect
Long term effects and biological Impacts have been affecting habitats for many years hence any lag effect will (lag) already be in evidence. There may be issues of sustainability relating to the cumulative impact of persistent pollutants within the mudflats
Duration of impact and The effect is likely to be long term but habitat would recover if discharge recovery/reversibility quality was improved or removed
Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site
Conflicting feature requirements There are no conflicting feature requirements
Off-site impacts The discharges have on site and off-site impacts (above and below MLW) for species associated with the habitat (typical species)
Uncertainty in cause and effect There is certainty of a relationship based upon results of benthic invertebrate relationships and a precautionary survey in the vicinity of outfalls approach
1 Licences considered in this table must be identified. In some instances, one Part 2 table will be needed per No answer, in others No’s can be grouped together and considered in the same Part 2 table 2 Where possible provide a measure of impact either as an area or percentage of the habitat or feature affected within the site (although beware of placing too much weight on percentages as impacts can nearly always be shown to have a small impact on a much bigger resource at a site, region, country or European level)
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PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT
3 WATER QUALITY ASSESSMENT
3.1 SUMMARY OF OUTCOMES The outcome of the appropriate assessment of the River Itchen cSAC for the Water Quality Functional Assessment is summarised in Table 3.1 below.
Table 3.1 Summary of Water Quality Functional Assessment conclusions.
Total number of Water Quality Permissions
Total No. of consents assessed in Stage 3. 115
Can be shown to not be having an adverse 62 effect on the integrity of the site Cannot be shown to not be having an adverse 15 effect on the integrity of the site alone Cannot be shown to not be having an adverse effect on the integrity of the site in- 51 combination
3.2 IDENTIFICATION OF ‘LIKELY SIGNIFICANT EFFECT’ PERMISSIONS The Review of Consents is a staged process of which this is the third stage. Figure 3.1 identifies the various consented water quality discharges which have passed through to Stage 3 of the review process and hence are considered in this assessment. There are 114 consented discharges in total which came forward for consideration in Stage 3, comprising:
- 5 water company sewage treatment works (STW). These are medium to large plants serving small villages up to large urban areas. All of the works considered here have at least secondary (biological) treatment systems.
- 72 private sewage discharges. These may be septic tanks (typically draining into the ground) or package plants serving only a few houses or a small industrial area. Effluent treatment levels are generally lower than at water company works but the volumes of these discharges are typically small, often less than 1 cubic metre per day.
- 23 trade discharges. These include effluents from watercress and fish farming operations, agricultural effluents.
- 14 intermittent discharges. This includes storm sewage overflows (which operate to reduce water levels in sewage networks during prolonged periods of heavy rain), emergency discharges (which operate only in times when there is no alternative e.g. a power failure combined with a failure of backup generators) and surface water drainage from industrial sites.
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The screening criteria used in Stages 1 & 2 are described below. The stage 2 assessment of ‘likely significant effect’ was made using locally derived criteria as no national guidance had been developed at that time. It was a pragmatic assessment based on effluent volume, nature of the effluent and location of the discharge.
Stage 1 : ALL consented discharges within the Itchen catchment, including all tributaries, were deemed ‘relevant’ to the River Itchen cSAC.
Stage 2 : The following groups of discharge consents were deemed NOT to be ‘likely to have a significant effect’: All discharges downstream of the designated area have been screened out on the basis that there is no mechanism for them to impact the designated area. (NB: Following further investigations in Stage 3, this decision was reconsidered to take account of potential off-site effects on migratory Atlantic salmon during their passage through Southampton Water and the Itchen Estuary. See later sections for details). All private sewage discharges <5m3/d which are >1km from any part of the site and are geographically isolated, i.e. no other sewage discharges within 1km, have been screened out on the basis of no impact due to dilution and dispersion of a small volume over at least 1km. Uncontaminated surface water and uncontaminated site drainage discharges have been screened out on the basis of no compounds of concern in the discharges. All discharges to ground which are greater than 250m from any part of the designated site, with volume <5m3/day and in an area of >2m unsaturated thickness have been screened out on the basis of microbial breakdown of sewage discharges and no significant dilution and dispersion in the underground strata.
All remaining discharges passed through to the appropriate assessment stage.
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- 38 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Figure 3.1 - Discharge consents identified as ‘likely to have a significant effect’ on the River Itchen cSAC.
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3.3 WATER QUALITY RELATED HAZARDS AND SENSITIVITIES As discussed in Section 3.1.2, consideration of hazards, sensitivities and risks of exposure of each permission type to each interest feature underpinned the appropriate assessments. The generic Water Quality function sensitivity matrix, adapted as appropriate for the site, is given as Tables 3.2 and 3.3.
The identified potential hazards associated with Water Quality Risks are:
toxic contamination nutrient enrichment pH salinity changes to thermal regime particulate transport including turbidity and siltation
Table 3.2: Sensitivity and Likely Exposure Matrix for Habitat Groups Considered in Water Quality Functional Assessments Habitat Groups
Hazard Upland Dry grassland Dry woodlands Standing waters Riverine habitats Riverine Standing waters not acidification sensitive acidification sensitive acidification sensitive acidification acidification sensitive acidification Dry heathland habitats Dry heathland Bogs and wet habitats, Fens and wet habitats not Fens and wet habitats Toxic contamination Nutrient enrichment pH Salinity Changes to thermal regime Turbidity and Siltation
Source: (EU Habitats and Birds Directives. Handbook for Agency Permissions and Activities)
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Table 3.3: Sensitivity and Likely Exposure Matrix for Species Groups Considered in Water Quality Functional Assessments Species Groups
Hazard habitats habitats grassland Liverworts wet habitats Amphibians aquatic habitats Invertebrates of Invertebrates Vascular plants, wooded habitats Anadromous fish Vascular plants of Vascular plants Mammals of riverine Mammals Mammals of wooded Mammals invertebrates of rivers Vascular plants, lower Vascular plants, plants & invertebrates, Non-migratory fish and fish Non-migratory Toxic contamination
Nutrient enrichment
pH
Salinity regime
Thermal regime
Turbidity and Siltation
Source: (EU Habitats and Birds Directives. Handbook for Agency Permissions and Activities)
The relationship between hazards, cSAC/SSSI habitats, favourable condition attributes, interest features and methods of assessment is given in Table 1.4. The designated interest features for the site are given in Table 1.5. Discussion of each of the identified hazards in relation to the interest features is given below. Further information on the status of cSAC and SSSI interest features and factors affecting status is given in Appendix C.
The following sections further characterise the potential hazards faced by the interest features of the Itchen cSAC.
Toxic Contamination All biota will be sensitive to toxic contamination. This includes a wide range of potential contaminants including pesticides, herbicides, heavy metals and hydrocarbons. However, by reference to the favourable condition tables, determinands that can be associated with toxic contamination also include biochemical oxygen demand (BOD) and ammonia, with potential adverse effects on interest features after discharge.
The nature of the Itchen catchment is such that there are few trade discharges from manufacturing-type industries, which are the typical public perception of ‘toxic’ discharges. The main toxic contamination threats to the Itchen cSAC are from agricultural sources (direct and diffuse pollution), watercress and fish farms, urban run-off and large sewage works.
Specific concerns which have been raised in relation to potential sources of toxic contamination in the Itchen are:
Pesticide inputs (from agriculture & watercress farms)
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Zinc inputs (from watercress farms)
Endocrine disruptors (from major sewage works)
The interest features associated with the site which potentially could be mostly affected by toxic contamination are: salmon and other fish, southern damselfly and river invertebrates.
Nutrient Enrichment The impact of nutrient enrichment on characteristic habitats and species may be direct or indirect. Direct impacts can be manifested through changes to species diversity and abundance. The macrophyte community is an interest feature which can display signs associated with direct impacts of nutrient enrichment.
The effects of elevated soluble phosphorus concentrations can produce a direct effect on the macrophyte community through altering the species diversity and abundance.
Indirect effects include the stimulation of excessive biofilm growth which impacts on the macrophyte community, the invertebrate population and hence on the fish population through reduced food availability and excessive dissolved oxygen diurnal variations
Sources of nutrients to the Itchen cSAC include direct input from Agency consented sewage and trade discharges and diffuse input through run-off.
The interest features associated with the site which are most likely to be affected by indirect impacts of nutrient enrichment include: salmon, southern damselfly larvae, trout and river invertebrates. pH pH values outwith the range of 6 to 9 can inhibit fish activity. Chalk river water has a strong buffering capacity and it is highly unlikely that pH levels will ever be of any concern in the Itchen cSAC. Therefore the features of this site are not seen as vulnerable to pH-related impacts.
Salinity The main potential salinity related hazard for the Itchen cSAC is any change in the salinity regime which might lead to changes in the migration patterns of Atlantic salmon into the river system. Saline intrusion to the lower end of the river is currently controlled by the flow controls at Woodmill. Saline water from the estuary may be able to overtop these controls during low river flow periods coinciding with high spring tides, however no documented evidence of this has become available. The extent of the saline intrusion will be limited by the slope of the river bed. Thus the potential for any salinity related impact on interest features will be limited to the lowest reaches of the river.
Conversely, any changes in river flow out into the estuary can alter the salinity structure of the estuary both vertically and longitudinally. However the salinity structure is dominated by tidal forces and thus any small change in river flow is unlikely to present a hazard.
Changes to Thermal Regime
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Changes in the thermal regime of the river could affect most if not all of the interest features of the cSAC, the nature and scale of the potential effects would depend on the magnitude of the deviation from the natural thermal regime.
Chalk stream habitats are often thought to be naturally resistant to significant changes in the thermal regime, due to the influence of the groundwater-fed base-flow, which remains within a small temperature range throughout the year. Measurements of water temperature at the lower reaches of the river indicate that the lower reaches are heavily influenced by air temperature. Given that the headwaters are often shallow and well mixed there appears to be ample opportunity for water of the upper catchment to exchange heat with the environment.
Groundwater temperature is normally in the range 10-12 C all year round whereas the river temperature at Gaters Mill varies between about 4 and 21 C, clearly river water temperature in the lower river is not dominated by the groundwater temperature.
River water temperature also appears to be highly correlated to river discharge, at low discharge water temperatures are high. This may be largely due to the seasonal nature of rainfall and day length but the time of travel from the headwaters to the sea is markedly higher at low discharge allowing more time for water to exchange heat with the air. It is conceivable therefore that factors affecting river discharge may influence river water temperature.
However, it is not considered likely that effluent discharges will significantly affect river water temperature.
Turbidity and Siltation Sediment transport in Chalk rivers such as the Itchen can lead to deposition in the gravels beds used by salmon for egg laying and hatching (redds). These activities occur over the winter period when flows and suspended sediment transport concentrations can be at their highest. In a natural system, water tends to flow through the gravels and help to keep the eggs well oxygenated. Blocking of redds by sediment can lead to harmful low oxygen concentrations. Organic particulate matter is a particular problem as it can both impede flow and lead to oxygen demand. Elevated organic matter levels can be a consequence of elevated phosphorus concentrations which lead to elevated levels of algal growth. Organic matter can also enter the river through agricultural run-off, watercress farms and via consented discharges.
3.4 KEY DETERMINANDS AND STANDARDS The key determinands result from EN’s ‘Common Targets’ and ‘Extra Targets’ for the seven interest features listed in the ‘Common objectives for the European Interest on the SSSI’ – the River Itchen cSAC conservation objectives (Appendix A). These are the determinands around which the majority of the water quality assessment has been carried out.
The most sensitive interest feature to water quality (as defined in the conservation objectives) is Atlantic salmon which require a RE (river ecosystem) class 1 river water quality standard and a limitation on suspended solids concentration to protect spawning processes in the redds. The RE class is determined on the basis of a three year rolling monitoring programme and depends on observed levels of the determinands listed in Table 3.4 below.
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Other key species do not require such tight standards; bullhead and brook lamprey require water quality to meet at least RE2 whilst white-clawed crayfish can survive in water of quality class RE3. These standards have been used in considering assessments for these three species, otherwise the general standard of RE1 has been used as there is no defined conservation objective with respect to general chemical water quality for the other designated features e.g. the macrophyte community.
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Table 3.4 – River Ecosystem (RE) class 1 standards Determinand Standard Compliance statistic Dissolved oxygen 80 % saturation 10 percentile Biological oxygen demand (BOD) 2.5 mg /l 90 percentile Total ammonia 0.25 mg N /l 90 percentile Unionised ammonia 0.021 mg N /l 95 percentile pH 6.0 to 9.0 n/a Dissolved copper * 112 μg /l 95 percentile Total zinc * 500 μg /l 95 percentile Notes to Table 3.4 * The standards for dissolved copper and total zinc are dependent on the hardness of the water. The standards quoted here are for hardness greater than 100 mg CaCo3 /l, as is typical of chalk streams such as the River Itchen.
The conservation objectives also define the a limit for suspended solids, to protect Atlantic salmon, as shown in Table 3.5.
Table 3.5 - Standard for suspended solids Determinand Standard Compliance statistic Suspended solids 10 mg/l Annual mean
The general habitat requirement for soluble reactive phosphorus levels has resulted in standards being agreed for the River Itchen between EN and the Agency. The standards depend on the dominant geology of the area and the long-term mean flow class of the river stretch. The standards aim to avoid high concentrations of phosphorus interfering with competitive interactions between plant species, leading to the dominance of attached forms of algae and loss of characteristic plant species. The standards are given in Table 3.6 below and may also be found in Table W2.1 of the Water Quality Technical Appendix.
Table 3.6 - Soluble phosphorus standards Management Unit (Reach) Soluble Phosphorus Standard (g P/l)
MU 1 (Upper Itchen) 40 MU 2 (River Alre) 60 MU 3 (Candover Stream) 40 MU 4 (Alre confluence - Easton) 60 MU 5 (Easton - Otterbourne) 60 MU 6 (Otterbourne – Chickenhall STW) 60 MU 6 (Chickenhall STW – tidal limit) 100* Notes to Table 3.6 These standards are defined as the annual long-term mean concentration required, typically assessed over 3 to 5 years.
* Due to the rapid transportation time from Chickenhall STW to the estuary, it has been agreed with English Nature that the 100g/l P standard for this reach is measured as soluble reactive phosphorus and not total phosphorus.
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3.5 SITE CHARACTERISATION This section describes the current status of the various water quality aspects of the cSAC. This characterisation is typically based on routine monitoring results at a number of key sampling locations through the catchment, however these data are supported by more detailed information where available. The routine data available to the study consisted mostly of monthly spot sampling for RE/GQA (General Quality Assessment) assessment purposes. Some additional water quality monitoring has been carried out in recent years to support the review of consents and results have been incorporated where appropriate.
A common limitation of traditional spot sampling techniques is that the results are not necessarily representative of the whole reach or of the extreme limits of quality at a given location. This problem has become more acute in recent years as sampling resource has been reduced with consequent reduction in data availability. It should however be noted that routine sampling locations are specifically chosen to be as representative as possible of the reach whose quality they define, and that the timing of sampling is staggered in order to provide as representative a picture as possible of temporal variations in quality. Where data gaps have been identified during the investigations on this site, it has been attempted to fill these gaps through a targeted sampling programme but again, limited resources meant that only key gaps could be addressed.
This section therefore, whilst heavily reliant on routine data from set locations, has attempted to describe the applicability of these results to the rest of the river stretches and the extent to which the data used are likely to reflect the occurrence of extreme values.
3.5.1 Toxic contamination Sanitary determinands - The sanitary determinands of ammonia and BOD are used to provide protection to fish from inappropriate levels of unionised ammonia and oxygen. Input sources of these determinands to the river include consented point sources (e.g. sewage treatment works, industrial discharges, storm sewer overflows) and diffuse sources (e.g. agricultural run-off, urban drainage).
The RE classification system includes standards for all these determinands. In 2002 the main river achieved the RE1 target for all determinands with the exception of the River Itchen reach from Eastleigh STW downstream to the British Rail outfall which met RE2 standards.
There are fourteen routine RE/GQA chemical water quality monitoring points within the cSAC. The RE classification is determined using the last three years worth of data. Thus the fact that all points except the one mentioned above have met RE1 is a good indication that water quality in the main river in general typically meets the RE1 standards except for the stretch immediately downstream of Eastleigh STW.
The RE class achieved in the four main tributaries which discharge into the cSAC is more variable. In 2002, the Nun’s Walk Stream also met RE1 but quality in the other tributaries was not as good. Bow Lake and Poles Lane Stream met RE2 and Allington Lane stream only achieved RE3. An examination of historical records shows that these 2002 results are fairly typical of the quality reached in each tributary over recent years. Whilst the tributaries do not themselves form part of the cSAC, they may be important habitats in supporting the interest
- 46 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. feature species off-site and thus water quality in those not achieving RE1 is of concern in terms of the integrity of the cSAC as a whole.
Metals - Zinc and copper levels in the river are well within the RE 1 standard. The buffering capacity of chalk river water is helpful in this respect.
Monitoring results for all river sampling points during the period 1994 to 2003 inclusive showed that the maximum observed zinc level in the river was 180 μg/l (compared to a standard of 500 μg/l as a 95 percentile). Thus despite the consented discharge of zinc from cress farms in the upper reaches of the river, there is no evidence to suggest that zinc is presenting a risk to the integrity of the cSAC.
An ecotoxicological study of metal accumulation in aquatic mosses supports this conclusion (see WQ Technical Appendix).
Pesticides – The only monitoring points at which a wide range of pesticides are monitored are at Otterbourne and Gaters Mill in the lower part of the Itchen catchment. Because these monitoring points are immediately upstream of large abstractions for drinking water purposes, samples are taken for those determinands listed in the Surface Water Abstraction for Drinking (SWAD) directive. Monitoring data from 1994 to present has been examined and no failures of any of the SWAD standards have been observed in this period. This suggests that there is no known problem with pesticide levels in the Itchen catchment. (Although these monitoring point is in the lower reaches of the catchment, the conservative nature of pesticides means that any inputs in the upper catchment would be reflected in the Otterbourne and Gaters Mill results).
In support of the assessment an investigation has been carried out into conditions in the actual and potential breeding habitats of Southern Damselfly larvae. This included water quality monitoring in a number of small streams and ditches, mostly around the middle to lower parts of the catchment. These types of habitat are more likely than the main river to exhibit high levels of pesticides if these are present anywhere in the catchment, since the small streams and ditches tend to act as the initial receptors for rainfall-induced run off from fields. Flow in the streams and ditches is generally slow and they may be stagnant at times, thus any persistent pollutants entering the streams would be likely to remain there for some time. The results of the southern damselfly monitoring showed that concentrations of all measured pesticides were below the limit of detection in all samples. Four herbicides (atrazine, simazine, dichlorprop and mecoprop) showed one or more result above the limit of detection but in all cases, the maximum observed concentration of these substances was less than 1.5% of the applicable EQS.
Further assessment of the potential effects of pesticides on a designated feature of the Itchen cSAC is provided in the Centre for Ecology and Hydrology’s report on otter and eel tissue bioaccumulation studies in the catchment, carried out in 2003 [see Technical Ref. E(S)01a of the Ecology and Fisheries technical appendix]. The report concludes that “organochlorine pesticide concentrations in [otters] from Hampshire and elsewhere were low and can be considered ‘background’. These were similar to or lower than concentrations in otters from south-west England that died between 1988 and 1996, a period during which the otter
- 47 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. populations in that area rapidly expanded. Organochlorine pesticide contamination does not currently appear to be a significant hazard to otter populations in Hampshire”.
The only consented discharges of pesticides to the Itchen cSAC are the consented discharges of malathion from cress farms. The consented concentration is 0.5μg/l as a maximum permitted concentration in the cress farm effluent; this level is set because it is equal to the EQS for malathion.
The nearest in-river sampling point where malathion is monitored is at Otterbourne, where the observed mean concentration (1994 to 2004) is 0.0063 μg/l which is well within the annual average EQS which is 0.01μg/l. Although malathion does biodegrade in fresh water, the half- life is of the order of a few days so given the rapid travel time of water from the upper parts of the Itchen to Otterbourne, the observed data at Otterbourne can be assumed to be representative of levels higher up the catchment. Therefore since the EQS is not failed, these consented discharges of malathion can be deemed to have no adverse effect on the integrity of the Itchen cSAC.
Overall given the data sources available, there is no evidence to suggest that pesticide or herbicide levels in the Itchen cSAC could be detrimental to the integrity of the cSAC or its designated features.
Endocrine disruptors - There is evidence that steroid oestrogenic endocrine disrupters, potentially from Chickenhall STW, are potentially causing endocrine disruption-like changes to roach in the vicinity of the outfall. Efforts were made to determine if similar effects exist in another cSAC interest feature, the bullhead. However, no useful results could be obtained because of experimental and sampling difficulties. The assessment has considered endocrine disruption further in Appendix M.
3.5.2 Nutrient enrichment The most frequent measurement of nutrient levels in the Itchen catchment is routine monitoring of orthophosphate (equivalent to soluble reactive phosphate) at RE/GQA monitoring sites. These points are typically monitored 12 times per year. Nitrogen levels are also monitored but are of less concern as it is not thought to be the limiting nutrient in the freshwater Itchen system.
The levels of soluble reactive phosphorus are above natural background levels in the whole of the Itchen catchment. The management units 1 to 4 typically either only just meet the Agency / EN agreed phosphate standards or else show slight exceedances of the quality targets. The lower management units (5 & 6), particularly downstream of Harestock and Eastleigh sewage treatment works discharges, show soluble reactive phosphorus levels substantially above the quality targets for these stretches.
By way of illustration, Table 3.7 below shows the mean soluble reactive phosphorus levels observed at each of the main management unit sampling locations over the five year period to December 2003.
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Table 3.7 - mean observed SRP levels, 1999 to 2003 Sampling point Mean observed SRP Target [mg/l P] [mg/l P] MU1: Itchen d/s Alresford by-pass 0.036 0.04 MU2: R. Arle at Drove Lane 0.078 0.06 MU3: Candover at Borough Bridge 0.028 0.04 MU4: Itchen at Easton 0.054 0.06 MU5: Itchen at Otterbourne 0.101 0.06 MU6: Itchen at Gaters Mill 0.322 0.10
Sources of nutrients to the river include consented point sources (e.g. sewage treatment works, cress and fish farms, agricultural effluents), diffuse inputs (particularly agricultural run-off) and in-river processes (release of sediment- or biota-bound nutrients back into the water column). However work by the Environment Agency on the Hampshire Avon, which is a similar river system to the Itchen, has shown that the annual budget for the latter input type is neutral. There is a net release of nutrients to the water column in the winter, balanced by a net loss into sediments in the summer. Thus at the time of lowest dilution, i.e. summer flows, this is actually a sink of nutrients rather than a source.
Since no detailed information is available for the sediment / water column budget in the Itchen, it is precautionary to ignore this as a factor, since the river is most vulnerable to nutrients in the summer and the Avon work suggests a net loss from the water column at this time. The issue of sediment-bound nutrients is therefore not considered further in this assessment. 3.5.3 pH pH levels at all sampling points in the Itchen cSAC are always well within the standards defined by the conservation objectives. This is due to the strong buffering capacity of Chalk river water. There are no consented discharges which are of a nature likely to significantly alter the pH of the river water. Therefore pH is not seen as a concern with regard to the integrity of the cSAC site features.
3.5.4 Salinity The Itchen cSAC is a freshwater habitat and thus salinity is not an issue within the designated site. The tidal limit of the site is at Woodmill Sluice, the presence of this structure normally preventing the flow of saline water any further up the lower reaches of the river. There may be some instances at times of very high tide or particular storm conditions when the sluice is overtopped and some saline water can access the extreme lowest reaches of the river through Riverside Park, however this happens infrequently and there is no perceived risk to the interest features of the site as the only feature likely to be present at that location and vulnerable to this impact type is Atlantic Salmon.
Within the Itchen estuary the river flow affects the salinity structure in terms of longitudinal and vertical salinity gradients. Low river flow leads to a steepening of both gradients. The resulting effect on the upstream migration of salmon into the lower reaches of the river is unknown. However there are no consented discharges which have the potential to influence river flows to the extent that estuarine salinity structures could be altered. Therefore, salinity issues are not considered further in this functional assessment.
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3.5.5 Thermal regime There are no known thermal discharges to the river, that is no discharges which could be operating at sufficiently above ambient temperature to potentially alter the thermal regime of the river.
There are some thermal discharges to Southampton Water. These off-site effects have been considered in relation to Atlantic Salmon – see Appendix J. However these discharges are all licensed under PIR legislation rather than water quality discharge consents. These permissions are therefore dealt with in Part B.4 of this appropriate assessment.
3.5.6 Turbidity and siltation The favourable condition tables’ annual mean suspended solids concentration target of 10 mg/l is met in all management units except MU 6 where a small exceedance occurs. Analysis of the proportions of volatile and non-volatile materials in the suspended solids samples has shown that in some samples, as much as 75% of the suspended material is of organic origin. This may be indicative of anthropogenic sources, either directly (i.e. from discharges) or indirectly (from high nutrient levels which lead to excessive growth).
For the period 1997 to 1999 within the Study’s hydro-ecological assessment period (1970 to 2000) only MU 6 failed the suspended solids concentration standard of 10 mg/l. This failure was by a small margin with a value of 10.6 mg/l.
3.6 ASSESSMENT METHODS 3.6.1 Introduction To assess adverse effects on characteristic features (including designated interests) sensitive to water quality impacts, the water quality consents have been grouped into seven (7) broad categories. These are:
Water Quality Group I Continuous Sewage Effluent Discharges – including water company STWs and private treatment plants
Water Quality Group II Watercress Farm Discharges
Water Quality Group III Fish Farm Discharges
Water Quality Group IV Discharges for Industrial/Trade/Agriculture Use
Water Quality Group V Septic Tanks (discharging to ground or surface water)
Water Quality Group VI Intermittent Sewerage Network Discharges (a – Non Emergency: b- Emergency). (Group VI was split into Group VIa and Group VIb. The latter was specifically for emergency discharges. This split was to accommodate the national guidance for such consents).
Water Quality Group VII Intermittent Surface Water Discharges
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A small number of consents cover more than one discharge type. For data handling simplicity, the consents were initially classified by ‘Discharge type 1’ which is the discharge deemed potentially most polluting (usually the continuous discharge). Other discharge types were then scanned to check that the decision made for the consent as a whole would not be altered by the presence of further discharge types. This approach worked well with the exception of Morestead Sewage Treatment Works where the ‘Discharge type 2’, a storm sewage intermittent discharge, failed the appropriate assessment test for that type of discharge. This is highlighted below.
The map above (Figure 3.1) shows all consents which are the subject of this assessment, identified in accordance with the groups defined above.
3.6.2 Assessment methodology and assumptions In order to carry out the assessment, a series of assessment rules were developed. These rules are described in this section. The results of the application of these rules are described in later sections and are given in detail in the water quality results spreadsheet, Appendix D.
Discharge load The assessment has been carried out by looking at the theoretical maximum daily load from all identified consents. Load is calculated from the product of flow and concentration. The maximum daily load is therefore the consented daily volume multiplied by the consented limit of a given determinand.
Not every consent has consented limits for all of the determinands of concern. For example, none of the consented discharges in the Itchen catchment have a phosphorus limit but since phosphorus is of concern, some assumptions have had to be made as to the likely maximum concentration in each effluent. In the absence of consented concentration limits for any relevant determinand, observed and/or modelled data have been used where available. Where this was not possible, the expert opinion of the water quality team has been used to make a suitable estimate of maximum concentration. Details of the assumptions made for each consent may be found in the water quality assessment spreadsheet, Appendix D.
Discharges to ground The Itchen catchment has many consented discharges which discharge to ground via soakaways. The majority of these are from small private discharges serving one or two dwellings but some are larger, including the two water company STW at Alresford and Morestead. Whilst it has long been known that the discharging of effluents to chalk geology provides a filtering and cleansing effect before the effluent reaches controlled waters (groundwater or surface water) there is little quantitative information available as to the actual reduction in loading which occurs as effluents pass through chalk. Some assumptions have therefore had to be made as to the likely ‘discharge load’ actually reaching the cSAC from these effluents.
The only semi-quantitative information available was for the two water company STW. As part of a wider study looking at ways of modelling phosphate inputs to rivers, a GIS-based Integrated Lake and Catchment (ILC) model of the catchment was built in 2002. In order to calibrate this model against observed in-river levels, it was found necessary to apply a 90% reduction in phosphorus loading from these two STW effluent sources to the river. The same
- 51 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. reduction has therefore been made for phosphorus loadings calculated as part of this assessment for the two large STW discharges. A report by Daldorph describing the ILC model in detail is included in the ‘supporting documentation’ appendix
Many of the other discharges to ground are from septic tanks which typically serve only one or two dwellings. Effluent discharge from these types of systems is therefore episodic and of small total volume, typically less than one cubic metre per day. A decision was therefore made to apply a 90% reduction in loadings of all relevant determinands from septic tank discharges. This takes into account the episodic nature of these discharges and the fact that such small volumes are likely to have long residence times in the dominant chalk geology before reaching the river.
Suspended solids are quickly reduced and effectively removed by the filtration action of passage through the chalk. Therefore the effective load to the river of suspended solids from all discharges to soakaway has been assumed to be zero.
For all other types of discharges (e.g. private sewage package treatment plants) and for all other determinands not detailed above (e.g. BOD and ammonia from Morestead and Alresford STW) it was not possible to make a reliable assessment of the likely reduction in loading. It has therefore been assumed that in these instances, 100% of the discharge load will reach the cSAC. Whilst this is obviously an unrealistic assumption, it is the most precautionary one which can be made and hence is in line with the principles inherent in the Habitats Regulations and Agency guidance.
Allowable river load For the assessment of continuous discharges, the maximum discharge load calculated as described above is compared to an ‘allowable river load’. The allowable river load used in the water quality functional assessment is defined as the observed mean flow for the period 1970 to 2000 multiplied by the determinand concentration defined in the relevant water quality standard (see Tables 3.4 to 3.6). The mean river flow used depends on the management unit in which the discharge reaches the cSAC, giving a spatial context to the assessment criteria.
(For non-continuous discharges or those for which it was not possible to reasonably estimate a maximum discharge load, other assessment rules were developed; these are outlined below).
Phosphorus modelling A steady state mass balance model (Technical ref W (PR) 04 of the RISS Water Quality Technical Appendix, see Appendix G) has been used to enhance the conceptual understanding of the inputs and in-stream processes affecting phosphorus concentrations in the river. The model was developed within an Excel spreadsheet. In-stream processes were included, though given the short length of the river the travel times are generally less than 24 hours and thus the influence of in-stream processes is limited.
A limitation of the model was the lack of availability of observed effluent discharge flow data. This makes the investigation of the effects of point and diffuse sources difficult. Also the length of record for phosphorus concentration for some discharges is rather short, thus creating uncertainty in the associated statistical values. Given these constraints a steady state mass balance model was deemed to be appropriate. A more expensive time dependent model would have been unlikely to achieve any improvement in fidelity.
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The calibration of the model was constrained by the distribution of the Agency water quality monitoring stations. However, these are usually strategically located to define spatial changes.
Due to the described uncertainties, the phosphorus modelling results were not directly used in making decisions as part of this assessment. They were however used to support and back up the decisions made with respect to phosphorus input from discharges, which is the determinand for which the most uncertainty exists and hence for which a number of assumptions had to be made. The calibrated value of inputs from the major discharges was also used in the calculations spreadsheet (see Appendix D) as the estimated phosphorus concentration in the effluent.
Endocrine Disruption. The assessment has undertaken a risk-assessment for the four WWTW discharges in the catchment for endocrine disruption in relation to steroid oestrogenic chemicals. That process and the results, including Integrity Tables, are described in Appendix M. Also see Water Quality Technical Appendix W(PR)07.
3.6.3 Assessment rules These rules are those developed to determine the status of all consented discharges. The results of the application of rules, including associated calculations, are shown in the water quality results spreadsheet, Appendix D of this document.
Rule 1: All consents that discharge to ground or soakaways that are further than 50m from the river and have discharges less than 5m3/d consented flow are deemed not to adversely effect the integrity of the site. This rule is include to make the assessment consistent with the current Habitats Directive Handbook water quality guidance on the assessment of small discharges to ground (section 4.6.3.3 document reference 95_01).
The Handbook advises that such discharges can be deemed ‘not likely to have a significant effect’ at Stage 2 of the review process. Since Stage 2 for the River Itchen was completed prior to publication of this joint EA/EN guidance, the rule has instead been applied at Stage 3. This approach has also been taken for other high priority designated sites in Hampshire and Isle of Wight Area.
The results of the application of Rule 1 can be found in the results spreadsheet, Appendix D. Column 37 shows the results of application of rule 1; any consent for which Rule 1 is identified as TRUE is automatically deemed not to represent adverse effect on the integrity of the site and hence the remaining calculation columns of the spreadsheet are blank.
Rule 2: This rule is used for the ‘Alone’ water quality functional assessment. Any discharge consent load greater than 50% of the allowable river load is deemed ‘cannot be shown not to have an adverse effect on site integrity’. The 50% cut-off was selected as even if there are no other consented discharges of a given substances, most substances may also be introduced to the river by some other means such as diffuse pollution or non-consented discharges. Therefore even if a discharge puts in only half
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of the allowable river load, it seems likely that this could lead to failure of the appropriate riverine water quality standard in the area immediately downstream of the discharge. The 50% cut-off also allows for errors in the assumptions made in the calculation spreadsheet.
Rule 2 was applied to all continuous discharges (groups I to V) for those substances for which an allowable river load could be calculated, namely BOD, ammonia, soluble phosphorus and suspended solids. The rule was applied whether or not the relevant stretch of river is currently failing the given quality standard. This was necessary to take account of the potential headroom in consents, i.e. where a consent may currently only actually discharge a proportion of its maximum consented load.
The results of the application of Rule 2 can be found in the results spreadsheet, Appendix D. Column 64 shows the results of application of rule 2 whilst columns 60 to 63 show which determinand(s) were the cause of the failure (indicated by orange shaded cells).
Rule 3: This rule is used for the ‘In-Combination’ water quality functional assessment. Any discharge consent load greater than 0.1% of the allowable river load is deemed ‘cannot be shown not to have an adverse effect on site integrity’ in-combination with other consented discharges.
The 0.1% cut-off limit was defined to reflect the cumulative effect of upstream loads and any prevailing environmental influences. This rule was applied to all continuous discharges (groups I to V). In effect this is a triviality definition., i.e. any discharges which contribute less that 0.1% of the allowable river load at the point of discharge are deemed to be trivial. Even if such discharges were removed completely from the system, there would be no measurable change in water quality and hence no change in the integrity of the designated site as affected by water quality consent permissions. Such permissions can be shown to be trivial in-combination, because their relative proportional contribution, in-combination, to water quality effects on site integrity is negligible. This assessment is based on professional judgement and site-specific experience.
It is acknowledged that this approach, whilst extremely precautionary in terms of the final decisions made for each consent, does not strictly take account of all impacts in combination with each other. An alternative approach was therefore used to check that the results obtained by using Rule 3 were identifying all consents which in- combination could be contributing to adverse effect on integrity. This alternative approach involved calculation of the cumulative loading of substances from all consents and the ranking of the cumulative loads to identify all consents contributing more than a negligible amount of this cumulative load. Further details of this approach can be found in the water quality supporting appendix.
The results of the application of Rule 3 can be found in the results spreadsheet, Appendix D. Column 65 shows the results of application of rule 3 whilst columns 60 to 63 show which determinand(s) were the cause of the failure (indicated by yellow shaded cells).
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Rule 4: This rule is used for the assessment where there is no defined consent volume limit for continuous discharges and there is insufficient information in the consent to enable a reliable estimate of daily volume to be made. Permissions for which it is not possible to define a daily maximum or dry weather flow volume are deemed ‘cannot be shown to have no adverse effect on the integrity of the site’ alone, due to lack of information.
This rule is applied to all continuous discharges (groups I to V). The overall results of the application of Rule 4 are shown in column 35 of the calculation spreadsheet, Appendix D.
Rule 5: This rule covers the assessment of intermittent discharges (storm sewage discharges, emergency discharges and surface water discharges).
Storm sewage intermittent discharges (group VI a) are deemed ‘can show no adverse effect on integrity’ alone and in combination UNLESS the discharge has been classified as ‘unsatisfactory’ through the AMP process. (AMP = Asset Management Plan, the five-yearly agreement between the Environment Agency and water companies which defines the environmental improvements which the companies must make to their assets). A set of rules which define an unsatisfactory intermittent discharges were defined as part of the guidelines for AMP2.
This element of rule 5 is defined so as to follow the Habitats Directive Handbook water quality guidance on the assessment of such discharges at Stage 2 of the review (section 4.6.3.1, document reference 95_01). The Handbook advises that such discharges can be deemed ‘not likely to have a significant effect’ at Stage 2 of the review process. Since Stage 2 for the River Itchen was completed prior to publication of this joint EA/EN guidance, the rule has instead been applied at Stage 3. This approach has also been taken for other high priority designated sites in Hampshire and Isle of Wight Area.
Emergency discharges (group VI b) are deemed ‘can show no adverse effect on integrity’ alone and in combination UNLESS there is a history of discharges from such a site which could affect a Natura 2000 site. This is lack of impact is assumed since emergency discharges are designed, built and operated to discharge very infrequently, if at all. Standard Environment Agency consent conditions for such discharges are considered to provide an adequate level of protection.
This element of rule 5 is defined so as to follow the Habitats Directive Handbook water quality guidance on the assessment of such discharges at Stage 2 of the review (section 4.6.3.2, document reference 95_01). The Handbook advises that such discharges can be deemed ‘not likely to have a significant effect’ at Stage 2 of the review process. Since Stage 2 for the River Itchen was completed prior to publication of this joint EA/EN guidance, the rule has instead been applied at Stage 3. This approach has also been taken for other high priority designated sites in Hampshire and Isle of Wight Area.
Surface water discharges (group VII) are deemed ‘cannot show no adverse effect on integrity’ alone and in combination. This is because all surface water drainage
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consented discharges which passed through to the appropriate assessment stage are from sites which are thought likely to produce contaminated drainage. (One of the screening criteria used at Stage 2 was that consents for uncontaminated site drainage were deemed ‘not likely to have a significant effect’). It has not been possible to further investigate the potential impact of these consents as part of this appropriate assessment and thus no further information has become available.
The results of the application of Rule 5 can be found in column 67 of the water quality assessment spreadsheet, Appendix D.
Implementation of assessment rules Implementation of the above rules for the alone and in-combination assessments may be described as follows:
Any consent which passes Rule 1 (i.e. for which rule 1 is True) is deemed ‘can show no adverse effect on integrity’. No further assessment is carried out for such consents.
Any consent which fails rules 2, 4 or 5 is deemed ‘cannot show no adverse effect on integrity’ alone.
Any consent which fails rules 2, 3, 4 or 5 is deemed ‘cannot show no adverse effect on integrity’ in combination with other consented water quality discharges.
3.6.4 Assessment of discharges to non-cSAC tributaries Although the lower tributaries of the Itchen (such as Bow Lake, Nuns Walk Stream and Allington Lane Stream) are outside of the cSAC, they act individually and collectively to enhance the ability of the riverine cSAC to support its characteristic habitats and species, including the designated interest features. For the tributary habitats to be available, water quality needs to be sufficiently high that the tributary’s ability to support the relevant habitats / populations is not compromised. The tributaries are not necessarily expected to meet the same water quality standards as the main river. Indeed, given their nature in that they arise on tertiary clay geology and typically flow through more intensively cultivated sub-catchments than the chalk streams higher up the Itchen catchment, it would be surprising if they could ever maintain the same high quality characteristics. However they can act as important off- site refuge habitats during extreme events affecting the main river.
There is therefore a need to assess the impact of consented discharges to these tributaries. This has been done in the following manner:
Rule 1 has been applied in terms of distance from the tributary, i.e. small volume discharges to land or soakaway which are more than 50m from the tributary have been removed from further assessment.
Rules 4 and 5 have been applied in the same way as for discharges to the main river.
Rules 2 and 3 have been applied as if the discharges were going directly to the nearest designated cSAC river stretch.
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INTEGRITY TABLE 1.1
Integrity of site check list with respect to Water Quality This appropriate assessment has shown that…….. ? Assessment of habitats Assessment of habitat and species Assessment of species populations populations Features for which the 1) The area of 2) There will be no 3) The 4) There will be no 5) There will be no 6) The natural 7) There will be no cSAC has been selected annex 1 habitats changes to the conservation interruption or direct effect on the range of the indirect effects on (or composite composition of the status of the site’s degradation of the population of the species within the the populations of features) will not habitats for which typical species is physical, chemical species for which site is neither species for which be reduced? the site was favourable (as or biological the site was being reduced nor the site was designated (e.g. defined in 5 – 7) processes that designated or is likely to be designated or reduction in species support habitats and classified reduced for the classified due to structure, species for which foreseeable future loss or degradation abundance or the site was of their habitat diversity that designated or (quantity/quality) comprises the classified habitat over time The river as a habitat for :
Floating formations of No – 51 consents No – 51 consents No – 51 consents No – 51 consents in --- water crowfoot in total. in total – the in total – the total – the same as (Ranunculus) of plain and same as for same as for for question 1. sub-mountainous rivers Nine failed the question 1. question 1. alone test are:- 63/150 P6145/H/96 PC37/209/H57/77 PC37/210/H58/77 P6669/R/H/97 51/217 A.712/H/96 COPA/5571 PP(A)38/48/H12/7
Those failed the in- combination test are:-
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63/150 P6145/H/96 PC37/209/H57/77 PC37/210/H58/77 P6669/R/H/97 51/217 A.712/H/96 COPA/5571 PP(A)38/48/H12/7 P47/H/85/1 P1550/H/88 63/1612 UV63/2154 P4064/H/91 UV63/2189 P4470/H/92 P889/H/87 P1363/H/87 P1051/H/87 P.6876/H/97 P46/H/85 63/17 UV-61/410 P.6407/H/96 63/2066 P31/H/85 63/987 P6138/H/96 P5770/H/95 P5769/H/95 P6140/H/96 P.3457/H/91 P5986/H/95 PC37/714/H240/77 P.6141/H/96 P5760/H/95 P6146/H/96 P5762/H/95 P5761/H/95 P5764/H/95
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Populations of Atlantic No – 51 consents – No – 51 consents – Yes No – 51 consents salmon (Salmo salar) the same as for the same as for – the same as for Macrophytes Macrophytes Macrophytes question 1. question 1. question 1. Populations of bullhead No - 51 consents in No – 51 consents in Yes No – 51 consents (Cottus gobio) total – the same 51 total – the same as in total – the same as for Macrophytes for Question 4. as for Question 4. Question 1.
Seven failed the alone test are:-
A.712/H/96 63/150 P6145/H/96 PC37/210/H58/77 51/217 COPA/5571 PP(A)38/48/H12/7
All 51 failed the in- combination test.
Populations of brook No – as above. No – as above. Yes No – as above. lamprey (Lampetra planeri) Populations of white- No - 51 consents in No – 51 consents in Yes No – 51 consents clawed crayfish total – the same 51 total – the same as in total – the same (Austropotamobius as for Macrophytes for Question 4. as for Question 4. pallipes) Question 1.
Five failed the alone test are:-
63/150
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All 51 failed the in- combination test.
and the river and adjoining land as habitat for :
Populations of southern Yes Yes Yes Yes damselfly (Coenagrion mercuriale) Populations of otter (Lutra Yes Yes Yes Yes lutra)
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RIVER ITCHEN cSAC. PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT.
INTEGRITY TABLE 2.1 Macrophytes
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Floating formations of water crowfoot (Ranunculus) of plain and sub-mountainous rivers
Scale of impact There is no standard set by EN for macrophytes in the Conservation Objectives. The Agency has applied the RE1 standard required of salmonids to the macrophytes.
Nine consents have failed rule 2.
63/150 P6145/H/96 PC37/209/H57/77 PC37/210/H58/77 P6669/R/H/97 51/217 A.712/H/96 COPA/5571 PP(A)38/48/H12/7
They are deemed cannot show no adverse effect alone because of the scale of their contribution to the allowable river load. The adverse effects were variously due to the maximum consented loads of ammonia, BOD and/or soluble reactive phosphorus. The ecological effects are to interfere with competitive interactions between plant species, leading to the dominance of attached forms of algae and loss of characteristic plant species. The magnitude of the impacts, both in geographic terms downstream of the discharges and in the exceedence of 50% of the allowable river loading are considered sufficient to conclude cannot show not adverse effect on integrity.
The 50% cut-off was selected as even if there are no other consented discharges of a given substances, most substances may also be introduced to the river by some other means such as diffuse pollution or non-consented discharges. Therefore
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even if a discharge puts in only half of the allowable river load, it seems likely that this could lead to failure of the RE 1 standard in the area immediately downstream of the discharge.
45 consents failed rule 3.
63/150 P6145/H/96 PC37/209/H57/77 PC37/210/H58/77 P6669/R/H/97 51/217 A.712/H/96 COPA/5571 PP(A)38/48/H12/7 P47/H/85/1 P1550/H/88 63/1612 UV63/2154 P4064/H/91 UV63/2189 P4470/H/92 P889/H/87 P1363/H/87 P1051/H/87 P.6876/H/97 P46/H/85 63/17 UV-61/410 P.6407/H/96 63/2066 P31/H/85 63/987 P6138/H/96 P5770/H/95 P5769/H/95
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P6140/H/96 P.3457/H/91 P5986/H/95 PC37/714/H240/77 P.6141/H/96 P5760/H/95 P6146/H/96 P5762/H/95 P5761/H/95 P5764/H/95 P5763/H/95 P.5425/H/94 P6144/H/96 51/119 P.6057/H/95
They are deemed cannot show no adverse effect in-combination. The adverse effects were variously due to the maximum consented loads of ammonia, BOD, soluble reactive phosphorus and/or suspended solids. The linear nature of the cSAC means that many discharges will be cumulative together with consents further downstream. The geographic scale of influence therefore of these consents in-combination with others is considered sufficient to conclude cannot show not adverse effect on integrity.
Any discharge consent load greater than 0.1% of the allowable river load is deemed ‘cannot be shown not to have an adverse effect on site integrity’ in-combination with other consented discharges. The 0.1% cut-off limit was defined to reflect the cumulative effect of upstream loads and any prevailing environmental influences. In effect this is a triviality definition., i.e. any discharges which contribute less that 0.1% of the allowable river load at the point of discharge are deemed to be trivial in-combination. Even if such discharges were removed completely from the system, there would be no measurable change in water quality. Any that are greater than trivial in-combination are deemed cannot show not adverse in-combination.
Discharges, in particular elevated nutrient levels, have been shown to have a significant effect on riverine macrophyte communities. High nutrient levels (particularly of the limiting nutrient phosphate) can change the composition of plant communities and result in a loss or reduction of species which prefer more oligotrophic conditions, such as Ranunculus spp., and a proliferation of species that tolerate eutrophication, such as Cladophora. Overall there may be a loss of biodiversity.
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Long term effects and biological The Agency perceive there to be a low risk of long term effects from discharge consents as there are few toxic discharges (lag) in the Itchen catchment.
Duration of impact and Impacts on the macrophyte community are likely to be reversible if discharge quality was improved however there is recovery/reversibility uncertainty about the timescale of any recovery. The rate of recovery would undoubtedly be dependant upon factors such as river flows, the persistence of pollutants in river sediments, and the extent of ongoing diffuse pollution. Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site. Conflicting feature requirements There are no conflicting feature requirements. Off-site impacts This feature is not exposed to off-site impacts. It does not travel off-site. Uncertainty in cause and effect Seven consents have failed rules 4 &/or 5. They are deemed cannot show no adverse effect alone. relationships and a precautionary approach Rule 4. UV-61/232 UV-61/35 UV-61/54 UV-REG FOLIO 3
There is no defined consent volume and it is not possible to estimate volume from consent wording for these four consents. There is a reasonably foreseeable risk that these consents have the potential to adversely effect site integrity alone and in- combination with others. They fail Rule 4 on the precautionary principle due to the lack of information on the potential contaminant loading.
Rule 5. A.712/H/96 C28 P6669/R/H/97
There is uncertainty, but foreseeable risk, that these intermittent discharges are cannot show no adverse effect, particularly in periods of heavy rainfall. Impacts would be associated with secondary effects such as reduced oxygen levels.
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RIVER ITCHEN CSAC. PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT.
INTEGRITY TABLE 2.2 Salmon
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of Atlantic salmon (Salmo salar)
Scale of impact The EN Conservation Objectives set an RE1 standard for salmon.
Nine consents have failed rule 2. These are the same as those considered above for Macrophytes. They are deemed cannot show no adverse effect alone because of the scale of their contribution to the allowable river load. The adverse effects were variously due to the maximum consented loads of ammonia, BOD and/or soluble reactive phosphorus. The scale of the impacts, both in geographic terms and in the exceedence of 50% of the allowable river loading are considered sufficient to conclude cannot show not adverse effect on integrity. Exceeding 50% loading has the capacity to alter the natural processes that support the species, and the habitat that supports the species. Direct effects such as toxic effluent, and secondary effects such as deoxygenation of the water column and siltation of gravels all impact upon the salmon population.
45 consents failed rule 3. These are the same as those considered above for Macrophytes. They are deemed cannot show no adverse effect in-combination. The adverse effects were variously due to the maximum consented loads of ammonia, BOD, soluble reactive phosphorus and/or suspended solids. The linear nature of the cSAC means that many discharges will be cumulative together with consents further downstream. The scale of influence therefore of these consents in-combination with others is considered sufficient to conclude cannot show not adverse effect on integrity.
Long term effects and biological The salmon population of the River Itchen is presently small and therefore comprises a relatively small gene pool, this (lag) together with the inability of the population to utilise the more suitable spawning habitat of the upper Itchen limits the populations ability to recover from short term impacts. The predominant generation time is three years so fish spawning in one year can be expected to contribute adults three years later leading to three semi-distinct cohorts. This feature also limits the rate with which the population can recover from impacts and therefore major improvements might be noticeable after 6-9 years.
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The Agency perceive there to be a low risk of long term effects from toxic discharge consents as there are few toxic discharges in the Itchen catchment. Toxic discharges outside of the catchment ‘off-site’ do occur but are considered unlikely to adversely effect salmon whilst off-site due to the relatively short period of their life-cycle spent in the in Southampton Water. Duration of impact and The reasons for a limited ability for the salmon population to recover from impacts are presented above. It should be noted recovery/reversibility that the population diversity may not be recoverable in many generations following a major impact. Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts Portswood PP(A)38/48/H12/7 fails Rules 2 and 3 and is determined cannot show not adverse effect on integrity both alone and in-combination. There is the potential for discharges to the estuary to impact on Atlantic Salmon, as the salmon have to migrate through the estuary before reaching the cSAC. Water quality modelling of the estuary has concluded that ammonia and BOD levels in the upper estuary are currently marginal with respect to the conditions required for successful passage of salmon. The model showed that the discharge from Portswood STW was a dominant factor in determining water quality conditions of the upper estuary.
Uncertainty in cause and effect Seven consents have failed rules 4 &/or 5. They are deemed cannot show no adverse effect alone. relationships and a precautionary approach Rule 4 These are the same as those considered above for Macrophytes. There is no defined consent volume and it is not possible to estimate volume from consent wording for these four consents. There is a reasonably foreseeable risk that these consents have the potential to adversely effect site integrity alone and in- combination with others. They fail Rule 4 on the precautionary principle due to the lack of information on the potential contaminant loading.
Rule 5. These are the same as those considered above for Macrophytes. Cite the three consents here. There is uncertainty, but foreseeable risk, that these intermittent discharges are cannot show no adverse effect, particularly in periods of heavy rainfall. Impacts would be associated with secondary effects such as reduced oxygen levels.
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RIVER ITCHEN CSAC. PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT.
INTEGRITY TABLE 2.3 Bullhead & Lamprey.
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of bullhead (Cottus gobio) Populations of brook lamprey (Lampetra planeri)
Scale of impact The Conservation Objectives set a target for these interest features as RE2.
Seven consents have failed rule 2. A.712/H/96 63/150 P6145/H/96 PC37/210/H58/77 51/217 COPA/5571 PP(A)38/48/H12/7
They are deemed cannot show no adverse effect alone because of the scale of their contribution to the allowable river load. The adverse effects were variously due to the maximum consented loads of ammonia, BOD and/or soluble reactive phosphorus. The scale of the impacts, both in geographic terms and in the exceedence of 50% of the allowable river loading are considered sufficient to conclude cannot show not adverse effect on integrity. Exceeding 50% loading has the capacity to alter the natural processes that support the species, and the habitat that supports the species. Direct effects such as toxic effluent, and secondary effects such as deoxygenation of the water column and siltation of gravels all impact upon the biology of the species and the habitats that support them.
45 consents failed rule 3. A.712/H/96 63/150 P6145/H/96 PC37/210/H58/77
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51/217 COPA/5571 PP(A)38/48/H12/7 PC37/209/H57/77 P6669/R/H/97 P47/H/85/1 P1550/H/88 63/1612 UV63/2154 P4064/H/91 UV63/2189 P4470/H/92 P889/H/87 P1363/H/87 P1051/H/87 P.6876/H/97 P46/H/85 63/17 UV-61/410 P.6407/H/96 63/2066 P31/H/85 63/987 P6138/H/96 P5770/H/95 P5769/H/95 P6140/H/96 P.3457/H/91 P5986/H/95 PC37/714/H240/77 P.6141/H/96 P5760/H/95 P6146/H/96 P5762/H/95 P5761/H/95
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P5764/H/95 P5763/H/95 P.5425/H/94 P6144/H/96 51/119 P.6057/H/95
These are the same as those considered above for Macrophytes. They are deemed cannot show no adverse effect in-combination. The adverse effects were variously due to the maximum consented loads of ammonia, BOD, soluble reactive phosphorus and/or suspended solids. The linear nature of the cSAC means that many discharges will be cumulative together with consents further downstream. The scale of influence therefore of these consents in-combination with others is considered sufficient to conclude cannot show not adverse effect on integrity.
Long term effects and Both Brook Lamprey and Bullhead show moderate resilience to environmental stresses. Both have a minimum population sustainability (lag) doubling time of a few years and although population level is not known in detail they are considered common throughout the Itchen where suitable habitat is surveyed. Duration of impact and Since these species are common throughout the Itchen catchment local impacts may be overcome by recolonisation in a recovery/reversibility relatively short time through migration and competitive release if the source of the impact is removed. Wide scale impacts are thought to be fully reversible at present indicators of population size. Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts These features are not exposed to off-site impacts. Uncertainty in cause and effect Seven consents have failed rules 4 &/or 5. They are deemed cannot show no adverse effect alone. relationships and a precautionary approach Rule 4 UV-61/232 UV-61/35 UV-61/54 UV-REG FOLIO 3
There is no defined consent volume and it is not possible to estimate volume from consent wording for these four consents. There is a reasonably foreseeable risk that these consents have the potential to adversely effect site integrity alone and in- combination with others. They fail Rule 4 on the precautionary principle due to the lack of information on the potential contaminant loading.
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Rule 5. C28 61/774 63/150
There is uncertainty, but foreseeable risk, that these intermittent discharges are cannot show no adverse effect, particularly in periods of heavy rainfall. Impacts would be associated with secondary effects such as reduced oxygen levels.
These consents have failed rules 4 &/or 5. They are deemed cannot show no adverse effect alone.
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RIVER ITCHEN CSAC. PART B.1 WATER QUALITY FUNCTIONAL ASSESSMENT.
INTEGRITY TABLE 2.4 Crayfish.
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of white-clawed crayfish (Austropotamobius pallipes)
Scale of impact The Conservation Objectives set a target standard of RE3 for Crayfish.
Five consents have failed rule 2. 63/150 P6145/H/96 PC37/210/H58/77 51/217 COPA/5571
They are deemed cannot show no adverse effect alone because of the scale of their contribution to the allowable river load. The adverse effects were variously due to the maximum consented loads of ammonia, BOD and/or soluble reactive phosphorus. The scale of the impacts, both in geographic terms and in the exceedence of 50% of the allowable river loading are considered sufficient to conclude cannot show not adverse effect on integrity. Exceeding 50% loading has the capacity to alter the natural processes that support the species, and the habitat that supports the species. Direct effects such as toxic effluent, and secondary effects such as deoxygenation of the water column upon the crayfish population and the habitats that support them.
45 consents failed rule 3. 63/150 P6145/H/96 PC37/210/H58/77 51/217 COPA/5571 A.712/H/96 PP(A)38/48/H12/7
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PC37/209/H57/77 P6669/R/H/97 P47/H/85/1 P1550/H/88 63/1612 UV63/2154 P4064/H/91 UV63/2189 P4470/H/92 P889/H/87 P1363/H/87 P1051/H/87 P.6876/H/97 P46/H/85 63/17 UV-61/410 P.6407/H/96 63/2066 P31/H/85 63/987 P6138/H/96 P5770/H/95 P5769/H/95 P6140/H/96 P.3457/H/91 P5986/H/95 PC37/714/H240/77 P.6141/H/96 P5760/H/95 P6146/H/96 P5762/H/95 P5761/H/95 P5764/H/95 P5763/H/95 P.5425/H/94
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P6144/H/96 51/119 P.6057/H/95
They are deemed cannot show no adverse effect in-combination. The adverse effects were variously due to the maximum consented loads of ammonia, BOD, soluble reactive phosphorus and/or suspended solids. The linear nature of the cSAC means that many discharges will be cumulative together with consents further downstream. The scale of influence therefore of these consents in-combination with others is considered sufficient to conclude cannot show not adverse effect on integrity.
Long term effects and The cumulative impact of exceeding 50% of the allowable river loading will be significant for this species. Persistent sustainability (lag) elevated suspended solids and BOD levels will have a long term effect and lead to the loss of this interest in the upper Itchen. The small fragmented populations are highly susceptible to direct toxic effluent events. Duration of impact and Populations of this species have been lost in rivers due to episodic and diffuse pollution incidents and are highly sensitive recovery/reversibility to habitat change. If discharge quality was improved this feature can recolonise if a source population is still extant in the river. Studies have shown a very slow recovery is possible and the process can be enhanced by restocking. Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts These features are not exposed to off-site impacts. Uncertainty in cause and effect relationships and a precautionary Seven consents have failed rules 4 &/or 5. They are deemed cannot show no adverse effect alone. approach Rule 4 UV-61/232 UV-61/35 UV-61/54 UV-REG FOLIO 3
There is no defined consent volume and it is not possible to estimate volume from consent wording for these four consents. There is a reasonably foreseeable risk that these consents have the potential to adversely effect site integrity alone and in-combination with others. They fail Rule 4 on the precautionary principle due to the lack of information on the potential contaminant loading.
Rule 5. C28
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61/774 A.712/H/96
There is uncertainty, but foreseeable risk, that these intermittent discharges are cannot show no adverse effect, particularly in periods of heavy rainfall. Impacts would be associated with secondary effects such as reduced oxygen levels.
It should be noted that many of the discharge consents deemed cannot show not adverse are scattered throughout the catchment. Yet the crayfish interest feature is currently found only in MUs 2&3. Historical evidence suggests that crayfish once occupied the whole system. The scope of the assessment covers the whole cSAC (all MUs). Therefore the determination of cannot show not adverse is based upon the impacts upon the species itself and the habitats that support the species, irrespective of whether or not the interest feature is currently there or not.
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3.7 DISCUSSION OF PERMISSIONS 3.7.1 Application of Water Quality Rule 1 This rule covers small volume discharges to ground which are remote from the river. Discharge consents which comply with this rule are not considered further in this assessment.
A total of 40 discharge consents were deemed ‘can show no adverse effect on integrity’ under this rule (see column 37 of the water quality assessment spreadsheet, Appendix D, for details).
Alone and in combination: The Environment Agency concludes that, alone and in combination, all discharge consents which comply with Rule 1 will not affect the integrity of the River Itchen cSAC.
3.7.2 Application of Water Quality Rule 2 Rule 2 is used for the ‘Alone’ water quality functional assessment. Any discharge consent load greater than 50% of the allowable river load will have an adverse effect alone.
Implementation of this rule resulted in nine consents showing adverse effects alone. See column 64 of the water quality assessment spreadsheet, Appendix D, for details. The adverse effects were variously due to the maximum consented loads of ammonia, BOD and/or soluble reactive phosphorus. The relevant determinand(s) are those for which the calculation result is shaded in a dark orange in columns 60 to 62. There were no identified impacts under this rule due to suspended solids loads.
Alone and in combination: The Environment Agency concludes that, alone and in combination, all discharge consents which fail Rule 2 have the potential to affect the integrity of the River Itchen cSAC.
3.7.3 Application of Water Quality Rule 3 Rule 3 is used for the ‘In-Combination’ water quality functional assessment. Any discharge consent load greater than 0.1% of the allowable river load will have an adverse effect in-combination.
Implementation of this rule resulted in 45 consents showing adverse effects in-combination. See column 65 of the water quality assessment spreadsheet, Appendix D, for details. The adverse effects were variously due to the maximum consented loads of ammonia, BOD, soluble reactive phosphorus and/or suspended solids. The relevant determinand(s) are those for which the calculation result is shaded in yellow or dark orange in columns 60 to 62. Yellow shading indicates that the load is identified as contributing to adverse effect in-combination but not alone.
Cumulative loads check: In addition to the application of Rule 3, a check was made on the results of this ‘in-combination’ assessment by looking at the cumulative contributions of consents. This showed that all of the consents which were deemed not to contribute to adverse effect on integrity through the application of Rule 3 could also be shown to contribute a negligible amount to the cumulative load of the relevant parameter to the river. All such consents together contribute less than 0.1% of the cumulative load to the river system, thus confirming that such consents are, alone and in combination, trivial. This is illustrated further in the water quality supporting appendix, Appendix G.
Alone: The Environment Agency concludes that alone, all discharge consents which pass Rule 3 will not affect the integrity of the River Itchen cSAC.
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Triviality: All consents which contribute a contaminant load to the river but which pass Rule 3 are considered to be trivial. These consents can be shown to be trivial in-combination because their relative proportional contribution, in combination, to effects on site integrity is negligible. This assessment is based on professional judgement and site-specific experience.
In combination: The Environment Agency concludes that in combination, all discharge consents which fail Rule 3 have the potential to affect the integrity of the River Itchen cSAC.
3.7.4 Application of Water Quality Rule 4 Rule 4 is used to assess consents for which there is no defined consent volume limit for continuous discharges and there is insufficient information in the consent to enable a reliable estimate of daily volume to be made. Such consents have had to be deemed ‘cannot show no adverse effect on site integrity’ alone, due to lack of information as to the potential contaminant load from the consented discharge.
Some consents include volume limits in words rather than a numerical limit. Such consents have, where possible, been allocated estimated maximum volumes as given in Table 3.8 below:
Table 3.8: Water Quality Consents with Volume Limits in Words
Permit No Folio No Consented Maximum Volume (as on Consent Maximum Volume Consent) Assumed UV63/2052 N01642 2 houses 1000 l/d UV-61/232 H01632 Wastewater from 60 cows and 200 pigs No estimate possible UV-61/35 H01522 Wastewater from a yard in which store 500 l/d + farmyard runoff / cattle are kept and domestic sewage washdown - No estimate possible from one house 63/424 H02855 Domestic premises at the Jolly Farmer 500 l/d 63/426 H02856 Domestic premises at the Ship Inn 500 l/d UV-51/103 H01981 Settled sewage, one house 500 l/d UV-51/126 H01988 Sewage, 2 cottages 1000 l/d UV-51/92 H01974 settled domestic sewage from North 500 l/d Court UV-61/54 H00532 wastewater from 60 cows No estimate possible UV-61/864 H01411 settled domestic sewage from one 500 l/d cottage
Implementation of this rule resulted in four consents failing this test. This includes the three consents in Table 3.8 for which no volume estimate was possible, also one further consent which has no volume condition in any form.
Alone and in combination: The Environment Agency concludes that, alone and in combination, all consents which fail Rule 4 have the potential to affect the integrity of the River Itchen cSAC.
3.7.5 Application of Water Quality Rule 5 This rule applies to all intermittent discharges, namely storm sewage discharges (group VI a), emergency discharges (group VI b) and surface water discharges (group VII).
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Of the water company operated intermittent discharges (groups VI a and VI b) currently identified in Stage 3 for the Itchen cSAC, only the discharge shown in Table 3.9 are currently identified as ‘unsatisfactory’ through the AMP process.
Table 3.9: AMP unsatisfactory intermittent discharges (as at 31st March 2004) Consent no. Folio no. Consent holder Site Discharge type Receiving water SOUTHERN WATER Morestead Wastewater Storm sewage Into land / A.712/H/96 A00712 SERVICES LTD Treatment Works effluent soakaway
The Morestead Road Wastewater Treatment Works storm sewage discharge appears in the Water Quality Functional Assessments spreadsheet as a Water Quality Group 1 discharge as it was classified by its main discharge type 1 characteristic. However it is also noted (in column 67) that this consent also fails the test under Rule 5.
None of the emergency discharges identified as ‘likely to have a significant effect’ on this site are considered to have inadequate protection measures. This is because standard Environment Agency consent conditions are applied, which are considered to provide the required level of protection. The rule therefore leads to satisfactory emergency overflows being judged to have no adverse effect alone or in-combination, on the integrity of the River Itchen cSAC.
Site drainage consents (N00034 and H01146) are both from sites, the nature of which means they have the potential to produce contaminated site drainage. These permissions are deemed ‘cannot be shown to have no adverse effect on site integrity’ alone and in combination, due to lack of information as to the nature and volume of the site drainage.
Implementation of the various elements of Rule 5 to permission categories VIa and VII therefore resulted in three consents failing this test.
Alone and in combination: The Environment Agency concludes that, alone and in combination, all consents which fail Rule 5 have the potential to affect the integrity of the River Itchen cSAC.
3.7.6 Summary of results by discharge type Water Quality Group I – Continuous Effluent Discharges – including STWs
The total number of consents in this category is thirty five (35). Five (5) consents are deemed ‘cannot show no adverse effect on integrity’ alone, with a further twelve (12) deemed so in combination.
The five consents which are deemed ‘cannot show no adverse effect’ alone represent all the large water company sewage treatment works in the catchment. The parameter(s) for which they are deemed adverse alone varies. Alresford STW is implicated alone for ammonia and soluble reactive phosphorus inputs, Harestock STW for soluble reactive phosphorus, Morestead and Portswood STWs for ammonia and BOD whilst Chickenhall STW is implicated for ammonia, BOD and soluble reactive phosphorus. For all of these consented discharges, the other parameter(s) are also implicated under the ‘in combination’ rules.
The remaining twelve consents in this category which fail the appropriate assessment test in- combination are all private sewage discharges. Ten of these fail under the application of Rule 3, typically for ammonia and soluble reactive phosphorus. Two fail under Rule 4 (no defined volume).
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The assessment also concludes that Eastleigh (Chickenhall) WWTW discharge cannot be shown not to adversely affect the integrity of the site due to the risk of endocrine disruption from the discharge of steroid eostrogens.
Water Quality Group II – Watercress Farm Consented Discharges
There are thirteen (13) consents in this group, all of which are deemed ‘cannot show no adverse effect on integrity’ in combination with other discharges through the application of Rule 3. In all cases, the discharge fails the rule 3 criteria for all four parameters (ammonia, BOD, soluble reactive phosphorus and suspended solids). Spring Gardens watercress effluent discharge also failed the test alone due to soluble reactive phosphorus loading.
Whilst substance concentrations in these cress bed effluents are often comparable to or lower than those in sewage effluents, their large consented volumes means that the potential input load of substances to the river is high.
Water Quality Group III – Fish Farm Discharges
There are four (4) consents in this group of which three (3) failed the appropriate assessment test alone and the last failed in-combination. For all four fish farm discharges, the four parameters ammonia, BOD, soluble reactive phosphorus and suspended solids were all identified as contributing impacts.
Itchen Valley trout farm, Itchen Abbas fish farm and Drove Lane fish farm all failed the ‘alone’ test due to ammonia inputs, with Drove Lane also implicated ‘alone’ due to phosphorus inputs.
Like the watercress farms, these discharges are typically consented for very large discharge volumes and thus consented maximum loads of substances can be very large.
Water Quality Group IV – Consented Discharges for Industrial/Trade/Agriculture Use
The total number of consents in this category is six (6). Five (5) of these consents cannot be shown to have no adverse effect on the integrity of the site. Two (2) failed alone under rule 4 (no defined volume), these were Fobdown Farm and Pudding Farm. An additional three (3) consents in this group failed in-combination due to the application of rule 3. The parameters of concern varied between the discharges.
Water Quality Group V – Septic Tanks
There are forty two (42) septic tanks considered in this assessment. Of these, thirty-two (32) are very small volume discharges to ground, more than 50m from the river and thus under current guidance can be deemed ‘can show no adverse effect’ alone and in combination.
Of the remaining ten (10) septic tank consents, all ten failed the appropriate assessment test under rule 3 and are thus deemed ‘cannot show adverse effect on integrity’ in-combination with other consents. In all cases, this was due to potential ammonia and soluble reactive phosphorus inputs. All ten of these are located in Management Unit 1.
Water Quality Group VI – Intermittent Sewerage Network Discharges
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This group of twelve (12) consents was split into Group VIa (storm sewage overflows) and Group Vib (emergency discharges). All of these consents passed the appropriate assessment test detailed in Rule 5 and are thus deemed ‘can show no adverse effect on integrity’ alone and in-combination.
However it should be noted that the storm overflow element of the consent at Morestead STW failed rule 5. This consent is listed under its major discharge type (continuous sewage effluent) in the water quality assessment spreadsheet. The storm overflow fails Rule 5 as it was found to be unsatisfactory under AMP rules and is thus deemed ‘cannot show no adverse effect on integrity’ alone and in-combination.
Water Quality Group VII – Intermittent Surface Water Discharges
Of the two (2) consents in this group, both failed the test described in Rule 5 and are thus deemed ‘cannot show no adverse effect on integrity’ alone and in-combination. This was due to the uncertain nature of the discharged effluent which could result from these consented discharges during periods of heavy rain.
3.8 OFF-SITE IMPACTS The most likely sources of off-site impacts due to water quality discharge consents within the catchment are where discharges enter non-cSAC designated tributaries of the river. Such discharges have been included in this assessment, the method of assessment was described above. There are twelve (12) discharge consents deemed cannot show not adverse on the integrity of the site and the results are included in the conclusion table below.
Table 3.10 Water quality discharge consents that discharges into non-cSAC designated tributaries of the River Itchen.
Permit Number Site Name Discharge Location 63/987 HOBBS CLOSE River Alre P.3457/H/91 KILN LANE HOUSING EST River Alre P6138/H/96 LOWER BISHOPS SUTTON River Alre P5770/H/95 THE NYTHE WATERCRESS River Alre P5769/H/95 DRAYTON BEDS River Alre P6140/H/96 MAXWELLS CRESS BEDS River Alre P.6141/H/96 MANOR FARM River Alre PC37/714/H240/77 MANOR FARM FISH FARM River Alre P6144/H/96 SPRINGVALE WATERCRESS Nuns Walk Stream UV-61/35 PUDDING FARM Nuns Walk Stream UV-61/54 LOW HILL FARM Bow Lake UV-REG FOLIO 3 ADMIRALTY VICTUALLING Allington Lane Stream
There is also the potential for discharges to the Itchen estuary to impact on Atlantic Salmon, as the salmon have to migrate through the estuary before reaching the cSAC. Water quality modelling of the estuary has been carried out as part of the Itchen Sustainability Study, this modelling concluded that ammonia and BOD levels in the upper estuary are currently marginal with respect to the conditions required for successful passage of salmon. The model showed that the discharge from Portswood STW was a dominant factor in determining water quality conditions of the upper estuary. This consent was therefore brought back into the appropriate assessment (despite having been removed at Stage 2) and is therefore considered alongside other such consents in the Part B.1 assessment. Another consent Southampton Geothermal Effluent (P11003 (PC37/879/H288/84)) is also considered in Part B.4 PIR along with PIR permissions as an off-site thermal discharge into Southampton Water.
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3.9 CONCLUSION The final decision for the Water Quality functional assessment is given as Table 3.10 below. The consents which are deemed ‘cannot show no adverse effect on integrity’ either alone or in combination are also illustrated in the map, Figure 3.2.
Table 3.11: Table of Decision – Water Quality permissions
Folio No (Permit No) Site Name (Discharge type) No adverse effect on site No adverse effect on site integrity can be shown: integrity cannot be shown:
Alone In Alone In Combination Combination P04739 (P4739/H/93) PLOT 2, GREYS FARM (TREATED SEWAGE EFFLUENT) P04740 (P4740/H/93) PLOT 3, GREYS FARM (TREATED SEWAGE EFFLUENT) P04741 (P4741/H/93) PLOT 4, GREYS FARM (TREATED SEWAGE EFFLUENT) P00047 (P47/H/85/1) PLOT 1 & 2 MARNE COTTAGE (SEPTIC TANK EFFLUENT) P00300 (P300/H/85/2) PLOT 4 MARNE COTTAGE (SEPTIC TANK EFFLUENT) P00950 (P950/H/87) ELM COTTAGE (SEPTIC TANK EFFLUENT) P00954 (P954/H/87) MERTON (SEPTIC TANK EFFLUENT) P01550 (P1550/H/88) WESTLANDS (SEPTIC TANK EFFLUENT) H02863 (63/1612) WHITE HOUSE (TREATED SEWAGE EFFLUENT) H02855 (63/424) THE JOLLY FARMER (TREATED SEWAGE EFFLUENT) N02875 (UV63/2108/3) NO. 3 PETERSFIELD ROAD (SEPTIC TANK EFFLUENT) P02120 (P2120/H/89) GOMMS, BRAMDEAN (SEPTIC TANK EFFLUENT) N02878 (UV2108/5) "THE BUNGALOW" PETERSFIELD RD (SEPTIC TANK EFFLUENT) P06497 (P.6497/H/97) Properties on Land Adjoining 3 & 9 Petersfield Rd (TREATED SEWAGE EFFLUENT) N02956 (UV63/2154) PORTREE (SEPTIC TANK EFFLUENT) P04064 (P4064/H/91) THE NOOK (SEPTIC TANK EFFLUENT) N03062 (UV63/2234) CARAVAN BUILDING PLOT (SEPTIC TANK EFFLUENT) P01002 (P1002/H/87) HIGHWAY COTTAGE (SEPTIC TANK EFFLUENT) P02181 (P2181/H/89) LAND ADJ. TO 1 MAHONE COTTAGE (SEPTIC TANK EFFLUENT) N02993 (UV63/2189) HOUSE ADJOINING BROOKLYN (SEPTIC TANK EFFLUENT) P04470 (P4470/H/92) LIME TREE COTT/CHERITON GARAGE (TREATED SEWAGE EFFLUENT) P00703 (P703/H/86/1) STYAL COTTAGE (SEPTIC TANK EFFLUENT) P00889 (P889/H/87) 1-2 SCHOOL LANE (SEPTIC TANK EFFLUENT) N02913 (UV63/2125) 2 GARDEN COTTAGES (SEPTIC TANK EFFLUENT)
- 80 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Folio No (Permit No) Site Name (Discharge type) No adverse effect on site No adverse effect on site integrity can be shown: integrity cannot be shown:
Alone In Alone In Combination Combination P01363 (P1363/H/87) APPLE TREE COTTAGE (SEPTIC TANK EFFLUENT) P01051 (P1051/H/87) COLYTON COTTAGE (SEPTIC TANK EFFLUENT) P06876 (P.6876/H/97) 1/2 Hideaway Cottages (TREATED SEWAGE EFFLUENT) P00046 (P46/H/85) THE CHAPEL, CHAPEL LANE (TREATED SEWAGE EFFLUENT) N03276 (UV63/2386) 2 HOUSES ADJ. C & F FREEMANS YARD (SEPTIC TANK EFFLUENT) H02631 (63/17) THE PASTURES (TREATED SEWAGE EFFLUENT) P02960 (P2960/H/90) 1 MAY COTTAGES (SEPTIC TANK EFFLUENT) H01841 (UV-61/410) NORTH END FARM (FARM EFFLUENT) P01840 (P1840/H/88) SHEPHERDS COTTAGE (SEPTIC TANK EFFLUENT) P02885 (P2885/H/90) CHERITON MILL (SEPTIC TANK EFFLUENT) P06407 (P.6407/H/96) TICHBORNE HOUSE (TREATED SEWAGE EFFLUENT) P02996 (P2996/H/90) GARDEN COTTAGE (SEPTIC TANK EFFLUENT) W00227 (63/150) ALRESFORD S.T.W. (TREATED SEWAGE EFFLUENT) N02832 (63/2066) WINCHESTER LODGE (SEPTIC TANK EFFLUENT) A00176 (COPA/11223) SPRING GARDENS STW (EMERGENCY SEWAGE EFFLUENT) A00211 (WACT/249) SPRING GARDENS P.S. (STORM SEWAGE OVERFLOW) P06145 (P6145/H/96) SPRING GARDENS WATERCRESS BEDS (WATERCRESS BED EFFLUENT) N02512 ITCHEN VALLEY TROUT FARM (FISH (PC37/209/H57/77) FARM EFFLUENT) P00031 (P31/H/85) LOWLAND HOUSE (SEPTIC TANK EFFLUENT) H02679 (63/987) HOBBS CLOSE (TREATED SEWAGE EFFLUENT) H02856 (63/426) THE SHIP INN (TREATED SEWAGE EFFLUENT) P06249 (P.6249/H/96) 5 HOUSES (TREATED SEWAGE EFFLUENT) P07602 (P.7602/H/99) House B, 'The Gallops' (TREATED SEWAGE EFFLUENT) P05107 (P5107/H/93) BISHOPS SUTTON VILLAGE HALL (SEPTIC TANK EFFLUENT) H01974 (UV-51/92) NORTH COURT (TREATED SEWAGE EFFLUENT) P02977 (P2977/H/90) STOCKS COTTAGE (SEPTIC TANK EFFLUENT) P04179 (P4179/H/92) THE BARN (SEPTIC TANK EFFLUENT) P06138 (P6138/H/96) LOWER BISHOPS SUTTON (WATERCRESS BED EFFLUENT) P05770 (P5770/H/95) THE NYTHE WATERCRESS FARM (WATERCRESS BED EFFLUENT)
- 81 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Folio No (Permit No) Site Name (Discharge type) No adverse effect on site No adverse effect on site integrity can be shown: integrity cannot be shown:
Alone In Alone In Combination Combination P05769 (P5769/H/95) DRAYTON BEDS (WATERCRESS BED EFFLUENT) P06140 (P6140/H/96) MAXWELLS CRESS BEDS (WATERCRESS BED EFFLUENT) P03457 (P.3457/H/91) KILN LANE HOUSING ESTATE (TREATED SEWAGE EFFLUENT) P00943 (P943/H/87) NORTHLEIGH COTTAGE (SEPTIC TANK EFFLUENT) P05986 (P5986/H/95) WEIR HOUSE (TREATED SEWAGE EFFLUENT) N00039 MANOR FARM FISH FARM (FISH (PC37/714/H240/77) FARM EFFLUENT) P06141 (P.6141/H/96) MANOR FARM (WATERCRESS BED EFFLUENT) P05127 (P5127/H/93) MANOR FARM (SEPTIC TANK EFFLUENT) P04932 (P4932/H/93) PINGLESTONE FARM (SEPTIC TANK EFFLUENT) P05760 (P5760/H/95) PINGLESTONE CRESSFARM (WATERCRESS BED EFFLUENT) N01283 DROVE LANE FISH FARM (FISH FARM (PC37/210/H58/77) EFFLUENT) P06146 (P6146/H/96) WEST LEA FARM SHOP WATERCRESS BEDS (WATERCRESS BED EFFLUENT) P02608 (P2608/H/89) HOLLY COTTAGE (SEPTIC TANK EFFLUENT) P01756 (P1756/H/88) WHITE RAILINGS (SEPTIC TANK EFFLUENT) P00647 (P647/H/86) KIELDER HOUSE (SEPTIC TANK EFFLUENT) P00612 (P612/H/86) MEADOW LODGE (SEPTIC TANK EFFLUENT) P03514 (P3514/H/91) LAND AT GRANNY CLOSE'S COTTAGE (SEPTIC TANK EFFLUENT) N03304 (UV63/2408) 173 ABBOTSTONE (SEPTIC TANK EFFLUENT) P05762 (P5762/H/95) FOBDOWN CRESSFARM UPPER BEDS STILLING POND (WATERCRESS BED EFFLUENT) P05761 (P5761/H/95) FOBDOWN CRESSFARM TOP END STILLING POND (WATERCRESS BED EFFLUENT) H01632 (UV-61/232) FOBDOWN FARM (FARM EFFLUENT) P05764 (P5764/H/95) FOBDOWN CRESSFARM BEDS 16-19A (WATERCRESS BED EFFLUENT) P05763 (P5763/H/95) FOBDOWN CRESSFARM BOTTOM END STILLING POND (WATERCRESS BED EFFLUENT) P04588 (P4588/H/92) LAND AT LOVINGTON HOUSE (TREATED SEWAGE EFFLUENT) N03155 (UV63/2301) ABBEY COTTAGE (SEPTIC TANK EFFLUENT) P05425 (P.5425/H/94) LITTLE HAYES ROAD (TREATED SEWAGE EFFLUENT) P06669R ITCHEN ABBAS FISH FARM (FISH (P6669/R/H/97) FARM EFFLUENT) H01981 (UV-51/103) MILL HOUSE (TREATED SEWAGE EFFLUENT)
- 82 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Folio No (Permit No) Site Name (Discharge type) No adverse effect on site No adverse effect on site integrity can be shown: integrity cannot be shown:
Alone In Alone In Combination Combination P02952 (P2952/H/90) 3 UNITS AT P.J.EDMONDS SITE (SEPTIC TANK EFFLUENT) P00266 (P266/H/85) CHILLAND PLACE (SEPTIC TANK EFFLUENT) N00035 LOWER CHILLAND HOUSE SEWAGE (PC37/385/H114/79) WORKS (TREATED SEWAGE EFFLUENT) P06144 (P6144/H/96) SPRINGVALE WATERCRESS BEDS (WATERCRESS BED EFFLUENT) H01522 (UV-61/35) PUDDING FARM (FARM EFFLUENT) W00235 (51/217) HARESTOCK STW (TREATED SEWAGE EFFLUENT) H01110 (51/119) WINCHESTER COLLEGE (SWIMMING POOL EFFLUENT) H01523 (61/36) GARNIER ROAD P.S. (STORM SEWAGE OVERFLOW) H01153 (51/198) GARNIER ROAD P.S. (EMERGENCY SEWAGE EFFLUENT) A00712 (A.712/H/96) MORESTEAD STW (TREATED SEWAGE EFFLUENT) N02983 (UV63/2176) HOCKLEY HOUSE (SEPTIC TANK EFFLUENT) H01647 (UV-61/252) SHAWFORD HOUSE (EMERGENCY SEWAGE EFFLUENT) P06542 (P.6542/H/96) WEIR COTTAGE (TREATED SEWAGE EFFLUENT) H01115 (51/159) SEWER:TWYFORD/CONSORT RD AREA (STORM SEWAGE OVERFLOW) H02836 (UV61/579) MARWELL MANOR (TREATED SEWAGE EFFLUENT) N01642 (UV63/2052) STOKE PARK FARMHOUSE & (TREATED SEWAGE EFFLUENT) H00532 (UV-61/54) LOW HILL FARM (TREATED SEWAGE EFFLUENT) W00304 SCOTTER ROAD (STORM SEWAGE (PC(A)84/H28/77) OVERFLOW) H01988 (UV-51/126) COTTAGES 1 & 2 (TREATED SEWAGE EFFLUENT) A00154 (COPA/5571) EASTLEIGH (CHICKENHALL ) STW (TREATED SEWAGE EFFLUENT) A00618 (A618/H/91) BOTLEY ROAD SEWAGE P.S. (STORM SEWAGE OVERFLOW) H01146 (C28) WAGON WORKS (SURFACE WATER) N00034 (61/774) EASTLEIGH B.R. WORKS (SURFACE WATER) P05927 (P5927/H/95) THE BARN (TREATED SEWAGE EFFLUENT) P03951 (P.3951/H/91) KNOWLE LANE/DUMPERS DROVE (EMERGENCY SEWAGE EFFLUENT) H01481 (UV-REG ADMIRALTY VICTUALLING DEPOT FOLIO 3) (TREATED SEWAGE EFFLUENT) P05210 (P.5210/H/93) FIRE TRAINING AREA (TRADE EFFLUENT) P06057 (P.6057/H/95) RIVER ITCHEN (GATERS MILL) WTW (TRADE EFFLUENT - WASH WATER) H01126 (51/175/1) STORM SEWAGE OVERFLOW, EASTLEIGH (STORM SEWAGE
- 83 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Folio No (Permit No) Site Name (Discharge type) No adverse effect on site No adverse effect on site integrity can be shown: integrity cannot be shown:
Alone In Alone In Combination Combination OVERFLOW)
H01411 (UV-61/864) GATERS MILL COTTAGE (TREATED SEWAGE EFFLUENT) W00298 GATERS MILL (STORM SEWAGE (PP(A)38/107/H37/) OVERFLOW) H01102 (51/135) MANHOLE NO. 68, QUOB LANE (STORM SEWAGE OVERFLOW) P11003 SOUTHAMPTON GEOTHERMAL (PC37/879/H288/84) EFFLUENT
W00314 PORTSWOOD STW (TREATED (PP(A)38/48/H12/7) SEWAGE EFFLUENT)
- 84 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Figure 3.2 - Discharge consents deemed ‘cannot show no adverse effect on integrity’, alone or in combination.
- 85 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
PART B.2 WATER RESOURCES FUNCTIONAL ASSESSMENT.
4 WATER RESOURCES ASSESSMENT
4.1 SUMMARY OF OUTCOMES The outcome of the appropriate assessment of the River Itchen cSAC for Water Resources Functional Assessment is summarised in Table 4.1 below.
Table 4.1 Summary of Water Resources Functional Assessment conclusions Total number of Water Resources Permissions Total No. of licences assessed in Stage 3 48 Can be shown to not be having an adverse 13 effect on the integrity of the site Cannot be shown to not be having an adverse effect on the integrity of the site 9 alone Cannot be shown to not be having an adverse effect on the integrity of the site in- 34 combination Other (Cannot be shown to not be having an 1 * adverse effect on the integrity of the site).
* note that Fobdown licence 22.3/158 was included in Stage 3 erroneously as it had already been subject to the Habitats Regulations (Reg 48) as a new permission. However, it is included here to formally record the Agency’s view through this appropriate assessment that that licence is now considered cannot show not adverse for lack of a fish screen. This issue will need to be dealt with outside of the HD RoC process through the Agency’s core legislation and powers.
There were 41 water resources permissions deemed to have likely significant effect after stage 2.
There were 45 licences within the Itchen catchment assessed in stage 3. The reasons for the mismatch are listed below.
Licence number 22.10/121 was revoked in December 2000 and so was included in Stage 2 but not in Stage 3.
Licence number 22.2/48 was revoked and replaced with licences 22.2/172 and 22.2/173.
Licence number 22.3/158 was erroneously included in Stage 3.
Licence number 22.9/168 and 22.9/163 were added in Stage 3 due to the requirement for a fish screen.
Although not considered in Stage 2, groundwater-modelling work suggested that licence number 28/39/30/0273 (Lasham) contributed an impact to the Candover Stream. It was then included in the Stage 3 assessment.
There were an additional 3 licences located in Southampton Water which were assessed as offsite impacts.
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4.2 STAGE 1 AND 2 CRITERIA The criteria used and applied by the Agency in Stage 1&2 are described below. a) Stage 1
Hampshire Area has many important and large areas of land designated as cSACs and SPAs. In Stage 1 of the Habitats Directive review, virtually every licence in Hampshire and Isle of Wight Area was identified as falling in the catchment area for one or several SACs and SPAs. The character of the designated areas is often quite unique which requires careful examination of the guidelines for stage 2 to ensure that they are appropriate. b) Stage 2
The approach identified in the document “Habitats Directive Stage 2 Review – Water Resources Authorisations” assumes that no site specific criteria are available from English Nature. The methods represent a first attempt at defining criteria to identify significant authorisations. However, the document does recognise that -
“nothing in the following advice should be seen as a constraint to Agency staff in reaching agreement with EN area teams on an approach to particular SAC/SPA sites”.
A meeting to discuss the stage 2 review of abstraction licences was held with English Nature on 24th November 1999. It was decided that not all elements of the proposed methodology would be appropriate and that additional criteria may be suggested. Different methods are suggested for different types of site. The sites in this Area can be broadly broken down into Marine, River and Other sites.
All licences in the Itchen catchment were included in the stage 1 review. It is then necessary to remove licences from the process which are not likely to have a significant effect. The proposed methodology for assessing the impact of abstraction on riverine cSACs is to determine a Hydrological Significance Threshold against which licences can be tested for significance. The HST is not necessarily related to a minimum river flow but enables comparison of the size of abstraction to what may be considered as a measurable impact on flow. The Licence Accumulation Diagram (LAD) shows cumulative abstraction after ranking abstraction licences from the smallest to the largest. Individual and cumulative abstraction below the HST may be considered as insignificant. The default criteria for the HST is 10% of naturalised Q95.
Naturalisation of flow records is problematic and cannot be done without detailed knowledge of effluent discharges. This information is not available from the water company so naturalisation is impossible. Using the non naturalised flow series probably results in use of a lower Q95 and hence a lower HST which will perhaps identify only a few more abstraction licences for Stage 3.
It is suggested that consumption rates should not be considered because flow naturalisation would add back any discharges. As naturalisation has not been carried out these returns to the river for specific abstractions are not assessed. Of particular importance are the large abstractions for watercress and fish farms. These will be included in stage 3 because the abstraction may have an impact on the cSAC but the discharges are usually made close by. The impact of these large abstractions should be rigorously tested in stage 3. At the other end of the scale, Agricultural and
- 87 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Domestic abstractions are usually small with discharges back to ground. It is not expected that any of these licences will be carried forward to stage 3.
A LAD and HST can be produced for each gauged section of a river catchment. This approach recognises the impact of smaller abstractions which are close to headwater streams. If a reach by reach approach is adopted, it is suggested that the 1% of Q95 measured at the lowest point of the catchment can be used to remove the very smallest abstractions from the approach. As the number of licences for stage 1 of the Itchen review was not excessive, it was decided to assess all licences on a reach by reach basis using the gauging stations at Drove Lane, Sewards Bridge, Borough Bridge, Easton and Allbrook and Highbridge.
The approach taken does not simply follow the precautionary approach – any potential impact must be a measurable or identifiable change. However, the precautionary approach has recently been used in issuing licences in the Itchen catchment. In the absence of any further detailed information, many licences are now issued with a Q50 condition for winter storage and no new consumptive abstractions are licensed. Until detailed flow requirements are available, this approach does seem justified and current licensing policy should be considered in the stage 2 assessment.
This approach does not consider any time variant aspects of the species requiring protection or of the flow series. The method only removes the smallest abstractions from the review. A fully calibrated groundwater model is being constructed and will be able to address the impact of abstraction on flows at a relatively detailed spatial and temporal resolution. This assessment is recognised as being coarse but is a consistent and defensible method. A threshold limit of 500 m3/d has been used to include a small number of extra licences above those identified by the 10% Q95 HST. The 500 m3/d limit departs slightly from the TRAG guidance but this was thought necessary to include a small number of licences mainly fish farms and watercress beds which are believed to have a significant effect on the river and hence the cSAC.
As well as the licences identified for stage 3 using this method, all consumptive abstractions will be included.
Site specific criteria:- 10% Q95 on a reach by reach basis using the gauging stations at Drove Lane, Sewards Bridge, Borough Bridge, Easton, Allbrook and Highbridge.
All consumptive abstractions in the catchment.
All licences between 500 m3/day and the 10% Q95 limit to provide a buffer including further fish farm and watercress licences which have been identified as having a possible impact.
A threshold limit of 500 m3/day has been used to include a small number of extra licences above those identified by the 10% Q95 HST. The 500 m3/day limit departs slightly from the TRAG guidance but this was thought necessary to include a small number (9) of licences mainly fish farms and watercress beds which are believed to have a significant effect on the river and hence the cSAC.
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4.3 HAZARDS AND SENSITIVITIES FOR PERMISSION TYPES As discussed in Appendix J, hazards and sensitivities (risks of exposure) of each permission type to each interest feature underpinned the appropriate assessments. The generic Water Resource function sensitivity matrix, adapted as appropriate for the site, is given in Table 4.2.
Table 4.2: Water Resources Sensitivity Matrix Standing Waters acidificationStanding Waters Mammals of riverine habitats Vascular plants, lower plants Mammals wooded habitats Vascular plants, grassland Vascular plants of aquatic Fens and wet habitats not Invertebrates of wooded Non-migratory fish and Bogs and wet habitats, Dry heathland habitats Standing waters not Riverine habitats† and invertebrates, wet invertebrates of rivers acidification sensitive acidification sensitive acidification sensitive Anadromous fish Dry woodlands Dry Grassland Liverworts Amphibia Upland sensitive habitats Hazards habitats habitats
Change in water levels or table Change in flow or velocity regime Change in freshwater flow to estuary Reduced dilution capacity Habitat loss Entrapment
Source: (EU Habitats and Birds Directives. Handbook for Agency Permissions and Activities)
The relationship between hazards, cSAC/SSSI habitats, favourable condition attributes, interest features and methods of assessment is given in Appendix J. The designated interest features for the site are highlighted in bold in Appendix J. Discussion of each of the identified hazards is given below. Further information on the status of cSAC and SSSI interest, features and factors affecting status is given in Appendix C.
4.3.1 Change in water levels or table The cSAC interest features affected by changes in water levels or table include: native crayfish in MU3 (habitats), salmon (barriers to movement and impacts on local water levels), bullhead and brook lamprey (through river/fisheries management), southern damselfly (habitats) and Ranunculus Community through river and fisheries management.
Typical species which are considered to be affected by changes in water levels or tables include: breeding river birds and wildfowl, breeding waders, breeding passerines through fishery management of banks, trout and invertebrates through fisheries management, molluscs and floodplain wet grassland and fen.
In respect of cSAC interest feature – native crayfish, there is a hazard related to the potential to lower water levels and impact on this interest whose current status is unfavourable. This water level impact on crayfish habitat highlights a serious problem in the Candover Stream (MU 3).
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4.3.2 Change in flow or velocity regime and reduced dilution capacity The species mostly correlated with changes in flow or velocity regime include: salmon, southern damselfly, Ranunculus Community, breeding river birds and wildfowl, breeding waders, breeding passerines, trout, river invertebrates, molluscs, and floodplain wet grassland and fen.
4.3.3 Change in freshwater flow to estuary The interest features most affected by changes in freshwater flow to estuary are Atlantic salmon (cSAC interest feature) and Sea trout – Annex II species.
4.3.4 Habitat loss Otter habitats may be affected indirectly by water resource activities through river/floodplain continuity and availability of sufficient food, given their position within the ‘food chain’. Atlantic salmon, bullhead, brook lamprey, southern damselfly, Ranunculus Community can also suffer from habitat loss through river/fisheries management and changes to channel morphology.
Water voles, breeding river birds and wildfowl, breeding waders, breeding passerines, trout, river invertebrates, molluscs and wet grassland plant communities are also likely to be affected by habitat loss through fisheries and river management
4.3.5 Entrapment The cSAC/SSSI fish species and other fish species are the interest features considered to be at the most risk of entrapment for example through surface water abstraction intakes. Unprotected intakes represent a major hazzard to migratory species including salmonids and lamprey. This assessment deals with fish screens and abstractions within the Itchen catchment (sections 4.7), and also large sea-water abstractions in Southampton Water as an off-site impact issue (section 4.14).
4.4 CHARACTERISTIC HYDROLOGY The River Itchen cSAC hydrology is characterised by an appreciable seasonality of flows from the high autumn/winter flows with a steady decline to the late spring/summer flows until recharge to the aquifer starts, with zero soil moisture deficit (see Figure 3.17).
The naturalised flow records over the period of the Study’s 30 year ecological/hydrological assessment period are given in Table 4.9 for Allbrook/Highbridge in MU 5. The 30 year period was chosen due to data availability limitations. The averages of the monthly mean naturalised discharges over the 30 years are calculated for each month, and for each year. The averaged monthly flows for January to December give the annual River Itchen flow regime for the assessment of ecological requirements of the riverine habitat. Table 4.9 includes the dry summer of 1976 and the dry period of 1989 to 1992.
In Table 4.3, it can be seen that the driest year, over the assessment period is 1992, with a minimum 30 year average naturalised flow statistic of 384Ml/d – see last column of Table 4.3 with the driest year shaded in yellow. Similarly, over the assessment period, the driest month is September with a 30 year averaged monthly naturalised flow of 451Ml/d – see the bottom row of Table 4.3 with the driest month also shaded in yellow.
- 90 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Table 4.3 Monthly Averaged Naturalised Flow (Ml/d) at Allbrook/Highbridge– 30 Year Ecological/Hydrological Assessment Period
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Aver 1970 750 774 718 633 553 504 489 473 453 398 576 554 57 1971 740 716 793 692 612 621 543 516 441 427 432 411 57 1972 490 627 689 610 565 513 467 439 396 372 399 559 51 1973 536 483 439 416 410 397 404 393 363 344 321 344 40 1974 512 721 653 559 506 492 475 457 548 530 824 795 58 1975 1014 921 904 803 703 609 561 531 545 514 504 497 67 1976 443 416 394 370 359 345 340 318 362 552 740 884 46 1977 978 1115 1061 890 770 683 591 569 502 474 514 607 72 1978 711 755 787 714 668 593 542 519 453 402 378 569 59 1979 659 726 820 768 733 702 620 613 523 483 480 588 64 1980 593 657 690 645 563 563 538 516 471 483 477 486 55 1981 471 433 660 610 579 525 487 463 489 566 552 644 54 1982 694 660 770 652 591 563 513 482 442 597 750 933 63 1983 903 803 703 702 643 628 555 511 498 479 438 519 61 1984 690 694 705 636 606 548 498 466 448 471 566 746 59 1985 799 766 677 653 588 566 524 541 470 427 405 505 57 1986 694 623 570 578 541 489 461 465 416 415 541 651 53 1987 615 554 596 657 578 553 514 464 426 549 622 567 55 1988 720 806 729 633 567 507 514 463 447 468 419 396 55 1989 375 408 519 506 450 429 403 380 353 359 372 581 42 1990 703 1069 862 732 623 570 511 472 422 416 404 419 60 1991 558 533 634 563 494 503 497 448 408 387 412 379 48 1992 358 352 350 362 348 338 371 375 360 343 433 615 38 1993 723 613 537 608 542 518 485 450 456 620 552 742 57 1994 955 948 798 777 697 613 541 494 499 478 586 700 67 1995 898 1119 1011 836 712 624 556 491 515 477 529 636 70 1996 726 767 713 634 575 513 481 479 419 406 509 493 55 1997 448 544 524 467 442 453 423 420 374 372 435 504 45 1998 720 599 593 664 568 560 508 472 448 483 585 668 57 1999 933 782 706 626 560 542 486 509 530 527 503 649 61 2000 647 676 625 790 730 639 605 528 510 614 919 1250 71 Average 679 699 685 638 577 539 500 475 451 466 522 609 57
Figure 4.11 shows the licences within stage 3 of the Review of Consents process which were deemed to have a significant impact. They are distributed throughout the catchment but are generally concentrated in the river valley. The largest public water supply licences are concentrated in the lower river valley and the Environment Agency operates two augmentation schemes in the catchment.
To assess adverse effects on site integrity, we have grouped the existing abstraction licences into seven broad categories. These are:
Water Resources Group I Spray Irrigation Licences
Spray irrigation licences are consumptive entitlements
Water Resources Group II Watercress Farm Licensed Abstractions
Agency permissions for watercress farm operation are in general, non consumptive. In average and wet years, most of the watercress licences operate as artesian springs. During dry periods, some of the watercress sources are pumped if local groundwater levels are low. Pumping may lead to local impacts on the riverine habitat
Water Resources Group III Fish Farm Licences
In general, fish farm licences are non consumptive, although some fish farms can be associated with local impacts due to their operation
Water Resources Group IV Abstraction Licences for Industrial Use
- 91 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
There is only one entitlement in this category. This permission is associated with the railway works at Eastleigh, MU6. The abstraction licence is thought to be partly consumptive, and there is a discharge consent associated with it.
Water Resources Group V Public Water Supply Abstraction Licences
The public water supply abstractions are consumptive although the study has taken into account returns of water to the catchment via sewage treatment works
Water Resources Group VI River Flow Augmentation Licences
The river flow augmentation licences were created for water quality support and are operated by Agency staff
Water Resources Group VII Licences for Agriculture
There are no Stage 3 licences in this category
4.5 DERIVATION OF TARGET FLOW REGIME The study has investigated a variety of different ways of defining a target flow regime. These are explained in H(PR)11 Development of Target Flow Regime Proposal (November 2003) in the Water Resources Technical Appendix and Appendices H & J of this document.
The current target flow regime is based upon using ecological data and investigations to define a flow below which ecological damage occurs. The target flow threshold should be precautionary to enable restrictions to come into place before damage occurs. The study has looked at the relationship of various individual interest features (such as salmon and the invertebrate community) to flow as well as using techniques such as PHABSIM to consider the impact of flow on habitat availability. Overall the study used independent techniques to derive a robust target flow regime which protects both designated interest features and more importantly the Chalk stream habitat.
The habitat and interest features considered most sensitive to abstraction are the habitats that support salmonids. When considering the concept of integrity, the recoverability of habitats and species is important and the salmonids are also considered to have poor recoverability from abstraction pressures compared with, for example, invertebrates. The most precautionary target for protecting the River Itchen cSAC is therefore likely to be one which protects salmonids.
The derived low flow threshold is therefore based on the fish migration model and the PHABSIM model and is supported by the invertebrate modelling work.
4.5.1 Salmon Migration Model Fish migration modelling outputs are available for MU6. A low flow threshold of 270 Mld ( 3.1 m3/s ) has been identified for the appropriate assessment. This flow threshold represents a 10 – 11% allowable reduction in the river entry probability from a 1 in 30 dry year critical naturalised low flow threshold of 360 Mld. Details of the low flow threshold and its derivation are superimposed on the model output given in Figure 4.1.
- 92 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
10 to 11% is the allowable reduction in river entry probability from the 1 in 30 dry year critical monthly flow threshold of 360 Ml/d. This is equivalent to a reduction of salmon numbers from approximately 560 salmon to 500 salmon by the end of a 1 in 30 dry year. 1 If impact is within allowable range – no adverse effect. If impact is outside the allowable 0.9 range – cannot be shown to have no adverse effect on site integrity
0.8 1 in 30 dry year allowable low flow threshold is 270 0.7 Ml/d or 3.1m 3 s -1
0.6 1 in 30 dry year 0.5 naturalised flow threshold is 360Ml/d or 0.4 4.21m 3 s -1 (See Table 4.9)
0.3
Probability of river entry Observed probabilities 0.2 Simulated probabilities Logistic relationship 0.1 Lower boundary of observations Upper boundary of observations 0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 River discharge (m3 s-1)
Figure 4.1 Low Flow Thresholds vs Observed and Simulated Probability of River Entry Dead fish were observed at Otterbourne in MU 5 in 1992 and this was thought to be due to low river flows. Recorded riverflows at that time were 240 Mld at Allbrook and Highbridge and 233 Mld at Riverside Park. A target flow of around 270 Mld at Riverside Park would allow a significant precautionary margin before ecological damage is expected. The dead fish and spawning stress observed in 1992 may have been caused by other impacts such as water quality, diffuse pollution or other factors identified in section 7 of this document.
4.5.2 PHABSIM Modelling As soon as salmon enter the river, the physical habitat has to be protected for survival. From the PHABSIM modelling undertaken as part of the Study, flow thresholds for reducing abstractions in MU 6 and MU5 were produced, and are summarised in Table 4.4 and 4.5.
Table 4.4 Flow Thresholds for Reducing Abstractions in Management Unit 6 PHABSIM Output – Indicative Flow Thresholds for Reducing Abstractions in Management Unit 6 410 Ml/d First threshold of reduced abstractions 340 Ml/d Second flow threshold for reduced abstractions - upper limit 310 Ml/d Normal year end of summer flow target 260 Ml/d Second flow threshold for reduced abstractions - lower limit
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Table 4.5 Flow Thresholds for Reducing Abstractions in Management Unit 5 PHABSIM Output – Indicative Flow Thresholds for Reducing Abstractions in Management Unit 5 450 Ml/d First threshold of reduced abstractions 320 Ml/d Second flow threshold for reduced abstractions - upper limit 300 Ml/d Normal year end of summer flow target 260 Ml/d Second flow threshold for reduced abstractions - lower limit
These tables are taken from Technical refs H (PR) 06 and further details are available in H (PR) 07 of the Water Resources and Flow Technical Appendix.
Derivation of the indicative flow thresholds in Tables 4.4 and 4.5 were based on an agreed set of hydrological scenarios. These flow scenarios were used to produce time series of physical habitat for juvenile trout in the upper Itchen and salmon in the middle to lower Itchen. The time series are then summarised to inform identification of flow thresholds.
The flow thresholds correspond to points associated with the habitat-flow relationship where habitat reductions are minimised (Figures 4.2 and 4.3) The interpretation of PHABSIM outputs concentrated on the summer months (April to September) as these are the times when fish are deemed most vulnerable. For each observation reach, physical habitat increases as flow increases.
20000
Full licence (Public Water Supply) 0
-20000
-40000
-60000 1 -80000
-100000
Physical habitat change from naturalised (m²) naturalised (m²) from habitat change Physical -120000 0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Discharge at Riverside Park (Ml/d)
Figure 4.2 Physical Habitat Reductions for Management Unit 6 Plotted against Discharge at Riverside Park, with Indicative Flow Thresholds Highlighted
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20000 Full licence (Public Water Supply)
0
-20000
-40000
-60000
Physical habitat change from naturalised (m²) (m²) naturalised from change habitat Physical -80000 0 200 400 600 800 1000 Discharge at Highbridge & Allbrook (Ml/d)
Figure 4.3 Physical Habitat Reductions for Management Unit 5 Plotted against Discharge at Highbridge & Allbrook, with Indicative Flow Thresholds Highlighted
Note that identification of the indicative flow thresholds based on the PHABSIM modelling focussed on the major flow impact zones of MU5 and MU6 as explained in Technical ref H (PR) 07 of the of the Water Resources and Flow Technical Appendix.
There are no clear breakpoints in the relationship between physical habitat and flow for MU1 to 4. This is probably due to the managed nature of the riverine system in these management units.
4.5.3 Macro-invertebrate six monthly mean flow thresholds Analysis of invertebrate data within the study demonstrated the importance of longer-term flow characteristics, for example six months of antecedent flow, as compared to shorter periods of low flows. Macro-invertebrate assessments within the Study produced six monthly mean flow thresholds, based on the LIFE EQI method – Appendices H, I & J. (Also see Technical Report E(FA)12 of the Ecology/Fisheries Technical Appendix).
Flow thresholds (in the ecologically relevant unit, six monthly antecedent mean flow) were established to prevent statistically significant decreases in the abundance of several important invertebrate families. The flow thresholds were also shown to prevent significant invertebrate community change. Figure 4.4 shows the derivation of invertebrate flow thresholds. The use of normalised flow on the horizontal axis simply allowed data from all River Itchen sites to be displayed on one graph. The figure therefore represents a catchment-wide perspective of invertebrate flow requirements. From Figure 4.4 a normalised flow threshold of 0.59, or 59% of long-term average flow was established for each River Itchen management unit.
Figure 4.4 Relationship between the abundance of Key Invertebrates and Normalised Flow for the River Itchen. A flow threshold was established to prevent two out of three key taxa from falling to one log abundance category below the expected level.
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3
2
1 Ephemerellidae Baetidae Gammaridae 0
-1
-2
abundance categories lowerthan expected.)-3 Invertebrate flow threshold Set at a level which prevents
Invertebrate Abundance (Observed - Expected Abundance) Expected - (Observed Abundance Invertebrate two out of three key River -4 Itchen invertebrates from
(Zero equalsthe expected level ofabundance, minusvalues indicate log falling to one log abundance category below expected. -5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Normalised Flow (Ml/d) (One equals long-term average flow, values below one indicate flow below the long-term average.)
Flow thresholds for individual management units can be derived by multiplying the long-term average flow of each management unit by the normalised flow threshold of 0.59. The following management unit specific flow thresholds were established in the unit, six monthly mean flow.
Table 4.6: Management unit specific macro-invertebrate flow thresholds Management Unit Six Monthly Mean Flow Threshold MU1 34 Ml/d MU2 85 Ml/d MU3 28 Ml/d MU4 208 Ml/d MU5 277 Ml/d MU6 284 Ml/d
In the future, as more invertebrate community data becomes available, it should be possible to derive invertebrate-flow relationships for all management units separately and use this as a basis for deriving management unit specific targets. Given that the lowest flow period for the River Itchen is generally during summer months, and that greatest invertebrate community impact was detected in the autumn, these six monthly mean flow thresholds are particularly relevant to the April to September period.
Figure 4.5 shows the six monthly mean flow threshold for MU 5 and illustrates how historic and naturalised River Itchen flows for the period 1970-2000 have compared with this threshold.
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1200 Naturalised Flow
Hi stor ic Fl ow
1000
800 High / Good to Moderate Status
600
400 Six monthly flow mean (Ml/d)
200 Six monthly mean flow target for Poor to the protection of the Bad Status invertebrate community of MU5
0 70 7 2 74 76 78 80 82 84 86 88 90 92 9 4 96 98 00 Date
Figure 4.5 Historic, Naturalised and Target Six Monthly Mean Flows for Management Unit 5 of the River Itchen Over the Period 1970-2000. From this data it is apparent that abstraction in MU 5 caused historic flows to fall below the six monthly mean flow threshold in 1973, 1976, 1992 and marginally in 1989. During these periods the River Itchen invertebrate community was assessed to be in poor status.
Due to difficulties incorporating the six monthly mean flow criteria into a rule for the appropriate assessment, tests were carried out to ensure that the low flow threshold for salmon/trout and the CAMS RFO would offer adequate protection to the invertebrate community during a 1 in 30 dry year event.
These tests are included as an addendum to the macro-invertebrate assessments in Appendix I of this document. The addendum concluded that the macro-invertebrate community was likely to be protected by application of the salmon/trout low flow thresholds and the CAMS RFO methodology. Therefore a separate rule to offer protection to the invertebrate community was not necessary.
Given the importance of the invertebrate community to the wider ecological integrity of the River Itchen it is anticipated that invertebrate flow criteria will be fully incorporated into the stage 4 process of the ROC.
4.5.4 Use of Available Information to Derive Target Flow Regime Following extensive research and investigation specific to the River Itchen, it became apparent that there are limited ways of quantifying abstraction impacts on the river particularly when extrapolating perceived impacts under conditions never observed or recorded in the river. Using the more robust information explained above provides a range of independently derived target flows beyond which ecological damage is anticipated.
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MU River Salmon PHABSIM Invertebrate six Migration monthly mean flow Work thresholds
MU1 Cheriton Stream - - 34 Mld
MU2 River Alre - - 85 Mld
MU3 Candover Stream - - 28 Mld MU4 Itchen at Easton - - 208 Mld MU5 Itchen at Allbrook & - 260 Mld 277 Mld Highbridge MU6 Itchen at Riverside Park 270 Mld 260 Mld 284 Mld
Table 4.7 Derivation of target flows based on various study results
These results show that neither the Salmon migration work or the PHABSIM work provided estimates of a target flow in the upper River Itchen.
Abstraction impacts in the upper river are generally far less than those observed in the lower river so it was considered appropriate to transpose the Salmon Migration target flows from MU 6 to the other management units as a proportion of naturalised Q95 flow. For MU 6, the target flow of 270 Mld is equivalent to 25% of the 1 in 30 year naturalised low flow value of 360 Mld. The threshold of 25% below the September 1992 monthly averaged flows equate to a reduction of 60 salmon from predicted naturalised levels (see Figure 4.1), and a 10 to 11% reduction in the naturalised probability of river entry.
It was not possible to derive flow targets for Management Units 1 – 4 using the PHABSIM approach as there was no relationship between a reduction in flows and a consequent reduction in habitat. As no such relationship was found, it seems precautionary to apply the targets from the lower river to the upper river. Protection of flow thresholds for fish in the upper tributaries to the cSAC will also serve the native crayfish habitats as flows are related to water levels in these areas, including the Candover Stream where the (largest of the two) remaining populations of crayfish exist.
Low flow thresholds associated with each management unit, for the critical low flow months are given as flow values and as percentage of naturalised flows respectively, in Table 4.8. Also see Figure 4.4.
Table 4.8: Low Flow Thresholds Management Unit (CAMS Low Flow Threshold (Ml/d) Low Flow Threshold Ledger Assessment Point) as % of September 1992 (Ml/d) monthly averaged flows MU 6 (Riverside Park) 75% of 360 Ml/d 270 Ml/d MU 5 (Allbrook/Highbridge) 75% of 360 Ml/d 270 Ml/d MU 4 (Easton) 75% of 213 Ml/d 157 Ml/d MU 3 (Borough Bridge) 75% of 24 Ml/d 18 Ml/d MU 2 (Drove Lane) 75% of 72 Ml/d 55 Ml/d MU 1 (Sewards Bridge) 75% of 31 Ml/d 22 Ml/d Ephemeral Reaches 100% winterbourne flows
- 98 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Flow statistics like Q95 are considered not appropriate for impact assessment in the winterbourne sections of the river. So, 100% of the naturalised 1 in 30 year flow threshold for the ephemeral reaches in Table 4.8 implies zero abstraction impact. The impact of abstraction versus ‘naturalised conditions’ in terms of the change in length of affected river reach, duration of dry spells and frequency of dry spells can be used to define criteria for a rule that assesses the abstraction impact in winterbourne sections, but this is outside the scope of this appropriate assessment.
An addendum to the macro-invertebrate assessments, in Appendix I, suggested that the protection of low flow thresholds and the CAMS RFO would offer adequate protection to the invertebrate community. Note that there are uncertainties associated with the recovery rate of the invertebrate species of interest, and linkage with the potential impact on food source for salmon. These uncertainties will be considered in Stage 4, with a view to integrating the salmon and invertebrate flow thresholds.
Tributaries to the main river such as Bow Lake stream and Nuns Walk stream (excluding the Allington Lane stream which can contribute up to 30% of the Riverside Park flows) do not add substantial flows to the river. Although the tributaries are outside of the cSAC, they act individually and collectively to enhance the ability of the riverine cSAC to support its characteristic species, including the designated interest features through providing habitat refuge, prey sources and corridors for movement. Although the flow impacts on the tributaries are small, they have been included in the assessment for completeness.
It is important to note that abstractions under non-extreme low flow conditions could also have adverse effect in addition to the low flow situations. This has been considered, with the need for further investigations flagged up, linked to salmonid egg survival issues and high flow requirements for flushing of gravels. Further work is needed to consider this and also abstraction impacts on winterbourne stretches and the impact of non consumptive abstractions.
A comparison of the low flow thresholds and monthly naturalised flows is given in Figure 4.6. This assessment is precautionary and it recognises the limitations of the catchment wide PHABSIM assessments and therefore errs on the side of caution.
- 99 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
MU6 LFT MU6 Naturalised Q95 2500 2500 flows at Riverside Low Flow Threshold Park (Ml/d) 364 2000 2000 MU6 LFT January 410 Unremarkable Year - 1987 1500 1500 February 340 March 340 1000 1000 Dry Year - 1992 April 260 Subject to future work May 260 linked to salmonid egg 500 500 June 260 = survival issues and Monthly Averaged Flow (Ml/d) Monthly Averaged Flow (Ml/d) Wet Year - 2000 July 260 flow requirements for flushing of gravels August 260 0 0 Jul Oct Apr Jun Jan Mar Feb Nov Dec Aug Sep September 270 May Month October 310 November 310 December 410
MU5 2500 2500
MU5 LFT Naturalised Q95 2000 2000 Low Flow Threshold flows at Allbrook & Highbridge (Ml/d) 370 1500 1500 Unremarkable Year-1987 MU5 LFT MU5 LFT as % of Naturalised Q95 at Allbrook & Highbridge January 0% 550 1000 1000 Dry Year-1992 February 0% 330 March 0% 320 Monthly Averaged Flow (Ml/d) Monthly Averaged Flow (Ml/d) Wet Year-2000 April 260 70% Subject to future work 500 500 May 260 70% linked to salmonid egg June 260 70% = survival issues and July 260 70% flow requirements for 0 0 flushing of gravels 70% August 260 Jul Apr Oct Jan Jun Feb Mar Aug Sep Nov Dec May September 270 73% Month October 0% 300 November 0% 300 December 0% 550
MU4 2500 2500 MU4 LFT Naturalised Q95 flows at Easton 2000 2000 Low Flow Threshold (Ml/d) 215 MU4 LFT January 0 1500 1500 Unremarkable Year-1987 February 0 March 0 Dry Year-1992 April 151 Subject to future work 1000 1000 May 151 linked to salmonid egg
June 151 = survival issues and Monthly Averaged Flow (Ml/d) Monthly Averaged Flow (Ml/d) 500 500 Wet Year-2000 July 151 flow requirements for flushing of gravels August 151
September 157 0 0 October 0 Jul Apr Oct Jun Jan Feb Mar Aug Sep Nov Dec November 0 May Month December 0
MU3 LFT Naturalised Q95 flows at Borough Bridge (Ml/d) 25 MU3 MU3 LFT 400 400 January 0 350 350 February 0 March 0 Low Flow Threshold 300 300 April 18 Subject to future work May 18 250 250 linked to salmonid egg Unremarkable Year-1987 June 18 = survival issues and July 18 flow requirements for 200 200 flushing of gravels August 18 Dry Year-1992 150 150 September 18 October 0 Monthly Averaged Flow (Ml/d) 100 100 Monthly Averaged Flow (Ml/d) Wet Year-2000 November 0 December 0 50 50
MU2 LFT 0 0
Naturalised Q95 Jul Apr Oct Jun Jan Feb Mar Aug Sep Nov Dec May flows at Drove Lane Month (Ml/d) 78 MU2 LFT January 0 February 0 MU2 March 0 400 400 April 55 Subject to future work 350 350 May 55 linked to salmonid egg Low Flow Threshold June 55 = survival issues and 300 300 July 55 flow requirements for flushing of gravels August 55 250 250 Unremarkable Year-1987 September 55 200 200 October 0 Dry Year-1992 November 0 150 150 December 0 100 100 Monthly Averaged Flow (Ml/d) Flow Averaged Monthly (Ml/d) Flow Averaged Monthly Wet Year-2000 MU1 LFT 50 50 Naturalised Q95 flows at Sewards 0 0 Bridge (Ml/d) 31 Jul Apr Oct Jan Jun Feb Mar Aug Sep Nov Dec MU1 LFT May Month January 0 February 0 March 0 April 22 Subject to future work MU1 May 22 linked to salmonid egg 400 400 June 22 = survival issues and July 22 flow requirements for 350 350 flushing of gravels August 22 Low Flow Threshold 300 300 September 22
October 0 250 250 Unremarkable Year-1987 November 0 December 0 200 200
Dry Year-1992 150 150
Monthly Averaged Flow (Ml/d) Flow Averaged Monthly 100 100 (Ml/d) Flow Averaged Monthly Wet Year-2000
50 50
0 0 Jul Oct Apr Jan Jun Mar Feb Nov Aug Sep Dec May Month
Figure 4.6 Low Flow Threshold vs Monthly Naturalised Flows
- 100 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
4.6 USE OF THE CAMS LEDGER A CAMS Ledger was created for the River Itchen. The CAMS Ledger is the Agency’s suggested tool for the water resources part of Riverine Appropriate Assessments where no other tools exist. For the Itchen Appropriate Assessment, it was considered that the variety of techniques which had been carried out specifically for the River Itchen would provide more robust and scientifically justified conclusions than the generic CAMS Ledger. However, to enable comparisons with other rivers, the CAMS Ledger was prepared. A further advantage of compiling the CAMS Ledger is that it gives a means of viewing abstraction impacts across the range of flows observed and in particular can be used to consider impacts of abstraction on high flows.
The Resource Assessment and Management (RAM) framework was developed by the Agency in 2002 to provide a consistent approach to water resource assessment and management at the catchment scale. In the RAM methodology, abstraction impacts are assessed against a river flow objective, to derive an indication of the catchment resource availability status. Subsequent to its publication, discussions between the Agency and EN on its application to SAC rivers have resulted in the generic river flow thresholds for cSAC/SSSI rivers reproduced as Table 4.9 below. For this assessment, EN advised that the River Itchen cSAC/SSSI should be taken to be of ‘moderate’ sensitivity as highlighted in Table 4.9.
Table 4.9: HDRFOs for SAC Rivers RAM EW band Maximum % reduction from daily naturalised (Sensitivity) flow
The CAMS Ledger uses a mechanism that allowed a take (called UNC) as a percentage of Q95 at all flows down to the lowest recorded. Such a scheme did not protect the lowest flows as the relationship between Q95 and the lowest recorded flows is variable for the site. Within the River Itchen cSAC, both the Q95 and the lowest recorded flows are affected by abstractions and flow enhancements from effluent discharges. Hence our assessment of critical flow thresholds was based on a careful examination of impacts upon the river and its biota so that the lowest flows are afforded a greater level of protection through the low flow threshold . An abstraction that is effectively without impact at Q95 could be close to completely drying up the river at the lowest flows.
It is the low flows and dry summers (as illustrated in Figures J7.1, J7.2, J7.3 and J9.4 in Appendix J) that will influence the hydrological yield and therefore the water resource availability.
The CAMS ledger parameters are expressed as a proportion of Q95. The defined low flow threshold for Allbrook and Highbridge is 270 Mld whilst the naturalised Q95 at that point is 370 Mld. Therefore the target can be expressed as 27% of Q95. This figure was used in the RAM river flow objective table as an override value of UNC together with the other parameters retained as advised by EN through the recommended EN’s HDRFO parameters in Table 4.14.
- 101 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
The ‘River AP Data & Results’ worksheet of the CAMS ledger was used to assess the water resource availability status (RAS) and the percentage cross over point between the ecological RFO and the scenario RFO as recommended by the TRAG Guidance – Appendix 4. In addition, we obtained constrained and unconstrained resource allocation balance expressed in the form of:
Total UNC compared with approximate remaining UNC
Total TAKE compared approximate remaining TAKE
The approximate remaining UNCs were added to the approximate remaining TAKEs and compared with the arithmetic sum of entitlements for each management unit to facilitate assessment of RAS on a river reach basis for comparison with deductions from the Study’s accretion profiles.
Outputs of the CAMS Ledger assessments are given in Tables 4.10 and 4.11 for the Full Licence and the ‘Recent Actual or Contemporary’ scenarios.
Table 4.10 CAMS Ledger Output - Full Licence Assessment
Assessment Point Sea Park & Allbrook Itchen - Easton Itchen - Sewards Bridge Borough Bridge Itchen - RiversideItchen - Candover Brook - Arle - Drove Lane Cheriton Stream - Cheriton Stream Itchen - Highbridge Rest of catchment - Resource Availability % (Licensed) 100% 100% 100% 100% 25% 30% 100% Recent Actual (red if overabstracted) - Surplus or Deficit at QN95, Ml/d 10.5 32.9 6.6 74.7 -43.2 -51.3 144.0 Uncertainty at QN95, +/- Ml/d +/- 0 +/- 0 +/- 0 +/- 0 +/- 0 +/- 0 +/- 0 Total UNC,Ml/d 6.7 21.1 8.4 58.1 99.9 98.2 0.0 approx. remaining UNC, (Licensed/Overrides) Ml/d 6.7 21.1 6.6 58.1 0.0 0.0 0.0 HOF1, Ml/d 24.7 78.1 31.2 215.3 370.1 363.9 0.0 Total TAKE1, Ml/d 2.8 4.1 2.5 11.7 17.2 19.6 0.0 approx. remaining TAKE1, (Licensed/Overrides) Ml/d 2.8 4.1 2.5 11.7 0.0 0.0 0.0 HOF2, Ml/d 30.4 86.3 36.3 238.8 404.5 403.1 0.0 Total TAKE2, Ml/d 5.6 8.2 5.1 23.5 34.4 39.2 0.0 approx. remaining TAKE2, (Licensed/Overrides) Ml/d 3.7 8.2 4.5 8.2 0.0 0.0 0.0 HOF3, Ml/d 41.6 102.8 46.4 285.7 473.3 481.4 0.0 Total TAKE3, Ml/d 9.9 14.4 8.8 41.1 60.2 68.6 0.0 approx. remaining TAKE3, (Licensed/Overrides) Ml/d 4.3 14.4 7.9 37.4 22.1 25.8 0.0 HOF4, Ml/d 61.3 131.6 64.0 367.9 593.7 618.6 0.0 note: TAKE4=Take*(Flow-HOF4)
Table 4.11 CAMS Ledger Output – Recent Actual or Contemporary Assessment
Assessment Point Lane Bridge Rest of Itchen - Itchen - Allbrook - Borough Arle - Drove Highbridge & Riverside Park Itchen - Easton Itchen - catchment - Sea Candover Brook Cheriton Stream - Sewards Bridge Resource Availability % (Licensed) Recent Actual (red if overabstracted) 53% 57% Surplus or Deficit at QN95, Ml/d 3.5 19.7 8.1 51.9 -23.6 -17.4 -72.9 Uncertainty at QN95, +/- Ml/d +/- 0 +/- 0 +/- 0 +/- 0 +/- 0 +/- 0 +/- 0
- 102 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Assessment Point Lane Bridge Rest of Itchen - Itchen - Allbrook - Borough Arle - Drove Highbridge & Riverside Park Itchen - Easton Itchen - catchment - Sea Candover Brook Cheriton Stream - Sewards Bridge Total UNC,Ml/d 6.7 21.1 8.4 58.1 99.9 98.2 0.0 approx. remaining UNC, (Recent 3.5 19.7 8.1 51.9 0.0 0.0 0.0 Actual/Overrides) Ml/d
HOF1, Ml/d 24.7 78.1 31.2 215.3 370. 363.9 0.0 1 Total TAKE1, Ml/d 2.8 4.1 2.5 11.7 17.2 19.6 0.0 approx. remaining TAKE1, (Recent 1.8 4.1 2.1 7.9 0.0 0.0 0.0 Actual/Overrides) Ml/d
HOF2, Ml/d 30.4 86.3 36.3 238.8 404. 403.1 0.0 5 Total TAKE2, Ml/d 5.6 8.2 5.1 23.5 34.4 39.2 0.0 approx. remaining TAKE2, (Recent 4.4 8.2 5.0 23.0 20.2 22.6 0.0 Actual/Overrides) Ml/d
HOF3, Ml/d 41.6 102.8 46.4 285.7 473. 481.4 0.0 3 Total TAKE3, Ml/d 9.9 14.4 8.8 41.1 60.2 68.6 0.0 approx. remaining TAKE3, (Recent 6.4 14.4 8.6 41.1 60.2 68.6 0.0 Actual/Overrides) Ml/d
HOF4, Ml/d 61.3 131.6 64.0 367.9 593. 618.6 0.0 7 Note: TAKE4=Take*(Flow-HOF4)
It has not been possible to derive high flow targets from the local hydro-ecological studies. However the HDRFOs of the CAMS Ledger enable a comparison to be made between the CAMS Ledger and scenario flows as shown on figure 4.7.
1200 Natural Flow 600 Min. % of Time 25% Scenario Flow > RFO Benchmark Flow, AP5 Itchen - Highbridge & Allbrook Total Q95 Surplus or Deficit, Ml/d -43.2 1000Surp. Or Def. Uncertainty, Ml/d Eco lo gical RFO, EW B and O 500 Licensable +/- 0 Resource to ) Denat for Complex & Unconstrained Q50 impacts only (based on Abs & Dis Scenario Flow, Override Ecological 800 Scenario 400 Gauge Data RFO), Ml/d
10% derogation of natural flow 600 EN proposed maximum flow 300 derogation
400 25 TAKE 3
Daily Flow (Ml/dayValues 200 TAKE 2
200 TAKE 1 100 UNC
0 0 0 102030405060708090100 Percentage of time flow exceeded
Figure 4.7 CAMS Ledger Output for MU5 Showing Resource Availability Assessment Linked to High Flows One of the most useful tools from the suite of spreadsheets used in CAMS is the Accprof tool which displays abstraction impacts along the river. This has the benefit of displaying depleted reaches as a result of non consumptive abstractions. The accprof tool has been the primary tool used to assess abstraction impacts on the river under rule 4 explained below. The target against which abstractions have been assessed is the override ecological river flow objective.
- 103 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
4.7 ASSESSMENT RULES A series of rules have been developed to ensure consistent assessment of all abstraction licences within stage 3 of the Review of Consents for the River Itchen. These rules define both alone and in combination impacts.
Rule 1: Stage 2 of the Review of Consents for the River Itchen was carried out using the TRAG guidance available at that time. The stage 2 test considered the cumulative impact of licences compared against naturalised Q95 flow. Where licence cumulatively amounted to less than 10% of the naturalised Q95 they were not considered significant. Unfortunately, estimates of naturalised flow were not available at that time so actual flows were used to compare abstractions with. This lead to an overly precautionary approach at stage 2. This test has been re-applied as the first test in stage 3 using flow data consistent with the wider study. The naturalised flow estimates are given in Table 4.12.
Table 4.12: Naturalised Q95 data (Technical Ref X (PR) 06) of the Water Resource and Flow Appendix Management Unit (CAMS Naturalised Q95 Ledger Assessment Point)
MU 6 (Riverside Park) 364 Ml/d MU 5 (Allbrook/Highbridge) 370 Ml/d MU 4 (Easton) 215 Ml/d MU 3 (Borough Bridge) 25 Ml/d MU 2 (Drove Lane) 78 Ml/d MU 1 (Sewards Bridge) 31 Ml/d
Licences which cumulatively amount to less then 10% naturalised Q95 flow will also be considered to be trivial.
Abstraction licences associated with cumulative impacts greater than naturalised Q95 are subject to further assessments through rule 2 as described below.
Rule 2: This rule is used for the Alone assessment. If the daily abstraction licence entitlement is greater than the allowable abstraction for each management unit and the licence operates within the critical September period, then the licence cannot be shown to have no adverse effect on the integrity of the site alone. The allowable abstraction for each Management Unit is defined as the difference between the naturalised flow and the target flow for each management unit (defined in Table 4.8).
Rule 3: CAMS Ledger Assessments. The CAMS Ledger is not used to determine adverse effect but is used as a check on decisions made. The Ledger uses the study’s over ride ERFO but also allows a qualitative assessment of impacts across the flow regime and at high flows at the Management Unit scale.
Rule 4:Water Resource Function ‘In-Combination’ Assessments. This is the rule for the in- combination assessment. The logic underpinning this rule is stated as follows.
Where there are no screens at an abstraction source (by reference to the Study report entitled ‘Screening intakes for the protection of fish’- Technical ref E(DD)04)- see Table 4.12 below; OR
- 104 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Where the abstraction licence failed alone under Rule 2; OR
Where cumulative impact is greater than 10% of naturalised flow under Rule 1 AND by looking at the scenario flows in a river reach associated with an abstraction source on river flow accretion plots of Figures 4.12 to 4.14, if the scenario take (see below) is greater than the allowable take, then the entitlement cannot be shown to have no adverse effect the integrity of the site in-combination.
Note that the river flow accretion plots given in Figures 4.8 to 4.10 incorporate the impacts of consumptive and non-consumptive abstractions. Also note that irrespective of the length of an impacted reach, local impacts associated with non consumptive abstractions have been taken to contribute to adverse effect on site integrity.
Entrapment (within the catchment).
The major surface water abstraction intakes within the catchment where lack of fish screening is likely to effect salmon and other fish species are listed in the table below. These are considered in Rule 1 and taken into account through Rule 4 (first bullet point above). The lack of screening and the associated hazards lead the Agency to determine cannot show not adverse effect upon site integrity for these licences.
Abstraction Location Type River (Unit) Grid Abstraction Period Licence Reference Upstream of Winchester. 22.1/147 Spring Gardens F.F. Cheriton (1) 5750 3180 Jan – Dec 22.3/124 Fobdown S.I. Candover (3) 5710 3370 Apr-Sep * 22.3/158 Fobdown S.I. Candover (3) 5710 3370 Nov-Mar 22.2/159 Manor Farm F.F. Candover (3) 5850 3350 Jan-Dec 22.2/167 Bishops Sutton S.I. Arle (2) 6046 3233 Apr-Sep 22.2/28 Pinglestone S.I. Arle (2) 58473347 Apr-Sep 22.2/158 Franklyns F.F. F.F. Arle (2) 5810 3290 Jan – Dec 22.4/150 Avington F.F. Itchen (4) 5430 3280 Jan – Dec 22.4/151 Itchen Abbas F.F. Itchen (4) 5390 3280 Jan – Dec Downstream of Winchester. 22.6/157 Mill H., St Cross F.F. Itchen (5) 4767 2741 Jan – Dec 22.6/93 Otterbourne P.W.S. Itchen (5)4 4702702 2326 Jan – Dec 22.10/119 Eastleigh Ind. Itchen (5) 4658 1772 Jan – Dec 22.10/134 Gaters Mill P.W.S. Itchen (6)4 4536536 11563563 Jan – Dec 22.9/159 Fishers Pond F.F. Bow Lake (6) 4890 2100 Jun-Nov 22.9/168 Fishers Pond F.F. Bow lake (6) 5041 2074 Nov-Mar 22.9/163 Stoke Common F.F. Bow Lake (6) 4750 2030 Jan – Dec 22.9/164 Morelands F.F. Bow Lake (6) 4950 2160 Jan – Dec 22.10/120 Fair Oak S.I. Trib. (6) 4790 1760 Apr-Aug
Table 4.13 Major surface-water intakes lacking fish screens related to the River Itchen cSAC. FF = fish farm, PWS = public water supply, S.I. = spray irrigation, Ind. = industrial, C = industrial cooling. * note that Fobdown licence 22.3/158 was included in Stage 3 erroneously as it had already been subject to the Habitats Regulations (Reg 48) as a new permission. However, it is included here to formally record the Agency’s view through this appropriate assessment that that licence is now considered cannot show not adverse for lack of a fish screen.
The Rule 4 assessment was applied to the Study’s Scenarios 3, 4, and 10 (also see Section 3.4.1) noted as follows.
- 105 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Study’s Scenario 10 – Full licence PWS. All PWS abstractions increased to their DAILY licence limit, with no augmentation applied.
Study’s Scenario 4 – Full licence abstraction (Watercress and Fish Farms). Watercress and Fish Farms at full licence rate. Abstractions matched by discharges, with no augmentation applied.
Study’s Scenario 3 – All uses (all licences at full rate though seasonality of public water supply abstractions removed. Augmentation operational. Watercress, Fish Farm and Augmentation abstractions matched by surface water discharges)
Note that it would be impractical to identify and characterise individual and collective impacts of all permission types using a single modelling scenario from the list of scenarios listed in Section 3.4.1.
Implementation of the above rules for the alone and functional assessments may be described as follows:
An abstraction licence cannot be shown not to have adverse effect ‘Alone’ if Rules 1 and 2 apply
If an abstraction licence passes rule 1 and in combination its impact is less than 10% of natural Q95 it will be considered to be trivial.
An abstraction licence cannot be shown not to have adverse effect ‘In-Combination’ if Rule 4 applies
Note that if an abstraction licence fails alone, it would also fail in-combination.
- 106 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. RIVER ITCHEN CSAC. PART B.2 WATER RESOURCES FUNCTIONAL ASSESSMENT.
INTEGRITY TABLE 1.
Integrity of site check list with respect to water resources
This appropriate assessment has shown that…….. ?
Assessment of habitats Assessment of habitat and species populations Assessment of species populations Features for which 1) The area of annex 1 2) There will be no 3) The 4) There will be no interruption 5) There will be 6) The natural 7) There will be no the cSAC has been habitats (or composite changes to the conservatio or degradation of the physical, no direct effect range of the indirect effects on selected chemical or biological processes features) will not be composition of the n status of that support habitats and species on the population species within the populations of reduced? habitats for which the the site’s for which the site was designated of the species for the site is species for which site was designated typical or classified which the site neither being the site was (e.g. reduction in species is was designated reduced nor is designated or species structure, favourable or classified likely to be classified due to abundance or diversity (as defined reduced for loss or degradation that comprises the in 5 – 7) the of their habitat habitat over time foreseeable (quantity/quality) future The river as a habitat for :
Floating formations of No – No – as for question 1. No – as for No – as for question 1. water crowfoot 10 licences failed the alone test:- question 1. (Ranunculus) of plain 22.1/147 Spring Gardens Alresford and sub-mountainous 22.2/166 Drayton Farm, Bighton rivers 22.2/165 Bishops Sutton Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/51 Fobdown Farm 22.3/150 Candover Boreholes 22.4/151 Avington 22.9/159 Fishers Pond, Hampshire 28/39/30/0273 Lasham PWS
34 licences failed the in-combination test:- 22.1/136 Itchen Valley Trout Farm 22.1/147 Spring Gardens Alresford 22.2/167 Bishops Sutton 22.2/28 Pinglestone Farm 22.2/166 Drayton Farm Bighton 22.2/165 Bishops Sutton, Alresford 22.2/171 Manor Farm, Old Alresford
- 107 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. 22.2/101 Pinglestone Farm 22.2/172 Dean Beds 22.2/173 Home Beds 22.2/159 Manor Farm, Old Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/124 Fobdown Farm 22.3/51 Fobdown Farm 22.3/132 Fobdown Farm 22.3/55 Totford PS 22.3/150 Candover Boreholes 22.4/151 Avington 22.4/150 Avington Trout Fishery 22.5/1 Headbourne Worthy 22.6/157 Mill House, St Cross, Winchester 22.7/94 Otterbourne PS (incl Twyford Moors) 22.6/93 Otterbourne Intake 22.6/92 Twyford PS 22.4/80 Easton (Itchen Valley and Winchester) 22.10/120 Fair Oak Lodge 22.9/159 Fishers Pond, Hampshire 22.9/164 Morelands Copse, Thompsons Lane 22.9/168 Fishers Pond 22.9/163 Stoke Common 22.10/119 Eastleigh Works 22.10/134 Gaters Mill Intake 28/39/30/0273 Lasham PWS
Populations of Atlantic No – as for Macrophytes No – as for Question No – as for No – as for Question 4. salmon (Salmo salar) question 1. 4. Question 4.
Additionally, 18 licences failed for lack of a fish screen.
22.1/147 Spring Gardens Alresford 22.2/167 Bishops Sutton 22.2/28 Pinglestone Farm 22.2/159 Manor Farm, Old Alresford 22.2/158 Drove Lane, Alresford 22.3/124 Fobdown Farm 22.4/151 Avington 22.4/150 Avington Trout Fishery 22.6/157 Mill House, St Cross, Winchester 22.6/93 Otterbourne Intake
- 108 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. 22.10/120 Fair Oak Lodge 22.9/159 Fishers Pond, Hampshire 22.9/164 Morelands Copse, Thompsons Lane 22.9/168 Fishers Pond 22.9/163 Stoke Common 22.10/119 Eastleigh Works 22.10/134 Gaters Mill Intake * 22.3/158 Fobdown see table 2 for note.
Populations of Yes Yes Yes Yes bullhead (Cottus gobio) Populations of brook Yes Yes Yes Yes lamprey (Lampetra planeri) Populations of white- No – 34 licences as for No – 34 licences as No – 34 licences No – 34 licences as for clawed crayfish Macrophytes question 1. for Macrophytes as for Macrophytes question (Austropotamobius question 1. Macrophytes 1. pallipes) question 1. and the river and adjoining land as habitat for :
Populations of southern No – 34 licences as for Yes No – 34 licences as for No – 34 licences as for damselfly (Coenagrion Macrophytes question 1. Macrophytes question Macrophytes question mercuriale) 1. 1. Populations of otter Yes Yes Yes Yes (Lutra lutra)
- 109 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
RIVER ITCHEN CSAC. PART B.2 WATER RESOURCES FUNCTIONALASSESSMENT.
INTEGRITY TABLE 2.1 Macrophytes
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Floating formations of water crowfoot (Ranunculus) of plain and sub-mountainous rivers
Scale of impact 9 licences failed the alone test - Rule 2
22.1/147 Spring Gardens Alresford 22.2/166 Drayton Farm, Bighton 22.2/165 Bishops Sutton Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/51 Fobdown Farm 22.3/150 Candover Boreholes 22.4/151 Avington 22.9/159 Fishers Pond, Hampshire
This rule is used for the Alone assessment. If the daily abstraction licence entitlement is greater than the allowable abstraction for each management unit and the licence operates within the critical September period, then the licence cannot be shown to have no adverse effect on the integrity of the site alone. The allowable abstraction for each Management Unit is defined as the difference between the naturalised flow and the target flow.
Abstraction has the potential to severely impact the status of the macrophyte community through changes to the flow velocity regime. A reduction in flow velocity would be expected to change the composition of the macrophyte community. Plants that require fast flowing water habitats, such as Ranunculus spp., will reduce in abundance and distribution whereas plants that prefer slow flowing habitats will increase in dominance. Increased algae affects the macrophyte assemblage through smothering. Changes in the plant community may result in a loss of biodiversity.
Abstraction will also have an impact on typical species associated with the macrophyte community. The Agency’s analysis of its invertebrate data suggests that abstraction has a similar impact on the invertebrate community as would be expected by the ecological differences caused by a low flow year compared to a normal flow year or a normal flow year compared to a high flow year. Abstraction results in a measurable deterioration in the abundance of several important
- 110 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. invertebrate taxa and was associated with a significant change in the composition of the invertebrate community of the River Itchen. The Agency considers these effects sufficient in magnitude to determine cannot show not adverse effect on site integrity.
The magnitude of the impacts, both in geographic terms downstream of the abstractions and in the exceedence of the allowable abstraction for each management unit are considered sufficient to conclude cannot show not adverse effect on integrity.
34 licences failed Rule 4 – the in-combination test.
22.1/136 Itchen Valley Trout Farm 22.1/147 Spring Gardens Alresford 22.2/167 Bishops Sutton 22.2/28 Pinglestone Farm 22.2/166 Drayton Farm Bighton 22.2/165 Bishops Sutton, Alresford 22.2/171 Manor Farm, Old Alresford 22.2/101 Pinglestone Farm 22.2/172 Dean Beds 22.2/173 Home Beds 22.2/159 Manor Farm, Old Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/124 Fobdown Farm 22.3/51 Fobdown Farm 22.3/132 Fobdown Farm 22.3/55 Totford PS 22.3/150 Candover Boreholes 22.4/151 Avington 22.4/150 Avington Trout Fishery 22.5/1 Headbourne Worthy 22.6/157 Mill House, St Cross, Winchester 22.7/94 Otterbourne PS (incl Twyford Moors) 22.6/93 Otterbourne Intake 22.6/92 Twyford PS 22.4/80 Easton (Itchen Valley and Winchester) 22.10/120 Fair Oak Lodge 22.9/159 Fishers Pond, Hampshire 22.9/164 Morelands Copse, Thompsons Lane 22.9/168 Fishers Pond 22.9/163 Stoke Common 22.10/119 Eastleigh Works 22.10/134 Gaters Mill Intake 28/39/30/0273 Lasham PWS.
Long term effects and biological The Agency perceive there to be a low risk of long term effects if abstraction impacts are reduced / removed. There is (lag) little evidence to suggest that low flows in the Itchen have ever resulted in a loss of species in the long term. It appears
- 111 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. that changes to the macrophyte assemblage are short term and favourable status is restored when suitable flow conditions return. Duration of impact and Impacts on the macrophyte community are likely to be reversible if abstraction was limited, however there is uncertainty recovery/reversibility about the timescale of any recovery. The rate of recovery would undoubtedly be dependant upon factors such as rainfall (natural river flows) and prevailing water quality conditions.
Invertebrates as typical species are considered able to recover rapidly from the impacts of low flows, and perhaps more rapidly than macrophytes if suitable habitats are available. Dynamic systems These abstractions do not contribute to the natural habitat dynamics of the site. Conflicting feature requirements There are no conflicting feature requirements. Off-site impacts This feature is not exposed to off-site impacts. It does not travel off-site. Uncertainty in cause and effect The relationship between macrophyte and invertebrate abundance and river flow (velocity) has been demonstrated for the relationships and a River Itchen and extensively in the scientific literature. precautionary approach
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INTEGRITY TABLE 2.2 Salmon
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of Atlantic salmon (Salmo salar)
Scale of impact 9 licences failed Rule 2 The same 9 as failed Rule 2 for macrophytes in the table above. This rule is used for the Alone assessment. If the daily abstraction licence entitlement is greater than the allowable abstraction for each management unit and the licence operates within the critical September period, then the licence cannot be shown to have no adverse effect on the integrity of the site alone. The allowable abstraction for each Management Unit is defined as the difference between the naturalised flow and the target flow.
The ecological effects upon the salmon are largely concerned with the access of salmon to freshwater and the available habitat for juvenile salmon. Present population monitoring suggests that Atlantic salmon can only on average just replace themselves leading to a small gene pool and large proportional changes in population size.. Therefore small changes in the success of each cohort may have disproportionate effects on overall population level. Thus the degree of siltation and the proportion of salmon entering freshwater may have substantial effects on subsequent cohorts. The Agency consider these effects sufficient in magnitude to determine cannot show not adverse effect on site integrity.
Fish Screens. 18 licences were deemed cannot show not adverse under Rule 1 for lack of a fish screen. Entrapment through abstraction intakes is an important issue in the river with direct impacts upon the population. Although each intake may only lead to the loss of a few individual salmon the population is so vulnerable to losses that this may be the difference between a population that is moving towards recovery and one that is in terminal decline. The sensitivity of the population to additional losses of fish is thought to be acute.
22.1/147 Spring Gardens Alresford 22.2/167 Bishops Sutton 22.2/28 Pinglestone Farm 22.2/159 Manor Farm, Old Alresford 22.2/158 Drove Lane, Alresford 22.3/124 Fobdown Farm 22.4/151 Avington
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22.4/150 Avington Trout Fishery 22.6/157 Mill House, St Cross, Winchester 22.6/93 Otterbourne Intake 22.10/120 Fair Oak Lodge 22.9/159 Fishers Pond, Hampshire 22.9/164 Morelands Copse, Thompsons Lane 22.9/168 Fishers Pond 22.9/163 Stoke Common 22.10/119 Eastleigh Works 22.10/134 Gaters Mill Intake * 22.3/158 Fobdown
* note that Fobdown licence 22.3/158 was included in Stage 3 erroneously as it had already been subject to the Habitats Regulations (Reg 48) as a new permission. However, it is included here to formally record the Agency’s view through this appropriate assessment that that licence is now considered cannot show not adverse for lack of a fish screen.
34 licences failed Rule 4 – the in-combination test. The same as failed Rule 4 for the macrophytes. Long term effects and biological Consumptive abstractions lead to a reduction in flow that can have an impact on all stages of salmon living in and returning (lag) to the river. Generally all aspects of life history are favoured by high flows and adversely impacted by low flows. There is thus a continuing impact of reduced flows that varies markedly between years. The long term effect is therefore a variable reduction in the population on a year by year basis. Low flows will have an impact on that years returning adults and spawning (and thus the resulting generation), and that years juveniles and thus the smolt run to the sea the following year.
Lack of screens on major intakes may result in the loss of a proportion of the smolt run of that year, and to a lesser extent, loss of juveniles in the Autumn when they undergo a fundamental redistribution within the river. The long-term effect will be a variable reduction in each years smolt run, and thus in subsequent years returning adults.
Duration of impact and These impacts are essentially short to medium term, affecting a single generation and to some extent the next. Recovery recovery/reversibility from the impacts should be rapid (e.g. within 1 to 2 generations) if the impact is removed. There is the possibility that these and other impacts could combine to cause a more catastrophic collapse in the population. This could result in a reduction in the genetic diversity and fitness of the stock and thus have a long-term and even permanent effect – possibly even leading to extinction of the population.
Dynamic systems These abstractions do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts Entrapment of salmon whilst off-site in Southampton Water has assessed by the Agency to not be adverse. Uncertainty in cause and effect relationships and a precautionary approach
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INTEGRITY TABLE 2.3 Crayfish.
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of white-clawed crayfish (Austropotamobius pallipes)
Scale of impact 9 licences failed Rule 2 The same 9 as failed Rule 2 for macrophytes in the table above. This rule is used for the Alone assessment. If the daily abstraction licence entitlement is greater than the allowable abstraction for each management unit and the licence operates within the critical September period, then the licence cannot be shown to have no adverse effect on the integrity of the site alone. The allowable abstraction for each Management Unit is defined as the difference between the naturalised flow and the target flow.
The ecological effects upon the crayfish are:
Low flows in autumn/winter and the following spring/early summer could result in increased adult and juvenile mortalities as traditional refuges are lost increasing interaction between age classes and exposure to predation, Low flows will lead to changes in habitat conditions, slower current velocity, increasing siltation, reduced marginal zone, infilling of refuges by silt will result in increasing fragmentation of the population, Elevated nutrient and depressed dissolved oxygen levels could lead directly to crayfish mortalities
The Agency consider this effect sufficient in magnitude to determine cannot show not adverse effect on site integrity.
The Candover Boreholes (Licences 22.3/150) are particularly worthy of note, as they are Agency owned and have the potential to directly effect the last existing remnant population of Crayfish in the Itchen cSAC. If used to its fill licensed capacity this licence has the potential to effect the Candover Brook after it has been used when the cone of depression will effect flows in the channel. That would particularly be adverse if there were two consecutive dry years when the augmentation scheme were used.
The other impact upon crayfish would be whilst the scheme is in operation: Rapid increases in current velocity may lead to the loss of marginal habitat and refuges and increase the affects of drift on juveniles, An influx of lower temperature water will lead to cooling of marginal slack waters and shorten the growing period of
- 115 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. juveniles, Some displacement and drift of individual crayfish, particularly juveniles, into unsuitable habitat areas downstream and within the Fobdown Farm stretch will occur, It is unlikely that colonisation downstream will happen, but the potential to establish a new colony will increase with the implementation of habitat enhancement work, Channel management practices could significantly increase the potential impact of augmentation, Late summer/early autumn augmentation may have lesser impact on the crayfish population than early and mid summer high flows
34 licences failed Rule 4 – the in-combination test. The same 34 that failed Rule 4 for macrophytes in the table above. Long term effects and biological The long term effect of persistent low flows would be a sustained decline in the population with increasing fragmentation (lag) and isolation of remnant colonies. The “In combination” effect of persistent low flows would ultimately lead to the loss of this species in the Candover Stream. Duration of impact and Crayfish have evolved in the chalk and limestone-rich waters of the British Isles and Europe and as such are highly adapted recovery/reversibility to the stable hydrological regime and annual flow cycle characteristic of these waters. This species therefore will recover from a “one off” low flow event, for example over several summer months, but will be substantially affected by persistent low flows over a period of years. Populations of this species have been lost in rivers due to persistent low flow conditions. If a source population is still extant in a river populations can recover albeit extremely slowly. Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts These features are not exposed to off-site impacts. Uncertainty in cause and effect With regards to the impacts of the augmentation scheme upon crayfish, the assessment concludes:- relationships and a No studies have assessed the direct impacts on a crayfish population of flow augmentation, but information on the precautionary approach ecological requirements and behaviour of this species can assist in investigating the potential consequences of such activities, Some form of negative impact will be inevitable, since augmentation represents an alien event (sometimes prolonged) in an otherwise stable hydrological regime, to which the native crayfish is adapted, Sympathetic use of the scheme in the Candover Stream catchment at times of prolonged extreme drought conditions could be beneficial to the survival of the crayfish population, The level and intensity of impact will be determined by the timing and duration of flow augmentation and abstraction episode and the extent of a diverse in-stream habitat.
Given the relatively large magnitude of the licence and the absence of rules governing it’s use with specific regards to impacts upon crayfish and their supporting habitats either in the Candover Stream or elsewhere in the Itchen catchment, where the interest feature should be expected to occur, the assessment concludes it cannot show the licence will not adversely effect the integrity of the site.
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It should be noted that many of the abstraction licences deemed cannot show not adverse are scattered throughout the catchment. Yet the crayfish interest feature is currently found only in MUs 2&3. Historical evidence suggests that crayfish once occupied the whole system. The scope of this assessment covers the whole cSAC (All MUs). Therefore the determination of cannot show not adverse is based upon the impacts upon the species itself and the habitats that support the species, irrespective of whether or not the interest feature is currently there or not.
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INTEGRITY TABLE 2.4 Southern Damselfly
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of southern damselfly (Coenagrion mercuriale)
Scale of impact 9 licences failed Rule 2 The same 9 as failed Rule 2 for macrophytes in the table above. This rule is used for the Alone assessment. If the daily abstraction licence entitlement is greater than the allowable abstraction for each management unit and the licence operates within the critical September period, then the licence cannot be shown to have no adverse effect on the integrity of the site alone. The allowable abstraction for each Management Unit is defined as the difference between the naturalised flow and the target flow.
Work on the River Itchen suggested that larval Southern Damselfly were strongly associated with slow flowing, permanent water habitats in drainage ditches of the lower Itchen valley. Most of these drainage ditches are supplied with water from the main River Itchen via flow control structures. Abstraction could potentially reduce the availability of water in the main channel of the Itchen and therefore limit the supply of water to the drainage ditch habitats inhabited by Southern Damselfly. Effectively abstraction could limit the extent and quality of habitat available to Southern Damselfly. The Agency considers this effect sufficient in magnitude to determine cannot show not adverse effect on site integrity.
34 licences failed Rule 4 – the in-combination test. The same 34 that failed Rule 4 for macrophytes in the table above.
Long term effects and biological The Agency perceive there to be a low risk of long term effects if abstraction impacts are reduced / removed. (lag) Duration of impact and The Agency perceive that recovery would occur rapidly, (probably in the following generation), if abstraction impacts are recovery/reversibility reduced / removed. Dynamic systems These abstractions do not contribute to the natural habitat dynamics of the site Conflicting feature requirements There are no conflicting feature requirements Off-site impacts These features are not exposed to off-site impacts. Uncertainty in cause and effect Southern Damselfly larvae have been shown to prefer slow flowing and permanent waterbodies. relationships and a The impact of abstraction on the availability of this type of habitat is predicted but uncertain. precautionary approach
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4.8 APPLICATION OF THE RULES The results of applying the rules to 45 abstraction licences (within the catchment e.g. excluding licences considered under off-site impacts) are shown on a spreadsheet output given in Appendix D. Each abstraction licence is listed along with type, and licence number. The results of applying the rules are indicated by true (red background) or false in the columns with orange coloured headers. The results of the assessments are given in the columns with orange headers.
4.8.1 Application of Water Resources Rule 1 to Abstraction Licences Rule 1 was applied to check the list of qualifying licences for Stage 3 based on the Study’s naturalised Q95 as opposed to the use of gauged flow records during Stage 2. This refined assessment was justified due to the availability of naturalised flows from the Study’s modelling activities subsequent to Stages 1 and 2. In effect this was an in-combination triviality test.
Rule 1 determined that 10 abstraction licences could be shown not to be having an adverse effect on the integrity of the site.
Table 4.14: Licences passing Rule 1. Licence No. Licence Name 22.1/146 Alresford 22.2/38 Harcombe, Ropley 22.2/45 The Weirs, Alresford 22.2/148 Franklyns Fish Farm, Alresford 22.4/67 Itchen Stoke 22.4/71 Borough Farm Itchen Stoke 22.4/149 Avington 22.6/95 Hockley Golf Club 22.4/146 Winnal Down Farm 22.9/160 Fishers Pond Hampshire
Triviality The impacts from these licences when considered together in-combination are considered to be trivial. These permissions can be shown to be trivial in-combination, because their relative proportional contribution, in-combination, to effects on site integrity is negligible. This assessment is based on professional judgement and site-specific experience.
In combination The Environment Agency concludes that in-combination these abstraction licences, will not affect the integrity of the Itchen cSAC.
4.8.2 Application of Water Resources Rule 2 to Abstraction Licences Rule 2 is used for the ‘Alone’ Assessment. If the daily abstraction licence entitlement in Ml/d (or daily equivalent of annual entitlement) is greater than the allowable (see statement on definition of allowable flow below) flow in a 1 in 30 dry year critical drought period, and the licence operates (by reference to the abstraction period associated with the permission), within the critical September period, then the entitlement cannot be shown to have no adverse effect on the integrity of the site.
The allowable flow value was calculated as the difference between the naturalised flow and the low flow threshold.
Rule 2 determined that 9 abstraction licences could not be shown not to be having no adverse effect on the integrity of the site.
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Table 4.15: Licences failing Rule 2. Licence Number Licence Name 22.1/147 Spring Gardens Alresford 22.2/166 Drayton Farm, Bighton 22.2/165 Bishops Sutton Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/51 Fobdown Farm 22.3/150 Candover Boreholes 22.4/151 Avington 22.9/159 Fishers Pond, Hampshire
Alone The Environment Agency concludes that alone these abstraction licences cannot be shown not to adversely affect the integrity of the Itchen cSAC.
See Rule 4 for the conclusions regarding the in combination test for these licences.
4.8.3 Application of Water Resources Rule 3 to Abstraction Licences This CAMS ledger assessment was based on CAMS Ledger version 3 founded on the RAM Framework, with the application of the EN’s HDRFOs supported with local hydro-ecological information. Application of the CAMS Ledger represents a high level assessment of the abstraction licences individually and collectively. Note that the CAMS Ledger tool was used to investigate high flow thresholds using ‘better than generic’ information available from the Study’s local hydro- ecological studies.
4.8.4 Application of Water Resources Rule 4 to Abstraction Licences The water resource function ‘In-Combination’ assessments were based on Rule 4 which makes use of a similar approach to the CAMS Accprof tool. Implementation of this rule resulted in thirty four (34) abstraction licences, which cannot be shown to have no adverse effect on the integrity of the site.
For Group V abstraction licences the assessment was based on Scenario 10 - Full Licence Abstractions - Public Water Supply. For Groups II and III, Scenario 4 - Full Licence Abstractions - Fish Farms and Watercress was used. For other Groups, Scenario 3 - Full Licence Abstractions - All Uses was used.
In combination test The Agency concludes that these licences in-combination with one another cannot be shown not to adversely effect the integrity of the Itchen cSAC.
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Table 4.16: Licences failing Rule 4.
Licence Number Licence Name 22.1/136 Itchen Valley Trout Farm 22.1/147 Spring Gardens Alresford 22.2/167 Bishops Sutton 22.2/28 Pinglestone Farm 22.2/166 Drayton Farm Bighton 22.2/165 Bishops Sutton, Alresford 22.2/171 Manor Farm, Old Alresford 22.2/101 Pinglestone Farm 22.2/172 Dean Beds 22.2/173 Home Beds 22.2/159 Manor Farm, Old Alresford 22.2/158 Drove Lane, Alresford 22.2/169 River Alre Augmentation Scheme 22.3/124 Fobdown Farm 22.3/51 Fobdown Farm 22.3/132 Fobdown Farm 22.3/55 Totford PS 22.3/150 Candover Boreholes 22.4/151 Avington 22.4/150 Avington Trout Fishery 22.5/1 Headbourne Worthy 22.6/157 Mill House, St Cross, Winchester 22.7/94 Otterbourne PS (incl Twyford Moors) 22.6/93 Otterbourne Intake 22.6/92 Twyford PS 22.4/80 Easton (Itchen Valley and Winchester) 22.10/120 Fair Oak Lodge 22.9/159 Fishers Pond, Hampshire 22.9/164 Morelands Copse, Thompsons Lane 22.9/168 Fishers Pond 22.9/163 Stoke Common 22.10/119 Eastleigh Works 22.10/134 Gaters Mill Intake 28/39/30/0273 Lasham PWS
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Figure 4.8a Predicted River Flows with Full licence abstraction (PWS Abstractions), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Figure 4.8b Predicted River Flows with Full licence abstraction (PWS Abstractions), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Figure 4.18c Predicted River Flows with Full licence abstraction (PWS Abstractions), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Table 4.17 Predicted River Flows with Full licence abstraction (PWS Abstractions), Naturalised Flows and Low Flow Threshold – Numerical Data
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Figure 4.9a Predicted River Flows with Full licence Abstraction (Watercress and Fish Farms), Naturalised Flows and Low Flow Threshold – Numerical Data
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Figure 4.9b Predicted River Flows with Full licence Abstraction (Watercress and Fish Farms), Naturalised Flows and Low Flow Threshold – Numerical Data
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Figure 4.9c Predicted River Flows with Full licence Abstraction (Watercress and Fish Farms), Naturalised Flows and Low Flow Threshold – Numerical Data
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Table 4.18 Predicted River Flows with Full licence Abstraction (Watercress and Fish Farms), Naturalised Flows and Low Flow Threshold – Numerical Data
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Figure 4.10a Predicted River Flows with Full licence Abstraction (All Uses), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Figure 4.10b Predicted River Flows with Full licence Abstraction (All Uses), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Figure 4.10c Predicted River Flows with Full licence Abstraction (All Uses), Naturalised Flows and Low Flow Threshold – Graphical Illustration
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Table 4.19 Predicted River Flows with Full licence Abstraction (All Uses), Naturalised Flows and Low Flow Threshold – Numerical Data
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4.9 MAPS SHOWING WATER RESOURCE PERMISSIONS The water resource abstraction licences deemed likely to have ‘significant effect’ on site integrity are given in Figure 4.11. These are the licences included in Stage 3.
Figure 4.11 Water Resource Abstraction Licences (Licences Deemed Likely to Have Significant Effect)
4.10 DISCUSSION OF PERMISSIONS To assess adverse affects on characteristic features (including designated interest features) sensitive to water resources and flow impacts, we have grouped the Agency abstraction licences into seven (7) broad categories stated in Section 4.4.5. Details are given in Appendix D - Excel spreadsheet on file as: Water Resource Functional Assessments.xls .
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Water Resources Group I – Spray Irrigation Licences (SI) The total number of abstraction licences considered as part of the Water Resources functional appropriate assessment in this category is nine (9). By application of Rule 1, four licences were deemed not to have adverse effect. By application of rule 2 none (0) of the permissions failed the alone test as the daily abstraction licence entitlements in Ml/d (or daily equivalent of annual entitlement) proved to be less than the allowable flow in a 1 in 30 critical drought period, and the licence operates (by reference to the abstraction period associated with the permission), within the critical September period. By application of Rule 4 , four (4) abstraction licences in this group failed the in-combination test.
Water Resources Group II – Watercress Farm Licensed Abstractions
MU 2 has the largest number of watercress bed farms with seven (7) out of a catchment total of thirteen (13). Two (2) of the abstraction licences in MU 2 (22.2/165 and 22.2/166) cannot be shown to have no adverse effect on the integrity of the site through the application of Rule 2 . Rule 2 is the alone test, and it involved testing the daily abstraction licence entitlements in Ml/d (or daily equivalent of annual entitlement) against the allowable flow in a 1 in 30 critical drought period.
There are six (6) watercress farms in MUs 1, 3, 4 and 5. One (1) failed alone, with additional three (3) in-combination. Two (2) – licence numbers 22.4/67 and 22.4/71 did not fail either the alone test or the in-combination test.
Water Resources Group III – Fish Farm Licences
There are thirteen (13) licences in this group considered under the Water Resources functional appropriate assessment. Application of rule 1 deemed 3 small licences not to be having an adverse effect on site integrity. Four (4) failed alone through application of Rule 2 . This is because their daily abstraction licence entitlements in Ml/d (or daily equivalent of annual entitlement) proved to be less than the allowable flow in a 1 in 30 critical drought period, and the licence operates (by reference to the abstraction period associated with the permission), within the critical September period. Additional six (6) fish farm licences failed the in-combination test.
At Franklyn’s fish farm there are two (2) licences. The smaller licence (22.2/148) operates outside the July to September critical period. The larger entitlement (22.2/158) operates within the critical period. The Franklyn’s fish farm (22.2/158) licence failed the alone test as well as the in- combination test. The Avington (Test Valley Trout at Itchen Abbas) farm (22.4/151) failed both the alone and the in-combination test under Rules 2 and 4 respectively. Licence 22.4/151 is associated with a localised impact on site integrity within MU4 through consideration of ecological targets.
A related issue for Franklyns Fish Farm can be seen from Appendix J. There are uncertainties with the mathematical modelling of the fish farm impact in this area, and although the data presented in Figure J9.1 shows that the full entitlements can dry up the river or that it can put more water into it than it takes, this is likely to be exaggerated than reality due to the model resolution in this area.
Licence number 22.4/151 is the subject of a licence application that is currently being determined by the Agency. As such, further discussion in relation to this appropriate assessment is limited to its inclusion to inform decisions on appropriate actions during Stage 4.
Water Resources Group IV – Abstraction Licences for Industrial Use
There is only one (1) abstraction licence in this category. This qualifying licence – licence number 22.10/119 fails the in-combination test only, linked to the requirement for a fish screen .
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Water Resources Group V – Public Water Supply Abstraction Licences
There are seven (7) qualifying public water supply licences in this category. None failed the alone test, and all failed the functional in-combination test through application of Rule 4. The public water abstraction sources that cannot be shown to have no adverse effect on the integrity of the site are:
1. Otterbourne PS (22.7/94)
2. Otterbourne Intake (22.6/93)
3. Twyford PS (22.6/92)
4. Gaters Mill (22.10/134)
5. Totford (22.3/55)
6. Lasham (28/39/30/0273) *
7. Easton (22.4/80)
* Although not part of the list of permissions in Stages 1 and 2, the Study’s modelling outputs suggest that the cone of depression associated with the Lasham public water abstraction source to the north east of the cSAC (Technical ref H (PR) 02 of the Water Resource and Flow Appendix and the associated Scenario Report – rr251i1_scenario10.Doc – PWS – Figure 4) could potentially have an adverse impact on site integrity.
The Lasham source has no impact on the site ‘alone’ when licenced quantities were apportioned using outputs from groundwater modelling work, but failed the in-combination test. On this basis, the Lasham abstraction licence cannot be shown to have no adverse effect on the integrity of the site.
Water Resources Group VI – River Flow Augmentation Licences
The augmentation schemes were created for water quality support. Due to their large annual entitlements (of the order of 90Ml/d), the augmentation licences failed the alone test as their daily licence entitlement is greater than the allowable flow, Rule 2 and also failed the in-combination test.
Crayfish and the Candover Augmentation Scheme.
Native crayfish in the Candover Stream have adapted to a stable flow regime characteristic of southern chalkstreams and their annual life cycle is finely tuned to the gross, macro and micro variations in channel flow velocity. The distribution of aquatic invertebrates generally is determined by a range of factors including flow velocity and many studies have looked at this relationship in some detail. Few specific studies have been undertaken on crayfish and their relationship with variations in channel flow, but there have been several investigations into the ecological and specific habitat preferences of the native British crayfish (A. pallipes). These studies have revealed the requirements of a range of inter-related factors including a diverse physical habitat, comprising an abundance of refuges, and moderate to slow flowing water. These requirements vary in accordance with the stage in the life cycle of an individual but are most critical during the early juvenile growing phase. Few studies have looked at the impact of extreme low
- 136 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. flows on crayfish but the basic physiological requirements of the native crayfish are known and there is little doubt that such conditions would have a detrimental affect on this species.
The potential impact of flow augmentation on the crayfish population may be considered in relation several possible scenarios: to a short one-off event, continuous augmented flow in summer and the longer term implications of groundwater drawdown as a result of prolonged abstraction.
The possible impacts of implementing the augmentation scheme as a short, one-off event are:
Rapid increases in current velocity may lead to the loss of marginal habitat and refuges and increase the affects of drift on juveniles, An influx of lower temperature water will lead to cooling of marginal slack waters and shorten the growing period of juveniles, Some displacement and drift of individual crayfish, particularly juveniles, into unsuitable habitat areas downstream and within the Fobdown Farm stretch will occur, It is unlikely that colonisation downstream will happen, but the potential to establish a new colony will increase with the implementation of habitat enhancement work, Channel management practices could significantly increase the potential impact of augmentation, Late summer/early autumn augmentation may have lesser impact on the crayfish population than early and mid summer high flows.
The possible impacts of implementing the augmentation scheme on a longer term basis over several months of the summer are:
Increased intensity of all the possible impacts mentioned earlier, The most serious implications relate to juvenile growth and survival, A small and regulated increase in flow velocity, simulating natural summer flows, could be beneficial but only at times of prolonged extreme drought.
The possible impacts of groundwater drawdown over a long period on the crayfish population at Fobdown Farm are:
Low flows in autumn/winter and the following spring/early summer could result in increased adult and juvenile mortalities as traditional refuges are lost, increasing interaction between age classes and exposure to predation, Low flows will lead to changes in habitat conditions, slower current velocity, increasing siltation, reduced marginal zone, infilling of refuges by silt will result in increasing fragmentation of the population, Elevated nutrient and depressed dissolved oxygen levels could lead directly to crayfish mortalities Implementing the augmentation scheme for short periods at times of extreme drought could benefit crayfish by at least ensuring their survival.
It is difficult to assess specific impacts but generally the following conclusions can be made:
No studies have assessed the direct impacts on a crayfish population of flow augmentation, but information on the ecological requirements and behaviour of this species can assist in investigating the potential consequences of such activities, Some form of negative impact will be inevitable, since augmentation represents an alien event (sometimes prolonged) in an otherwise stable hydrological regime, to which the native crayfish is adapted,
- 137 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Sympathetic use of the scheme in the Candover Stream catchment at times of prolonged extreme drought conditions could be beneficial to the survival of the crayfish population, The level and intensity of impact will be determined by the timing and duration of flow augmentation and abstraction episode and the extent of a diverse in-stream habitat.
Given the relatively large magnitude of the licence and the absence of rules governing it’s use with specific regards to impacts upon crayfish and their supporting habitats either in the Candover Stream or elsewhere in the Itchen catchment, where the interest feature should be expected to occur, the assessment concludes it cannot show the licence will not adversely effect the integrity of the site.
Water Resources Group VII – Licences for Agriculture
There are no Stage 3 qualifying licences for the site in this category.
- 138 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. In accordance with the requirements of the Appendix 21 Pro Forma, the Table of Decisions for Water Resource functional assessment is given as Table 4.22 below.
Table 4.20: Table of Decision - Water Resources Permissions Licence Site Name, Licence type No adverse effect on site No adverse effect on site number integrity can be shown integrity cannot be shown
Alone In Combination Alone In Combination 22.1/146 Alresford, Spray Irrigation
22.1/136 Itchen Valley Trout Farm,, Watercress
22.1/147 Spring Gardens, Alresford, Fish Farm
22.2/38 Harcombe, Ropley, Spray Irrigation
22.2/167 Bishops Sutton, Spray Irrigation
22.2/28 Pinglestone Farm, Spray Irrigation
22.2/166 Drayton Farm, Bighton, Watercress
22.2/165 Bishops Sutton, Alresford, Watercress
22.2/171 Manor Farm, Old Alresford, Watercress 22.2/101 Pinglestone Farm, Watercress
22.2/172 Dean Beds, Watercress
22.2/173 Home Beds, Watercress
22.2/45 The Weirs, Alresford, Watercress
22.2/159 Manor Farm, Old Alresford, Fish Farm 22.2/158 Drove Lane, Alresford, Fish Farm
22.2/148 Franklyn Fish Farm, Alresford, Fish Farm 22.2/169 River Alre Augmentation Scheme, Augmentation 22.3/124 Fobdown Farm, Spray Irrigation
22.3/158 Fobdown, Spray Irrigation *
22.3/51 Fobdown Farm, Watercress
22.3/132 Fobdown Farm, Watercress
22.3/55 Totford P S, PWS
22.3/150 Candover Boreholes, Augmentation
22.4/67 Itchen Stoke, Watercress
22.4/71 Borough Farm, Itchen Stoke, Watercress 22.4/151 Avington, Fish Farm
- 139 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Licence Site Name, Licence type No adverse effect on site No adverse effect on site number integrity can be shown integrity cannot be shown
Alone In Combination Alone In Combination 22.4/149 Avington, Fish Farm
22.4/150 Avington Trout Fishery, Fish Farm
22.6/95 Hockley Golf Club, Spray Irrigation
22.4/146 Winnall Down Farm, Spray Irrigation
22.5/1 Headbourne Worthy, Watercress
22.6/157 Mill House, St Cross, Winchester, Fish Farm 22.7/94 Otterbourne P S ( Inc. Twy. Moors ), PWS 22.6/93 Otterbourne Intake, PWS
22.6/92 Twyford P S, PWS
22.4/80 Easton (Itchen Valley & Winchester), PWS 22.10/120 Fair Oak Lodge, Spray Irrigation
22.9/159 Fishers Pond, Hampshire, Fish Farm
22.9/164 Morelands Copse, Thompsons Lane, Fish Farm 22.9/160 Fishers Pond, Hampshire, Fish Farm
22.9/168 Fishers Pond, Fish Farm
22.9/163 Stoke Common, Fish Farm
22.10/119 Eastleigh Works, Industrial
22.10/134 Gaters Mill Intake, PWS
Lasham PWS, PWS 28/39/30/027 3 14/2 Esso Refinery
14/3 Fawley Power Station
23/3 RMC Aggregates
* note that Fobdown licence 22.3/158 was included in Stage 3 erroneously as it had already been subject to the Habitats Regulations (Reg 48) as a new permission. However, it is included here to formally record the Agency’s view through this appropriate assessment that that licence is now considered cannot show not adverse for lack of a fish screen.
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4.11 SUMMARY CONCLUSION – WATER RESOURCE ASSESSMENTS
Management Unit 1: The total number of licences associated with MU 1 is three (3). One (1) - 22.1/147 failed alone, and an additional one (1) - 22.1/136 failed in-combination.
Management Unit 2: Of the fourteen (14) licences in MU 2, four (4) failed alone and an additional seven (7) in-combination. There are seven (7) watercress farms in this management unit – two (2) failed alone, and an addition four (4) failed in-combination.
Management Unit 3: The total number of licences associated with MU 3 is seven (7). Two (2) failed alone, with additional five (5) in-combination.
Abstraction licences in this management unit include – Totford (22.3/55) – failed the in- combination, Candover augmentation (22.3/150)- failed both the alone and in-combination test, Fobdown (22.3/51) – failed both the alone and in-combination test, Fobdown (22.3/132) –failed the in-combination test.
Licence 22.3/158 was issued in 2000 and an Appropriate Assessment was carried out at that time. It should not have been included in the stage 3 list and will be removed from stage 4.
Management Unit 4: Of the five (5) licences in MU 4, one (1) failed alone, and an additional one (1) failed in-combination. Licence number 22.4/151 (fish farm licence) failed the alone test through application of Rule 2 as its daily licence entitlement is greater than the allowable flow. See Section 4.4.4 for definition of Rule 2 and Section 4.4.6 for the definition of allowable flow.
Management Unit 5: The total number of licences associated with MU 5 is eight (8). None (0) failed alone, six (6) failed the in-combination test.
Management Unit 6: Of the eight (8) licences in MU 6 considered for the functional appropriate assessment. One (1) failed alone, with an additional six (6) following the in- combination test.
The distribution of Water Resource abstraction licences which cannot be determined not to be having an adverse effect on site integrity is given in Figure 4.16.
4.12 CONCLUSION Having undertaken an appropriate assessment of water resource permissions for the River Itchen cSAC, in view of its conservation objectives, the Agency cannot ascertain those identified in Table 4.20 will not adversely affect the integrity of the site.
This conclusion is based upon the following summary assessment (Table WR-C) of these permissions for the habitats and species populations for which the site has been classified or designated.
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4.13 ROBUSTNESS OF DECISION MAKING The Appropriate Assessment has concluded that 10 out of 45 abstraction licences within the catchment identified in Stage 3 cannot be deemed not to be having an adverse effect on site integrity.
The study has used best available science and techniques to define a target flow regime to aid decision making. Application of the target flow regime has not resulted in any licences not being considered as adverse and so has not affected the result of stage 3. The Agency will be refining the target flow regime in stage 4 when licences will need to be affirmed, modified or revoked.
4.14 OFF SITE IMPACTS – WATER RESOURCE ASSESSMENTS
Entrapment (off-site in Southampton Water/Itchen estuary).
Entrapment or impingement of salmon in large sea-water abstractions whilst migrating through Southampton Water is a potential risk. The Agency assessed the potential impact from these abstractions as an off-site impact upon the Itchen salmon population. Salmon pass through the estuary at three different stages of their lifecycle. Young salmon (smolts) move down the rivers in spring to migrate to the sea. Adult fish on their breeding migration move up the rivers in summer and early autumn. Spent fish, those that have bred and survived, pass back through the estuary once spawning has finished.
Adult salmon on their upstream migration are strong swimmers and can usually swim away from an intake. Smolts and spent fish are weaker swimmers and may be caught.
There are three water abstraction intakes on the Itchen estuary and Southampton Water on the route that Atlantic salmon take between the river and the open sea.
The major surface water intakes related to Southampton Water and the River Itchen Estuary are listed in Table 2.1.
Table 2.1 Major surface-water intakes related to Southampton Water & the River Itchen Estuary. Abstraction Location River (Unit) Grid Abstraction Period Licence Reference 14/3 Fawley Power Estuary 4764 221 Jan to Dec Station 14/2 Esso Refinery Estuary 4690 495 Jan to Dec 23/3 RMC Aggregates Estuary 4311 1193 Jan to Dec
The assessment concludes that about 1 Itchen salmon are estimated to be impinged annually by the existing intakes. This is mainly due to the impingement at Esso Refinery of smolts returning to the sea. Evidence suggests that negligible numbers of adult returning fish will be impinged. The Agency considers this impact to not be adverse upon the integrity of the Itchen cSAC. (Sealby & Fewings, 2003). See Appendix I.
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Figure 4.12 Water Resource Abstraction Licences (Licences which Cannot be Determined Not to be Having an Adverse Effect on Site Integrity)
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PART B.3 WASTE FUNCTIONAL ASSESSMENT.
5 WASTE LICENSING ASSESSMENT
There are no qualifying waste licensing permissions (from the Stage 1 list given in Table 1.6) for the Stage 3 appropriate assessments.
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PART B.4 PIR FUNCTIONAL ASSESSMENT.
6 PIR APPROPRIATE ASSESSMENT
6.1 SUMMARY OF OUTCOMES The outcome of the appropriate assessment of the River Itchen cSAC for PIR is summarised in Tables 6.1 and 6.2 below.
Table 6.1 Summary of PIR Consents (Releases to Air) Assessment conclusions PIR Consents (Releases to Air) Total number of Permissions Total No. of PIR licences assessed in Stage 3 26 (Releases to Air) Can be shown to not be having an adverse effect on 10 the integrity of the site Cannot be shown to not be having an adverse 0 effect on the integrity of the site alone Cannot be shown to not be having an adverse 0 effect on the integrity of the site in-combination Revoked since completion of Stage 2 4 Repermitted or within 12 months of repermitting 12 under Reg.48
Table 6.2 Summary of PIR Consents (Releases to Controlled Water) Assessment conclusions PIR Consents (Releases to Controlled Water) Total number of Permissions (relating to off-site impacts only) Total No. of PIR licences assessed in Stage 3 7 (Releases to Controlled Water) Can be shown to not be having an adverse effect on 1 the integrity of the site Cannot be shown to not be having an adverse 3 effect on the integrity of the site alone Cannot be shown to not be having an adverse 3 effect on the integrity of the site in-combination Revoked since completion of Stage 2 1 Repermitted or within 12 months of repermitting 2 under Reg.48
New permissions permitted under Reg. 48 but mentioned in Technical Report17 (not included in 2 total above)
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6.2 INTRODUCTION The Environment Agency controls releases into the environment by granting authorisations under the provisions Part 1 of the Environmental Protection Act 1990 (IPC) or The Pollution Prevention and Control (England and Wales) Regulations 2000 (PPC). The Conservation (Natural Habitats, &c.) Regulations 1994 established a requirement to review existing permissions to ensure that no Agency permission results in an adverse effect, directly or indirectly, on the integrity of a classified Special Protection Area (SPA) or candidate or designated Special Area of Conservation (SAC). All PPC permits have been determined in accordance with Reg. 48 of The Conservation (Natural Habitats, &c.) Regulations 1994 and are not considered further in this assessment.
Relevance to the review process (Stage 1) was determined according to the guidance available3. The criteria were:
Emissions to air from IPC authorised processes may have effects over both long and short ranges depending on the size and nature of the emission. The largest emitters of SOx and NOx will be reviewed nationally to determine long range eutrophication/acidification impacts on European sites across England and Wales. PIR officers should identify any authorised processes which could have short range effects on the European site.
In practice this can be achieved using a simple distance criterion of 10 km or for Power Stations 15 km. In some cases the PIR officer may feel that an IPC authorised process other than power generation which is more than 10 km distant should, by virtue of its magnitude, be considered relevant. Conversely, some authorisations which meet the 10 km criterion can be discounted if they clearly do not have the capacity to have an effect on the designated features of the European site.
Due to the nature of emissions to air the PIR officer for the Review at a European site may well need to involve colleagues from neighbouring Areas or Regions of the Agency.
If an IPC authorisation includes a discharge direct to controlled waters this should be assessed in the same way as other consented discharges to water.
Where an IPC authorisation includes a discharge to a sewer, the final effluent from the Sewage Treatment Works will be consented by Water Quality staff. The Review will consider only the consented discharge to controlled water and the PIR officer need not consider discharges to sewers at this point in the Review process. The same applies for Special Category Effluents discharged to sewers. However, should an appropriate assessment in Stage 3 establish that the Sewage Treatment Works effluent is having an adverse effect on a European site and this is caused by a PIR authorised discharge to a sewer, then the relevant authorisation may need to be subsequently revoked or amended.
It was considered that an oil refinery would have emissions of sufficient magnitude to be encompassed by the 15 km criteria; furthermore, for the purposes of Stage 1 all manufacturing/processing on the refinery site was included as requiring consideration up to 15 km.
Significance for the review process (Stage 2) was determined, solely, on whether emissions could reach levels greater than 2% of an Environmental Action Level (EAL) or Critical Level (CL)4.
3 EAS/3100/3/1\Version 1 3.14 – 3.18
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However, as the guidance on ‘in combination’ was unclear at the time, all of the relevant permissions along the western shore of Southampton Water were put forward for appropriate assessment (Stage 3) without further consideration.
During the course of this assessment that has been worked on for over 18 months circumstances have changed. Consequently, some of the air dispersion modelling undertaken to inform the assessment includes the impacts of permissions that have been revoked or whose emission limits have been changed. In all cases the emission limits have been reduced. The modelling output will, then, be more pessimistic than reality. In instances where this circumstance may affect the decision it is mentioned in the text.
Dispersion modelling conducted by AQMAU to inform the decisions on deposition of acidifying and eutrophying species includes the impact of 10 local permissions. The same modelling output is used for all High Priority sites. However, for an individual High Priority site some of these permissions may have been screened out at stage 1 or 2 as not relevant or not significant, revoked since the modelling was completed or are PPC transition sites included to inform the in- combination assessment. This is indicated, where relevant, in this assessment or its attachments.
The modelling output provided by AQMAU has been modified locally to incorporate amendments suggested by English Nature (Letter from Dr. Z Masters (EN) to Jo Simmons (EA) dated 1 July 2004).
6.3 ASSESSMENT TOOLS Attachment ‘PIR – Environmental Benchmarks’ lists the critical levels and critical loads against which this assessment has been made. The origin of the critical level or critical load is also given. EC and National Environmental Quality Standards (EQS) exist for only a limited number of substances emitted to air and water; where these exist they are the critical level or load used for assessment. However, provisional benchmarks have been derived for substances released to each environmental medium from a variety of published UK and international sources, known as Environmental Assessment Levels5 (EAL). Although these do not carry any statutory basis, they are a benchmark for harm against which any exceedance should be viewed as unacceptable6. Throughout this assessment ‘critical level’ will refer to an air concentration and ‘critical load’ will refer to a deposition except where stated otherwise.
It is important to consider the constraints associated with applying any given environmental benchmark. The critical level or critical load values presented within the attachment ‘PIR – Environmental Benchmarks’ include separate values for ‘Emissions to Air’ and ‘Deposition to Land’.
For ambient air the critical level is the concentration or benchmark for harm against which any exceedance should be viewed as unacceptable. In most cases the sources for critical levels do not provide the mechanism of impact (e.g. toxic contamination, acidification, or eutrophication etc), nor do they provide for different critical levels to account for variability in feature sensitivity – i.e. except for sulphur dioxide only one value is given ‘for the protection of vegetation and ecosystems’. It is, therefore, not possible to attribute the precise mechanism of harm to the feature of a European
4 EAS/3100/3/1 Section 8, step l. 5 Environmental Assessment Levels are mainly, though not exclusively, derived from measures to protect human health. Full details of the origin of each EAL are given in IPPC H1: Environmental Assessment and Appraisal of BAT, v6. 6 IPPC H1: Environmental Assessment and Appraisal of BAT, v6, Page 27, Note 3.
- 147 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. site and it is only possible to conclude that harm might be expected if a critical level is exceeded or that harm might not be expected if a critical level is not exceeded.
In respect of oxides of nitrogen and sulphur dioxide, critical loads for deposition to land are derived from the Environment Agency Database. This lists all the different European site features and (by virtue of a critical load value being given or not) makes some differentiation between those features that are sensitive and those that are not as well as indicating the mechanism of sensitivity (acidification, eutrophication etc). Those features that are not sensitive to a given impact type, are therefore easily eliminated from further assessment.
Local air dispersion modelling was carried out in accordance with Agency guidance7. Details of the modelling can be found in attachment ‘PIR – Modelling Report’.
Attachment ‘PIR - Authorised Emissions from PIR Sources’ summarises all the authorised emissions to air from PIR sources within Hampshire relevant to the high priority sites. (Permission nos. AS1258 - AM1542 are grouped together as these permissions relate to multi-purpose plant that can be used for a variety of processes, which are individually permitted, but only one process can be carried out at a time.)
Dispersion modelling was carried out for all these substances except where only emitted by a permission in or about to be in transition to PPC19 or where the emission is below the level of significance8. Attachment ‘PIR - Substances Modelled’ summarises the substances for which dispersion modelling was carried out.
Where similar descriptions appear for authorised substances (e.g. hydrocarbons and VOC) they have been modelled together. For assessment purposes VOC emissions have been assessed against the criteria for toluene (for aerial effects) as this has the lower Environmental Action Level9 (EAL) and xylene (for deposition) as this has the lower Maximum Deposition Rate10 (MDR); benzene, which is normally used as a surrogate, has been modelled separately as a discrete authorised substance. This approach was agreed in an e-mail Caroline Chapman (English Nature) b John Massie (Environment Agency) 3 September 2003.
For clarity ‘flagpole’ receptors situated within parts of the high priority sites are included in the dispersion modelling. The location of each ‘flagpole’ receptor is given in Attachment ‘PIR - Flagpole Receptors’.
The output from the air dispersion modelling has been used to calculate deposition rates for xylene and benzene.
Deposition of eutrophying and acidifying species has been assessed against critical loads from the Agency European Sites Database by AQMAU for both local and large national sources.
6.4 ASSESSMENT CRITERIA The results of the modelling and resultant calculation are then assessed in the following way:
7 37_02 v2: Work Instruction: (Appendix 7) – Further Guidance on Applying the Habitats Regulations to IPC, PPC and COMAH. 8 TGN E1: Best Practicable Environmental Option Assessments for Integrated Pollution Control, Table D1. 9 IPPC H1: Environmental Assessment and Appraisal of BAT, v6, Table D4. 10 TGN E1: Best Practicable Environmental Option Assessments for Integrated Pollution Control, Table C1.
- 148 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Where the predicted environmental concentration11 (PEC) is less than a critical level or load then it can be demonstrated that there is no adverse effect on integrity. This appears in Guidance as ‘If the process contribution plus background is less than the appropriate environmental criteria then it can be assumed that there will be no adverse effect’.12
Where the PEC exceeds a critical level the following considerations have been taken into account. Guidance12 says ‘If the background concentration is less than the appropriate environmental criteria, but a small process contribution leads to an exceedance then a decision should be made on the basis of local circumstances. In making the decision it will be important to take into account the magnitude of the exceedance, the likely ecological effect of exceedance on the features, relative contributions of different sources (e.g., traffic) and whether the environmental criteria is likely to be met at some future date’ and ‘If the background concentration is currently exceeding the appropriate environmental criteria and the new process contribution will cause an additional small increase then, as for (ii) a decision will have to be made based on the individual circumstances’. At a joint English Nature/Agency Habitats Directive workshop held in Birmingham (14 January 2003) it was proposed that an ‘in combination’ contribution of < 10% of a critical load would be a suitable screening criteria at Stage 2 (i.e. assessment of significance). Draft Agency guidance on assessment13 provided at an Agency training course on ‘Air quality modelling and assessment in relation to the Habitats Directive’ held on 13 January 2004 that says ‘If PEC > Critical Level, then, if PC > 10% of Critical Level, then it cannot be ascertained in view of the site’s conservation objectives, that the proposal would not have an adverse effect on the integrity of the European site’. Collectively, these are interpreted as meaning that if PEC exceeds a critical level or load then a consideration of proportionality is required.
On the basis of the comments above, for the purposes of this assessment, the following criteria will be used to assess adverse effect on integrity resulting from aerial concentrations of pollutants:
A. Where the PEC is less than the critical level then for all permissions it can be demonstrated that there will not be an adverse effect alone or in-combination.
B. Where the PEC is greater than the critical level but an individual permission contributes less than 1% of the critical level then for that permission it can be demonstrated that it will not have an adverse effect alone or in-combination.
C. Where the PEC is greater than the critical level but an individual permission contributes less than 10% of the critical level then for that permission it can be demonstrated that it will not have an adverse effect alone.
D. Where the PEC is greater than the critical level but an individual permission contributes more than 10% of the critical level then for that permission it cannot be demonstrated that it will not have an adverse effect alone.
E. Where the PEC is greater than the critical level and the contribution from all permissions is more than 10% of the critical level (excluding those permissions individually contributing less than 1% of the critical level) then for those permissions it cannot be demonstrated that they will not have an adverse effect in-combination.
11 Predicted environmental concentration means process contribution (PC) from modelling plus background level. 12 Habitats Directive Handbook, Appendix 7 – Further Guidance on Applying the Habitats Regulations to IPC, PPC and COMAH. No. 37_02, v2, section 5.11 i), ii) and iii). 13 Draft Guidance on Appropriate Assessment produced by Environment Agency Air Quality Modelling and Assessment Unit.
- 149 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. This approach is summarised in the following table. Where local circumstances dictate it may be necessary to deviate from this but on these occasions the reasons will be given in the text.
Criteria for: ‘can Criteria for: ‘can Criteria for: ‘cannot Criteria for: ‘cannot demonstrate no demonstrate no demonstrate no demonstrate no adverse effect alone adverse effect alone’ adverse effect alone’ adverse effect in- and in-combination’ combination’ PEC < CL PEC > CL but single PEC > CL but single PEC > CL but ( source contribution < source contribution > single source 10%CL 10%CL contributions > 1%CL) > 10%CL PEC > CL but single source contribution < 1%CL where, PEC = predicted environmental concentration, CL = critical level and = sum of all (…)
It has not been considered necessary to consider uncertainty in the local modelling as almost all the significant elements used for the assessment include precaution and the output will be, consequently, very precautionary. These include: the modelling assumes maximum emissions, from all permissions, at all times; the modelling has used the meteorological data from the year that has in the past produced the most conservative results; the critical levels applied are the most stringent in use even if they do not yet have any legal status (e.g. EALs) or specificity to particular features; the background levels used are frequently derived from measured data and as such will include the actual contribution from these permissions. (However, where the permissions under review are large contributors to the background levels then further consideration is given to account for double counting and avoid unreasonable pessimism in the outcome.)
As the European site is geographically widespread the criteria above are applied at the part of the site where the dispersion modelling indicates that it will be worst affected by emissions from the permissions under review; all other parts of the site will be less affected (in most cases very much less affected). The decision on whether no adverse effect can or cannot be demonstrated is made as if the entire site were affected to the same extent as the worst affected part. Any deviation from this (e.g. if a feature is confined to a small geographic area) is detailed below.
For assessment of the impact of deposition of eutrophying or acidifying species the guidance contained in AQTAG0814 has been followed. In particular section 6.1.1 (Section 4.6 of Appendix 7 of the overall Habitats Guidance15 indicates that Where the concentration within the emission footprint in any part of the European Site is less than 1% of the relevant benchmark, the emission is unlikely to have a significant effect irrespective of the background levels. From the histograms given in section 4.6 and the supporting table of the Stage 3 proforma, processes which individually contribute less than 1% of the critical load should be identified. Where there are multiple polygons and a bar showing the range of contributions is given, the maximum value should be used); section 6.1.2 (Unless the aggregate contribution of processes which individually contribute less than 1% is large (for example, in the order of 10-20% of the critical load) a conclusion of no adverse effect on site integrity alone and in combination with other processes can be reached, and they should therefore progress to Stage 4 to be affirmed); and section 6.3.5 (Consequently, if the results of the screening assessment indicate that the site polygons’ are mainly designated H, HM or LM the site can be considered as being clearly exceeded and it is not possible to conclude no adverse effect. If the site is predominantly designated L then it is unlikely that in reality the site is actually exceeded
14 ‘Guidance on the determination of appropriate assessments for the review of Consents at High Priority Sites’. Version 4.1, 23 July 2004. 15 Work Instruction: (Appendix 7) – Further Guidance on Applying the Habitats Regulations to Integrated Pollution Control (IPC), Pollution Prevention and Control (PPC) and Control of Major Accident Hazards (COMAH), Comprising of Appendix 7A for IPC and PPC and Appendices 7B and 7C for COMAH. Version 3, 01/07/04
- 150 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. and a conclusion of no adverse effect may be justifiable). Other sections may be referred to in the discussion below.
Thus, for acid and nutrient deposition where the predominate designation is L this is equivalent to the ‘PEC less than critical level’ criterion used for aerial concentrations. Where the predominant designation is H, HM or LM this is equivalent to ‘PEC greater than critical level’ criterion used for aerial concentrations and further consideration of proportionality using the same criteria as for aerial concentrations is undertaken.
The Agency has considered ‘off–site impacts’ in the appropriate assessment. In the case of PIR the Agency has assessed impacts of certain discharges in Southampton Water upon salmon, as an interest feature of the Itchen cSAC. In relation to the feature ‘Atlantic Salmon’, assessment of impact on site integrity specifically resulting from the effects of thermal discharges to controlled waters can be measured in terms of the number of adult salmon that would not return to the River Itchen cSAC. In recent years the run of returning adult salmon has been significantly below the ‘conservation limit’ (this is the number of returning adults required to sustain the population16. Any further reduction in the number of returning adults may have a significant negative impact on the population. Under these circumstances, any reduction in returning adults that can be equated to one or more returning adult female salmon would bring about a conclusion that no adverse effect on site integrity could not be demonstrated. This threshold is based on returning females as significant numbers of males do not undertake oceanic migration but are available to mate with returning females. Thus, this represents the threshold against which impacts on integrity are assessed.
6.5 MAPS SHOWING PIR PERMISSIONS The PIR permissions deemed likely to have ‘significant effect’ on site integrity are given in Figure 6.1.
16 CEFAS and Environment Agency, (2001). Salmon stocks and fisheries in England and Wales 2000. Preliminary Assessment prepared by ICES.
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Figure 6.1 Map Showing Locations of PIR Permissions (Licences Deemed Likely to Have Significant Effect)
- 152 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
6.6 LIST OF FEATURES SENSITIVE TO PIR PERMISSIONS Table 6.3 shows an extract from the sensitivity matrix7 of the sensitivity of the species/habitat to the hazards that may arise from the permissions under assessment.
Table 6.3 SAC Species/habitat groups considered in PIR Assessments Hazard 2.9 Mammals of 2.6Non-migratory 2.5Anadromous 2.2Vascular plants, 1.3Riverine riverine habitats fish and fish lower plants and habitats invertebrates of invertebrates, wet rivers habitats Toxic contamination Nutrient enrichment Acidification Changes in salinity regime Changes in thermal regime Habitat loss Physical damage by IPC/PPC Processes Smothering Turbidity Siltation Entrapment Disturbance (noise)
Toxic contamination, nutrient enrichment, changes in salinity regime, changes in thermal regime, turbidity and siltation cannot result from the permissions under assessment as there are no aqueous discharges into the River Itchen. However, impacts resulting from changes in the thermal regime along the migration route of Atlantic Salmon are considered further under the section ‘Off-site Impacts’ below.
Abstraction does not form part of any IPC permission and so entrapment is not considered.
Noise is not regulated under any of the IPC permissions.
Toxic contamination, nutrient enrichment and acidification are considered in the discussion of permissions below. Habitat loss and physical damage by IPC/PPC processes is considered only insofar as they can only result from toxic contamination etc. as the permissions are all remote from the site. Thus, the same outcome with respect to adverse effect or otherwise will be concluded as for toxic contamination etc. Smothering can only result from emissions of particulate matter. Thus, the same outcome with respect to adverse effect or otherwise will be concluded as for toxic contamination.
For the purposes of this assessment toxic contamination is taken to result from ground level concentrations or deposition of pollutants but acidification or nutrient enrichment from deposition only.
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Table 6.4 Extract from the Favourable Condition Tables provided by English Nature in Relation to PIR Permissions Species/Habitat Attribute Measure Target Atlantic salmon Habitat Area of submerged Maintain patchy cover structure and marginal plants Extent of bankside Maintain to an extent tree cover with characteristic of the river type submerged tree root systems Bullhead Habitat Extent of high Maintain intermittent cover structure canopy tree cover [where characteristic of the river/reach] Brook lamprey Habitat Area of emergent Maintain a high extent structure riparian vegetation throughout the river system Extent of bankside Maintain to an extent tree cover characteristic of the river type White-clawed Habitat Extent of submerged Maintain patchy cover where crayfish structure and marginal characteristic of the river type. vegetation Extent of Should be present intermittently overhanging riparian along the bank throughout the vegetation year. Extent of bankside Maintain to an extent tree cover characteristic of the river type Southern Vegetation frequency or Channels in the occupied area damselfly composition percentage cover with frequent to dominant cover of Apium nodiflorum, Rorippa nasturtium-aquaticum and/or Veronica beccabunga. Tall marginal vegetation (e.g. Glyceria maxima, Sparganium erectum) not entirely obscuring channels by the end of July along three-quarters of channels in the occupied area. Extent of comparison with No year-on-year reduction of suitable reference point map channels, runnels or the area of larval seepages. habitat Shade percentage cover Not more than 10% increase in cover of trees and scrub, compared with baseline map over six years. Otter Bankside Proportion of bank No overall permanent decrease cover lined with trees, scrub or other thick cover
The threshold criteria are set at levels that will ensure that these targets are not compromised.
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6.7 OFF SITE IMPACTS – PIR ASSESSMENTS The passage of Atlantic salmon through Southampton Water could be impacted by releases to controlled water. (There are no releases directly into the River Itchen). The following permissions have releases to controlled water:
Table 6.5 PIR Permissions having releases to controlled waters considered in the Technical Report17 Permission Number Identifier AF7541 BP, Hamble AK5547 Polimeri Europa, Hythe AF8009 Esso Petroleum, Fawley AA3115 RWE npower, Fawley AG8047 Shanks, Hythe BR8271 Cognis, Hythe AJ7269 Koppers, Totton BL6217 Marchwood Power, Marchwood BJ7093 Onyx, Marchwood
One other permission was considered within the assessment of thermal impacts in Southampton Water. That is a water quality discharge – Geothermal
To quantify the effect of thermal effluents from these releases on Atlantic Salmon in Southampton Water a model was produced based on the temporal pattern of fish arrival and the temperature of the estuary17.
Of the permissions listed above AF7541 (BP, Hamble) discharges only surface rainwater essentially at ambient temperature. Thus, this permission is judged not to contribute to changes in the thermal regime that could affect Atlantic Salmon migration and is not considered further.
Other licences with thermal impacts not considered further in the assessment are:-
Shanks (AG8047). This licence is due to be repermitted under PPC in 2005. It is therefore Agency policy19 for it to be submitted to the Habitats Regulations (48) as a new permit at that time rather than through the review of consents process.
Cognis (BR8271 – previously AK4494). This licence has recently been repermitted through the PPC and was submitted to the Habitats Regulations tests as a new licence. The permit was granted and the licence deemed not adverse.
Koppers (AJ7269). This site is closed and the permission has been revoked.
Marchwood Power Station (BL6217) & Marchwood Energy Recovery Facility (BJ7093). These licences have both been submitted to the Habitats Regulations (Reg 48) as new permissions. Their effects alone and in-combination were deemed not adverse upon the Itchen cSAC.
17 Technical Report ref. W (DD) 03 of the Water Quality Technical Appendix on ‘Predicting the Effects of Heated Outfalls and Water Intakes on Itchen River Salmon in Southampton Water’ & ‘Predicting the effects of the Fawley Power Station’s heated outfall on Itchen River salmon in Southampton Water’.
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The Technical Report17 estimated that thermal releases from the above permissions could, at worst, deter migration to the River Itchen of about 8.7 adult Atlantic salmon. The relative contribution of impact from each of these permissions is summarised in the table below. This is adapted from Table 10 of the Technical Report17.
Table 6.6 Numbers of salmon deterred from passing through the estuary Number of adult salmon deterred Permission Number Identifier Total Female AK5547 Polimeri Europa, Hythe 2.52 ~ 1.51 AF8009 Esso Petroleum, Fawley 4.11 ~ 2.47 AA3115 RWE npower, Fawley 2.06 ~ 1.24 Total 8.69 ~ 5.22
The deterrence of 8.7 adults in total from returning to the River Itchen represents approximately 5% of the recent run of Atlantic salmon..
Only thermal impacts are considered in this assessment, although other potential impact types are identified in the sensitivity matrix. The reason for this is that the vulnerability of a species to a particular type of impact depends on both the sensitivity of the feature and the exposure to the impact. For the other identified impact types, salmon may be sensitive but during their passage through the estuary it was deemed that their exposure to these potential impacts would be limited. For example, an effluent plume from the plume may introduce toxic contamination, but the nature of the discharges involved means that these contaminants will not be present at high enough levels to be immediately lethal to salmon. Any impacts would have to be realised over time due to build- up of toxins or through bio-accumulation. However, salmon would not be present in the area for long enough for these impacts to occur and they are not thought to feed in the estuary.
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INTEGRITY TABLE 1.1 Integrity of site check list with respect to PIR This appropriate assessment has shown that…….. ? Assessment of habitats Assessment of habitat and species Assessment of species populations populations Features for which the cSAC has 1) The area of 2) There will be no 3) The 4) There will be no 5) There will be no 6) The natural 7) There will be no been selected annex 1 habitats changes to the conservation interruption or direct effect on the range of the indirect effects on degradation of the (or composite composition of the status of the site’s physical, chemical or population of the species within the the populations of features) will habitats for which typical species is biological processes that species for which site is neither species for which not be reduced? the site was favourable (as support habitats and the site was being reduced nor the site was designated (e.g. defined in 5 – 7) species for which the site designated or is likely to be designated or was designated or reduction in species classified classified reduced for the classified due to structure, foreseeable future loss or degradation abundance or of their habitat diversity that (quantity/quality) comprises the habitat over time The river as a habitat for :
Floating formations of water Yes Yes Yes Yes crowfoot (Ranunculus) of plain and sub-mountainous rivers Populations of Atlantic salmon No – both off-site No – both off-site No – both off-site No – both off-site (Salmo salar) releases to water releases to water releases to water releases to water AK5547 AK5547 AK5547 AK5547 AF8009 AF8009 AF8009 AF8009 AA3115 AA3115 AA3115 AA3115 Populations of bullhead (Cottus Yes Yes Yes Yes gobio) Populations of brook lamprey Yes Yes Yes Yes (Lampetra planeri)
Populations of white-clawed Yes Yes Yes Yes crayfish (Austropotamobius pallipes) and the river and adjoining land as habitat for :
Populations of southern damselfly Yes Yes Yes Yes (Coenagrion mercuriale) Populations of otter (Lutra lutra) Yes Yes Yes Yes
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INTEGRITY TABLE 2.1 Salmon – off-site impact of three releases to water in Southampton Water.
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Populations of Atlantic salmon (Salmo salar)
Scale of impact AK5547 Polimeri Europa, Hythe AF8009 ESSO Petroleum, Fawley AA3115 RWE npower, Fawley
The Agency estimates that existing thermal effluents could deter migration of about 10 Itchen salmon through Southampton Water into the River Itchen. About 85% of the deterrence (8.7fish annually) was linked to the Esso Refinery, Fawley P.S. and Polimeri outfalls. The total number of Itchen salmon affected by present and proposed thermal effluents is about 11 fish.
The Itchen cSAC Conservation Objectives set a target for the Itchen salmon population, expressed as the Conservation Limit, which is a minimum number of returning fish to sustain a viable population in the long term. The Itchen salmon conservation limit is set at the equivalent of 660 adult spawning fish. The estimated mean returning stock between 1999 and 2003 was calculated to be 210 fish. Hence there is a high degree of confidence that the salmon interest feature is currently in unfavourable condition and cannot be described as a self-sustaining viable population in the long term.
Within that context, the further loss of 5% of the estimated returning stock due to thermal discharges in Southampton Water from these permissions is considered sufficient in magnitude to be determined cannot show not adverse.
These licences are also considered in terms of impacts upon habitat in Southampton Water. But the ways of addressing this line of assessment are complex, particularly so in terms of understanding salmon biology and the migration of these fish through Southampton Water.
- 158 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. The temperature increase in Southampton Water caused by the effluent raising the water temperature, is to such a degree and geographical extent that the number of fish entering the Itchen estuary is reduced.
The effects of high water temperature are thought to act as a barrier to the movement of fish. This reduces the suitability of the habitat and effectively reduces the ability of the species to reproduce.
Long term effects and The salmon population of the River Itchen is presently small and therefore comprises a relatively small gene pool, biological (lag) this together with the restricted ability of the population to utilise the more suitable spawning habitat of the upper Itchen limits the populations ability to recover from short term impacts.
The predominant generation time is three years so fish spawning in one year can be expected to contribute adults three years later leading to three semi-distinct cohorts. This feature also limits the rate with which the population can recover from impacts and therefore major improvements might be noticeable after 6-9 years. At present the population is small and thought on average to be only capable of just replacing itself therefore the sensitivity of the population to additional losses of fish is thought to be acute.
Duration of impact and The reasons for a limited ability for the salmon population to recover from impacts are presented above. It should recovery/reversibility be noted that the population diversity may not be recoverable in many generations following a major impact. The sensitivity of the population to additional losses of fish is thought to be acute.
Dynamic systems These discharges do not contribute to the natural habitat dynamics of the site Conflicting feature There are no conflicting feature requirements requirements Off-site impacts These two licences are off-site impacts, effecting the Itchen interest feature as the salmon migrate through Southampton Water.
Uncertainty in cause and There are uncertainties in this element of the assessment. Our understanding of salmon biology is insufficiently effect relationships and a developed to enable us to state in empirical terms with absolute confidence what the actual effects of these thermal precautionary approach discharges are upon the Itchen salmon population. The modelling approach adopted by the Agency has caveats attached, and also margins of error. However, the Agency has based the assessment on the best available information and adopted a precautionary approach. The Agency will review the data and modelling with the licence holders in Stage 4.
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This appropriate assessment of the potential impacts from warm water discharges expresses results in the form of the number of salmon affected. In this instance, the salmon so affected are deemed to not enter freshwater and therefore contribute to recruitment of the stock. The number of salmon was estimated at recent population levels of 210 salmon for the River Itchen.
The Agency has also attempted to express the measures of impact in other ways, such as area of habitat impacted, to set the assessment in context.
To allow relative impact to be measured under varying population size the percentage of the population that were additionally prevented from entering freshwater due to thermal discharges was included (Table 1). This estimate is unlikely to underestimate the impact for a number of reasons as indicated in the report by Seaby and Fewings (2003) and by Seaby (2005) (both in Appendix J). In addition to the percentage impact the number of salmon impacted were calculated at the conservation limit for the river18. The conservation limit egg deposition back calculated to returning stock is currently 660 salmon on the River Itchen. The reader may then gauge the significance of the number of salmon impacted in the context of the minimum desired population levels.
Since estimates of environmental impact are often expressed as the magnitude of habitat impacted, both the width of estuary affected and area of estuary affected have been included. The latter was then also expressed as a percentage of the total estuary area. These measures, though consistent with the measurement of habitat impact elsewhere, are difficult to relate to habitat integrity at the point of the off-site impact (as opposed to a proportion of the Itchen cSAC) unless some relationship is known or suspected between the habitat and the effects on the species of interest. The level of uncertainty, and the fact that this is an off-site impact and measures of habitat loss are tenuous when considering integrity of the Itchen cSAC. For example, whilst some plumes may extend across a substantial portion of the estuary width and have the potential to expose a significant number of salmon to elevated water temperatures, other factors may heavily influence the effect on salmon. These factors may include the ambient water temperature and the timing of arrival of fish from the ocean. For this reason the measures are presented here but the Agency consider this additional analysis as an unhelpful measure of impact on the species, Atlantic salmon.
Another measure of habitat impact is the proportion of habitat area affected. This measure produces very low estimates of impact but again has little relevance to the effects on the species in question.
18 “Conservation limits demarcate undesirable spawning stock levels. When stocks fall below the conservation limit the number of adult fish produced in the next generation will be significantly reduced. It is therefore the level below which stocks should not be allowed to fall” (CEFAS & Environment Agency, 2001).
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Table 6.7 Assessments of impact from thermal discharges in Southampton Water
Percentage of Percentage of Calculated Area of estuary width estuary area R Itchen Salmon R Itchen Salmon Outfall Name Plume (semi circle) Radius of Plume Estuary width affected affected Affected Affected (male and female) (male and female)
2 (m ) (m) (m) (%) (%) Number of salmon (%) Esso 3 2474 8 1283 0.63% 0.011% 0.01 0.005% Shanks 9843 74 1758 4.23% 0.043% 0.70 0.333% Cognis 5083 53 1758 3.03% 0.022% 0.50 0.238% Geothermal 280 13 1050 1.27% 0.001% 0.21 0.100% Koppers 56 6 250 2.39% 0.000% 0.04 0.019%
Esso 1 &2 157545 317 1283 24.68% 0.682% 4.11 1.957% Polmeri 111723 267 1758 15.17% 0.484% 2.52 1.200% Fawley PS 331752 800 2000 40.00% 1.436% 2.06 0.981%
Marchwood Power Station 161252 320 712 45.00% 0.698% 0.67 0.319% Marchwood Energy Recovery Facility 45867 171 712 24.00% 0.199% 0.36 0.171%
Totals assuming recent stock levels Existing discharges 2.679% 10.15 4.833% Licensed discharges [non-operational] 0.897% 1.03 0.490%
Totals Assuming Conservation limit stock levels Existing discharges 2.679% 31.90 4.833% Licensed discharges [non-operational] 0.897% 3.24 0.490%
Total Estuary area (m2) 23,105,100
NB The estimate of area for Fawley PS is derated to account for the fact that it is only in southampton water for about 33% of the tidal cycle
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6.8 DISCUSSION OF PERMISSIONS Permission nos. AA2917, AI4212, AJ7269 and AM1534 have been revoked. NB both local and AQMAU modelling includes the contribution from AJ7269 as this was not revoked until after the modelling had been completed.
Permission nos. AK4494, AG1042, AK6861 and AK4486 and AS1258, AM1496, AJ8338, AM1500, AM1518, AM1526 and AM1542 have been the subject of PPC Applications that have been determined by the Agency as new permissions19. As such further discussion, in relation to this appropriate assessment, is limited to their inclusion in some modelling to inform decisions on in- combination assessment.
Permission no. AG8047 will be the subject of a PPC Application (March 2005) and will be determined by the Agency as a new permission19. As such further discussion, in relation to this appropriate assessment, is limited to its inclusion in some modelling to inform decisions on in- combination assessment.
Local modelling output.
The modelling output for local sources is shown on the contour plots, Attachment ‘PIR - Contour Plots’, and spreadsheets showing ground level concentrations at flagpole receptors, Attachment ‘PIR – Results at Flagpole Receptors’. NB Contour plots have not been produced where there is no glc greater than 10 % of the critical level.
The results are summarised in Attachment ‘PIR - Modelling Output (River Itchen)’, Appendix E.
AQMAU modelling output for eutrophying and acidifying species is given in Attachment ‘UK0012599 SAC River Itchen’.
6.8.1 Summary Conclusions – PIR Assessments
Annual mean air concentrations (see Table 1 of ‘PIR - Modelling Output (River Itchen)’, reproduced as Table 6.7 above)
The critical levels for all modelled pollutants, except for oxides of nitrogen and particulate matter, are not exceeded by the predicted environmental concentration (PEC) annual average ground level concentration (glc) and the process contributions (PC) annual average glc are small (all are 4% or lower and most are <1% of the critical level). Hence it can be shown that toxic contamination arising from the annual mean air concentration of these pollutants from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
For oxides of nitrogen the background contribution is the major cause of exceedance of the critical level with the PC from all local permissions contributing 1.4% to the PEC (or 1.7% of the critical level). It is, therefore, unlikely that any one permission has a contribution greater
19 AQTAG01 “Review of IPC authorisations and implementation of IPPC permits; solutions to ‘in combination’ assessments and timetable conflicts”: 3.2.2 For those IPC authorisations where the transition to IPPC is in advance, or within 12 months of the completion of the HD Review of consents programme, treat the processes that are in transition as new applications.
- 162 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. than ~1% of the critical level (and the closest local source (AJ7269) included in the modelling has been revoked). Hence it can be shown that toxic contamination arising from the annual mean air concentration of oxides of nitrogen from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
For particulate matter the background contribution is the major cause of exceedance of the critical level with a PC of <1% to the PEC (or <1% of the critical level). No one source can be said to contribute > 1% of the critical level. Hence it can be shown that toxic contamination arising from the annual mean air concentration of particulate matter from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
Short-term mean air concentrations (see Table 2 of ‘PIR - Modelling Output (River Itchen)’).
The critical levels for all modelled pollutants are not exceeded by the predicted environmental concentration (PEC) short-term average ground level concentration (glc). The PEC for particulate (98%) approaches the critical level; however, the PC is small (<1%). Hence it can be shown that toxic contamination arising from the short-term air concentration of these pollutants from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
Conclusions - deposition of acidifying and eutrophying species (see ‘UK0012599 SAC River Itchen’). N.B. The acidification and eutrophication critical loads used are taken from the Environment Agency Habitats Directive Database. The critical loads used are the same or equivalent to or most similar to the Annex 1 habitat feature but may have a different description to the actual habitat.
From the Environment Agency Database only the southern damselfly (Coenagrion mercuriale) is susceptible to acidifying or eutrophying species.
For the majority of polygons that make up this site there is a Low Medium confidence that the critical load for acidification is exceeded.
However, the exceedance is clearly caused by the background sources of acidic nitrogen (see Acidity deposition - % of CLmaxN and Acidity deposition - % of CLmaxS tables in attachment).
Although, the CLmaxN is exceeded no permission contributes > 0.7% (see Acid Deposition – Nitrogen histogram in the attachment). The total acidic nitrogen deposition from all local and national sources is < 4% of CLmaxN.
The ClmaxS is not exceeded.
Hence, it can be shown that toxic contamination or acidification arising from deposition of acidic species from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
For all the polygons that make up this site there is a High Medium confidence that the critical load for eutrophication is exceeded.
However, the exceedance is clearly caused by the background sources of nutrient nitrogen (see Nutrient deposition - % of CL table in attachment).
- 163 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. Although, the nutrient CL is exceeded no permission contributes more than ~ 1% (see Nutrient Deposition histogram in the attachment). The total nutrient deposition from all local and large national permissions is 9% of nutrient CL.
Hence it can be shown that toxic contamination or nutrient enrichment arising from nitrogen deposition from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
Conclusions - deposition of other pollutants (see Table 3 of ‘PIR - Modelling Output (River Itchen)’).
The annual average process deposition fluxes for benzene and xylene are <1% of the maximum deposition rate.
Hence it can be shown that toxic contamination arising from the deposition of benzene or xylene from PIR permissions alone and in combination will not have an adverse effect on the integrity of the site.
Summary conclusions – Releases to Air For permission numbers AF7541, AK5539, AK5547, AF7053, AF8009, AJ3000, AL0567, AL0559, AL0524 and AA3115.
Alone The Environment Agency concludes that alone these licences will not affect the integrity of the Itchen cSAC.
In combination The Environment Agency concludes that in-combination these permissions will not adversely affect the integrity of the Itchen cSAC.
6.9 OFF-SITE IMPACTS Thermal discharges to Southampton Water.
ESSO 1 &2 The assessment concludes it cannot be shown this licence does not have adverse effect upon site integrity. This determination is based upon best available information and professional judgement. (Note: The ESSO 3 discharge is part of the ESSO 1&2 licence. Hence it is part of the licence that is deemed cannot show not adverse, although the modelling clearly shows this actual discharge is trivial).
Polmeri The assessment concludes it cannot be shown this licence does not have adverse effect upon site integrity. This determination is based upon best available information and professional judgement.
RWE npower The assessment concludes it cannot be shown this licence does not have adverse effect upon site integrity. This determination is based upon best available information and professional judgement.
Alone The Environment Agency concludes that alone the ESSO 1&2 , Polmeri and RWE npower licences cannot be shown not to adversely affect the integrity of the Itchen cSAC.
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In combination The Environment Agency concludes that in-combination the ESSO 1 &2 , Polmeri and RWE npower licences cannot be shown not to adversely affect the integrity of the Itchen cSAC.
Geothermal (P11003 (PC37/879/H288/84). This is a water quality discharge consent. It is dealt with here for ease of presentation and understanding. Its relative impacts upon the Itchen salmon interest feature are considered to be trivial in-combination. In this context a trivial effect is one where, due to the scale, nature and duration of the consents considered and their associated environmental influences, it is not reasonably foreseeable that their contribution, alone or in- combination, to the effects on the site will result in any measurable change to the structure and/or function of the site.
Alone The Environment Agency concludes that alone the Geothermal licence will not affect the integrity of the Itchen cSAC.
Triviality The impacts from this licence, in-combination with ESSO 1 &2,Polmeri and RWE npower is considered to be trivial. It’s relative impacts upon the Itchen salmon interest feature are considered to be trivial in-combination. In this context a trivial effect is one where, due to the scale, nature and duration of the consents considered and their associated environmental influences, it is not reasonably foreseeable that their contribution, alone or in-combination, to the effects on the site will result in any measurable change to the structure and/or function of the site.
In combination The Environment Agency concludes that in-combination with ESSO 1 &2,Polmeri and RWE npower the Geothermal licence will not affect the integrity of the Itchen cSAC.
Table 6.8 summarises the conclusions on adverse effect resulting from emissions to air.
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Table 6.8: Table of Decisions as to Adverse Effect - Process Industry Regulation Assessments Permission Site Name No adverse effect on site No adverse effect on Number integrity can be shown site integrity cannot be shown Alone In Alone In Combination Combination AF7541 BP, Hamble AK5539 Polimeri Europa, Hythe AK5547 Polimeri Europa, Hythe AF7053 Polimeri Europa, Hythe AF8009 Esso Petroleum, Fawley AJ3000 Exxon Mobil Chemicals, Fawley AL0567 Exxon Mobil Chemicals, Fawley AL0559 Exxon Mobil Chemicals, Fawley AL0524 Exxon Mobil Chemicals, Fawley AA3115 RWE Innogy, Fawley
6.9.1 Summary conclusions – Off-site Impacts
Table 6.9 summarises the conclusions on adverse effect resulting from emissions to controlled waters (Southampton Water) in relation to off-site impacts upon salmon.
Table 6.9: Table of Decisions as to Adverse Effect –Emissions to Controlled Waters No adverse effect on No adverse effect on site site integrity can be integrity cannot be Permission Site Name shown shown Number In In Alone Alone Combination Combination P11003 (PC37/879/H28 Geothermal 8/84) Polimeri Europa, AK5547 Hythe Esso Petroleum, AF8009 Fawley RWE Innogy, AA3115 Fawley
Having undertaken an appropriate assessment of PIR permissions for the River Itchen cSAC, in view of its conservation objectives, the Agency cannot ascertain those identified in Table 6.9 will not adversely affect the integrity of the site. These are all located outside of the cSAC boundary within Southampton Water.
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PART B.5 RSR FUNCTIONAL ASSESSMENT.
7 RSR (RADIOACTIVE SUBSTANCES REGULATION) APPROPRIATE ASSESSMENT
7.1 SUMMARY OF OUTCOMES The outcome of the appropriate assessment of the River Itchen cSAC for PIR is summarised in Table 7.1 below.
Table 7.1 Summary of RSR (Radioactive Substances Regulation) Assessment conclusions Total number of RSR (Radioactive Substances Regulation) Permissions Total No. of RSR licences assessed in Stage 3. 21 Can be shown to not be having an adverse 21 effect on the integrity of the site Cannot be shown to not be having an adverse 0 effect on the integrity of the site alone Cannot be shown to not be having an adverse effect on the integrity of the site in- 0 combination.
7.2 INTRODUCTION The Agency also controls releases into the environment by granting authorisations under the provisions of the Radioactive Substances Act 1993. The implementation of the Habitats Regulations established a requirement to review existing permissions to ensure that no Agency permission results in an adverse effect, directly or indirectly, on the integrity of a classified SPA or candidate or cSAC.
The guidance20 used for determining relevance and significance under Stages 1 and 2 of the RoC process was unclear. Hence, the reasons for inclusion or exclusion of any particular permission may not have been consistent during Stages 1 and 2.
Thus, to avoid any doubt this appropriate assessment considers all permissions to dispose of radioactive material that have a release into the air, an aqueous release directly into or within 10 km of part of a high priority European site and an aqueous release into a sewer whose outfall is in or within 10 km of part of a high priority European site.
20 EAS/3100/3/1\Version 1 3.23 In the case of other sites (category b), a significant effect is unlikely due to the scale of the discharges authorised. However, in the event that one of the following criteria apply the officer should consider the discharge(s) relevant for consideration during Stage 2: a) The discharge/emission is within 1 km of a European site. b) Several discharges/emissions are adjacent to a European site and could act in combination to affect that site. NB. category b means Other sites authorised for the disposal of radioactive waste: these are sites where handling or use of radioactive substances is not the main activity but minor amounts of radioactive material are discharged to the environment (e.g. Hospitals).
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Additionally, some permissions21 that are new or modified were not fully considered under the Habitat Regulations as there was no guidance available. It was agreed, with Alistair Burn (EN), that assessment of these permissions could be included as part of this review when guidance would be available.
All permission numbers have been changed since the Stages 1 and 2 processes. This is due either to a general variation issued to require Pollution Inventory reporting or as a result of changes requested by the permit holder.
7.3 ASSESSMENT TOOLS The Agency’s Radioactive Substances (RAS) process group has produced a ‘Habitat Assessment Tool’. Rather than providing an assessment it acts as a further screening tool and is known as the Stage 3a Tool. The methodology employed provides, for various species, a dose per unit release.
The dose is then assessed against a threshold criterion. The threshold criterion provided by RAS process is 50 μGy/hour. This figure has yet to appear as guidance. However, it compares well with guideline values recommended by the IAEA22 and the UNSCEAR23. (40 μGy/hour for terrestrial animals and 400 μGy/hour for terrestrial plants and aquatic biota.) The EC, through FASSET24 D4, have suggested that these be standardised to 100 μGy/hour.
21 Permission nos. BU6603, BT9208, BT7442 and BV2280. 22 International Atomic Energy Authority 23 United Nations Scientific Committee on the Effects of Atomic Radiation 24 Framework for Assessment of Environmental Impact
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Figure 7.1 Map Showing Locations of RSR Permissions (Licences Deemed Likely to Have Significant Effect)
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7.4 LIST OF FEATURES SENSITIVE TO RSR PERMISSIONS All biota will be sensitive to toxic contamination. Table 6.3 is an extract from the favourable condition tables provided by EN for this particular assessment. Other than direct toxic contamination of the interest features this is the only attribute that can be impacted.
Table 7.2 Extract from the Favourable Condition Tables provided by English Nature in Relation to RSR Permissions Location Attribute Measure Target During migration Atlantic Adult Total run size at least matching the Minimum salmon run Biological Acceptable Level (MBAL) for the river in 4 years out of 5, including a seasonal pattern of migration characteristic of the river and maintenance of the multi-sea-winter component.
The threshold criterion is set a level that will ensure that this target is unaffected.
7.5 DISCUSSION OF PERMISSIONS There are no discharges directly or indirectly into the River Itchen cSAC. This assessment solely considers the impact on Atlantic Salmon when migrating through the Solent and Southampton Water.
7.5.1 Aqueous discharges Using a very pessimistic dispersion rate of 2.4 m3s-1 (Technical Guidance for Water Quality: Review of Permissions to Discharge and New Applications – No.95_01 v2 17/12/02 Appendix B) gives an in-combination worst-case dose of 29 μGy hour-1 (see attachment ‘River Itchen Coastal 3a Assessment Sheet) compared to the screening threshold of 50 μGy hour-1 given in the Stage 3a methodology. This is a very pessimistic outcome for the reasons given in Section 7.2. Atlantic salmon would receive a dose of 1.1 μGy hour-1.
7.5.2 Aerial releases These were assessed using the 3a assessment tool provided by RAS Process. This gives an in combination worst-case dose of 4.1 μGy hour-1 (see attachment ‘River Itchen Terrestrial 3a Assessment Sheet) compared to the screening threshold of 50 μGy hour-1 given in the Stage 3a methodology. An otter would receive a dose of 4.1 μGy hour-1. However, the River Itchen cSAC is well outside the area impacted by aerial releases.
170 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
7.6 SUMMARY CONCLUSIONS – RSR ASSESSMENTS As an in-combination assessment tool has been used and given an output that is below the screening threshold it has been demonstrated that none of these permissions have an adverse effect on the integrity of the site either alone or in combination, in view of the site’s conservation objectives.
Table 7.3 Table of decisions as to adverse effect – RSR Assessments No adverse effect on site No adverse effect on site integrity cannot be Permission integrity can be shown S/No Site Name shown Number In In Alone Alone Combination Combination BR7127 1 (AL5160) Shanks, Hythe
BV6536 Esso Petroleum Co. 2 (BF7066) Ltd, Fawley BT7442 Southampton 3 (BB5274) General Hospital BV6587 Royal South Hants 4 (AZ8722) Hospital, Southampton BV2514 Ferring Research 5 (BC0758) Ltd., Chilworth University of BT9208 6 Southampton, Medical School BM4821 University of 7 (AC7189) Southampton, Boldrewood BS6254 Southampton 8 (AY9197) Oceanography Centre BU6603 BUPA Chalybeate, 9 Southampton BV6471 Wyeth Research Ltd, 10 (BB2291) Gosport BV6498 Royal Hospital, 11 Haslar BV6552 Queen Alexandra 12 (AQ9758) Hospital, Portsmouth BV6579 University of 13 (AV8143) Portsmouth BV6625 Phoenix NBCD 14 (AI1167) School, Whale Island BV6633 Institute of Naval 15 (AY6848) Medicine, Gosport BV6641 HMS Sultan, 16 (BA6704) Gosport
171 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. No adverse effect on site No adverse effect on site integrity cannot be Permission integrity can be shown S/No Site Name shown Number In In Alone Alone Combination Combination BU7260 Apollo Fire 17 (AW6707) Detectors Ltd, Havant BU7600 PALL Europe plc, 18 (AD7443) Portsmouth BV2280 St. Richards 19 (BI1510) Hospital, Chichester BV6684 Royal Hospital, 20 (AV5381) Haslar BT7060 St. Marys Hospital, 21 (AQ9740) Portsmouth
Note to Table 7.3: *Original nos (Stage 2) in brackets.
172 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
PART B.6 GROUNDWATER REGULATIONS ASSESSMENT.
8 GROUNDWATER REGULATIONS AUTHORISATIONS ASSESSMENT
Authorised discharges to groundwater issued under the Groundwater Regulations. None were identified in Stage 1 and 2 of the Review of Consents process.
173 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
PART C (1) - MULTI-FUNCTIONAL IN-COMBINATION ASSESSMENT OF AGENCY PERMISSIONS
9 MULTI FUNCTIONAL IN COMBINATION ASSESSMENTS
9.1 SUMMARY
It is concluded that consideration of between function, in combination effects does change the conclusions in Part B.1 the Water Quality Functional assessment, for two discharge consents, when assessed in-combination with water abstraction licences.
The in-combination assessment changes no other Part B. conclusions.
9.2 INTRODUCTION
The Habitats Regulations require that all Agency permissions within stage 3 of the review of consents have to be assessed in combination with all other Agency permissions. In combination within each function has been carried out and is described in Parts B. This chapter, Part C.1, considers the potential for in combination interaction between these functional permissions in order to establish the sum of influences acting on a feature for which the River Itchen cSAC has been designated.
Any permission determined to have no likely significant effect in stage 2 of the Review of Consents would also by definition have no potential to exert an additive in combination impact with other functional permissions in Stage 3.
This multi-functional in combination assessment for the River Itchen cSAC assesses additive in combination effects between Water Quality Discharge Consents, Process Industries Regulations Permissions (aerial emissions), Radioactive Substances Regulation Consents and Water Resources Abstraction Licences.
The focus of the multi-functional in-combination assessment process is intended to examine: the effect of Agency permissions, with one another, multi-functionally, rather than within function, which was addressed in Part B; and To consider whether that combined influence is sufficient to warrant coming to a different conclusion from those in Part B in relation to the effect of any Agency permissions on site integrity.
174 Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005.
Table C1.1 Impacts arising from Environment Agency Functional Permissions in the River Itchen cSAC.
IMPACT Water Resources Water quality PIR – IPC PIR – IPC RSR releases Abstraction discharges Authorisations to Authorisations to air * water **
Toxic contamination Y Y Y Nutrient enrichment Y Y PH Y Salinity Y Changes to thermal regime Y Turbidity and Siltation Y Change in water levels or table Y Change in flow or velocity regime Y Change in freshwater flow to estuary Y Reduced dilution capacity Y Y Habitat loss Y Entrapment Y Acidification Y Physical damage by IPC/PPC Process Y Y Smothering Disturbance (noise)
* PIR aerial emissions do have other associated impact types (e.g. smothering1) but in this case the emissions are geographically too far from the site to have an effect. Hence these impact types are discounted here. See Part B.4 for further discussion. ** There are no PIR aqueous discharges directly to the Itchen cSAC.
1 Agency Habitats Directive Handbook 37_02 V.3. Sect.7.6.
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From Table C1.1 it can be concluded that the impacts of toxic contamination, nutrient enrichment, reduced dilution capacity and physical damage by IPC/PPC process have the potential to act in a multifunctional in-combination way.
Physical damage associated with PIR and RSR permissions are those which may occur as a result of the footprint of the PIR and RSR sites. Since all PIR and RSR premises are remote from the cSAC this assessment has concluded that there is no potential for an in-combination impact through physical damage by IPC/PPC process.
The three remaining potential in-combination impacts (from toxic contamination, nutrient enrichment and reduced dilution capacity) are considered in greater detail below.
Table C1.2 Risk of additive, between function, in combination impacts on the interest features, sub- features and attributes of the River Itchen cSAC
Interest Feature Attribute Toxic Contamination Nutrient Enrichment Reduced Dilution Capacity Common targets for all Flow N/A N/A N/A features. Biological class Medium OPO = WQ Medium River Ecosystem class OPO = WQ OPO = WQ Medium Suspended solids. N/A N/A Medium Soluble Reactive Phosphorus N/A Medium Medium River substrate N/A N/A N/A Macrophyte community Extent and composition Medium High Medium Reproduction Medium Medium Medium River form N/A N/A N/A Salmon Habitat structure Medium Medium N/A Access N/A N/A N/A Biological disturbance N/A N/A N/A Bullhead Habitat structure Medium Medium N/A Access N/A N/A N/A Biological disturbance N/A N/A N/A Lamprey Habitat structure Medium Medium N/A Access N/A N/A N/A Biological disturbance N/A N/A N/A Crayfish Habitat structure Medium Medium N/A Biological disturbance N/A N/A N/A Southern Damselfly Vegetation composition Medium Medium Medium Extent of suitable larval habitat Medium N/A Medium Shade N/A N/A N/A Otter Site integrity N/A N/A N/A Fish stocks Medium Medium Low Disturbance N/A N/A N/A Bankside cover N/A N/A N/A Presence of otters N/A N/A N/A
N/A = Not applicable; OPO = One Function’s Permissions only
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9.3 DISCUSSION OF BETWEEN FUNCTION IMPACT TYPES
The multifunctional in-combination impacts, identified in Table C1.1 and detailed in Table C1.2 involve toxic contamination, nutrient enrichment and reduced dilution capacity. A discussion of these in-combination impacts is presented below.
Toxic contamination There is potential for PIR/RSR permissions and discharge consents to act in an additive way in- combination.
Toxic compounds from effluent discharges, land run-off, shipping activity, atmospheric deposition etc. can build up in water, sediments and biota. If inputs are high this may result in lethal and sublethal effects on invertebrates and the fish and birds that eat them. The fate and behaviour of a substance entering the water column is determined by its physical and chemical properties.
Properties such as solubility, volatility and its affinity for organic matter determine whether a substance remains dissolved in the water column, evaporates into the atmosphere or becomes associated with suspended or deposited organic material or sediment. Therefore dissolved toxic substances in an effluent discharge may disappear relatively quickly from the water column, but persist in sediments where they may continue to be available to the sediment fauna, or risk re- suspension when sediment is disturbed.
IPC authorised discharges to air include releases of toxic compounds (organic substances, acidic compounds and nutrient nitrogen). Toxic contamination can result following the deposition of these compounds to land or water. Deposition of organic substances to water is considered to be trivial (e.g. the environment quality standard (EQS) for benzene = 30ug/l whereas disposition rate is 0.013ug/m2/day e.g. for 10cm depth of static water this is equivalent to a daily concentration increment of 1.3 x 10–3 ug/l. For flowing water this is trivial). Leaching from deposition to land into water is unlikely to occur in a timescale less than the environmental half-life of the deposited substances.
Deposition of acidic species to land or water will be inconsequential due to the buffering effect of the chalk dominated environment.
Deposition of nutrient nitrogen from PIR permissions is very low (<1kg/ha/yr). As deposition to water this is trivial. As a component of leachate/run-off it is also tiny.
As the Itchen cSAC is geographically widespread the criteria above are applied at the part of the site where the dispersion modelling indicates that it will be worst affected by emissions from the permissions under review. All other parts of the site will be less affected (in most cases very much less affected). The decision on whether no adverse effect can or cannot be demonstrated is made as if the entire site were affected to the same extent as the worst affected part. However, it is clear that the impacts of PIR and RSR aerial emissions are small.
The Agency concludes that overall these deposition rates are trivial when compared to those from point sources, especially when water environment concentrations from most toxic substances are below 10% of the relevant EQS. Close to point source effluent discharges the relative contribution from aerial deposition will be even more inconsequential.
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It is therefore possible to conclude that consideration of between-function in combination effects does not result in any changes to the conclusions of the functional assessments in Part B for Toxic contamination.
There is potential for water abstraction licences and discharge consents to act in an additive way in- combination. The in-combination relationship between water abstraction licences and water discharge consents is discussed separately below.
Nutrient enrichment There is potential for PIR permissions and discharge consents to act in an additive way in- combination.
PIR authorised discharges to air include releases of oxides of nitrogen some of which deposit to land and water. Process contributions at sites in the Itchen cSAC are discussed above.
Nutrient inputs and impacts from water quality consents, PIR authorisations to water and riverine inputs were considered in combination in Parts B1 and B.4.
It is therefore possible to conclude that consideration of between-function in combination effects does not result in any changes to the conclusions of the functional assessments in Part B for nutrient enrichment.
There is potential for water abstraction licences and discharge consents to act in an additive way in- combination. The in-combination relationship between water abstraction licences and water discharge consents is discussed separately below.
Reduced dilution capacity There is potential for water abstraction licences and discharge consents to act in an additive way in- combination. This impact has been modelled and is discussed separately in Section 9.3 below.
9.4 ASSESSMENT OF WATER DISCHARGE AND WATER ABSTRACTION PERMISSIONS.
There is an obvious mechanism of impact between water quality discharge consents and abstraction licences, in that abstraction licences can reduce the flow of water within the river which in turn leads to less dilution being afforded to consented discharges.
Consequently, this part of the multifunctional assessments have been carried out based on the assessed interactions between the operation of the water quality and water resource permissions. Increased concentrations of potentially harmful substances due to reduced dilution of discharged loads at times of low flows could lead to a deterioration of habitat quality or distortion of species diversity/abundance and other detrimental effects.
9.4.1 ASSESSMENT RULES
The assessment of multi-functional impacts resulting from interactions between abstraction licences and discharge consents has been assessed in a similar manner to the functional in-combination assessment for water quality of Part B.1. The maximum consented load from each discharge for
- 178 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. each parameter of concern was compared against an ‘allowable river load’. However the multi- functional element was incorporated into the assessment by using the predicted worst case lowest flows in each part of the catchment.
The worst case flows were identified by examining the results of the maximum abstraction scenario modelled using the hydraulic river model, as described in the Water Resources Functional assessment – Part B.2. The lowest flow predicted to occur at any point in each management unit under this scenario was identified and defined as the ‘worst case river flow’ for that management unit.
The water quality load assessment was then carried out as for the functional assessment but using the ‘worst case river flow’ to define the allowable river load in each part of the catchment. The multi-functional assessment was then defined as Rule 6: Any consent which contributes more than 0.1% of the allowable river load at worst case flows (maximum abstraction) is deemed ‘cannot show no adverse effect on integrity’.
9.4.2 RESULTS
The results of this assessment can be seen in Appendix D, the Water Quality assessment spreadsheet, columns 70 to 79.
As a result of the multi-functional in-combination assessment, between water discharge consents and water abstraction licences the Part B.1 conclusions for two water discharge consents have changed.
These permissions failed Rule 6 as a result of high phosphate levels failing to attain RE1 standards in the worst case flow scenario. The impacts of these consents are chiefly upon salmon and the macrophyte habitat. Elevated levels of phosphates especially during low flow conditions can produce direct effects on the macrophyte community by altering community composition, species diversity and abundance. The changes in habitat availability will have knock-on effects for associated, typical species such as invertebrates and fish.
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9.5 DISCUSSION OF OUTCOMES In addition to the functional assessments described in Part B, multifunctional in-combination assessments have been carried out to reflect the synergies between permissions which come under the different Agency functions, following the methodology outlined in Section 9.2 above.
The assessment concludes that there are foreseeable in-combination impacts that would be likely to change the conclusions in Part B.1 for two water quality discharge consents. All permissions which change from can show no adverse effect when considered by the single function to cannot show no adverse effect when considered in combination with other functions, are highlighted in Table 9.1.
Following careful consideration of the nature, scale and distribution of the different impact types, it is considered that there are no foreseeable risks of any other in combination effects having an adverse effect on the integrity of the European site
Table 9.1: Table of Decisions - Water Quality Consents and Abstraction Licences Multi Functional Assessments
Permission number Site Name (Permission type) No adverse effect on No adverse effect on site site integrity in integrity in combination combination can be cannot be shown shown
Water Quality Discharge Consents P04588 (P4588/H/92) Land at Lovington House (treated sewage effluent) P06542 (P65426/H/96) Weir Cottage (treated sewage effluent)
9.6 CONCLUSIONS - PART C.1 MULTI-FINCTIONAL IN-COMBINATION ASSESSMENT.
An appropriate assessment of the multi-functional in-combination impacts of Agency permissions was undertaken in view of the River Itchen conservation objectives. From this work it is concluded that the findings of the Water Quality functional assessment in Part B.1 must be changed for two discharge consents.
No other Part B conclusions were changed as a result of the Part C.1 multi functional in- combination assessment.
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RIVER ITCHEN cSAC. PART C.1 MULTI-FUNCTIONAL IN-COMBINATION ASSESSMENT.
INTEGRITY TABLE 1.1 Integrity of site check list with respect to multi-functional in-combination This appropriate assessment has shown that…….. ? Assessment of habitats Assessment of habitat and species Assessment of species populations populations Features for which the 1) The area of 2) There will be no 3) The 4) There will be no 5) There will be no 6) The natural 7) There will be no cSAC has been selected annex 1 habitats changes to the conservation interruption or direct effect on the range of the indirect effects on (or composite composition of the status of the site’s degradation of the population of the species within the the populations of features) will habitats for which typical species is physical, chemical species for which site is neither species for which not be reduced? the site was favourable (as or biological the site was being reduced nor the site was designated (e.g. defined in 5 – 7) processes that designated or is likely to be designated or reduction in species support habitats and classified reduced for the classified due to structure, species for which foreseeable future loss or degradation abundance or the site was of their habitat diversity that designated or (quantity/quality) comprises the classified habitat over time The river as a habitat for :
Floating formations of water NO – two crowfoot (Ranunculus) of discharge NO – two discharge NO – two NO – two discharge plain and sub-mountainous consents :- consents :- as for discharge consents :- as for rivers P04588 question 1. consents :- as for question 1. (P4588/H/92) question 1. P06542 (P65426/H/96) Populations of Atlantic NO – two discharge NO – two discharge NO – two NO – two salmon (Salmo salar) consents :- as for consents :- as for discharge discharge consents question 1. question 1. consents :- as for :- as for question question 1. 1. Populations of bullhead (Cottus gobio) YES YES YES YES Populations of brook lamprey (Lampetra planeri) YES YES YES YES Populations of white-clawed crayfish (Austropotamobius Yes Yes Yes Yes pallipes)
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Populations of southern Yes Yes Yes Yes damselfly (Coenagrion mercuriale) Populations of otter (Lutra Yes Yes Yes Yes lutra)
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INTEGRITY TABLE 2.1 WATER QUALITY CONSENTS THAT CHANGE AS A RESULT OF THE MULTIFUNCTIONAL IN-COMBINATION ASSESSMENT.
Habitats or Populations with ‘No’ answers in table 1
Site Specific Integrity Factors Floating formations of water crowfoot (Ranunculus) of plain and sub-mountainous rivers; Populations of Atlantic salmon (Salmo salar).
Scale of impact Two discharge consents have failed the multi-functional in-combination assessment.
P04588 (P4588/H/92) P06542 (P65426/H/96)
These consents fail Rule 6 – the multi-functional in-combination test, due to phosphate levels failing to attain RE 1 standards in the worst case scenario. The impacts of these consents are chiefly upon salmon and macrophytes as interest features, and are the same as described in the Integrity Tables in Part B.1. Please refer to those.
Long term effects and biological (lag) Duration of impact and recovery/reversibility Dynamic systems Conflicting feature requirements Off-site impacts Uncertainty in cause and effect relationships and a precautionary approach
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PART C (2) – EXTERNAL IN-COMBINATION ASSESSMENTS
10 EXTERNAL PLANS AND PROJECTS
10.1 INTRODUCTION. All Agency licenses within Stage 3 of the RoC have to be assessed in combination with the effects of current plans or projects permitted by external competent authorities (hereafter ‘external permissions’) and prevailing background conditions. Prevailing background conditions include those factors contributing to a cumulative effect (historic impacts, the effect of which becomes additive over time) and any other unregulated factors that have the potential to affect the integrity of a European site.
In relation to the two factors that need to be considered (external permissions and prevailing background conditions), these are described separately below for clarity, although both are considered together in terms of the in combination assessment.
The focus of the external in-combination assessment process is not to undertake an appropriate assessment of external permissions. It is intended to examine:
the effect of Agency permissions, when considered in combination with the effects of external plans or projects and prevailing conditions, and to re examine the combined influence of these effects on the integrity of a European site; and
to consider whether that combined influence is sufficient to warrant coming to a different conclusion from those made in Parts B and C.1, in relation to the effect of any Agency permissions on site integrity.
10.2 CONSULTATION WITH COMPETENT AUTHORITIES Area staff conducted the “in-combination” consultation in accordance with Appendix 22 of the Agency Handbook. In November 2003 the Area identified the known plans and projects relevant to the River Itchen cSAC. The EN Local Team audited the list and added to it in December 2003. On 9th January the Area wrote to eighteen (18) competent authorities, asking them to identify relevant plans and projects and to supply information about these, including those plans and projects on the Agency/EN list. The deadline for that information request was set at 8th February (28 days). In the event the Agency accepted responses up to the 8th March 2004.
The types of response obtained from the competent authorities are given in Table 10.1 below, and the technical information supplied is the basis of our in-combination assessment for plans and projects.
Table 10.1 Summary Outcome of Consultation with Competent Authorities Competent Authority Response with Response without Nil response plans/projects plans/projects (as of 8th March 2004)
English Nature (Hants & IoW) Basingstoke & Deane Borough Council Eastleigh Borough Council
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Competent Authority Response with Response without Nil response plans/projects plans/projects (as of 8th March 2004)
East Hampshire District Council Hampshire County Council Southampton Unitary Authority Winchester City Council Marine Consents Environmental Unit Associated British Ports Crown Estates Highways Agency Network Rail Southern Electric Defence Estates South East Portsmouth Water Southern Water British Airports Authority – Southampton Airport Civil Aviation Authority
10.3 EXTERNAL PLANS AND PROJECTS Seven (7) external plans and projects associated with the River Itchen cSAC were found through the course of the consultation exercise described in Section 10.1. Each of these plans is described as follows:
1. Shamrock Quay Marina, Southampton. Revetment Works and pontoon reconfiguration
We do not have information to determine whether this plan has been completed. It is thought that potential impacts due to this plan are likely to be localised. However, future progress on the development might result in issues linked to salmon as an interest feature.
2. Vosper Thorneycroft site. Demolition of site
This plan relates to a large contaminated land site. There is no application as yet for demolition although this is planned for April 2004, over a period of 12 months. Scoping for an environmental impact assessment is underway, but details are not available at this time. Impacts are likely to be associated with disturbance to birds and other river fauna, including salmon, plus impacts associated with contamination released as a result of retreating the existing shoreline. Dust, noise, site drainage and other issues are important factors too. Potential impacts to water quality will be localised and restricted to the demolition period.
3. Itchen Estuary, Hazel Road/Spitfire Quay and Quayside Road/Kemps Quay
For this plan, some planning permissions exist, but implementation is outstanding. The Agency concludes that effects associated with this plan are unlikely to alter conclusions of the functional assessments.
4. Nursling Industrial Estate. New Combined Heat and Power station
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The impacts associated with this plan (emissions to air, all aqueous releases will be to sewer) can be associated with nitrogen dioxide, carbon monoxide and other related issues. The process contributions given in the plan are less than 1% of the critical levels and, on the basis of this information this proposal would be screened out at Stage 2.
5. Dibden Bay – New Forest DC
With respect to the Dibden Bay plan, appropriate assessment was carried out by Association of British Ports and contested by a number of competent authorities including EN.
Currently, there is no definitive or universally accepted view in relation to impact on site integrity resulting from this proposed development. However, the view taken by EN was “.. adverse effect on the Itchen cSAC due to impacts to migratory salmon”.
Theoretically, if Dibden Bay plan implementation results in adverse effect on integrity of these European sites alone, the combined effect of other external plans and projects and Agency permissions can only further adversely affect integrity and all Agency permissions that contribute to that effect would, in combination, result in adverse effect.
This one permission therefore takes all Agency permissions contributing to an impact on the same features adversely affected by Dibden Bay into Stage 4 of the RoC process as cannot show not adverse, unless they are deemed 'trivial' in terms of the relative proportion of impact. However, the Secretary of State has yet to determine the outcome of the Public Inquiry.
That was the position at the time this assessment was drafted, March 2004.
The Dibden Bay Public Inquiry specifically considered the impact of the proposed development upon salmon as an interest feature of the River Itchen cSAC.
In this respect the Inspector stated “I consider that the construction of the Dibden Terminal would be likely to have a significant effect on the River Itchen cSAC.” (para 36.165.).
He went on to conclude “I do not consider that it could be ascertained that ABP’s proposals would not adversely affect the integrity of the River Itchen cSAC.” (para 36.405).
The Secretary of State, Transport Minister Tony McNulty published his decision on 20th April 2004 accepting the recommendation of the Dibden Bay Inquiry Inspector to turn down proposals for a new container terminal on Southampton Water.
Hence this plan/project it is no longer relevant to this assessment.
6. Winchester North Major Development Area and Eastleigh Development Area The key planned development area in Winchester is the Barton Farm triangle, which will comprise a 2.6 km2 infill in the north of the City. Note that the Revised Deposit Local Plan defines a specific site for the development, which is smaller than the 2.6 km2 triangle. Also note that the Revised Deposit version of the Winchester plan was published in May 2003 and the Council will be publishing Pre-Inquiry Changes in advance of the Public Inquiry, which starts in May 2004. The Eastleigh Borough Council Development Plans set out the main considerations on which planning applications are decided and they provide guidance for a range of local agencies and interested parties. In the Borough of Eastleigh the Development Plan consists of the Hampshire County Structure Plan and the Eastleigh Borough Local Plan Review (2001 to 2011) First Deposit, which was approved in October 2001.
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The Winchester North Major Development Area and Eastleigh Development Area are currently not sufficiently defined in terms of water resource and wastewater treatment requirements and related potential impacts to facilitate an in-combination assessment with Agency permissions at this time.
7. Small Sewage Treatment Plant – to service affordable homes, located opposite Benbow Cottages, Herriad, Basingstoke (SU 6711 4515)
The planning application number for this plan is BDB5308. It was approved by the Agency on 19 April 2002.
10.4 CONCLUSIONS PART C.2 IN-COMBINATION ASSESSMENT – EXTERNAL PLANS AND PROJECTS.
Assessment of the likelihood and nature of potential impacts associated with the above plans revealed that there could theoretically be a mechanism for some of the plans/projects to be additive to Agency permissions.
However, the plans/projects are insufficiently well developed to enable a meaningful in- combination assessment to be undertaken - there is currently insufficient information available concerning the likely impact on river flow and concentration of determinands likely to arise from these plans and projects. Given this lack of information, with the exception of Dibden Bay, the in- combination assessments of these external plans and projects for the site concludes that it is not possible to justify changing any of the decisions in Parts B and Part C.1.
There are no ‘trivial’ Agency permissions whose specific effect would be elevated to cannot show not adverse effect by consideration of additional affect from these external permissions.
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11 BACKGROUND/PREVAILING CONDITIONS INCLUDING OFF-SITE IMPACTS.
11.1 INTRODUCTION Prevailing background conditions are the cumulative result of all historic influences upon a European site feature that are still currently exerting that influence. All anthropogenic and natural influences that have the potential to influence the condition of a site feature and which could act in combination with the effect of an Agency permission are relevant.
A useful discussion of the ecological interests of chalkstreams and the many influences prevailing on them in general terms is presented in the EN publication “ChalkRivers – nature conservation and management, C.P.Mainstone, 1999.”
11.1.1 Generic Factors Considered Through the In-Combination Assessments Factors Identified Through EN Condition Assessment
Information from the EN’s web site for the River Itchen cSAC summarised in Section 1.3 has been used to compile Table 7.1, which illustrates the relationship between the River Itchen SSSI Units, management units and reasons for adverse impacts.
The reasons for adverse condition (ref EN condition assessment of site) are noted as follows.
Under-grazing Inappropriate scrub control Forestry and woodland management Inappropriate cutting/mowing Fertiliser use Agricultural practices Inappropriate ditch management Public access/disturbance Freshwater abstraction Siltation Diffuse pollution Direct pollution
Table 11.1 Relationship Between River Itchen SSSI Units, Management Units and Reasons for Adverse Impacts
Management Unit River Itchen SSSI Units Reason for Adverse Impact 1 15, 16, 17, 18, 19, 20, 21, Undergrazing 22, 23, 24, 25, 26, 27, 28, 103 Forestry and woodland management
Total: 15 Inappropriate cutting/mowing 2 1, 2, 6, 7, 9, 104 Undergrazing Inappropriate scrub control Forestry and woodland management
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Management Unit River Itchen SSSI Units Reason for Adverse Impact Inappropriate cutting/mowing Freshwater abstraction Siltation Diffuse pollution Direct pollution 3 3, 4, 5, 8, 9, 10, 11, 12, Undergrazing 14, 105 Freshwater abstraction Total: 10 Diffuse pollution Direct pollution 13, 29, 30, 31, 32, 33, 34, Undergrazing 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, Inappropriate scrub control 49, 106 Populus plantation over Phragmites Total: 23 Inappropriate cutting/mowing 4 Freshwater abstraction Siltation Diffuse pollution Direct pollution 48, 49, 50, 51, 52, 53, 54, Undergrazing 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, Inappropriate scrub control 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, Populus plantation over Phragmites 83, 84, 85, 86, 107 5 Freshwater abstraction Total: 40 Siltation Diffuse pollution Direct pollution 86, 87, 88, 89, 90, 91, 92, Undergrazing 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 108 Fertiliser use
Total: 18 Agriculture - other Inappropriate ditch management Public access/disturbance 6 Inappropriate scrub control Freshwater abstraction Siltation Diffuse pollution Direct pollution
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11.1.2 Other Factors Identified Through the Study In addition to the reasons for adverse condition of site outlined in Section 7.3.2, other background factors identified through the Study include the following:
River/floodplain continuity, safe access through system, road casualties, sufficient food e.g. otter Siltation of gravels, barriers to fish movement, sea fisheries (e.g. Irish Drift Net Fishery), angling e.g. salmon, trout Changes to channel morphology, river/fisheries management e.g. salmon, bullhead, brook lamprey, macrophyte community, river invertebrates Fish stocking and crayfish plague e.g. historic loss of crayfish and recovery possibly linked to crayfish plague being introduced via stocked fish and transport water Habitat quality and fragmentation including water level management affecting southern damselfly Predation, land use and management, fishery management of banks, e.g. southern damselfly, water vole (mink predation), breeding passerines Physical character of water bodies and vegetation management - breeding river birds and wildfowl Drying out of floodplain (changes in flow management and drainage practices), land-use – especially grazing regimes, Intensification of cress-bed management affecting breeding waders, molluscs Over/under grazing, application of herbicides (historic), application of fertilizer (historic and present) affecting status of floodplain wet grassland and fen
Changes to natural fish communities including stocking and culling of native species.
11.2 DISCUSSION OF INFLUENCES AND THEIR RELATIVE IMPACTS.
This section is presented in two sections. Firstly, a discussion of generic water quality and water resource related issues; and secondly a discussion of impacts on a feature by feature basis, along with their supporting habitats.
11.2.1 GENERAL ISSUES.
There are a number of currently un-consented activities associated with the River Itchen cSAC, which may be influencing site integrity. These include, but are not limited to the following:
11.2.1.1 WATER QUALITY:-
(a) Farming and general development activities contributing to diffuse pollution. The issue of sediment in gravels is discussed elsewhere in Part C. However, diffuse pollution encapsulates a wide variety of other impacts from diverse range of sources.
Agriculture is a major source of diffuse pollution in the Itchen catchment, related to arable operations and intensive livestock systems. The main pollutants involved in agricultural diffuse water pollution are: silt, nutrients (and in particular phosphorus which is the main limiting nutrient in freshwater systems), toxic and other chemicals, faecal pathogens and organic matter.
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Clearly, agriculture is not the only form of land use from which diffuse pollution may arise. For example, roads, urbanisation, forestry and construction all contribute to the problem as sources of and/or pathways for pollution.
In the Itchen valley a key diffuse pollution issue results from rural inputs of soluble phosphorus due to the agricultural use of fertilisers, with some additional contributions from other waste disposal activities, such as proliferation of small volume septic tank discharges in areas with no mains foul sewerage.
Diffuse pollution is of particular concern in the middle and upper catchment where the EN/Agency have set higher standards.
(b) Endocrine disruptors. There is little doubt that effluents discharging from STWs into UK rivers are a (if not the) major source of steroid oestrogenic (and anti-androgenic) contamination (Jobling et al., 1998). Very little is known, however, about other (potential) sources of EDCs entering UK Rivers. It is likely, however, that diffuse run off from agricultural practices contribute to EDC contamination in UK Rivers. Recent studies have demonstrated that natural steroid oestrogens excreted by livestock (cattle and pigs) could contribute to endocrine disruption in nearby streams (Orlando et al., 2004; Soto et al., 2004). The biggest potential contributors are dairy cattle, at any one time a large part of the UK herd will be pregnant, and they excrete high concentrations of a range of oestrogens throughout their pregnancy (Lange et al., 2002; Hanselman et al., 2003). Both farm yard manure, and slurry applications could be an important source of steroid oestrogens (Raman et al., 2004). However, potential impacts are likely to be very site specific in the catchment depending on the livestock, agricultural practice and proximity to water courses.
Run off from roads often contains a complex mixture of EDCs, including oestrogenic xenobiotics, but their contribution to the load of EDCs in UK rivers has not been established. Recent reports have also identified elevated levels of oestrogenic compounds such as PCB’s in farmed Atlantic salmon, possibly as a result of bioaccumulation within pelleted feedstuffs (Jacobs et al., 2002). Similar food is used by freshwater fish farms similar to those found in the Itchen catchment, potentially present another possible source of ED’s to the river.
Further afield, there remain uncertainties about the possible exposure of salmon to EDCs and other toxic chemicals both in the freshwater environment and whilst out at sea (Servos, 1999; Matthiessen, 2003). Some of these xenobiotic weak oestrogens, such as nonylphenol, could bioaccumulate in the salmon and lead to some form of endocrine disruption over time. However, the extent of the potential hazard to these fish is still not clear.
This assessment does not change any of the conclusions reached for Agency permissions in Parts B and Part C.1.
( c) Discharge from river flow augmentation schemes. The Agency’s augmentation schemes have abstraction licences but not discharge consents. There is potential concern for the lack of information on the potential contaminant loading of these discharges.
Being unconsented these discharges have not been considered within this review of consents process. If the augmentation scheme were operated it is likely that it would be illegal until such time as a discharge consent is obtained. That would possibly require the consent being subject to the Habitats Regulations, as a new plan/project.
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For the record this assessment concludes that based upon the best available information at this time, and in keeping with the precautionary approach adopted in Part B.1 for similar consents, that it cannot be shown that these consents are not adversely effecting the integrity of the Itchen cSAC.
This assessment does not change any of the conclusions reached for Agency permissions in Parts B and Part C.1.
11.2.1.2 WATER RESOURCES:
(a) Water Resources Exempt Abstractions. There are abstractions which are currently exempt from the Agency’s abstraction licensing system. These exemptions are explained in the Water Resources Act 1991 and cover activities such as small domestic abstractions, one off small abstractions, land drainage, fire fighting and dewatering. The Water Act 2003 will change parts of the Water Resources Act 1991 and will remove exemptions for some of the larger abstractions.
Small abstractions of less than 20 m3 per day will not require a licence in the future. These parts of the Water Act 2003 have not currently been implemented so the exemptions explained in the Water Resources Act 1991 still apply at this time. The nature of these exempt abstractions means that the Agency does not hold full details on the location or size of these abstractions. The majority of these types of abstraction are used for trickle irrigation, Ministry of Defence (MOD) purposes and for dewatering.
Although the Agency has reasonable records for MOD abstractions and trickle irrigators, records for dewatering activities are not so good. Small abstractions and one off small abstractions are extremely unlikely to have an adverse effect on any Natura 2000 site. The water resource exempt abstractions are discussed below.
(a i) Trickle Irrigation. The largest concentrations of trickle irrigation are outside of the River Itchen catchment, so assessment of the trickle irrigations will not change the Part B.1 and Part C.1 conclusions of this appropriate assessment.
(a ii) Ministry of Defence Abstractions. The Agency is aware of one abstractions used by the Ministry of Defence at Worthy Down, Winchester based on the Itchen Chalk aquifer. The impact of this abstraction was considered as part of the Study’s Groundwater modelling activities (see Figure 3.16). The associated impacts will be in MU 4 and are not considered to be adverse.
(a iii) Dewatering. Dewatering activities should be notified to the Agency under the Water Resources Act 1991. In practice this does not always occur and many are unknown to the Agency. In most cases abstractions for dewatering are accompanied by discharge consents for the abstracted water and are therefore non consumptive. It is unlikely that any dewatering activities will have a significant impact on Natura 2000 sites unless they are very close to the site and large in scale and/or time duration.
The activities related to exempt abstractions may combine with Agency permissions to potentially have an adverse effect on the integrity of the site, but we do not have any evidence to justify changing any of the Part B and Part C.1. decisions at this time as a result of this assessment.
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11.2.2 DISCUSSION OF FEATURES AND THEIR SUPPORTING HABITATS.
There follows a discussion of the many impacts from unregulated activities/prevailing conditions upon each interest feature and their supporting habitats, including typical species of the chalkstream biotope.
The assessment attempts to assign a degree of proportionality to these influences in order to put the impact of Agency permissions into a wider context. The precise proportion to which each activity may contribute to an effect is unknown, and professional judgement underpins this discussion.
The assessment has adopted a four-point scale to rank the probable degree of influence each factor may have on the interest features and their supporting habitats: these are listed below.
Major Influence
Moderate Influence
Relatively Low Influence
None, Minor or Currently Unknown
Individual Interest Features and their supporting habitats
I - Otter Assessment was based on whole catchment habitat surveys, DNA fingerprinting, eco-toxicology (of food and otter tissues) work and post-mortems of road casualties. Otters have recovered dramatically in recent years (from pesticide poisoning), but status is still considered to be Poor due to extreme dangers from road traffic (a major influence) which could account for a 10-20% reduction in otter numbers in the Itchen valley. Abstraction and discharges are not considered a major influence on the otter directly.
The Agency has identified a number of unregulated activities/prevailing conditions as off-site factors that impact upon the River Itchen cSAC otter population (Technical ref E (S) 01a-b of the Ecology/Fisheries Technical Appendix). These include: anthropogenic mortality (particularly road deaths), together with any factor which might deplete their food supply. The Agency is also concerned about the genetic variability and viability of the Itchen population and the extent to which free movement between catchments can be maintained.
The Conservation Objectives have general targets for otter relating to water quality, flow and fish stocks. These are considered elsewhere in this assessment and are not considered major influences on otter habitats.
However, in terms of supporting habitat, the otter population is influenced by the availability and quality of wet grassland, fen and woodland habitat types. The suitability of theses habitats for otter would appear to be dominated (major) by site management including woodland management, water level management, scrub control, management of the grazing regime. Abstraction and discharges are minor influences in comparison and in-combination. Floodplain wet grassland and fens are key otter habitats (apart from the river) and are discussed further below.
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However, all of these impact types exist to varying degrees elsewhere in the UK where otter populations are demonstrably recovering e.g. the South West.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
II - Salmon The population of salmon in the Itchen is considered to be in Poor condition with a gradual decline from the late 1960s followed by a sharp fall between 1989 and 1992, a period which coincided with the groundwater drought of 1988-92, from which the stock is still struggling to recover at the time of this assessment.
A range of factors contribute to this poor status, some effecting the salmon directly and others indirectly by affecting it’s supporting habitats. The assessment has identified 4 activities which are considered to be having a major influence on the population and its supporting habitats. These include water quality, water abstraction, diffuse pollution (specifically sedimentation of gravels) and (over-)stocking of large fish.
Sedimentation of gravel in the spawning areas causes poor survival of eggs and alevins. The highly organic nature of the sediments exacerbates this problem. The dynamics of sediment within the river is imperfectly understood but it appears that changes in agricultural practices are at least partly responsible. Roads, tracks and farmyards appear to be both a source of sediments and also conduits carrying mobilised material to the river. Low flows during the series of dry years between 1989 and 1992 also appear to be implicated.
Artificially high populations of (stocked) trout (especially large ones), above the carrying capacity of the natural fishery, also increases predation on salmon parr.
Factors affecting salmon are discussed further at the end of Part C.2.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
III – Bullhead Past and recent surveys show the bullhead to be abundant and thriving throughout the catchment wherever it would be expected to be so. Suitable habitat is considered to exist in extent, location and condition throughout the catchment where it might be expected to occur. It is less abundant in the lower reaches, which are considered naturally sub-optimal in habitat terms. Overall the bullhead population and it’s supporting habitats are considered to be in favourable condition (ref E(FA)03). Channel morphology (major) and site management - fisheries and river management (moderate) are the key influences on this interest feature and it’s habitats. Abstraction and discharges are not considered a major influence.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
IV - Brook Lamprey Recent surveys show that brook lampreys occur throughout the catchment where they would be expected. For most of the year this means in silt and sediment banks. Suitable habitat is considered
- 194 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. to exist in extent, location and condition throughout the catchment where it might be expected to occur. Overall the Brook Lamprey population and their supporting habitats is considered to be in favourable condition (ref E(FA)04). Channel morphology (major) and site management - fisheries and river management (moderate) are the key influences on this interest feature and it’s habitats. Abstraction and discharges are not considered a major influence.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
V - White-clawed (Native) Crayfish Native crayfish were once a very common species throughout the Itchen, but isolated small populations are now limited to the Arle (MU2) and the Candover (MU3). Unlike most other interests, a single factor is critical to the present status – the crayfish plague that wiped out all other populations in the Cheriton or Tichbourne (MU1) and Itchen (MU4-6).
Alien (signal) crayfish, the typical carrier of the disease, appear not to be present in the Itchen (Ecology and Fisheries Technical Appendix). Signal crayfish carry, and are in some cases immune to the disease, and typically they become abundant in rivers when the native species disappears. The lack of signal crayfish in the catchment implicates the potential transfer of the disease by fish stocking (a major influence – see Water Quality Technical; Appendix E(FA)14) and fish farming, and possibly other faunal carriers as they migrate from neighbouring, infected, catchments. Suitable habitat in terms of location, extent and condition is found throughout the catchment and is deemed to be in favourable condition.
Abstraction is considered to potentially be a major influence on crayfish directly and their supporting habitats in the Candover Stream where the remnant population exists. This particularly includes the Agency’s augmentation scheme. Elsewhere in all other management units abstraction is not considered a major influence. Discharges are not considered a major influence.
Overall the current status is the worst of all the interest features on the river (Bad).
The transfer of fish between fish farms and hence possibly from plague-infected to native crayfish catchments is a matter of concern. The Diseases of Fish Act 1937 (amended 1983) has no provision for directly regulating fish movements between registered fish farms - the requirements are for farm managers to maintain records of fish movements and inform CEFAS of suspected outbreaks of notifiable fish diseases. The Fish Health Inspectorate based at CEFAS will visit farms annually to inspect the site and health of stocks (see http://www.efishbusiness.co.uk/movements/part01.asp and http://www. efishbusiness. co.uk/register/default.asp for more details on the inspecting process). By then of course, the crayfish plague would have been introduced to a river system.
The issue of fish movements between farms is potentially a greater threat to the crayfish population than stocking of fish directly to the River Itchen, in the latter situation at least the Agency’s Section 30 consenting process has already been subject to an Appropriate Assessment. This issue should be reviewed at a national level as a matter of some urgency. One option would be to add the crayfish plague to the list of notifyable fish diseases.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
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VI - Southern Damselfly All present day, and historic, records for southern damselfly in the Itchen are for sites below Winchester (although a historic reference refers to their presence a century ago ‘near Winchester’). No records exist for any sites, either on the river or in the floodplain, in river reaches 1-4 (MU1-4).
Due to lack of adequate historic data, it was not possible to categorically determine if the status had varied greatly over the past 30 years. As with otter, pioneering research was carried out during this Study (involving Liverpool University) on population studies associated with DNA fingerprinting. Surveys commissioned by the Study indicate that the majority of the existing and potential sites supporting southern damselfly in MU5B are either in Bad or Poor habitat status, whereas those in MU6 are generally in either Good or Moderate status.
Habitat quality (including good water quality), and habitat management (including water level management and site management e.g. ditch management, grazing regime) are regarded as the most significant factors (major) affecting the status of this species, and it’s supporting habitats in the Itchen. Overall the status of the southern damselfly has been assessed as Poor. Abstraction/inputs were considered to potentially have moderate impacts on habitat in MU5B, but elsewhere are considered a minor influence.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
VII - Macrophyte Community The macrophyte community of the Itchen is considered to be in Good status in the majority of years, especially when there is good Chalk aquifer recharge. In low flow years, and potentially during periods of moderate flow status might be considered as only Moderate due to the impacts of eutrophication and abstraction The influence of Agency permissions on the macrophyte community are discussed in B1, B2 and C1.
In terms of unregulated activities/prevailing conditions it is acknowledged that the occurrence of natural drought periods and enrichment from diffuse sources have a considerable impact on the status of the macrophyte community. Drought periods have been shown to cause the occurrence of naturally sub-optimal habitat conditions in the absence of any abstraction pressure. Similarly diffuse pollution sources have been shown to result in ecological signs of eutrophication (such as extensive growths of filamentous algae or diatoms) even in locations where there are no consented discharges or potential sources of enrichment.
Abstractions and discharges have a moderate influence and are discussed in B1, B2 and C1.
Channel character, and its impacts on flow velocity (major), historic channel modification (moderate) and fisheries management (major) can influence the macrophyte community.
(a) Weed cutting typically during the critical April to September periods. There is no nature conservation requirement for weed cutting in the Itchen, but is an activity that has been traditionally undertaken by fishing interests.
Weedcutting itself is an unregulated activity. The Agency has the powers to regulate management of the weed once it is cut to prevent pollution and avoid increased flood risk. In the Itchen weedcutting is not driven by flood defence needs but almost entirely by fishing interests. The vast majority of the weedcut is performed by private fisheries groups. The Agency do not cut weed in the Itchen.
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The submerged and emergent plan community provide the key matrix, along with the bed and bank structure to supporting the chalkstream biotipe. The plants are host to a wide range of invertebrate species, constituting a fundamentally important element of the fauna in their own right as well as an essential prey resource e.g. to fish, and also provide important cover for fish populations.
In addition to this direct function as a habitat, dense beds of plants in chalk streams are known to maintain water levels in the channel, increasing summer depths and thereby sustaining channel habitats whilst helping to maintain water table levels in associated riparian habitats. The extra water resistance of these plants in winter additionally increases the likelihood of beneficial flooding of meadowland. Focussed and intense scouring of channel gravels is generated by increased current velocities between beds, helping to reduce the extent of siltation. Weedcutting has the capacity to interfere with all of these functions if undertaken in an insensitive manner.
The Agency has identified what would be considered best practice. It is the Agency’s professional judgement that in some cases current practice does not conform to best practice, but in many cases it does. This varies year to year and reach to reach depending upon the judgement of the private individuals doing the task. There are several reaches which are cut using powered weed cutting boats. There is evidence to suggest that channel morphology and the invertebrate community may be adversely affected by this operation.
The assessment suggests that in the worst case scenario, if 100% of the weed were cut at the wrong time, and/or by boat, then that would negatively affect the macrophyte community and associated fauna. However, such impacts are normally localised and the macrophyte community has the capacity to recover in following years, unless poor weed management persists year after year. Such impacts might be additive in nature to abstraction licences.
Even in such a modified chalkstream environment it is clear that inappropriate management of the in-stream and marginal vegetation can and does negatively affect the macrophytes and associated biota. The impact of this on the integrity of the cSAC has not been assessed.
The plant communities are similar throughout much of the river, but change gradually on passing downstream. This is a natural transition that adds significantly to the value of the representation of the Ranunculus habitat within the Itchen. Conserving this diversity is an important element of the Conservation Objectives. Fisheries management of weedcutting may prevent natural cycling of macrophyte communities and maintains it at a prescribed state. This is not ‘natural’ but it is probably ‘traditional’. To what extent fisheries management of weed is blurring natural variation is not assessed here.
What can be said is that precious resources to manage the weed might be saved if directed in a more efficient way, one that would also enhance the biotic and abiotic attributes of the SSSI and cSAC.
(b) Swan grazing of macrophytes. The grazing of macrophytes, especially Ranunculus beds by large flocks of unmated mute swans is a growing problem in some chalkstreams and the past few decades have seen increases in swan numbers in the Itchen valley.
The potential consequences for the river include the denuding of submerged plant habitats at a critical time of year. This locally affects water levels, the flow regime and the scouring potential of many river reaches. Macrophytes recover, but in the short-term the localised impacts also include loss of habitat for invertebrates, and loss of cover for fish species, possibly exposing them to greater predation.
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It is possible that this behaviour is exacerbated by low flows and other anthropogenic influences, but otherwise it is a natural event. The Itchen appears to suffer less from this problem than other chalkstreams. Further work is needed to clarify the magnitude and extent of impact and to identify suitable strategies for minimising adverse effects.
At the local level the impacts are major, but in the context of cSAC integrity as a whole, and compared to other influences, it is currently considered to be a minor influence.
This assessment does not change any of the conclusions reached for Agency permissions in Parts B and Part C.1.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
VIII - River Invertebrates Like the Macrophyte community, river invertebrates of the Itchen are considered to be in Good status in the majority of years, especially when there is good Chalk aquifer recharge to support the habitats. Conversely, the status is considered Moderate in low flow years as the community changes, and typical species of fast flows and clean gravel decline. Channel morphology has the most influence on the community (major). Natural drought periods will result in natural periodic sub-optimal or anthropogenically induced status. (see Technical Appendix E(FA)11-12). River and fisheries management (moderate), abstraction (moderate) and discharges (minor) are all influences.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
IX - Molluscs Desmoulin’s whorl snail is the principal interest of the Study’s assessment of molluscs, but several other nationally and regionally rare snails are present. In general where habitats are suitable the status is considered Good and not materially changed in the past 30 years (although annual fluctuations occur). Water table and water level are the most critical factors (major), with bank and riparian management (e.g. over grazing/scrub encroachment) and fisheries management also having a moderate effect. Abstraction is considered to have a low influence, and discharges thought to have no impacts.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
X – Brown Trout Trout, a characteristic fish species of Chalk streams are considered to be in Good status, with the best reaches being in the upper catchment (MU1-4). Naturally the population is lower in MU5, and MU6 where water depths are much deeper, and habitats are thought to be naturally sub-optimal, although a strong population of migratory trout flourish. Channel morphology is considered to be the main (major) determinant of the distribution of this species, with siltation of gravels and fishery management practices also having major impacts upon it’s status, especially in MU5. Abstraction and discharges generally have only minor effect through most of the river, but may have a moderate effect in MU’s 2 and 3 in dry years.
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The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XI - Water Vole Mink predation is considered to be the critical factor affecting water voles on the Itchen, and recovery towards historic levels has occurred recently due to the efforts by the Agency and many riparian owners and fishing associations to control mink. Parts of the river habitat are in Good status, and the remainder Moderate. Abstraction and discharges are considered to have no, or minimal, influence. Water levels, bank and fisheries management and many other factors interact to influence the status of water voles, but individually none have a critically adverse effect over water vole habitat as a whole. Abstraction and discharges are not considered a major influence.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XII - Breeding River Birds and Wildfowl A decline in this interest from Good to Moderate has been observed over recent decades for the Itchen system as a whole.
The Agency’s assessment shows that breeding wildfowl and kingfisher populations in the Itchen Valley are generally in favourable condition. However, this masks some considerable variation in population size and distribution. Most important are the very low populations of little grebe, tufted duck and coot in the valley south of Winchester (MU5-6) although there are sections of the valley above Winchester that also have inexplicably suppressed populations. The significant split in breeding wildfowl above and below Winchester contrasts with the populations of these species recorded in the 1976 survey. Further investigation is needed to understand the reasons for this apparent change.
The lower Itchen also supports lower numbers of breeding kingfisher although there is less evidence that this represents a decline in recent years. However, it may be that the availability of suitable nest sites is suppressing kingfisher populations in this part of the valley and initiatives to improve the provision of nest sites should be considered.
MU2 (Arle) and MU4 remain in Good status, but the small size of wet areas in MU1 and MU3, and being winterbournes in the headwaters, make the habitats here sub-optimal for breeding river birds and wildfowl. Physical character and morphology of the waterbodies, and bank and vegetation management are key (major) factors affecting these interests, with abstraction considered to be having only a minor effect, and discharges minimal, or no, effect.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XIII - Waders This interest feature has shown a catastrophic decline since the 1970s, leaving the whole river floodplain assessed as Bad. The recent (2002-03) surveys suggest that current status is Unfavourable. The key (major) reason for the decline has been land use change (ref L(DD)01), especially drainage and drying of land previously regularly flooded, or with retained high water tables as part of water level management planning. Intensification of water-cress bed management has further influenced available habitat (moderate) for this group.
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Previously, snipe, redshank and lapwing bred, but none were observed in the recent surveys. Even at Winnall Moors Nature Reserve (MU5A) where sympathetic management occurs, the three key wader species have declined from a combined total of around 10 pairs in the mid 1990s, to zero in 2002. Abstraction is considered to be having only a minor effect (perhaps moderate in MU6), and discharges minimal, or no, effect on habitat extent or quality.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XIV - Breeding Passerines Good status is reported for the whole of the river and in all units with improvements over the past 30 years. Land use change, leading to increased riverside scrub and reed beds, is thought to be primarily responsible. Abstraction may have a minor effect, but discharges are considered to have minimal, or no effects.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XV - Floodplain Wet Grassland and Fen No significant change is considered to have occurred in recent decades, but there has been a decline from Good status to Poor over a longer timescale. Land management, coupled with herbicide/ fertiliser application is primarily (major influence) responsible. Abstraction and discharges are considered to have low impacts compared with the other factors. Drying of the floodplain is a key reason for this interest not being in favourable condition. However the reason is primarily land drainage (major), not direct effects of abstractions. Crucial to protecting and restoring this interest feature to favourable condition is the development of an integrated land use and water level management plan.
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XVI Woodland and scrub. Woodland cover in the Itchen catchment has increased in area since the 19th century with the planting of some extensive areas of woodland and the creation of landscape features. Countering this has been a decline in the extent and condition of hedges within the agricultural landscape of the catchment, particularly during the latter half of the 20th century. This has left many of the remaining hedges in a poor condition for wildlife due to in appropriate management. However, within the flood plain, hedges have not been a significant historical landscape feature with much of the flood plain being traditionally devoid of trees and hedges.
The dereliction of water meadows and polarisation of land use that has been seen throughout the catchment over the last 50 years has enabled some extensive areas of tall fen, scrub and secondary woodland to become established in the flood plain, whilst other areas have been planted with poplar plantations.
In places, there are numerous mature trees and some of these are known to be utilised by otters. These are a particular feature of the Itchen valley above Winchester.
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These fen habitats offer excellent cover and prey resource to otters, especially if extensive in scale, over and above the value of individual trees.
However, the growth of scrub and woodland within the flood plain increases landscape enclosure and reduces the value of the flood plain for breeding wading birds that show a strong avoidance of scrub and woodland cover. Management of habitats that obscure sight lines and reduce the open landscape of the flood plain need to be balanced between the needs of otters and other species dependent upon this cover and those that are deterred by it.
Woodland management and to a larger extent agricultural practices and land use management are considered key factors influencing the condition and maintenance if this habitat type in the Itchen valley for otters.
Fisheries management is known to sometimes involve clearance of bankside scrub in order to open access and allow easier angling opportunities. This has potentially negative impacts upon otter.
Agency permissions are not considered a major influence on these habitats
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
XVII Standing open water bodies (ponds) There are a number of standing open water bodies in the cSAC (see Table 1.4). Some of these have been created or restored by the Agency in recent years. Some are historic in their creation and management. All are very small.
Some of these small ponds are on-line, and there is potential for these to be directly affected by discharge consents into the river which then feeds the ponds. Most of the ponds are off-line standing water bodies. Based upon familiarity with the Itchen valley and with many of these ponds, the Agency determines that it is extremely unlikely that any existing pond habitat is having a significant adverse impact upon water quality or water resource issues within the cSAC, or that Agency permissions are adversely affecting these ponds.
Many of these ponds are in favourable condition.
In the Agency’s view the biggest issues influencing those ponds that may be in unfavourable condition relates to site management e.g. siltation, water level management, fisheries management (if they are stocked and fished – not all are) and over-shading from scrub/trees.
Within the Itchen valley the vast majority of the standing open water lie outside of the cSAC boundary. That includes numerous small ponds e.g., Decoy Covet at IVCP, and Woodmill; as well as significant water bodies such as The Grange, Alresford Pond, Avington Pond, the RMC ponds at High Bridge, Fishers Pond, and an assemblage of ponds at Hog Wood, West End. These water bodies offer valuable off-site supporting habitat to the otter population feature of the cSAC, particularly as valuable source of prey (especially where the ponds are stocked).
The Agency concludes that these unregulated activities/prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off- site do not change the decisions made for Agency permissions in Parts B and Part C.1.
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XVIII Non-native species. Like much of southern England the Itchen valley hosts a number of non-native species. Some, like mink, are known to have profoundly important impacts upon native wildlife. Mink and the impacts of the plague introduced with the American crayfish are discussed elsewhere in Part C.2.
A range of non-native plant species are recorded in the Itchen valley, including Giant Hogweed, Japanese Knotweed and Himalayan Balsam.
These species are highly competitive and are capably of forming dense stands of vegetation that overwhelm the native bankside flora. These species are likely to affect the bankside and riparian fen meadow flora rather than the aquatic macrophyte community.
Whilst records for these species are widespread, at no location in the cSAC, or the valley as a whole, is there a known extensive colony of any of these species. However, clearly there is the potential for them to spread, in terms of extent and number of affected sites. It is the Agency’s view that these species do not currently represent a significant threat to the integrity of the SSSI or cSAC.
A range of other non-native species have been recorded in the Itchen, including terrapin. Rainbow trout are stocked to the River – fish stocking is discussed above.
Little Egret have increased in number in recent years and are becoming more common in the area as a whole. These represent a potential for local impacts through predation of salmon, trout and other fish species. The scale of this impact is unknown but currently is considered to be local and minor and short term. The impact of predation from Egrets can be considered a natural event, (unlike for example, mink) as the species has not been introduced to the UK and predation is a nature process.
The Agency concludes that these prevailing condition factors when assessed in- combination with one another and with Agency permissions both on-site and off-site do not change the decisions made for Agency permissions in Parts B and Part C.1.
11.3 DISCUSSION OF AGENCY PERMISSIONS IN-COMBINATION WITH NON-AGENCY REGULATED INFLUENCES ON THE SALMON POPULATION AND ITS SUPPORTING HABITATS.
Up to this point in the assessment it is clear that Agency permissions affect a number of the cSAC interest features and show some of these may be having an adverse effect on site integrity. It is also apparent that one of the most affected interest features is the salmon population and its supporting habitats. The Conservation Objectives set the highest water quality standards for this feature and the assessment has shown that abstraction licences and discharge consents have the potential to adversely affect the species on spatial and temporal levels through key parts of its lifecycle in the cSAC and off-site.
The salmon population is also known to be in unfavourable condition and is slow to recover from Agency-related impacts. Furthermore, there are numerous and diverse non-Agency regulated influences on overlapping and different stages of the species’ lifecycle, including off-site impacts. This part of the assessment discusses those factors in greater depth in order to put the Agency’s decisions regarding it’s permissions in the full context, with notes on the probable proportionate effect of each.
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It should be noted that there are difficulties in estimating the relative importance of each impact on the interest feature. This is due to a number of reasons including the following:-
1. Whilst some factors act almost alone on a single life history stage (and thus one could treat them as serial or additive effects) others act together to cause poor conditions e.g. sediment in gravels and low flows causing low in-gravel survival of eggs and alevins. It is difficult to apportion quantitative blame on two such factors.
2. The population control mechanisms for salmon are complex and involve compensatory survival strategies at low densities. For example, if the number of young fish emerging from the gravel is low due to poor egg survival, survival through the next year may be relatively high due to reduced competition for food and territory; removing one bottleneck may cause another to emerge.
3. We simply do not know enough about some of the factors to make a confident quantitative assessment of their impacts under various conditions.
The Agency has attempted to rank the impacts according their severity, at least in semi-quantitative terms, based upon professional judgement. This is done in the list below. Some of the placing are indicative; those which are particularly doubtful have a question mark.
Impacts of more than 10% Sediment in gravels (diffuse pollution) Abstraction (in dry years, and in average years if full abstraction entitlement is taken). Note that abstractions in wet years is a very small proportion of the highest flows. Fish stocking. Large populations of trout above those likely to be naturally sustained by the fishery. Effluent discharges e.g. WWTWs, Watercress farms, Fish farms
Impacts of 1% to 10% Irish drift-net fishery Angling (Must be balanced against the loss of protection for salmon from fishery interests if legal angling is restricted or banned). Diffuse pollution (other than sediment) Poaching Estuary disturbance ? Fisheries Management (excluding stocking, e.g. weedcutting).
Impacts of less than 1% Intakes – entrainment River management ?
Others. Overall marine survival Homewater netting Obstructions to migration.
Each of the above factors is discussed in the following sections.
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Sediment in Gravels. Poor intra-gravel survival of embryos has been shown to be limiting salmon production in chalk streams (Scott & Beaumont, 1993) and is further identified as being one of the major limiting factors to the recovery of salmon stocks in the Itchen (Environment Agency, 1997) (Environment Agency, 1998).
Survival of eggs and alevins in clean gravel with a good flow can be high – over 90% has been achieved using stream-side gravel incubators on the Itchen, and over 60% has been observed in gravels in the river the first season after cleaning by pressure-jet. This compares to levels observed in natural redds in uncleaned gravel in the river of 0 to 3.6% in low-flow years (1989 and 1990) to 15 to 20 in 1991. It may be higher in wetter winters.
The research work has shown quite clearly that spawning gravel silt loads cause low survival of chalk stream salmon eggs, to a level of around 4% (range 0%-26%). Additional research has clearly identified that the bulk of organically rich sediments found in spawning gravels are derived from land, including watercress beds, rather than in-river sources.
To try and combat the adverse effects of organically rich silt loads in spawning gravels, the Environment Agency runs an annual programme of gravel cleaning. This work involves identifying known spawning sites and ensuring that they are in good condition prior to any spawning activity by blasting the gravel bed with modified water pumps. The introduction of a Landcare Project Officer to deliver a range of initiatives designed to minimise the impacts of agricultural run-off is viewed as contributing towards, but not the only action needed to achieve a sustainable long-term solution to this problem.
It is likely that survival has been low and variable for many years, and may naturally be so in Chalk streams, but it does appear that the situation has got worse in the past 15 years. Turning these low survival rates into impact rates that can be compared to other impacts such as drift netting is not straightforward for a number of reasons. Firstly, the “natural” condition for Chalk streams is unknown. Secondly, action to greatly increase in-gravel survival would not result in commensurate increase in numbers of smolts leaving the river because density dependent mortality of juveniles would restrict the carrying capacity of the river. Thirdly, reduced survival (say 20% of natural levels) of eggs in all redds will have a lesser impact on stocks that would reducing spawning stock to 20% because the distribution of emerging young fish would be more optimal, because small numbers of fish would be emerging from a large number of redds.
Abstraction – this is discussed elsewhere in the assessment.
Fish stocking. Under Section 30 of the 1975 Salmon and Freshwater Fisheries Act any proposals to introduce fish into inland waters requires prior written consent from the Environment Agency.
It is recognised that trout stocking into the River Itchen SAC can potentially have an adverse effect on juvenile salmon through increased levels of competition and predation. This is particularly the case when large trout are stocked. Unfortunately many reaches, particularly those found downstream of Winchester, have very limited habitat capable of supporting financially viable trout fisheries reliant solely on natural production. Trout stocking on these stretches has, therefore, been an integral part of the fisheries management regime. Yet this reach of the Itchen is also the primary salmon spawning area.
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Guidance to enable Fisheries Technical Officers to determine Section 30 applications on European designated sites is currently being formulated by the Fisheries Technical Advisory Group. The new guidance will attempt to provide a method of capping the level of trout stocking to ensure that there are no additional pressures on salmon stocks.
Although the aims and objectives set out within the National Trout and Grayling Fisheries Strategy are primarily aimed at improving and developing trout and grayling fisheries, there are provisions to provide some additional protection for juvenile salmon from any potential adverse effects of stocking. This mechanism would be through the setting up of areas designated as Wild Fisheries Protection Zones. It should be recognised that one of the primary objectives within the Strategy is to ensure that trout fisheries are economically viable.
Another key component of the NT&GFS is to identify and classify the Itchen as a Native Trout Water, capable of significant natural production of brown and sea trout. The Area is currently consulting with the fisheries interests over the classification of all rivers in Hampshire and Isle of Wight Area. As the NTW classification has the potential to restrict certain stocking practises, it has been treated with considerable scepticism by some fisheries interests.
Waste water discharges - this is discussed elsewhere in the assessment.
Non UK Fisheries A number of fisheries outside the UK exploit mixed-stocks of salmon including those from the Itchen. Those at West Greenland and Faeroe, which have been major factors in the past, are currently operated only as subsistence and research fisheries, regulated by the North Atlantic Salmon Conservation Organisation (NASCO). Only the Irish drift-net fishery has a substantial effect on Itchen stocks. This drift net fishery intercepts adult fish returning to home waters and is thought to hit South Coast rivers the hardest. The situation is currently being assessed by CEFAS and the Irish Marine Institute so reliable estimates of the effect on Itchen stocks are hopefully in the pipeline. In the meantime the best assessment we have is that produced by the Agency of 10 to 20% for South Coast rivers in the 1990s. Since then, restrictions on the fishery have reduced exploitation by the order of half, so the best estimate is 5 to 10% current exploitation of South Coast stocks.
Mixed-stock fisheries such as the Irish drift-net fishery have been the focus of much attention by salmon conservationists in recent years. It is pressure from many directions, including the Agency and anglers, which has led to the virtual closure of the Greenland and Faeroes fisheries, and the restriction of the Irish fishery. Pressure will continue to be applied and this assessment suggests that further reductions may be needed in the future.
Angling The exploitation rate by angling in the Itchen has historically been high, typically of the order of 50% when most fish caught were killed. However, there has been a remarkable level of acceptance of catch and release in recent years, with virtually no fish killed intentionally. Some mortality is likely as a result of hooking, landing and handling but this is thought to be low, probably less than 10% of fish caught. Thus the mortality due to angling has fallen from around 50% of the stock down to perhaps 5% in the past ten years.
Salmon fishing activity is restricted to the lower reaches of the River Itchen from Lower Bishopstoke down to Woodmill. The fisheries are currently maintaining a commitment to returning all rod caught salmon to the river. The level of protection afforded to adult stocks by the salmon fisheries interests and the data received via rod catch returns are valuable tools in our combined efforts to protect and improve Itchen salmon stocks.
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Diffuse pollution (excluding siltation, which is discussed separately above) - this is discussed elsewhere in Part C.2 above.
Poaching. Illegal netting and snatching (intentional foul-hooking of fish) does take place in the estuary and river. The exact level is not known but it is largely kept under control by the activities of the Agency fisheries staff and of fishery owners. The Agency estimate that the current levels of poaching may account for approximately 5% of the population.
Estuary Disturbance Salmon have to pass through the estuary at least twice (once in each direction) to successfully complete their life-cycle. The estuary of the Itchen and Southampton Water are already highly modified and developed, with considerable disturbance due to shipping and associated port activities.. It is not possible to quantify any effects of disturbance and modification of the estuarine environment on salmon survival, but it is apparent that rivers with major ports at their mouths generally have much reduced stocks of salmon compared to historic levels.
Discharge of waste water may also affect salmon whilst in the estuary. Such issues are addressed elsewhere in this assessment.
Fisheries Management. When assessing the impact of riparian fisheries management practises on the status of River Itchen salmon stocks, there is a need to look at both the positive and negative aspects of this management. The protection of key salmonid spawning and juvenile habitats is in the best interests of fishery managers wishing to promote and develop natural trout stocks. Anti-poaching is one example of the benefits that can be derived for salmon from having managed trout fisheries.
Weedcutting. Weed cutting is a traditional practice in chalk rivers that helps maintain the macrophyte community in a state that is optimal for brown trout and access to these fish for anglers. However, such intervention prevents natural cyclical changes in macrophyte composition within any given section of the river. In an unmanaged state, this would result in greater variation in macrophyte composition in any given section of the river over time. This has been described by Mike Ladle (EFE) As Ranunculus naturally accumulates silt around its roots, it is displaced by Callitriche and other macrophyte species which in turn continue to accumulate silt and increase resistance to flow. Eventually this leads to catastrophic rip-outs of weed in winter high flows. These events result in release of silt and the creation of an unvegetated gravel bed suitable for colonisation of Ranunculus. This natural cycling of aquatic community is maintained at a point by weed cutting that encourages the dominance of Ranunculus and creates small scale diversity of flow and weed distribution. However, this management prevents the winter rip-outs of weed and redistribution of accumulated silt. Further investigation of natural weed growth patterns in chalk rivers is needed to better understand its ecological implications for the macrophyte community as a whole and associated fauna.
Control of predators. Predation is a natural element of any functioning ecosystem. It is one of many factors that have shaped the population biology of salmon.
This assessment has largely restricted it’s considerations to anthropogenic influences. Whilst predation is a natural process, the manipulation of salmon populations in the Itchen extends to artificially controlling populations of other species in an attempt to promote salmon and trout. This point is discussed here.
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Otter, mink, pike, trout, cormorants and heron are all known to take Itchen salmon. Very little work has been undertaken to try and evaluate the impacts that any of these species have on salmon at a population level although pike and cormorants are known to take significant numbers of parr. In order to limit the impact of predation on trout, some river keepers actively control of pike, mink and cormorant populations. Licences to shoot cormorants in the Itchen valley have been issued by DEFRA in the past and with new relaxed guidelines now in existence it is likely that increased numbers will be annually culled. Pike culling has been traditionally undertaken using electric fishing techniques, however, numbers of applications to use such devices for culls has dropped in recent years. It is understood, however, that significant numbers of pike are caught and removed by keepers and anglers using rod and line methods.
The real value to salmon from culling predators by the fisheries interests is unknown. However, such efforts are offset to some extent by the introduction of stocked trout which themselves predate natural salmon and trout.
Bankworks: In order to facilitate access for the fly fishing trout angler, riparian management of river banks have largely revolved around providing unobstructed access for fishing, sometimes from both banks. This includes creating a sound bank top for access and sometimes clearance of trees and scrub for some distance back from the bank top to make for easier casting. Scrub clearance may adversely effect other SSSI/cSAC interest features.
This regime has revolved around consolidating a known line of the bank, often fighting against natural river processes. Historical river routes are maintained using revetment materials such as timber piles or faggot bundles and back filling, usually with imported chalk. Although rarely seen these days, some banks have been reveted with inappropriate materials such as corrugated tin sheets or geotextiles supported by driven galvanised scaffold tubes and backfilled with gravel excavated from the river bed (with negative impacts for fisheries) or imported builders rubble.
Other common works undertaken includes: Mowing of bankside paths Autumn strimming of the marginal fringe Coppicing and pollarding of marginal trees/scrub Clearance of woody debris within the channel Stock fencing to protect banks from cattle poaching Hatch control Gravel raking and cleaning to improve conditions for spawning fish. “Mudding”. Raking back of marginal vegetation in the Autumn. The use of temporary groynes to shift silt beds downstream.
It should be recognised that some of these measures will benefit salmon stocks while others could be regarded as potentially having an adverse effect on salmon. Moreover, some of this management will likewise benefit some other forms of flora and fauna and also disbenefit other interests.
The Water Framework Directive will highlight the fact that the Itchen is failing to meet good ecological status due to the fact that it’s salmon stocks are failing to meet their conservation targets. The Water Framework Directive aspires to achieve a natural fish community as a measure of good ecological status. Within the context of a highly managed system such as the Itchen, this objective will need to be reconciled with fisheries practices such as culling of pike and other species and fish stocking.
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Entrapment - this is discussed elsewhere in Part B.2.
River Management. Effects of River Management on Juvenile Rearing One of the most striking impressions of electric fishing for juvenile salmonids in Chalk streams, especially salmon, is how their distribution is highly discontinuous and centred on riffles (shallow fast-flowing water with steep gradient). Head-retaining structures such as mills, hatches and weirs have greatly reduced the area of suitable habitat, while the creation of fast-flowing carriers has probably had a beneficial effect. Overall, juvenile salmon squeeze into a small proportion of the highly-modified Chalk stream environment. However, like other factors that restrict available territory such as obstructions in Winchester, this factor limits the population size but does not act as a constant percentage mortality as most others do. It thus affects the size of the population rather than its well-being.
Overall Marine Survival From a range of investigations around Europe we know that survival between emigrating wild smolts and returning adults varies considerably, from 1 to 40%. The main factor affecting this appears to be marine conditions affecting the area where the fish can go to feed, and the feeding conditions. In the last 20 years there has been a steady fall in marine survival to current low levels. Reliable records do not go back far enough to allow a good assessment as to just how bad things are in relative terms, but records of periods of poor catches in the past suggest that this is largely a cyclical phenomenon and probably largely natural. However, two things must be borne in mind. Firstly, even if the effect is natural it means that other anthropogenic impacts are more critical at such times and we cannot predict when, and indeed if, better conditions will return. Secondly, it is possible that the current cycle of poor marine conditions is exaggerated or even caused by anthropogenic factors, and better conditions may not return.
Homewater Net Fisheries There are nowadays no legal homewater net fisheries having a major effect upon Itchen salmon. Coastal fisheries in the Hampshire area and the Woodmill netting station have been closed for several years as a conservation measure.
Obstructions to Migration There are a number of obstructions to migration in the lower river. Most are minor and are being addressed by the Agency. The major remaining issue is passage of salmon past Winchester. It is likely that salmon ascended the river freely well above Winchester in pre-historic times.
However, construction of mills and other obstructions over the centuries greatly reduced access. Although odd salmon have been reported upstream of Winchester over the past 30 years there is no evidence of successful recent spawning there. Stocking of this area with fry from incubator boxes over the past few years has indicated good juvenile survival and the potential to at least double the area available for spawning and rearing by engineering routine access for spawning fish.
While this is a part of the proposals for management of Itchen salmon stocks it cannot be used as compensation for losses of fish downstream. Even if the Itchen salmon stock were twice the present size, most of the other impacts being considered here affect a proportion of the stock so their relative impacts would remain the same.
This impact type from many different structures in the Itchen, but especially Durngate can similarly affect other fish species, e.g. eel, trout, as well as invertebrates e.g. crayfish.
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11.4 LONGER TERM INFLEUNCES. The assessment has shown that the River Itchen is substantially affected by low river flow and high soluble phosphorus concentrations, amongst other factors. Licensed abstractions that take water during the summer without flow constraints were considered to be unsustainable. During natural drought periods, these abstractions cause river flows to drop to levels which impact upon river ecosystem functioning.
Planned and future development - Impacts upon water demand and waste water management. Planned population growth in Hampshire has the potential to significantly increase water abstraction from the Itchen catchment. . In the longer term, the current best (and far from perfect) estimates of future water demand indicate an additional demand of some 47Ml/d for the 2050s. 47 Ml/d equates to 20% of abstraction currently licenced for public water supply. As well as the increased demands for public water supply abstraction there will be a consequent increase in phosphorus loads to the river due to the associated increase in STW discharges.
Climate change. Climate change estimates suggest a reduction of natural inputs of water to the Itchen catchment of around 46 Ml/d for the critical September period during a 1 in 30 'dry year'. The River Itchen Groundwater Model calculated that for September 1976 (a drought year), the natural flow would have been 308 Ml/d at Allbrook and Highbridge. 46Ml/d would equate to a 15% reduction in natural flows. This has potential water quality issues in terms of dilution as well as water resource issues.
Planned and future development combined to the impacts of climate change clearly have the potential to influence site integrity in the future. Although of concern, the Agency considers that, at this time, such influences cannot be integrated into this assessment due to the many uncertainties associated with them.
11.5 PART C.2 IN-COMBINATION ASSESSMENT - BACKGROUND/PREVAILING CONDITIONS INCLUDING OFF SITE IMPACTS.
CONCLUSIONS.
1) This assessment has demonstrated that the salmon interest feature is not meeting the Conservation Objective for the population. It is currently a non-viable population, incapable of sustaining itself in the long term until the anthropogenic influences shown to be impacting upon the species and it’s supporting habitats are addressed. Clearly abstractions and discharges have a role to play in that process.
2) This assessment has identified that the Agency’s augmentation schemes do not have discharge consents. Being unconsented these discharges have not been considered within this review of consents process. If the augmentation scheme were operated it is likely that it would be illegal until such time as a discharge consent is obtained. That would possibly require the consent being subject to the Habitats Regulations, as a new plan/project.
The Agency concludes that consideration of these external back ground and prevailing conditions and unregulated activities does not change the determinations on Agency permissions made earlier in the assessment in Parts B and C.1.
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RIVER ITCHEN cSAC. PART C.2 IN-COMBINATION ASSESSMENT.
INTEGRITY TABLE 1.1
Integrity of site check list with respect to in-combination with external plans/projects and background.
This appropriate assessment has shown that…….. ?
Assessment of habitats Assessment of habitat and species Assessment of species populations populations
Features for which the 1) The area of 2) There will be no 3) The 4) There will be no 5) There will be no 6) The natural 7) There will be no cSAC has been selected annex 1 habitats changes to the conservation interruption or direct effect on the range of the indirect effects on (or composite composition of the status of the site’s degradation of the population of the species within the the populations of features) will habitats for which typical species is physical, chemical species for which site is neither species for which not be reduced? the site was favourable (as or biological the site was being reduced nor the site was designated (e.g. defined in 5 – 7) processes that designated or is likely to be designated or reduction in species support habitats and classified reduced for the classified due to structure, species for which foreseeable future loss or degradation abundance or the site was of their habitat diversity that designated or (quantity/quality) comprises the classified habitat over time The river as a habitat for :
Floating formations of water Yes Yes yes Yes crowfoot (Ranunculus) of plain and sub-mountainous rivers
Populations of Atlantic Yes Yes Yes Yes salmon (Salmo salar)
Populations of bullhead Yes Yes Yes Yes (Cottus gobio)
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Populations of brook Yes Yes Yes Yes lamprey (Lampetra planeri)
Populations of white-clawed yes yes yes Yes crayfish (Austropotamobius pallipes) and the river and adjoining land as habitat for :
Populations of southern Yes Yes Yes Yes damselfly (Coenagrion mercuriale) Populations of otter (Lutra Yes Yes Yes Yes lutra)
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11.6 OVERARCHING CONCLUSIONS TO PART C.2
The background/prevailing conditions and “off-site” impacts considered above include factors that can reasonably be foreseen to have an additive impact upon Agency permissions. Quantitative assessment of these factors in-combination with existing permissions is difficult due to paucity of data.
The assessment has identified a number of influences upon the interest features of the River Itchen from unregulated activities/background conditions, some of them effecting the features off-site, that clearly have profoundly important effects on the integrity of the cSAC.
Considering these influences in-combination with Agency permissions is important to ensure that the assessment takes account of the wider picture of influences upon the site. The question is: does assessment of these non-Agency regulated activities and prevailing influences change any of the Agency’s conclusions in Parts B and Part C.1 above?
The Agency concludes that the decisions in Parts B and Part C.1 remain unchanged, when considered in-combination with these other factors, because in this case it is the totality of many of these factors together, impacting alone or in-combination on the structure and function of the system as whole that is important in this case, not one or another.
For example, if one considers the salmon interest feature, and the many influencing factors discussed above, it becomes clear that whilst some might possibly have a more tangible and/or apparently larger scale impact, a number of them are fundamentally important, partly because they affect different stages of the salmon’s life-cycle and it’s supporting habitats spatially and temporally.
Hence it would not be correct, in terms of the Habitats Regulations appropriate assessment process, to adopt a less precautionary line when considering say, abstraction licences, compared to the obviously profound impact from diffuse pollution upon the success of salmon spawning. Both impact types are important to the survival of the interest feature and one cannot be said to be less important, and warrant a less precautionary approach, just because the other influence is also fundamentally important.
That justifies the Agency’s precautionary approach in Stage 3 to assessing it’s own extant permissions. It has consequential implications for the Agency’s actions in Stage 4. It likewise means that these non-Agency regulated, unregulated activities and background conditions must be addressed by whatever means possible.
It is therefore concluded that there are no external plans or projects, or prevailing conditions and unregulated activities that could act in combination with the effects from Agency permissions such that the conclusions for ‘within function’ (Part B) or ‘between function’ (Part C.1) appropriate assessments would change.
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12 OVERALL CONCLUSIONS
12.1 OVERVIEW The Stage 3 appropriate assessment work includes site status assessments, over the ecological and hydrological assessment period – 30 years from 1970 to 2000, which were based on a combination of field surveys, expert opinion, DNA work (for southern damselfly and otters), laboratory analyses in relation to eco-toxicological assessments/water quality determinands, and mathematical modelling and data analysis in a holistic manner. Assessments were carried out for the River Itchen system as a whole and the Study investigated the ability of the river to support characteristic species (including the designated species), with a separation of the effects of abstractions and droughts.
12.2 WATER QUALITY CONCLUSIONS WITH REFERENCE TO INTEREST FEATURES The site status is substantially affected by low river flow and high soluble phosphorus concentrations. The exceedances are greater during the 1 in 10 low flow period.
Consequently, in periods of low flow, the high soluble phosphorus concentrations in the River Itchen cSAC are likely to result in adverse effects on the macrophyte habitat (technically named ‘water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho- Batrachion vegetation’) and populations of Atlantic salmon, Bullhead, Lamprey and Crayfish within the River Itchen cSAC.
The macrophyte habitat is likely to be adversely affected by: A reduction in area of habitat Changes to the composition of the habitat (e.g. reduction in species structure, abundance or diversity that comprises the habitat over time). Adverse effects on the typical species of the habitats; and Interruption or degradation of the processes that support the habitat.
The Atlantic Salmon is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; and There may not be a sufficiently large habitat to maintain the population on a long term basis.
The Bullhead is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; and There may not be a sufficiently large habitat to maintain the population on a long term basis.
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The lamprey is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; an There may not be a sufficiently large habitat to maintain the population on a long term basis.
The Crayfish is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; an There may not be a sufficiently large habitat to maintain the population on a long term basis.
12.3 WATER RESOURCES CONCLUSIONS WITH REFERENCE TO INTEREST FEATURES The site status is substantially affected by low river flow, particularly during dry years. The effects of abstractions during a dry year lead to conditions of about 35% below the critical September naturalised flow in the Candover Stream, the upper tributary of the Itchen to the north, and in the lower river Itchen south of Winchester. Downstream of the Otterbourne surface water abstraction intake, the public water supply abstraction impacts on the 7 kilometres of river channel to the Chickenhall sewage treatment works outfall. The Chickenhall sewage treatment works effluent discharge ensures that the Gaters Mill abstraction does not cause a fall in river flows to levels below 35% of the September naturalised flow.
These effects are likely to have adverse effects on the macrophyte habitat and populations of southern damselfly, Atlantic Salmon and native crayfish within the River Itchen cSAC.
The macrophyte habitat is likely to be adversely affected by: A reduction in area of habitat Changes to the composition of the habitat (e.g. reduction in species structure, abundance or diversity that comprises the habitat over time). Adverse effects on the typical species of the habitats; and Interruption or degradation of the processes that support the habitat.
The southern damselfly is likely to be adversely affected because: There may be interruption or degradation of the processes that support the species The range of the species population may be reduced; and There may not be a sufficiently large habitat to maintain the population on a long term basis.
The Atlantic Salmon is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; The range of the species population may be reduced; and There may not be a sufficiently large habitat to maintain the population on a long term basis.
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The native crayfish is likely to be adversely affected because: There may interruption or degradation of the processes that support the species population The range of the species may be reduced; The population may not be able to maintain itself as a viable component of its natural habitat; an There may not be a sufficiently large habitat to maintain the population on a long term basis.
12.4 PIR CONCLUSIONS WITH REFERENCE TO INTEREST FEATURES Having undertaken an appropriate assessment of PIR permissions affecting the River Itchen cSAC, in view of its conservation objectives, the Agency can ascertain that those identified in Table 6.8 will not adversely affect the integrity of the site.
However, it cannot be ascertained that those identified in Table 6.9, that are located outside of the site boundary, will not adversely affect the integrity of the site. These are likely to have adverse effect the populations of Atlantic Salmon within the River Itchen cSAC.
The Atlantic Salmon is likely to be adversely affected because: There is likely to be interruption or degradation of the processes that support the species population The population may not be able to maintain itself as a viable component of its natural habitat; The range of the species population may be reduced; and There may not be a sufficiently large habitat to maintain the population on a long term basis.
12.5 RSR CONCLUSIONS WITH REFERENCE TO INTEREST FEATURES Having undertaken an appropriate assessment of RSR permissions affecting the River Itchen cSAC, in view of its conservation objectives, the Agency can ascertain that none of those considered will adversely affect the integrity of the site.
12.6 FINAL NUMBER PERMISSIONS AND DECISION 12.6.1 Overview The final number of permissions through the Stage 3 appropriate assessments is given in Table 13.1
12.6.2 No Adverse Effect on Site Integrity Cannot be Shown The Agency determines that for ninety (90) permissions, it cannot be shown that they will not interrupt or compromise progress towards achieving the Conservation Objectives of the River Itchen cSAC. Considering the effect of these permissions in relation to the area of Annex I habitats (or composite features), the Agency cannot conclude that there will not be an adverse effect on site integrity.
In considering the effect of these permissions in relation to the effect on the population of the species (and their supporting habitats), for which the sites was designated or classified, the Agency cannot conclude that there will not be an adverse effect on site integrity.
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12.6.3 No Adverse Effect on Site Integrity Can be Shown The Agency also determines that for one hundred and three (103) permissions, it can be shown that they will not interrupt or compromise progress towards achieving the Conservation Objectives of the River Itchen cSAC. In considering the effect of these permissions in relation to the area of Annex I habitats (or composite features), the Agency can conclude that there will not be an adverse effect on site integrity.
In considering the effect of these permissions in relation to the effect on the population of the species (and their supporting habitats) for which the sites was designated or classified, the Agency can conclude that there will not be an adverse effect on site integrity.
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PART E – FINAL APPROPRIATE ASSESSMENT RECORD
13 FINAL APPROPRIATE ASSESSMENT RECORD
13.1 SUMMARY TABLE OF ALL PERMISSIONS The information contained in this document and used for decision-making purposes has been produced using 'best available information' and current understanding of the site.
The final numbers of permissions are given in Table13.1 below: All permissions for which a conclusion of ‘cannot show no adverse effect on site integrity’ has been reached are detailed in Table 13.2 below.
Table 13.1: Final Numbers of Permissions by Function and conclusions. Total No. of No adverse No adverse Others Agency No adverse effect on site effect on site permissions effect on site integrity integrity Function assessed in integrity can be cannot be cannot be Stage 3. shown shown alone shown in- combination 115 15 53 0 Water Quality 62 48 9341 * Water Resources 13 0 000 Waste 0 Process Industry 26 3 3 16** 7 Regulation Radioactive 21 000 Substances 21 Regulation Groundwater 0 0 0 0 0 Authorisations * See Part B.2. for explanation. ** Revoked, repermitted under Reg. 48 or within 12 months of repermitting under Reg.48
Table 13.2: Summary table of permissions for which a decision of ‘cannot show no adverse effect on site integrity’ has been reached. Permission number Site Name (Permission type) No adverse effect on site No adverse effect on site integrity can be shown integrity cannot be shown
Alone In Alone In Combination Combination Water Quality - Discharge Consents P00047 PLOT 1 & 2 MARNE COTTAGE (P47/H/85/1) (SEPTIC TANK EFFLUENT) P01550 WESTLANDS (SEPTIC TANK (P1550/H/88) EFFLUENT) H02863 (63/1612) WHITE HOUSE (TREATED SEWAGE EFFLUENT) N02956 PORTREE (SEPTIC TANK (UV63/2154) EFFLUENT)
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Permission number Site Name (Permission type) No adverse effect on site No adverse effect on site integrity can be shown integrity cannot be shown
Alone In Alone In Combination Combination P04064 THE NOOK (SEPTIC TANK (P4064/H/91) EFFLUENT) N02993 HOUSE ADJOINING (UV63/2189) BROOKLYN (SEPTIC TANK EFFLUENT) P04470 LIME TREE COTT/CHERITON (P4470/H/92) GARAGE (TREATED SEWAGE EFFLUENT) P00889 (P889/H/87) 1-2 SCHOOL LANE (SEPTIC TANK EFFLUENT) P01363 APPLE TREE COTTAGE (P1363/H/87) (SEPTIC TANK EFFLUENT) P01051 COLYTON COTTAGE (SEPTIC (P1051/H/87) TANK EFFLUENT) P06876 1/2 Hideaway Cottages (TREATED (P.6876/H/97) SEWAGE EFFLUENT) P00046 (P46/H/85) THE CHAPEL, CHAPEL LANE (TREATED SEWAGE EFFLUENT) H02631 (63/17) THE PASTURES (TREATED SEWAGE EFFLUENT) H01841 (UV- NORTH END FARM (FARM 61/410) EFFLUENT) P06407 TICHBORNE HOUSE (TREATED (P.6407/H/96) SEWAGE EFFLUENT) W00227 (63/150) ALRESFORD S.T.W. (TREATED SEWAGE EFFLUENT) N02832 (63/2066) WINCHESTER LODGE (SEPTIC TANK EFFLUENT) P06145 SPRING GARDENS (P6145/H/96) WATERCRESS BEDS (WATERCRESS BED EFFLUENT) N02512 ITCHEN VALLEY TROUT FARM (PC37/209/H57/77) (FISH FARM EFFLUENT) P00031 (P31/H/85) LOWLAND HOUSE (SEPTIC TANK EFFLUENT) H02679 (63/987) HOBBS CLOSE (TREATED SEWAGE EFFLUENT) P06138 LOWER BISHOPS SUTTON (P6138/H/96) (WATERCRESS BED EFFLUENT) P05770 THE NYTHE WATERCRESS (P5770/H/95) FARM (WATERCRESS BED EFFLUENT) P05769 DRAYTON BEDS (P5769/H/95) (WATERCRESS BED EFFLUENT) P06140 MAXWELLS CRESS BEDS (P6140/H/96) (WATERCRESS BED EFFLUENT) P03457 KILN LANE HOUSING ESTATE (P.3457/H/91) (TREATED SEWAGE EFFLUENT) P05986 WEIR HOUSE (TREATED (P5986/H/95) SEWAGE EFFLUENT)
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Permission number Site Name (Permission type) No adverse effect on site No adverse effect on site integrity can be shown integrity cannot be shown
Alone In Alone In Combination Combination N00039 MANOR FARM FISH FARM (PC37/714/H240/77 (FISH FARM EFFLUENT) ) P06141 MANOR FARM (WATERCRESS (P.6141/H/96) BED EFFLUENT) P05760 PINGLESTONE CRESSFARM (P5760/H/95) (WATERCRESS BED EFFLUENT) N01283 DROVE LANE FISH FARM (PC37/210/H58/77) (FISH FARM EFFLUENT) P06146 WEST LEA FARM SHOP (P6146/H/96) WATERCRESS BEDS (WATERCRESS BED EFFLUENT) P05762 FOBDOWN CRESSFARM UPPER (P5762/H/95) BEDS STILLING POND (WATERCRESS BED EFFLUENT) P05761 FOBDOWN CRESSFARM TOP (P5761/H/95) END STILLING POND (WATERCRESS BED EFFLUENT) H01632 (UV- FOBDOWN FARM (FARM 61/232) EFFLUENT) P05764 FOBDOWN CRESSFARM BEDS (P5764/H/95) 16-19A (WATERCRESS BED EFFLUENT) P05763 FOBDOWN CRESSFARM (P5763/H/95) BOTTOM END STILLING POND (WATERCRESS BED EFFLUENT) P05425 LITTLE HAYES ROAD (P.5425/H/94) (TREATED SEWAGE EFFLUENT) P06669R ITCHEN ABBAS FISH FARM (P6669/R/H/97) (FISH FARM EFFLUENT) P06144 SPRINGVALE WATERCRESS (P6144/H/96) BEDS (WATERCRESS BED EFFLUENT) H01522 (UV-61/35) PUDDING FARM (FARM EFFLUENT) W00235 (51/217) HARESTOCK STW (TREATED SEWAGE EFFLUENT) H01110 (51/119) WINCHESTER COLLEGE (SWIMMING POOL EFFLUENT) A00712 MORESTEAD STW (TREATED (A.712/H/96) SEWAGE EFFLUENT) H00532 (UV-61/54) LOW HILL FARM (TREATED SEWAGE EFFLUENT) A00154 EASTLEIGH (CHICKENHALL ) (COPA/5571) STW (TREATED SEWAGE EFFLUENT) H01146 (C28) WAGON WORKS (SURFACE WATER) N00034 (61/774) EASTLEIGH B.R. WORKS (SURFACE WATER)
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Permission number Site Name (Permission type) No adverse effect on site No adverse effect on site integrity can be shown integrity cannot be shown
Alone In Alone In Combination Combination H01481 (UV-REG ADMIRALTY VICTUALLING FOLIO 3) DEPOT (TREATED SEWAGE EFFLUENT) P06057 RIVER ITCHEN (GATERS MILL) (P.6057/H/95) WTW (TRADE EFFLUENT - WASH WATER) W00314 PORTSWOOD STW (TREATED (PP(A)38/48/H12/7) SEWAGE EFFLUENT) P11003 SOUTHAMPTON (PC37/879/H288/84 GEOTHERMAL EFFLUENT ) P04588 Land at Lovington House (treated (P4588/H/92) sewage affluent) P06542 Weir Cottage (treated sewage (P6542/H/96) effluent)
Water Resources - Abstraction Licences
22.1/136 Itchen Valley Trout Farm,, Watercress 22.1/147 Spring Gardens, Alresford, Fish Farm 22.2/167 Bishops Sutton, Spray Irrigation
22.2/28 Pinglestone Farm, Spray Irrigation
22.2/166 Drayton Farm, Bighton, Watercress
22.2/165 Bishops Sutton, Alresford, Watercress 22.2/171 Manor Farm, Old Alresford, Watercress 22.2/101 Pinglestone Farm, Watercress
22.2/172 Dean Beds, Watercress
22.2/173 Home Beds, Watercress
22.2/159 Manor Farm, Old Alresford, Fish Farm 22.2/158 Drove Lane, Alresford, Fish Farm
22.2/169 River Alre Augmentation Scheme, Augmentation 22.3/124 Fobdown Farm, Spray Irrigation
22.3/158 Fobdown, Spray Irrigation *
22.3/51 Fobdown Farm, Watercress
22.3/132 Fobdown Farm, Watercress
22.3/55 Totford P S, PWS
22.3/150 Candover Boreholes, Augmentation
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Permission number Site Name (Permission type) No adverse effect on site No adverse effect on site integrity can be shown integrity cannot be shown
Alone In Alone In Combination Combination 22.4/151 Avington, Fish Farm
22.4/150 Avington Trout Fishery, Fish Farm
22.5/1 Headbourne Worthy, Watercress
22.6/157 Mill House, St Cross, Winchester, Fish Farm 22.7/94 Otterbourne P S ( Inc. Twy. Moors ), PWS 22.6/93 Otterbourne Intake, PWS
22.6/92 Twyford P S, PWS
22.4/80 Easton (Itchen Valley & Winchester), PWS 22.10/120 Fair Oak Lodge, Spray Irrigation
22.9/159 Fishers Pond, Hampshire, Fish Farm
22.9/164 Morelands Copse, Thompsons Lane, Fish Farm 22.9/168 Fishers Pond, Fish Farm
22.9/163 Stoke Common, Fish Farm
22.10/119 Eastleigh Works, Industrial
22.10/134 Gaters Mill Intake, PWS
28/39/30/0273 Lasham PWS, PWS
PIR – Authorisations to controlled waters AK5547 Polimeri Europa, Hythe AF8009 Esso Petroleum, Fawley AA3115 RWE Innogy, Fawley
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13.2 CONCLUSION
This is a record of the appropriate assessment required by Regulation 50 and/or 3(4) of the Conservation (Natural Habitats, &c) Regulations (“Habitats Regulations”) 1994, undertaken by the Environment Agency in respect of the Review of Existing Consents, in accordance with the Habitats Directive (Council Directive 92/43/EEC). Having considered that the existing permissions would be likely to have a significant effect on the River Itchen cSAC and that the existing permissions were not directly connected with or necessary to the management of the site for nature conservation, an appropriate assessment has been undertaken of the implications of the plans/projects in view of the site’s conservation objectives.
The site’s nature conservation objectives have been taken into account, including consideration of the citation for the site and information supplied by EN. The likely effects of the existing permissions on the international nature conservation interests for which the site was classified or designated may be summarised as: low flows, high levels of ammonia / BOD / soluble reactive phosphorus / suspended solids, thermal impacts, biotic and a-biotic factors.
The assessment has concluded that:
The existing permissions are a combination of those which can be shown to have no adverse effect on site integrity and those which cannot. Permissions which cannot be shown to have no adverse effect on site integrity will be taken forward for consideration in Stage 4 of the Agency’s Review of Consents process; those which can be shown to have no adverse effect on site integrity will be affirmed in Stage 4.
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Name of Agency officer signing on behalf of Review of Consents group:
Signed: Date:
Name of relevant Agency Area Manager:
Signed: Date:
EN comments on appropriate assessment:
Is there agreement with the conclusion? YES/NO
Signed: (EN local team manager / area officer) Date:
- 223 - Hampshire and Isle of Wight Area River Itchen cSAC HD RoC Stage 3 Appropriate Assessment – final version February 2005. REFERENCES.
Number refers to superscript reference within text. Note that not all references are cited within the text in that way.
PART A:
1. Hughes, M. (1984). Man and the landscape. Hampshire’s Countryside Heritage Series, Hampshire county Council, Winchester, 41 pp.
PART B:
B.1 Water Quality.
Das, B.S., Lee, L.S., Rao, P.S.C., Hultgren, R.P. (2004). Sorption and degradation of steroid hormones in soils during transport: Column studies and model evaluation. Environmental Science and Technology, 38, 1460-1470.
Desbrow, C., Routledge, E.J., Brighty, G.C., Sumpter, J.P. and Waldock, M. (1998). Identification of estrogenic chemicals in STW effluent. 1. Chemical fractionation and in vitro biological screening. Environmental Science & Technology, 32, 1549-1558.
Fourth Otter Survey of England 2000-2002, Environment Agency Report W1-061/TR, A.Crawford, 2003;
Otter Survey of England 1991-1994, The Vincent Wildlife Trust, R.Strachan & D.J.Jefferies, 1996.
Effects of pollution on fish; Molecular Effects and Population Responses Ed. AJ Lawrence and KL Hemingway Blackwell Publishing, 2003.
Holthaus, K.I.E., Johnson, A.C., Jürgens, M.D., Williams, R.J., and Carter, J.E. (2002) The potential for estradiol and ethinylestradiol to sorb to suspended and bed-sediments in some English rivers. Environmental Toxicology and Chemistry 21, 2526-2535.
Jobling, S., Nolan, M., Tyler, C.R., Brighty, G. and Sumpter, J.P. (1998). Widespread sexual disruption in wild fish. Environmental Science & Technology, 32, 2498-2506.
Johnson, A.C and Sumpter J.P. (2001). Removal of endocrine disrupting chemicals in activated sludge treatment works. Environmental Science & Technology 35, 4697-4703.
Johnson, A.C., Williams, R.J. (2004). A model to estimate influent and effluent concentrations of estradiol, estrone and ethinyloestradiol at sewage treatment works. Environmental Science & Technology 38, 3649-3658.
Jürgens, M.D., Holthaus, K.I.E., Johnson, A.C., Smith J.J.L., Hetheridge, M. and Williams, R.J. (2002). The potential for estradiol and ethinylestradiol degradation in English rivers. Environmental Toxicology and Chemistry 21, 480-488.
Körner, W., Bolz, U., Süssmuth, W., Hiller, G., Schuller, W., Hanf, V., Hagenmaier, H. 2000. Input/output balance of estrogenic active compounds in a major municipal sewage plant in Germany. Chemosphere, 40, 1131-1142.
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Wastewater Discharges to Ground New Alresford Waste Water Treatment Works, Groundwater Investigations Interpretative Report, DRAFT – No.50669-4, KOMEX CLARKE BOND Ltd., January 2005.
Molecular Effects and Population Responses Ed. AJ Lawrence and KL Hemingway Blackwell Publishing, 2003.
Oscar Faber report DJC/Itchen/W19313aber report DJC/Itchen/W19313, March 1999.
Peck M, Gibson RW, Kortenkamp A, Hill, E.M. (2004). Sediments are major sinks of steroidal estrogens in two United Kingdom rivers. Environ. Toxicol. Chem. 23, 945-952.
Young, W.F., Whitehouse, P., Johnson, I., Sorokin, N. (2002). Proposed predicted no effect concentrations (PNECs) for natural and synthetic steroid oestrogens in surface waters.
Environment Agency R&D Technical Report P2-T04/1, England and Wales Environment Agency, Bristol, 172 pp.
Young A.R., Grew R.and Holmes M.G.R. 2003. Low Flows 2000: a national water resources assessment and decision support tool. Water Science & Technology 48, 119-126
Schowanek, D., Webb, S. 2002. Exposure simulation for pharmaceuticals in European surface waters with GREAT-ER. Toxicology Letters 131, 39-50.
Effects of pollution on fish; Molecular Effects and Population Responses Ed. AJ Lawrence and KL Hemingway Blackwell Publishing, 2003.
B.4 PIR
2. Environment Agency, 2003. Habitat Directive Work Instruction: (Appendix 21). Further Guidance and Proforma for Stage 3 of the Review of Consents under the Habitat Directive
3. Environment Agency, 2001. EU Habitats and Birds Directives. Handbook for Agency permissions and activities
4. Environment Agency, 2003. Memo and Attachment dated 19 September 2003 from Nick Hopwood entitled ‘Clarification of the Agency’s Responsibilities at Stage 3 and Stage 4 of the Review of Consents’
5. English Nature, 2001. Habitat Regulations Guidance Note – ‘Alone or In Combination’
6. Environment Agency, 2002. River Itchen Site Action Plan, Site Issues Briefing
7. Environment Agency, 2002. Proforma for Stages 1 and 2 of the Review of Consents under the Habitats Directive
8. Halcrow, 2003. River Itchen Sustainability Study. Draft Strategy Document and Technical Appendices – Ecology/Fisheries, Land Management, Water Quality, Water Resources and Flow
9. Environment Agency, 2003. HD Bulletin 44
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10. Environment Agency, 2001. EU Habitats and Birds Directives. Handbook for Agency permissions and activities. Appendix 21 – Version 2
11. Email Correspondence – Tim Sykes/Kunle Akande entitled ‘Who, What, How and When in Q4
12. Email Correspondence – Tim Sykes/Kunle Akande entitled ‘HD RoC – Incorporating the External In-Combination Element of the Stage 3 Appropriate Assessments’
13. Notes of Meeting with Agency staff to clarify requirements of Stage 3 Appropriate Assessment for the River Itchen cSAC dated 13 January, 2004.
14. River Itchen Sustainability Study, 2004. Technical Report and Technical Appendices.
CEFAS & Environment Agency (2001). Salmon Stocks and Fisheries in England and Wales 2000. Preliminary assessment prepared for ICES, April 2001. Environment Agency, National Salmon and Trout Fisheries Centre.
Seaby, R. & Fewings, G. A. (2003) Predicting the effects of heated outfalls and Water intakes on the Itchen River salmon in Southampton Water. Aug 2003
Seaby, R. (2005) Predicting the effects of the Fawley Power Station’s heated outfall on Itchen River salmon in Southampton Water. Jan 2005
PART C.
Hanselman, T.A., Graetz, D.A., Wilkie, A.C. (2003). Manure borne estrogens as potential environmental contaminants: A review. Environmental Science and Technology, 37, 5471-5478.
Jacobs MN, Covaci A, Schepens P (2002). Investigation of selected persistent organic pollutants in farmed Atlantic salmon (Salmo salar), salmon aquaculture feed, and fish oil components of the feed. Environmental Science and Technology 36, 2797-2805.
Jobling, S., Nolan, M., Tyler, C.R., Brighty, G. and Sumpter, J.P. (1998). Widespread sexual disruption in wild fish. Environmental Science & Technology, 32, 2498-2506.
Lange, I.G., Daxenberger, A., Schiffer, B., Witters, H., Ibarreta, D., Meyer, H.H.D. (2002). Sex hormones originating from different livestock production systems: fate and potential disrupting activity in the environment. Analytica Chimica Acta 473, 27-37.
Matthiessen P (2003). Endocrine disruption in marine fish. Pure and Applied Chemistry 75, 2249- 2261.
Orlando, E.F., Kolok. A.S., Binzcik, G.A., Gtes, J.L., Horton, M.K., Lambright, C.S., Gray, L.E., Soto, A.M. and Guillette, L.J. 2004. Endocrine-disrupting effects of cattle feedlot effluent on an aquatic sentinel species, the Fathead Minnow. Environ. Health. Persp. 112, 353-358.
Raman, D.R., Williams, E.L., Layton, A.C., Burns, R.T., Easter, J.P., Daugherty, A.S., Mullen, M.D., Sayler, G.S. (2004). Estrogen content of dairy and swine wastes. Environmental Science and Technology, 38, 3567-3573.
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Servos MR (1999). Review of the aquatic toxicity, estrogenic responses and bioaccumulation of alkylphenols and alkylphenol polyethoxylates. Water Quality Research Journal of Canada 34, 123- 177.
Soto, A.M., Calabro, J.M., Prechtl, N.V., Yau, A.Y., Orlando, E.F., Daxenberger, A., Kolok, A.S., Guillette, L.J., le Bizec, B., Lange, I.G., Sonnenschein, C. (2004). Androgenic and estrogenic activity in water bodies receiving cattle feedlot effluent in Eastern Nebraska, USA. Environmental Health Perspectives 112, 346-352.
ChalkRivers – nature conservation and management, C.P.Mainstone, 1999
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