Habitats Directive: Appropriate Assessment form for new applications
Environment Agency record of Appropriate Assessment of adverse effect on site integrity of the European site (Stage 3)
Part A: Technical consideration
Permission, plan or project (PPP) details Type of PPP: Water Abstraction Licences (Licence renewal) Environment Agency reference no: NPS/WR/007223 (Plumsgate Road) NPS/WR/007224 (Ludham Road) National Grid Reference: TG 382 223 TG 386 206 Site reference: Plumsgate Road, Catfield, Norfolk Ludham Road, Catfield, Norfolk
Note: Redactions have been made to remove any information that would allow for the location of public water supply abstraction to be identified. This is in line with guidance issued by DEFRA. If you wish to view the un-redacted documents which includes Figure 8.1 and Annex 1 of this document, these can be made available at either our Norwich or Ipswich offices. Please contact [email protected] to arrange an appointment.
Contents:
1.0 Introduction
1.1 Appropriate Assessment
1.2 Decision Flow Chart
2.0 Summary of Proposal
2.1 Maps and Plans
3.0 The Broads SAC, Broadland SPA and Broadland Ramsar
3.1 Sensitive Features and Hazards
3.2 Overview and Conservation Objectives
3.3 Ant Broads and Marshes SSSI 3.3.1 Geological Setting
3.4 Overview of the Hydrological Sub Areas of the Ant Broads and Marshes SSSI 3.4.1 Sutton Broad 3.4.2 Sutton Fen
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3.4.3 Barton Broad 3.4.4 Catfield Fen 3.4.5 Sharp Street 3.4.6 Crome’s Broad
3.5 Assessment Focus
4.0 Ecology and Sensitivity
4.1 H7210 SAC and Ramsar Feature: Calcareous Fens with Cladium mariscus and species of the Caricion davallianae
4.2 H7140 SAC Feature: Transition Mires and Quaking Bogs
4.3 H6410 SAC Feature: Molinia Meadows on calcareous, peaty or clayey-silt- laden soils (Molinion caeruleae)
4.4 S1903 SAC and Ramsar Feature: Fen Orchid (Liparis loeselii)
5.0 Previous Work
5.1 Reviews and Reports 5.1.1 Habitats Directive Review of Consents (2010) 5.1.2 Ecological Compendium (2011) 5.1.3 Catfield Fen Investigation (Amec, 2012) 5.1.4 Reports 1 - 4, Natural England (July - November 2013) 5.1.5 Reports 5 - 7, Natural England (September – November 2013) 5.1.6 Groundwater Summary Report (Environment Agency, 2014a) 5.1.7 Further Information
6.0 Observed Monitoring Data
7.0 Groundwater Modelling
7.1 North East Anglian Chalk (NEAC) Groundwater Model
7.2 Abstraction Scenarios
7.3 Water Chemistry: Water Balance Method
8.0 Assessment of the Potential Effect of Abstraction
8.1 Groundwater Abstraction In-combination
8.2 Hydrological Functioning and Decision Tables
8.3 Baseline for assessment
8.4 Conceptual Understanding of Groundwater Flow in the Area
8.5 Changes in Flow or Velocity Regime 8.5.1 Conclusion
8.6 Changes in Water Levels or Table 8.6.1 Conclusion
8.7 Changes in Water Chemistry 8.7.1 Conclusion
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8.8 Habitat Loss 8.8.1 Conclusion
8.9 Summary of the Potential Effect of Abstraction Against Hazards
9.0 Other Plans, Permissions or Projects
9.1 Other Agency permissions
9.2 Other competent authority permissions
9.3 Other plans or projects
10.0 Other Potentially Contributing Factors
10.1 Water Level Management
10.2 Land Management
10.3 Rainfall
10.4 Air Quality
10.5 Climate Change
10.6 Summary of Other Contributing Factors
11.0 Environment Agency Conclusion . 12.0 Glossary
13.0 References
Annex 1. Hydrological Monitoring and Licensed Abstractions in the Vicinity of Catfield Fen Annex 2. Site Designation Hierarchy Annex 3. Distribution of SAC Features across Ant Broads and Marshes SSSI
Note: Hyperlinks have been used to link key documents and information to our webpage where they are already available. Unless otherwise stated, the use of ‘link’ takes the reader to the following webpage. http://www.environment-agency.gov.uk/research/library/consultations/143536.aspx
Please note, due to the convergence of the Environment Agency website to ‘.GOV’ on 01 April 2014, this link may redirect to a different address.
Maps within this document are reproduced under © Crown copyright. All rights reserved. Environment Agency, 100026380, 2014.
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1.0 Introduction
1.1 Appropriate Assessment
Regulation 61 of The Conservation of Habitats and Species Regulations 20101 (‘the Regulations’) requires all competent authorities to appraise new activities (plans, projects and permissions) for which they have responsibility (in line with Article 6(3) of the Habitats Directive (‘the Directive)) and where these are deemed to have a likely significant effect on a Natura 2000 site and are not necessary for the management of the site, through an ‘Appropriate Assessment’.
This process is preceded by a conclusion of likely significant effect. An Appendix 11 proforma (Environment Agency, 2013a) has been completed and agreed by Natural England on 22 August 2013. The Appendix 11 concluded a likely significant effect on the Ant Broads and Marshes component SSSI of The Broads SAC, see section 2.0.
The Appropriate Assessment allows the competent authority to determine whether an activity, either on its own or in-combination with other plans and projects, would adversely affect the integrity of the site.
The Habitats Directive does not set out a prescriptive procedure for an Appropriate Assessment, but the European Commission has issued general guidance, including checklists of what to consider in carrying out an assessment (European Commission, 2001). In the absence of detailed technical guidance, we have developed, tested and used our own technical procedures which are compliant with the Directive and Regulations. Our Appropriate Assessment procedure for new permissions (Environment Agency, 2010a) underpins this Appropriate Assessment.
1.2 Decision Flow Chart
The key steps in the Appropriate Assessment for these renewal applications were:
• Identify, obtain and review the information needed that describes the special conservation interest of the site (provided by Natural England, 2008) and the likely effect associated with the permit application (based on information provided by the applicant, Catfield Fen Investigation (Amec, 2012) and the Groundwater Summary Report (Environment Agency, 2014a)); • Establish the effects of the proposed abstraction by matching the predicted effects with the distribution of the most sensitive features known to be vulnerable to such changes; • Establish the risk to these features by predicting the most likely changes, if any, in the extent and distribution of the features, based on best available scientific knowledge; • Determine if any predicted changes would compromise the conservation status of the features, using Conservation Objectives and criteria for favourable condition status to inform that judgement; • Ensure that the judgement took full account of the effects of other activities already acting on the site and likely anticipated changes in the prevailing environmental conditions (either natural or influenced by humans);
1 The European Commission Habitats Directive (Council Directive 92/43/EEC on the Conservation of Natural Habitats & of Wild Flora & Fauna) passed in to domestic law by way of the Habitat Regulations (Conservation (Habitats &c) Regulations, 1994). This was superseded in April 2010 by the Conservation of Habitats and Species Regulations 2010 and subsequently amended 2012.
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• Conclude, beyond all reasonable scientific doubt2 and taking account of uncertainties and assumptions made, whether or not the effects of the proposed permitted activity, acting alone or in-combination with others, would adversely affect the integrity of the site i.e. the structure and ecological functioning of the site.
These steps and sources of information are summarised in Figure 1.1. Our overall conclusion was based on a sequential and systematic scrutiny of the predicted effects and likely ecological response.
2 This is defined as any doubts about the significance of impact on site integrity. These need to be removed as far as reasonably and practicable to do so and relies on the best available information. In practice, scientific doubts can be removed by being certain about the available scientific information and commissioning new research or studies if current knowledge is inadequate. This includes the quality of the data and the validity of assumptions and in particular predicted changes derived by surrogate means such as mathematical and ecological models (simulations). Where scientific knowledge is considered inadequate, expert judgement and local knowledge in particular are legitimate contributions to decision-making (Environment Agency, 2011).
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START Applications submitted (December 2011)
A compendium of ecological and eco-hydrological evidence from Catfield Fen, Norfolk at 31 January Likely significant effect 2011 (Natural England et al, 2011). assessment (LSE) through an Appendix 11 document Reviewof Consents outcomes and methodology. Based on the Yare & North Norfolk Groundwater First issue: 24/10/2012 Natural England & the Broads Authority consulted. Model Updated: 26/11/2012 Due regard given to their comments. LSE Finalised and agreed: conclusion agreed. 22/08/2013
Applications publicised 15/08/2012. Relevant information considered in assessment
RSPB, Broads Authority, Nofolk Wildlife Trust & Collation of ecological Butterfly Conservation management plans evidence
NE ecological advice via Reports 1 - 4 (Natural England, 2013 a-d).
NE ecological advice via
Pump test information and monitoring NE ecological advice via Reports 5 - 7 (Natural NE ecological advice viaEngland, Reports 2013 5 - 7 (Natural e-g). England,NE ecological 2013 e-gadv
These reports take account of additional Appropriate Assessment: information received from Parmenter, Barendregt Ecohydrological guidelines for lowland wetland Technical assessment of , Mountford, the RSPB and Broads Authority plant communities Fens and Mires (Environment hazards against Agency , 2010) abstraction - Alone and In- combination Individual designated interest features of the Ant Broads & Marshes SSSI of The Broads SAC, Broadland SPA and Ramsar Conservation Groundwater summary report. Based on the Objectives v2.1 (Draft) (Natural England, 2008) Northern East Anglian Chalk (NEAC) groundwater model
Catfield Fen Investigation Report (Amec 2012)
Appropriate Assessment: Information on other contributing factors Site Management TechnicalNote (Amec 2014d) Cumulative Effects
Rainfall Trends in an Area of North East Norfolk (Environment Agency, 2013b)
Internal Environment Agency Technicalpanel reviews Complete Appropriate Assessment Legal review
Natural England & Broads Authority consulted Key: Due regard to Natural England & Broads Authority comments Information received from external sources via consultation
Information received through internal consultation END Final Appropriate Key steps in the appropriate assessment process assessment
Figure 1.1 Decision flow chart showing how the Appropriate Assessment was carried out and the sources of information and advice.
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2.0 Summary of Proposals
These applications seek to renew two water abstraction licences at Catfield in Norfolk on the same terms. Both applications are considered under this single assessment as new permissions.
In cases where permissions are time limited, have been ongoing and the application is to renew on the same terms, we would normally expect to renew time limited licences on those same terms (subject to three principles3, one of which is environmental sustainability). In some cases however, it may be identified that the abstraction could result in a likely significant effect or adverse effect to site integrity of a European site, further action to investigate the environmental sustainability is then required.
New legislation brought about by the Water Act 2003 made it a legal requirement for all new abstraction licences to be time limited through an expiry date. Most time limited licences will be linked to the Common End Date (CED) stated in the Catchment Abstraction Management Strategy (CAMS). A licence will be time limited to the relevant CAMS in which the licence is situated.
In considering whether a plan or project will adversely affect the integrity of a site, the competent authority must have regard to the manner in which it is proposed to be carried out, or to any conditions or restrictions subject to which they propose that the consent, permission or other authorisation should be given.
Both abstraction licences expired on 31 March 2012, however, the previously licensed operations have been extended in agreement with the applicant to 31 March 2014. This extension is permitted under Section 46A of the Water Resources Act 1991 (as amended by the Water Act 2003) as the licences have met the criteria for limited extended validity. This means that while we are determining the applications, the licences remain in force until such time as we grant new ones, or if we refuse the applications until such time as any appeal is determined (or if there is no appeal, the time limit for bringing the appeal). The applicant is therefore entitled to abstract water under the terms of the previous licences until such time as defined above.
The location of the abstraction boreholes and their proximity to the European site is shown in Figures 2.1 and 2.2.
Application NPS/WR/007223 - Plumsgate Road
This application is to renew licence AN/034/0009/008 which expired on 31 March 2012, with no changes to the conditions. The licence authorises abstraction from a Crag borehole at National Grid Reference TG 382 223, approximately 0.9km east of the Ant Broad and Marshes SSSI, a component of The Broads Special Area of Conservation (SAC), Broadland Special Protection Area (SPA) and Broadland Ramsar (see Figures 2.1 and 2.2). The licence authorised abstraction of 1,090m³/day and 68,000m³/year at an instantaneous rate of 15 litres per second between April and October for spray irrigation. The abstraction point is located at Plumsgate Road, Catfield and is henceforth referred to as the Plumsgate Road abstraction.
3 The application to renew is environmental sustainable, there is continued justification of need and the water is used efficiently.
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There is a monitoring addendum attached to the licence which includes three piezometers that the applicant is requested to maintain and monitor on a daily basis during the abstraction period and weekly the rest of the year. These are located at National Grid References TG 3831 2262 (piezometers at 3m deep and 15m deep, both referred to as ‘Alston Obs’) and TG 3825 2240 (referred to as TG32/815D). TG32/815D is an Environment Agency piezometer which the applicant is also required to monitor. The location of the monitoring points is shown in Annex 1.
Application NPS/WR/007224 - Ludham Road
This application is to renew licence AN/034/0009/009 which expired on 31 March 2012, with no changes to the conditions. The licence authorises abstraction from a Crag borehole at National Grid Reference TG 386 206, approximately 0.65km east of the Ant Broad and Marshes SSSI, a component of The Broads SAC, Broadland SPA and Broadland Ramsar (see Figures 2.1 and 2.2). The licence authorised abstraction of 45m³/hour, 800m³/day and 22,700m³/year at an instantaneous rate of 12.5 litres per second between April and October for spray irrigation. The abstraction point is located at Ludham Road, Catfield and is henceforth referred to as the Ludham Road abstraction.
There is a monitoring addendum attached to the licence, which includes three piezometers that the applicant is requested to maintain and monitor on a daily basis during the abstraction period and weekly the rest of the year. These are located at National Grid References TG 3850 2059 (referenced as TG32/805), TG 3813 2078 (TG32/801) and TG 3821 2029 (Alston Obs3), with TG32/805 and TG/32/801 now being monitored using data loggers. The location of the monitoring points is shown in Annex 1.
Both licences were last renewed in March 2010 on the same terms for a period of two years. Short term renewals were granted as groundwater levels were healthy and both abstractions had been included within the groundwater modelling work (including the fully licensed scenario model runs) which informed the assessment of the in-combination effects of abstraction under the Review of Consents (RoC) for the Ant Broads and Marshes SSSI. On this basis, and due to the RoC decision, a conclusion of no adverse effect on The Broads SAC, Broadland SPA and Broadland Ramsar was reached.
An Appendix 11 proforma (Environment Agency, 2013a) was completed, and agreed by Natural England on 22 August 2013. This assessment concluded that both abstractions have no likely significant effect on the Upper Thurne Broads and Marshes SSSI, component site of The Broads SAC, Broadland SPA and Broadland Ramsar, when considered both alone and in-combination with other plans, projects or permissions. The Upper Thurne Broads and Marshes SSSI component is therefore, not considered any further in this assessment. We could not conclude no likely significant effect alone and in- combination on the Ant Broads and Marshes SSSI, a second component of the SAC, SPA and Ramsar.
Since the abstraction licences were last renewed in March 2010, Natural England provided information which described a long-term trend of drying of Catfield Fen, a hydrological sub area of the Ant Broads and Marshes SSSI – see Figure 2.3. This reported on-site vegetation change consistent with drying of a wetland habitat (Natural England et al., 2011). While a high level of uncertainty regarding causes of the drying out were acknowledged by Natural England, the contribution of abstraction could not be ruled out. Our conclusion of likely significant effect alone and in-combination via an Appendix 11 proforma on the Ant Broads and Marshes SSSI took this information into account.
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Following completion of the Appendix 11 (as agreed on 22 August 2013 and available on our webpage at link), Natural England have provided further new evidence (Natural England, 2013d) which refines some of the evidence presented in Natural England et al, 2011. In July 2013, Natural England re-surveyed the Ant Broads and Marshes SSSI units (see section 3.4 for explanation of SSSI units) which comprise Catfield Fen (3, 11 & 35) and subsequently updated the condition status of Units 3 and 35 from Unfavourable No Change to Unfavourable Recovering4 and Unit 11 from Unfavourable No Change to Favourable4. Some of the conclusions drawn in the Appendix 11 regarding Catfield Fen are therefore revisited in this document as a result of this change. The ecological evidence is explored further in sections 8 and 9.
4 Note that threat categories of changes in species distributions and hydrological changes have been attached to these favourable condition statuses, see section 3.4.3.
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2.1 Maps and Plans
Maps showing location of abstraction licences and European site
Map showing the location of the 28 Map showing the location of the Figure 2.1 Figure 2.2 SSSIs that make up The Broads SAC abstraction points in relation to the Ant Broads and Marshes SSSI N.B. This extent equals that of the Broadland SPA and Broadland Ramsar with the exception of Trinity Broads and Damgate Marshes (SAC only components)
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Figure 2.3 Map showing the abstraction points in relation to the nine hydrological sub areas of the Ant Broads and Marshes SSSI.
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3.0 The Broads SAC, Broadland SPA and Broadland Ramsar
3.1 Sensitive Features and Hazards
Site details: The Broads SAC, Broadland SPA & Broadland Ramsar. Note: the features listed below are relevant to both abstraction licence renewal applications.
Features List
Feature including which Potential hazards Details of hazard designated site they are associated with associated with: applications to which the features are sensitive : 1.1 Fens & wet habitats (not sensitive to acidification)
Priority Feature: Alkaline Fens (SAC and Ramsar feature) Changes in flow or velocity Molinia Meadows on regime calcareous, peaty or clayey- silt-laden soils (Molinion Changes in water levels or caeruleae) (SAC) table
Alluvial forests with Alnus Changes in water chemistry glutinosa and Fraxinus excelsior (Alno-Padion, Alnion Habitat Loss incanae, Salicion albae) (SAC, Ramsar) 1.2 Bogs & wet habitats (sensitive to acidification)
Priority Feature: Calcareous Changes in flow or velocity Fens with Cladium mariscus regime and species of the Caricion davallianae (SAC, Ramsar) Changes in water levels or table Transition Mires and Quaking Bogs (SAC) Changes in water chemistry
Habitat Loss 1.4 Standing waters (sensitive to acidification)
Oligotrophic waters containing Changes in flow or velocity very few minerals of Atlantic regime sandy plains (Littorelletalia uniflorae) (SAC) Changes in water levels or table
Changes in water chemistry
Habitat Loss 1.5 Standing waters (not sensitive to acidification)
Natural eutrophic lakes with Changes in flow or velocity Magnopotamion or regime
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Hydrocharition type vegetation (SAC) Changes in water levels or table
Changes in water chemistry
Habitat Loss 2.2 Vascular plants lower plants and invertebrates of wet habitats
Desmoulins whorl snail (SAC, Changes in flow or velocity Ramsar) regime
Fen Orchid (SAC, Ramsar) Changes in water levels or Ramshorn snail (SAC) table
Changes in water chemistry
Habitat Loss 2.9 Mammals of riverine habitats
Otter (SAC, Ramsar) Changes in flow or velocity regime
Changes in water levels or table
Changes in water chemistry
Habitat Loss 3.3 Birds of lowland heaths and brecks
Hen Harrier (SPA) Habitat Loss 3.4 Birds of lowland wet grasslands
Bewicks swan (SPA, Ramsar) Changes in flow or velocity regime Hen Harrier (SPA)
Ruff (SPA) Changes in water levels or table Whooper swan (SPA)
Greylag goose (Ramsar) Changes in water chemistry
Pink-footed goose (Ramsar) Habitat Loss 3.6 Birds of lowland freshwaters
and their margins Bewicks swan (SPA, Ramsar) Changes in flow or velocity Gadwall (SPA, Ramsar) regime Greylag goose (Ramsar) Changes in water levels or Bittern (SPA) table Hen Harrier (SPA) Changes in water chemistry Marsh harrier (SPA) Habitat Loss Ruff (SPA)
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Shoveler (SPA, Ramsar)
Whooper swan (SPA)
Pink-footed goose (Ramsar)
Shoveler (SPA, Ramsar)
Wigeon (SPA, Ramsar) 3.7 Birds of farmland
Bewicks swan (SPA, Ramsar)
Marsh harrier (SPA)
Whooper swan (SPA) None Wigeon (SPA, Ramsar)
Greylag goose (Ramsar)
Pink-footed goose (Ramsar) 3.8 Birds of coastal habitats
Bewicks swan (Ramsar) Changes in flow or velocity regime Pink-footed goose (Ramsar)
Wigeon (Ramsar) Changes in water levels or table
Habitat Loss 3.9 Birds of estuarine habitats
Pink-footed goose (Ramsar) Changes in flow or velocity regime Shoveler (Ramsar)
Wigeon (Ramsar) Changes in water levels or table
Habitat Loss
3.2 Overview and Conservation Objectives
The Broads SAC and Broadland SPA and Broadland Ramsar is an archipelago site made up 5 of 28 (covering an area of 5865.6 ha ) and 26 (covering an area of 5,485.85 ha) separate SSSIs respectively, as shown in Figure 2.1. The Broads SAC features support those of the Broadland SPA and Broadland Ramsar.
A hierarchy table has been produced for the European site to indicate how the designations sit together and to clarify the spatial terms used within this document. This is provided in Annex 2.
This Appropriate Assessment has been carried out with regards to the Conservation Objectives for the European site. The assessment will focus on the Ant Broads and Marshes SSSI (shown marked in Figure 2.2) as the preceding Appendix 11 assessment (Environment Agency, 2013a) was unable to conclude no likely significant effect on this component SSSI of the European site. All other SSSIs that make up the European site are either located within different, unconnected catchments or in the case of the Upper Thurne Broads and
5 Note this figure is smaller than the accumulated extent of the 28 SSSIs. Approximately 50% of Halvergate Marsh SSSI is not designated as part of The Broads SAC.
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Marshes SSSI (marked in Figure 2.2), the abstractions have been assessed having no likely significant effect on the site either alone or in-combination with other plans, projects or permissions (Environment Agency, 2013a, agreed with Natural England on 22 August 2013).
The Conservation Objectives for the interest features of the Ant Broads and Marshes SSSI are to maintain6 in favourable condition the interest features, with particular reference to any dependent component special interest features (habitats, vegetation types, species, species assemblages, etc. as cited within the Conservation Objectives) for which the site is designated.
The Conservation Objectives used in this assessment are the latest available version (Natural England 2008, and confirmed with Natural England, 2014a) and form a consultation draft, dated 29 September 2008. Natural England is in the process of producing final versions as indicated at: http://www.naturalengland.org.uk/ourwork/conservation/designations/sac/conservationobjecti ves.aspx
These Conservation Objectives cover designated features for all nature conservation sites (SSSI / SAC / SPA / Ramsar) and are used as the best available information at the time of this assessment.
The interest features for the European site are numerous and are summarised in the Conservation Objectives (Natural England, 2008) and listed in section 3.1. Natural England have confirmed in their communication dated 13 August 2013 (Natural England, 2013i) that, of these interest features, the Fen Orchid (Liparis loeselii) and National Vegetation Classification (NVC) communities M24, S24 and S27, are the most sensitive features on the Ant Broads and Marshes SSSI. These are shown with their associated European feature below in Table 3.1 and discussed in more detail in section 4 of this document.
Assemblage Feature and associated European Constituent NVC designation Community Molinia Meadows on calcareous, peaty or Fens & wet habitats (not clayey-silt-laden soils (Molinion caeruleae) M24 sensitive to acidification) (SAC) Priority Feature: Calcareous Fens with Bogs & wet habitats Cladium mariscus and species of the Caricion S24 (sensitive to acidification) davallianae (SAC, Ramsar) Transition Mires and Quaking Bogs (SAC) S27 Vascular plants lower plants and invertebrates Fen Orchid (SAC, Ramsar) - of wet habitats
Table 3.1. Interest features and NVC communities highlighted as being the most sensitive features on the Ant Broads and Marshes SSSI.
3.3 Ant Broads and Marshes SSSI
The Ant Broads and Marshes SSSI is a component part of The Broads SAC and Broadland SPA and Broadland Ramsar. Covering an area on the east and west banks of the River Ant it extends for approximately 5.5km down river from the southern edge of Stalham to an area approximately 2km to the north of Ludham Bridge (NGR: TG 3719 1706). The range of supporting habitats includes dykes, fen, reedbeds, carr woodland and open broads. The Ant Broads and Marshes SSSI comprises nine hydrological sub areas, of which six are of
6 or restore to Favourable condition if features are judged to be Unfavourable.
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particular interest to this assessment, and are discussed further in section 3.4 and shown in Figure 2.3.
The flood-plain of the middle Ant Valley, one of the five principal river valley systems constituting the Broadland area, supports one of the most extensive remaining areas of undeveloped primary fen habitats in Britain, and is considered to form the finest example of unpolluted valley fen in Western Europe (Natural England, 1974).
Nationally important stands of carr woodland (comprising The Broads SAC feature Residual Alluvial Forests) are also present, principally in the vicinity of Barton Broad, and the wide range of wetland habitats has given rise to an associated fauna of exceptional interest.
Extensive areas of fen vegetation have developed on flat waterlogged floodplains on peat alongside the river, which shows a range of species variation, including plant communities almost wholly restricted to the Broads. These species-rich fens (associated with SAC feature Calcareous Fens) are principally dominated by Common Reed and associates, including Great Fen-sedge Cladium mariscus, Common Valerian Valeriana officianalis, and a large population of Milk Parsley Peucedanum palustre, amongst others. A community of dominant Purple Moor-grass with frequent Meadow Thistle Cirsium dissectum (SAC feature Molinia Meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae)), Heather Calluna vulagaris, Cross-leaved Heath Erica tetralix, Mat Grass Nardus stricta and Tormentil Potentilla erecta also occurs along the edge of the fens where they abut the valley slopes of the adjoining upland (Natural England,1974).
Small pools and stands of mire vegetation (comprising the SAC feature Transition Mires and Quaking Bogs) occur in shallow depressions as an intimate mosaic within the tall fen (associated with SAC feature Calcareous Fens), and are largely associated with nineteenth century peat-diggings and turf ponds. Such areas are relatively isolated from the influence of nutrient-rich river water and support a number of plant communities not found elsewhere in the Broads. The numerous permanent pools attest to the high water levels throughout the year, and support a diversity of aquatic plants including the local species: Lesser Water- plantain Baldellia ranunculoides and three species of Bladderwort Utricularia spp. These pools, together with associated wetter areas of fen support the existence of the Fen Orchid (Liparis loeselii - a SAC and Ramsar feature). The site is of national importance for its fenland invertebrate fauna, and a considerable number of rare or notable species have been recorded from several groups (Natural England, 1974).
The Review of Consents (see section 5) Site Action Plan for Ant Broads and Marshes, Alderfen Broad and Broad Fen SSSIs (Environment Agency, 2010b) states that no separate hydrological target was set for the Broadland SPA features, and that they would be adequately covered by The Broads SAC features and associated targets. This assumption will also be applied to the features of the Broadland Ramsar. Natural England have confirmed that this approach is still appropriate (meeting of 18 January 2013, notes available on our website at link).
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Figure 3.1 Ant Broads and Marshes SSSI with respect to the Broads Internal Drainage Board (IDB) Boundary
The low lying area of the Ant Broads and Marshes SSSI and that of the wider Broadland area has developed through human influence. A network of drains cross the SSSI, and the boundary of the SSSI is encompassed by that of the Broads Internal Drainage Board (IDB) as shown outlined red in Figure 3.1. There are three IDB pumping stations in the vicinity: Sutton which is inside the SSSI boundary, and Chapelfield and Irstead which are both just outside. There is also a water control structure at Howhill, shown marked yellow on Figure 3.1. The Broads IDB operates pumps on the Ant Broads and Marshes SSSI boundary although these pumps have a limited effect on the overall hydrology of the SSSI, given their relative scale and operating regime. Maintenance of drains and sluices in the area is undertaken by various conservation organisations including the RSPB, Butterfly Conservation, the Broads Authority and Norfolk Wildlife Trust. This is discussed further in section 3.4.
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3.3.1 Geological Setting
The River Ant catchment is underlain by a Chalk aquifer which outcrops to the west and dips gently to the east. To the east of a roughly north-south line through Barton Broad, the Chalk is overlain by the London Clay, which thickens as it dips towards the east. The London Clay is then overlain by the Crag which extends to the west of Barton Broad where it lies directly on the Chalk. This geological sequence, particularly within the valley areas, is overlain by a mix of sand and clay with extensive areas of peat.
To the east of Barton Broad, the London Clay restricts vertical water flows into and out of the Chalk. The combination of depth to the Chalk and the variable water quality has meant that the Crag has become the main aquifer for water supply.
3.4 Overview of the Hydrological Sub Areas of the Ant Broads and Marshes SSSI
As part of the Ant Broads and Marshes SSSI Review of Consents assessment, the SSSI was divided into nine hydrological sub areas, as shown in Figure 2.3. Due to the location of the abstraction points, this assessment will focus on the six hydrological sub areas listed below only:
1. Sutton Broad 2. Sutton Fen 3. Barton Broad 4. Catfield Fen 5. Sharp Street 6. Crome’s Broad
The remaining three hydrological sub areas (Barton Fen, Hall Fen and Reedham Marshes & Water) are located on the western side of the River Ant. These areas are remote from the abstractions within the Ludham-Catfield area. The impacts of abstraction will be mitigated by the natural hydraulic recharge boundary represented by Barton Broad and the River Ant. From a conceptual point of view, the alone and in-combination effects of abstraction of the Ludham Road and Plumsgate Road abstractions are unlikely to propagate beyond this recharge boundary. The findings of the Groundwater Summary Report also suggest that the modelled impacts of abstraction to the west of Barton Broad can be screened out; the three areas of Barton Fen, Hall Fen and Reedham Marshes & Water are therefore not considered further in this Appendix 12 in relation to the effect from the two abstractions.
The 742.64ha expanse of the Ant Broads and Marshes SSSI is divided into 35 SSSI units as shown in the site hierarchy table in Annex 2. These are divisions of a SSSI which Natural England uses to record management and condition details. Units are the smallest areas for which a condition assessment is given. The size of the units varies depending on the types of management and the conservation drivers. Each of the nine hydrological sub areas compromise varying numbers of SSSI units, these are shown in the tables of the following sections.
The condition of each SSSI unit in England is assessed by Natural England using categories agreed across England, Scotland, Wales, and Northern Ireland through the Joint Nature Conservation Committee (JNCC). There are six reportable condition categories: Favourable, Unfavourable Recovering, Unfavourable No Change, Unfavourable Declining, Part Destroyed and Destroyed. The process by which these assessments are carried out is called Common Standards Monitoring (CSM). Figure 3.2 below shows how this system works in practice (JNCC, 2006). It should be noted that while a status of Favourable provides a good overview of the SSSI unit, this is based on specific features and not a range of ecological
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attributes. This status ensures a base minimum standard is maintained for a feature, rather than protecting the highest quality and/or best possible condition. It is however a good starting point for assessing the quality and status of particular habitat and species features present on site (Broads Authority, 2013a).
Figure 3.2 Overview of the Common Standards Monitoring system. Taken from JNCC (2006)
The current condition of the various SSSI units which are located in each of the six hydrological sub areas is included in the sections below. The Broads SAC has been highlighted here rather than the Broadland SPA and Broadland Ramsar, as this assessment focuses on the SAC features and their associated targets which will ensure that the SPA and Ramsar targets are met (see section 3.3).
3.4.1 Sutton Broad
The Sutton Broad sub area is in a side arm valley of the Ant Broads and Marshes SSSI and comprises large areas of fen, swamp and open water (the open water is named Sutton Broad). The site covers the area of a former, larger broad which was created by the flooding of medieval peat-diggings. It has been almost completely re-vegetated with the exception of a central navigable channel to the River Ant. The open water of Sutton Broad flows through the hydrological sub areas of Sutton Fen and Sutton Broad, converging with Stalham Dike at National Grid Reference (NGR) TG 36608 23618 and subsequently flowing into the River Ant a further 0.4km downstream. The Sutton Broad area is fed primarily by precipitation and river water, by flow either over or under the vegetation mat (Entec, 2006).
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Figure 3.3 Map showing the Sutton Broad and Sutton Fen sub areas.
This hydrological area is included within an area which is owned and managed by the Royal Society for the Protection of Birds (RSPB) as the Sutton Fen Reserve. The RSPB have a management plan in place for the reserve (RSPB, 2013a). The area this plan covers is shown in green in Figure 3.3 above.
The open water of Sutton Broad is fed by the River Ant with additional input from the surrounding upland, both through surface water and potentially through underground seepage and springs on the periphery of the floodplain area. Flooding of the area occurs episodically.
There are two known water control structures in the Sutton Broad area, shown marked yellow in Figure 3.3: 1. Boat House Sluice (NGR TG 3701 2356): A one-way sluice which controls the movement of water between the open water of Sutton Broad and the main fen dyke system.
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2. Broad Pipe Sluice (NGR TG 3729 2344): Controls movement of water between the northern grass dykes and the fen on the south edge of the Sutton Broad sub area.
Broad Pipe Sluice was installed with other sluices by the RSPB to allow fen water to be separated from upland water during drought periods – this allows for improved control and buffering of nutrient rich arable water inputs. Water quality in the area is influenced by surface flow from Sutton and Stalham villages, the road network, arable drainage and discharges from Stalham sewage works.
The hydrology of the Sutton Broad area is also influenced by the Broads IDB pump at NGR TG 38014 23271, shown in Figure 3.1 (labelled Sutton Pump). The pump is located on the eastern edge of the Sutton Broad area, just outside of the RSPB reserve boundary. The IDB pump has a rated capacity of 350 litres per second, and according to the District Engineer, is “probably 75-80% efficient” (Broads IDB, 2013a). Electricity useage and the telemetry for 2011-2012 show the pump operated for 31 hours per month on average. Figure 3.4 shows the quantity of water pumped per month by this pump which is used to move water west into Sutton Broad from the drains south east of Stalham, operating predominantly at night. Although the pump is not explicitly included in the model, a useful comparison can be made between the estimated pumped volumes and the simulated surface flow at the pump location.
600
500
400
300
200
100 Volume of water pumped (tcma)
0
Date
Figure 3.4 Total monthly volumes pumped by the Sutton IDB Pump between 2011 and 2012. Note, the data set from mid 2007 – late 2009 is incomplete.
The information we have regarding the ecology of this area is based on RSPB data and is described further in the Sutton Fen section 3.4.2 and section 8. Natural England have confirmed 8 of the 11 qualifying features for which The Broads SAC is designated are found at Sutton Broad, see Annex 3.
Table 3.2 provides an overview of the condition status’ for the SSSI units comprising the Sutton Broad hydrological sub area.
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SSSI Area Date last Main habitat Condition Comments unit (ha) assessed Recovering well following Fen, marsh and Unfavourable 04 February 10 123 scrub removal, restoration swamp - lowland Recovering 2010 7 of the unit continues Fen, marsh and Unfavourable 21 January 30 3.1 - swamp - lowland Declining 2010
Table 3.2. Summary of the condition of Sutton Broad hydrological area (Natural England, 2014c)
The favourable condition status of SSSI Unit 30 has been assessed as Unfavourable Declining (21 January 2010). Natural England have confirmed (Natural England, 2013b) that Unit 30 is Unfavourable Declining due to an ochre issue which may be influenced by the operation of the Sutton IDB Pump. The IDB have drawn up a Water Level Management Plan to address this, and this is expected to be actioned in the near future. This was confirmed in correspondence with the District Engineer for the Broads IDB who noted that the plan may include relocating the Sutton Pump (Broads IDB, 2013b). The cause for the condition status of Unit 30 has no overlap with groundwater abstraction; there is no effect alone or in- combination (whether additive, cumulative or synergistic) with the ochre issue and therefore we do not consider the condition status of Unit 30 any further in this Appropriate Assessment.
3.4.2 Sutton Fen
Sutton Fen (see Figure 3.3 for map) is fed primarily by precipitation and river water, by flow either over or under the vegetation mat (Entec, 2006). As with Sutton Broad, there is input from the surrounding upland, both through surface water and potentially through underground seepage and springs on the periphery of the floodplain area. Flooding of the area occurs episodically.
Sutton Fen is partially isolated from the river by a peat bank stretching along the western boundary on the edge of the River Ant (NGR TG 3624 2274 to TG 3702 2357). This bank is overtopped when the water level (as measured at the gauge board at NGR TG 3686 2342) reaches approximately 0.9m above Ordnance Datum (AOD). Below this level the only connection to the river is via the Boat House sluice (except for leakage issues).
The fen also receives input through surface flow and arable drainage dykes, which are known to be a source of poor quality water. Water is also lost over and through an old bank (and piling) along the boundary at NGR TG 3726 2254 to TG 3734 2263. This is considered significant in limiting the potential water level in the spring and also allowing input of nutrient laden arable water (Amec, 2012).
There are four water control structures in the Sutton Fen area, shown in yellow in Figure 3.3:
1. Pump House North Pipe Sluice (NGR TG 3702 2311): Controls movement of water between ‘the triangle’ and ‘the island’ and the main fen dyke system. 2. Pump House South Sluice (NGR TG 3704 2304): Controls the movement of water between the southern grass dykes and ‘the triangle’ and ‘the island’.
7 The ‘Comments’ field has been taken from the Natural England condition table webpage, accessed 18 March 2014. The RSPB Sutton Fen Reserve covers SSSI Units 8, 10 and 24 and the associated management plan has further comments on the condition of these three Units (section 3.4.2 of this report for further comments on Units 8 and 24). For Unit 10 which extends over both hydrological areas of Sutton Broad and Sutton Fen, Natural England and the RSPB have agreed a five year remediation plan (2011-2016) which will see the removal of a total of 7.7Ha of scrub. This action is expected to return the Unit to Favourable condition once the fen has recovered.
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3. Jetty Pipe Sluice (NGR TG 3733 2264): Controls movement of water between the Yates’ Marsh and the southern grass dykes. 4. Drakes Sluice (NGR TG 3640 2209): Controls movement of water between the southern edge of the Sutton Fen sub area and a dyke leading to Barton Broad.
Pump House North, South and Jetty Pipe sluices were installed by the RSPB as part of their management of the Sutton Fen Reserve (the boundary of which overlaps this hydrological sub area) to allow fen water to be separated from upland water during drought periods. This allows for improved control and buffering of nutrient rich arable water inputs. As with Sutton Broad the water quality in the Sutton Fen is influenced by surface flow from Sutton and Stalham village, the road network, arable drainage and discharges from Stalham sewage works.
Table 3.3 below provides a summary of the SSSI units that make up the Sutton Fen hydrological sub area.
SSSI Area Date last 8 Main habitat Condition Comments unit (ha) assessed Fen, marsh and Unfavourable 04 February Recovering well following 8 36 swamp - lowland Recovering 2010 extensive scrub removal Recovering well following Fen, marsh and Unfavourable 04 February 10 123 scrub removal, restoration swamp - lowland Recovering 2010 of the unit continues Fen, marsh and Unfavourable 04 February Recovering well following 23 12.05 swamp - lowland Recovering 2010 extensive scrub removal. Recovering well following Fen, marsh and Unfavourable 04 February 24 24.05 scrub removal, restoration swamp - lowland Recovering 2010 of the unit continues.
Table 3.3. Summary of the condition of Sutton Fen hydrological area (Natural England, 2014c).
Natural England have confirmed that 8 of the 11 qualifying features for which The Broads SAC is designated are found at Sutton Fen, see Annex 3. The fen to the south of the Sutton Broad open water and Stalham Dike is considered amongst the most important areas for rare fen plants in the UK. This is demonstrated in the 2007 Ecology Land & People - Fen Plant Communities of Broadland survey, with quadrats consistently within the top few percentiles of all those in the Broads in terms of number of species and rarity weighting (RSPB, 2013a; ELP, 2010).
Vegetation becomes taller and less species rich towards the open water. This transition is reported by the RSPB through vegetation surveys (RSPB, 2012) and is thought to be caused by increasing nutrient levels nearer the Broad: “The river water quality is generally poorer (higher in Phosphate, Nitrate and conductivity) and more alkaline than the spring / surface water inputs and this is demonstrated by a vegetation gradient showing species rich, fen meadow communities near the upland edge, grading through species rich fen to tall herb fen and reed swamp toward the Broad channel.” (RSPB, 2012).
8 The ‘Comments’ field has been taken from the Natural England condition table webpage, accessed 18 March 2014. The RSPB Sutton Fen Reserve covers SSSI Units 8, 10 and 24 and the RSPB have further comments on the condition of these three Units. • For Unit 10, which extends over both hydrological areas of Sutton Broad and Sutton Fen, Natural England and the RSPB have agreed a five year remediation plan (2011-2016) which will see the removal of a total of 7.7Ha of scrub across Unit 10. This action will return the Unit to Favourable condition once the fen has recovered. • Units 8 and 24 actions also refer to scrub removal. Over the past 15 years scrub removal has reduced scrub cover to an acceptable level. The condition status’ of Units 8 and 24 are expected to return to favourable once the fen has recovered.
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In light of the work carried out for Catfield Fen, Natural England were asked in early 2013 to confirm the status of Sutton Fen in relation to any new information. They confirmed that they do not not have any evidence nor are they aware of any evidence to suggest that the site is drying out (Natural England, 2013h). Natural England’s ecological advice for this area developed through further work carried out in 2013 (see section 5). They have noted there is no clear evidence for ecological change in this area. This work is summarised in their Ecological Report 7 (Natural England, 2013g).
The RSPB have submitted comments to us regarding local groundwater abstraction (RSPB, 2013b). Their position on the site is one of serious concern about any potential impact of water abstraction, but that they clearly acknowledge that there is a lack of understanding of actual impact and will be increasing their own monitoring on site over the coming years to help build a better picture.The RSPB raised concerns with the Broads Authority and Natural England in 2009 regarding the potential impact on Sutton Fen from groundwater abstraction. Further comments were provided to us on 16 December 2013 (RSPB, 2013b), in which the RSPB perceived the greatest threat to be any impact of abstraction on the water quantity and quality entering the fen around Sutton Broad. They note that the vegetation here depends upon exceptional water quality and on a transition from spring / upland water and poorer quality river water. The Broads Authority have also expressed concerns after interpreting the most recent ecological information (Broads Authority, 2013). The observations and concerns reported to us have been considered in our assessment (also see section 3.5).
Natural England have confirmed that the most sensitive feature on Sutton Fen is the Fen Orchid, located in the northern part of the site (Natural England, 2013h). In addition, the RSPB Management Plan (RSPB, 2012) records significant numbers of Fen Orchids.
3.4.3 Barton Broad (including Catfield Fen external system)
Barton Broad hydrological area is the largest of the nine areas comprising the Ant Broads and Marshes SSSI, approximately 245 hectares in size, and covers the central area of the SSSI including the open water of Barton Broad. The Broad was created by medieval peat diggings which have subsequently flooded. The main channel of the River Ant flows directly through Barton Broad and influences the hydrological regime. The River Ant is only weakly tidal upstream of Ludham Bridge (NGR: TG 3719 1706), so the water levels in Barton Broad may rise and fall under normal tidal conditions, however saline water coming up-river from the sea only rarely reaches this area. Freshwater flooding, as a result of heavy rain in the area, also occurs from time to time. In addition, the Broad also receives runoff from the west (Norfolk Wildlife Trust, 2005).
Norfolk Wildlife Trust (NWT) manage a 153ha area of the Ant Broads and Marshes National Nature Reserve (NNR), including 65% of the Barton Broad hydrological area as shown in Figure 3.5. NWT have a comprehensive management plan for the site which includes the following management objectives:
• To reach and maintain favourable condition status for the internationally important site features; and • To protect and enhance populations of species for which the site is nationally and internationally important.
Barton Broad is separated from Catfield ‘Internal’ Fen (see section 3.4.4) by a peat bank known as the Commissioner’s Rond (shown marked on Figure 3.6). Catfield Fen external system (also known as Great Fen) to the west of the Commissioner’s Rond also receives some surface water input from Catfield ‘Internal’ Fen through a sluice in the Rond
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(particularly when opening of the sluice is permitted (see section 10.0 for surface water management) but also from leakage and overflow through the Rond).
Figure 3.5 Map showing the Barton Broad hydrological area. The area covered by the Norfolk Wildlife Trust management plan is shown labelled NWT.
The NWT Management Plan (2005) for this area approximates that 20% of the total area under NWT management is open fen vegetation and approximately 50% is made up of the expanse of open water, with the remainder categorised as scrub and carr woodland. Together with adjacent sites in the Ant Valley, Barton Broad represents one of the largest areas of open fen vegetation in Broadland, being the second largest in the region.
Barton Broad has been the subject of a programme of restoration, including a reduction of nutrient input from effluent discharge and restoration of the lake bed through a programme of dredging. Mud-pumping to remove accumulated phosphate and nitrate enriched sediment from the basin of Barton Broad commenced in 1995 (Norfolk Wildlife Trust, 2005). The Broads Authority Barton Broad Water Space Management Plan states that there has been a continued improvement in water quality since dredging commenced (Broads Authority, 2006). This corroborates information in the NWT plan which notes that the water quality is quite high by comparison with many other of the broads in this region.
The majority of interest features for which The Broads SAC, Broadland SPA and Broadland Ramsar are designated are recorded in the NWT management plan as present in the Barton Broad area. Natural England confirmed the presence of 8 of the 11 interest features, see Annex 3. The plan asserts that the diversity of NVC communities is very high at Barton Broad in comparison to other fen habitats within the European site, and attributes this in part to the large area of open fen, presence of pH gradients, and mosaic effects produced by historic management activities.
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This site also supports a diverse array of aquatic and terrestrial invertebrate species, a reflection of comprehensive recording as well as a reflection of habitat quality. A variety of management actions are detailed in the plan, with scrub invasion being noted as a particular issue. Without management, many of the open tall herb fen communities at this site are extremely prone to scrub invasion, and will quickly succeed to carr woodland, with the consequent loss of many important species (Norfolk Wildlife Trust, 2005).
There are 14 SSSI units wholly or partly within Barton Broad, these are listed in Table 3.4 below.
SSSI Area Date last Main habitat Condition Comments unit (ha) assessed Fen, marsh and 28 January 2 30.58 Favourable - swamp - lowland 2010 Fen, marsh and 28 January 6 16.65 Favourable - swamp - lowland 2010 Fen, marsh and Unfavourable 04 February Recovering well following 8 36 swamp - lowland Recovering 2010 extensive scrub removal Fen, marsh and 28 January 12 7.4 Favourable - swamp - lowland 2010 Fen, marsh and 01 February 13 2.63 Favourable - swamp - lowland 2010 Fen, marsh and 29 January 16 7.94 Favourable - swamp - lowland 2010 Fen, marsh and Unfavourable 28 January Recovering well following 18 8.41 swamp - lowland Recovering 2010 restoration Fen, marsh and 21 January 20 1.99 Favourable - swamp - lowland 2010 Fen, marsh and Unfavourable 21 January 21 5.73 - swamp - lowland Recovering 2010 Fen, marsh and Unfavourable 28 January 25 16.95 - swamp - lowland Recovering 2010 Fen, marsh and Unfavourable 01 February Recovering well following 26 68.15 swamp - lowland Recovering 2010 scrub removal Fen, marsh and 28 January 27 16.43 Favourable - swamp - lowland 2010 Largely non-intervention Fen, marsh and 01 February 32 0.11 Favourable wet woodland, with some swamp - lowland 2010 small open areas of fen Steadily increasing abundance and richness of aquatic macrophytes in recent years, although reduction in 2009 Standing open Unfavourable 12 November 33 71.26 suggests non stable state; water and canals Recovering 2010 Diffuse Water Pollution plan in place November 2010, therefore all remedies underway for this unit.
Table 3.4. Summary of the condition of Barton Broad hydrological area (Natural England, 2014c).
The Diffuse Water Pollution Plan (DWPP) for the Ant Broads and Marshes SSSI (Natural England & Environment Agency, 2010) identifies Barton Broad, specifically Unit 33, as being one of two hydrological sub areas under pressure from agricultural runoff. Remedies defined in the DWPP are in place and the favourable condition status is listed as Unfavourable Recovering, in part due to these remedies. This is considered in section 10.1.
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3.4.4 Catfield Fen (Internal system)
Catfield Fen is located on the eastern side of the SSSI, between Barton Broad and the village of Catfield. The fen is separated into two distinct parts by a large peat bank known as the Commissioner’s Rond; termed the external system (or Great Fen) and the internal system. The external system is directly connected to Barton Broad and the River Ant by an extensive dyke network and is discussed in section 3.4.3.
Within the Rond, there are two structures through which water can move between the external and internal systems, one in the north of the fen and one to the south as shown in Figure 3.6. There is potential for water transfer through a bund at the southern end of Catfield Fen. It is also unknown to what extent water can seep through the Rond itself.
The internal system is fed primarily by precipitation and drainage inputs from the upland area. There is potential for groundwater inputs either by upwelling or by through-flow being intercepted by drainage dykes (Entec, 2006). Catfield Fen includes areas of both open fen and areas of taller scrub, interspersed with shallow turf ponds which are in the main now subject to re-vegetation (Amec, 2012).
The internal system compromises SSSI Units 3, 11 and 35 as shown in Figure 3.6. Unit 3 is owned by Butterfly Conservation and managed in partnership with the RSPB on a ten year management agreement, while Units 11 and 35 are privately owned.
A comprehensive management plan exists for Unit 3, which is also part of the Ant Broads and Marshes National Nature Reserve (NNR). The latest version of the management plan, applies for the period between April 2013 – March 2018 (RSPB, no date). There is no known management plan for Units 11 and 35, both of which are privately owned, however a higher level stewardship9 (HLS) agreement exists between the landowner and Natural England.
9 An HLS agreement is set up to encourage effective environmental management. The main objectives include: • conserving wildlife and maintaining biodiversity • maintaining and enhancing landscape quality and character • protecting the historic environment and natural resources • promoting public access and understanding of the countryside • protecting natural resources The secondary objectives of Environmental Stewardship (ES) are genetic conservation - including traditional breeds of cattle and varieties of fruit trees - and flood management. ES also has a general aim of helping the natural environment to adapt to climate change. See Section 10 for further details.
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Figure 3.6 Map showing the Catfield Fen (Internal system) hydrological sub area.
Historic management of Unit 3 is described in the NNR management plan. Until relatively recently the site was managed largely to produce commercial products such as peat for burning, marsh hay and marsh litter, thatching sedge and thatching reed. During the 20th century, these practices declined throughout the Broads including at Catfield Fen (RSPB, no date). Commercial reed and sedge cutting continued on a limited scale until 2010, when it ceased due to a reported decline in the quality of the reed and sedge. Site management at Catfield Fen is discussed in more detail in section 10.
Butterfly Conservation are in active management in Unit 3 to maintain the fen communities, control the development of scrub and woodland, and enable commercial harvesting of reed and sedge under contract (Butterfly Conservation, 2012). The NNR management plan recognises scrub control in Unit 3 as an important management action towards achieving favourable condition status. Butterfly Conservation and the RSPB have provided information on the water levels, water chemistry and vegetation characteristics of Unit 3. This is discussed further in section 8 of this document.
In July 2013 Natural England (2013d) provided new evidence which refines information presented in Natural England et al (2011). Catfield Fen was re-surveyed and subsequently the condition status of Units 3, 11 and 35 were updated along with the addition of threat
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categories10 (species distributions and hydrological changes) – see Table 3.5 below. The threat categories reflect the changes in species distribution across the fen. In addition it was noted that Unit 11 and part of Unit 3 were showing evidence of increased frequency and abundance of Sphagnum spp.
SSSI Area Date last Main habitat Condition Comments unit (ha) assessed Assessment consistent with previous visits, using the data gathered in the Broads' Fen Survey to identify survey locations. Previous assessments marked as unfavourable due to remedies. Currently recovering due to the recent and 16 Fen, marsh and Unfavourable proposed work on scrub 3 25.25 September swamp - lowland Recovering clearance. Increase in 2013 Sphagnum (and associates) have been identified, and are consistent with independent work carried out in 2013 by RSPB. This observed change is now registered as threats, and work is ongoing to identify the causal factors. Assessment consistent with that carried out in 2009, in focusing on the key sensitive features. Assessments in 2009, 2011 (non CSM) and 2013 all show the notified features to be currently favourable and meeting all key attributes. 2009 and 2011 assessments marked as unfavourable 16 Fen, marsh and due to remedies. Increase 11 35.84 Favourable September swamp - lowland in Sphagnum (and 2013 associates) in Middle Marsh (in particular) have been identified, and are consistent with independent work carried out in 2013 (Wheeler, 2013; Parmenter, 2013). This observed change is now registered as threats, and work is ongoing to identify the causal factors.
10 Factors identified that have a reasonable chance of preventing the attainment, or maintenance of, favourable condition. Once identified, actions are implemented to address these factors either by Natural England or in agreement with other relevant organisations.
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Linked to units 3 and 11, where any actions taken to address current concerns will also impact 13 unit 35. Unit 35 included Standing open Unfavourable 35 1.25 September due to its hydrological water and canals Recovering 2013 connectivity with units 3 and 11. Still marked as recovering, due to the ongoing recovery since mud pumping.
Table 3.5 Summary of the condition of the SSSI units comprising the Catfield Fen hydrological sub area.
Natural England have confirmed 9 of the 11 qualifying features for which The Broads SAC is designated are found at Catfield Fen, see Annex 3.
3.4.5 Sharp Street
The Sharp Street hydrological sub area is situated on the eastern side of the River Ant, north of How Hill, shown in Figure 3.7. It is the smallest of the nine hydrological sub areas of the SSSI and lies between Barton Broad and Crome’s Broad. The area is semi-isolated from the river but is flooded when river levels rise due to the poor condition of the river banks. In semi isolated parts of the system the water balance is dominated by surface water flows during periods of winter flooding. However in areas where water levels are controlled by sluices in the summer, water balances and levels will be controlled by the local balance between rainfall and evaporation, groundwater inputs and subsurface inflow from drains. The extent of surface drain influence on water levels of the surrounding marshes is dependent on horizontal permeability through the upper stratigraphic layers (Entec, 2006). It is likely that Sharp Street receives groundwater where the eastern boundary meets the upland. Natural England have advised that the semi isolation of Sharp Street from the influence of river water makes it potentially sensitive to changes in groundwater input (Natural England, 2013g).
A management agreement exists between Natural England and the landowner of Sharp Street. The agreement specifies that scrub will be cleared from the area by cutting and treating stumps with appropriate herbicide. Open areas will be maintained through light grazing where possible, or mowing on a variety of rotations to encourage tall herb fen species. Cut material should be removed and dykes should be maintained by clearing accumulated vegetation and silt on a rotational basis (Entec, 2001).
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Figure 3.7 Map showing the Sharp Street hydrological sub area.
Table 3.6 below summaries the condition of the units making up the Sharp Street hydrological sub area (Natural England, 2014c);
SSSI Area Date last Main habitat Condition Comments unit (ha) assessed 4 Fen, marsh and 18.29 Favourable 29 January - swamp - lowland 2010 6 Fen, marsh and 16.65 Favourable 28 January - swamp - lowland 2010
Table 3.6 Summary of the condition of Sharp Street hydrological sub area (Natural England, 2014c).
Natural England have confirmed 7 of the 11 qualifying features for which The Broads SAC is designated are found at Sharp Street, see Annex 3.
3.4.6 Crome’s Broad
Crome’s Broad lies in a small side-valley of the Ant Broads and Marshes SSSI, and is more isolated from the river than the other hydrological sub areas (Natural England, 1974). The area spans from the eastern bank of the River Ant, north-east to Grove Farm as shown in Figure 3.8.
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Approximately 89% of the Crome’s Broad hydrological area falls within the Howhill National Nature Reserve (NNR) which is managed by The Broads Authority. The NNR covers 130ha and extends to both sides of the River Ant covering the Reedham and Crome’s Broad hydrological sub areas. The Broads Authority has a management plan for the Howhill NNR (Broads Authority, 2011).
This hydrological sub area is fed by precipitation and drainage inputs at Summer House Wood to the east of Crome’s Broad. Water flows through the Broad and passes into the dykes of Clayrack Marshes (Broads Authority, 2011). In addition, water can enter the system from the river either by overtopping the embankment or by movement through three sluice structures marked in yellow in Figure 3.8 (Entec, 2006). These control structures aim to maintain the dykes at marsh level between January and April, and no more than 45cm below marsh level between June and October (Broads Authority, 2011).
• WCS 1 (NGR: TG 37235 19488) maintains high water levels in the adjacent water gardens. • WCS 3 (NGR: TG 37223 19711) maintains high water levels on the whole area during the summer as without this structure, dyke levels would be undesirably low. • WCS 4 (NGR: TG 37010 19141) which was installed to isolate Crome’s Broad from the river.
The open water of Crome’s Broad, which was created by the flooding of peat excavation has become in-filled with mud and silt and recently been subject to a restoration project involving mud-pumping. The southern section has seen significant improvements in nutrient status, clarity, aquatic macrophytes and its fish community. This positive response, particularly by macrophytes, prompted further mud pumping of the deeper northern section of the Broad; however signs of successful recovery were limited (Broads Authority, 2011).
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Figure 3.8 Map showing the Crome’s Broad hydrological sub area.
Vegetation mapped in the Howhill NNR management plan indicates Crome’s Broad hydrological sub area is (excluding the open water) dominated by Alluvial Forest, and the Ant Broads and Marshes SSSI Citation notes that Crome’s Broad supports a less impoverished aquatic flora than other areas of the SSSI (Natural England, 1974). The Broads Authority (Broads Authority, 2012) reports that the open water of the broad is dominated by almost 100% cover of hornwort, with some stonewort beds and areas of white water lily. It also has the occasional water solider plant.
Natural England has confirmed that 5 of the 11 qualifying features for which The Broads SAC is designated are found at Crome’s Broad, see Annex 3.
Crome’s Broad consists of 3 SSSI units (4, 5 and 36), as shown in Table 3.7 below (Natural England, 2014c).
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SSSI Area Date last Main habitat Condition Comments unit (ha) assessed 4 Fen, marsh and 18.29 Favourable 29 January - swamp - lowland 2010 5 Fen, marsh and 121.82 Favourable 04 February - swamp - lowland 2010 36 Standing open 4.22 Unfavourable 12 Nov 2010 Crome's Broad continues water and canals Recovering to benefit from the mud pumping that has been carried out; the macrophyte diversity appears to be stable, particularly in the south basin; Diffuse Water Pollution plan now in place so all remedies underway for this unit.
Table 3.7 Summary of the condition of Crome’s Broad hydrological area (Natural England, 2014c).
The DWPP for the Ant Broads and Marshes SSSI (Natural England & Environment Agency, 2010) identifies Crome’s Broad, specifically SSSI Unit 36, as being one of two areas under pressure from agricultural runoff. Remedies defined in the DWPP are in place and the favourable condition status is listed as Unfavourable Recovering, in part due to these remedies. This is considered in section 10.1.
As with other management plans in the Ant Broads and Marshes SSSI, the Broads Authority acknowledge the importance of scrub removal as a management tool. They also raise concerns regarding local groundwater abstraction when discussing catchment issues, noting its vulnerability to changes in water quantity and quality. Water abstraction from the numerous agricultural boreholes that surround the site is also cause for concern (Broads Authority, 2011).
3.5 Assessment Focus
We have assessed the Plumsgate Road and Ludham Road applications to renew groundwater abstraction licences as new permissions.
Our preceding assessment of likely significant effect concluded likely significant effect on the Ant Broads and Marshes SSSI component of The Broads SAC, Broadland SPA and Broadland Ramsar. There is no likely significant effect from these abstractions on the other component SSSIs of The Broads SAC, Broadland SPA and Broadland Ramsar.
The Ant Broads and Marshes SSSI compromises 35 SSSI units. Two of these 35 units are currently listed as Unfavourable No Change or Unfavourable Declining (30, 31). The reasons we do not consider Unit 30 further are given in section 3.4.1 – Sutton Broad. Unit 31 which is within the Barton Fen hydrological area, is located on the west of the River Ant and will not be impacted by these applications as the River Ant forms a natural hydraulic recharge boundary across which the impact from the abstraction will not propagate, section 3.4.
During the Review of Consents process we applied a methodology (agreed with Natural England (Natural England, 2009)) when screening the potential effect from abstractions, whereby we considered that for SSSI units assessed as Favourable or Unfavourable Recovering that the effect of historical abstraction levels was acceptable (note: the condition
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status of the other units (excepting 30 and 31) are listed as either Favourable or Unfavourable Recovering). However, this screening methodology will not be applied here in the assessment of Catfield Fen, Sutton Broad, Sutton Fen and Sharp Street. The ecological information we have been presented with at Catfield Fen, Sutton Broad and Sutton Fen is new and furthers our understanding following RoC, our assessment has therefore been adapted accordingly and work has been undertaken to establish whether historical abstraction is acceptable.
This Appropriate Assessment focuses on four of the hydrological sub areas of Ant Broads and Marshes SSSI (Catfield Fen, Sutton Broad, Sutton Fen and Sharp Street) for the reasons stated in Table 3.8 below. We have been advised by Natural England these areas are particularly sensitive to changes in groundwater as they border the highland and may receive lateral groundwater input from the east. In the case of Catfield Fen and Sutton Fen, ecological change has reportedly also been observed.
Hydrological sub Further area of the Ant assessment Reason for decision Broads and required Marshes SSSI These hydrological sub areas require further assessment both due to their proximity of the abstraction points and Sutton Broad recent ecological information. Concerns about the potential Yes impact from groundwater abstraction have been raised for these hydrological sub areas. Note that Unit 30 of Sutton Broad will not be discussed further as the ochre issue is Sutton Fen being resolved with the IDB. There are no reported concerns with water levels in this area, there are no concerns with water abstraction and the area has not been flagged as sensitive to changes in Barton Broad No groundwater input; water levels are influenced primarily by the River Ant. Groundwater abstraction is not considered to be having an impact and so there will be no further assessment undertaken for this area. This area requires further assessment due to the proximity of the abstraction points and recent ecological information. Catfield Fen Yes Concerns have been expressed by interested parties about the potential impact from groundwater abstraction on this hydrological sub area. We have not received any concerns over the quality of the ecology of Sharp Street or the potential impact from groundwater abstraction. However, due to the proximity of Sharp Street Yes the abstraction points to the fen and it potential sensitivity to groundwater abstraction, we will be investigating the potential impact from abstraction on this area Natural England have confirmed that they are not aware of any changes in the ecology or hydrology on Crome’s Broad. Crome’s Broad No On this basis, this sub area will not be assessed in any further detail.
Table 3.8 Explanation of which hydrological sub areas of the Ant Broads and Marshes SSSI
The wider ‘Area of Interest’ on which the technical assessment is based includes the screening area for our preceding assessment of likely significant effect. This area is described in section 3 and shown in the Groundwater Summary Report (Environment Agency, 2014a), Figure 1.1.
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4.0 Ecology and Sensitivity
As mentioned in section 3.3, during the Review of Consents no hydrological target was set for the features of the Broadland SPA or those of the Broadland Ramsar. Due to their higher sensitivity, it was reasoned that if the features of The Broads SAC were protected, those of the Broadland SPA and Broadland Ramsar would also be protected.
Natural England have confirmed that this approach is still appropriate (meeting of 18 January 2013, notes available on our website at link). We will therefore apply the same conclusions to the Broadland SPA and Broadland Ramsar as we reach for The Broads SAC.
Annex 3 provides an overview of The Broads SAC features and the hydrological sub areas of the Ant Broads and Marshes SSSI in which they are present. While most of the interest features are fairly common across all 28 SSSIs which make up The Broads SAC, certain interest features are considered to be ‘rare’, based on their limited frequency and distribution.
Natural England (2013i) confirmed the most sensitive features of The Broads SAC which are present on the Ant Broads and Marshes SSSI are the Fen Orchid (Liparis loeselii) and National Vegetation Communities (NVC) S24, M24 and S27, as shown in Table 4.1 below. Of these, the Fen Orchid (Liparis loeselii) was confirmed as the most sensitive; discussed in further detail in section 4.4.
Ecological Interest Feature Associated SAC Feature community
- Liparis loeselii (Fen Orchid) S1903 Fen Orchid Liparis loeselii 11
H7210 Calcareous Fens with Phragmites australis Peucedanum palustre S24 Cladium mariscus and species of (Tall Herb Fen) 11 the Caricion davallianae H6410 Molinia Meadows on Molinia caerulea – Cirsium dissectum (Fen M24 calcareous, peaty or clayey-silt- Meadow laden soils (Molinion caeruleae) Carex rostrata – Potentilla palustris (Tall Herb H7410 Transition Mire and Quaking S27 Fen) Bogs
Table 4.1 The most sensitive features present on the Ant Broads and Marshes SSSI.
In order to produce the most precautionary assessment, we have identified the most sensitive features (as confirmed by Natural England, 2013i) in the most sensitive component hydrological sub areas. Table 4.2 below shows this.
11 Also a feature of the Broadland Ramsar
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Hydrological sub Interest Feature Groundwater area model cell Catfield Fen Calcareous Fen (S24) G
Catfield Fen Transition Mire (S27) H
Catfield Fen Fen Orchid I Sutton Broad (and 12 Molinia Meadows (M24) E Sutton Fen) Sharp Street Calcareous Fen (S24) C
Sharp Street Calcareous Fen (S24) J
Table 4.2 Approximate locations and interest features confirmed by Natural England as being most sensitive on the Ant Broads and Marshes SSSI.
The location of the above features, by reference to the associated groundwater model cells, is shown in Figure 4.1. The groundwater model is discussed in more detail in section 7. Note: Cell J is primarily a water chemistry Assessment Cell.
To establish the hydrological needs of the ecological features and communities, identified in Table 4.1, we refer to a key source document which sets out the range of hydrological conditions supporting different ecological communities: the Ecohydrological Guidelines. These guidelines have recently been updated and re-published (Environment Agency, 2010d). These are discussed in the following sections.
12 Note: Cell E represents the largest impacts across Sutton Broad and Sutton Fen due to its proximity to the Plumsgate Road abstraction. The output results for this cell represent the maximum impact at Sutton Broad and Sutton Fen
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Figure 4.1 Location of NEAC groundwater model Assessment Cells
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4.1 H7210 SAC and Ramsar Feature: Calcareous Fens with Cladium mariscus and species of the Caricion davallianae (European Priority Feature13)
Calcareous Fens are rare in the UK, having a restricted and discontinuous geographical range with two main centres of distribution, the Broads and, to a lesser extent, the fen systems of Anglesey. The Broads SAC has the largest example of Calcareous Fens in the UK and possibly the largest occurrence in the EU outside Sweden (JNCC, 2014a). The interest feature is defined by the presence of Cladium mariscus and species of the Caricion davallianae. The primary constituent communities are those for which the Broads is well known, S2 Cladium mariscus swamp and sedge beds, S24 Phragmites australis, Peucedanum palustris tall-herb fen and S25 Phragmites australis Eupatorium cannabinum tall-herb fen.
The total extent of this feature in the United Kingdom is estimated to be less than 1,000 hectares. The areas within the Ant Broads and Marshes SSSI are also considered to be one of the best in the United Kingdom (JNCC, 2011). Extensive populations of the character species were recorded to occur at nearly all sites on the main Ant Valley floor (Broads Authority, 2013b).
S24 Phragmites australis, Peucedanum palustris (Tall-Herb Fen)
S24 is the most characteristic fen vegetation type in the Broadland area and the second most abundant, only marginally less in extent than S4 (Ecology Land & People, 2010). S24 usually occurs on solid peat or as a quaking or semi-floating turf pond infill over fen peat. The floristic composition of S24 is extremely variable, ranging from species-rich to species poor with a wide range of associated tall forbs (Environment Agency, 2010d).
The hydrological functioning supporting S24 is described within the Ant Broads and Marshes Site Action Plan (Environment Agency, 2010b) as areas of permanent seepage and shallow water table supported by upward groundwater flow from the drift / Crag aquifers.
The target identified for S24 through the Environmental Outcomes14 for The Broads SAC (Environment Agency, 2010b) is a summer water table between 3cm above and 36cm below ground level during the summer months (July-September). This is the mean water level for S24 on a number of sites across East Anglia ±1 Standard Deviation (but curtailing the maximum water table to water at 4cm above ground level). Winter water levels are expected to be at the surface. The target for S24 covers both of the communities (S24 and S25) that contribute to the Calcareous Fen feature.
Although substrate and hydrology may determine the gross division and floristics of S24 sub communities, management can strongly influence the composition and in particular the degree of dominance by certain species, especially those with a crop value. Where the influence of management is particularly strong, and especially where it is combined with artificial manipulation of environmental factors, shifts to other communities can occur (Ecology Land & People, 2010).
13 This feature is a priority under the Habitats Directive, being very rare in the UK and Europe. It is recorded in only 13 SACs, the smallest number for any mire or fen feature (JNCC, 2014b / ELP, 2010).
14 Environment Outcomes are defined as a statement of the nature conservation aspirations for the site, expressed in terms of the favourable condition that the species and/or habitats for which the site has been selected should attain (Environment Agency, 2010b).
The hydrological criteria are linked to the Stage 4 Environmental Outcomes provided by Natural England. The Environmental Outcomes for The Broads SAC and Broadland SPA as supplied by Natural England on 17 January 2008.
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Assessment Cells have been located based on the location of S24 within Catfield Fen and Sharp Street.
4.2 H7140 SAC Feature: Transition Mires and Quaking Bogs
The habitat comprises vegetation which is transitional between acid mire and alkaline fen, with surface conditions ranging from markedly acid to mildly base-rich (JNCC 2014c / Ecology Land & People, 2010). Transition Mires and Quaking Bogs are widespread, but with local variations in ecologically and geomorphology (JNCC, 2014c).
The Broads SAC contains examples of transition mire in a flood plain, containing mainly communities of M5, M9 and S27, which are relatively small, having developed in re- vegetated peat-cuttings as part of a complex habitat mosaic of fen, carr and open water (Broads Authority, 2013b).
Approximately 47% of the Transition Mires and Quaking Bogs in The Broads SAC are concentrated in the Ant Valley (Broads Authority, 2013b).
S27 Carex rostrata – Potentilla palustris (Tall Herb Fen)
S27 mainly occurs as a buoyant loose mat of vegetation in basins, turf ponds or hydroseral vegetation rafts along the margins of lakes and pools, though it is sometimes found on the margins of floodplains as in Catfield Fen. The S27 community supports a large number of species, but most stands are relatively species poor, supporting relatively few uncommon species (Environment Agency, 2010d).
Stands of S27 are widely scattered in the Ant Valley, with particular concentrations on the Irstead Street, Broad, Stalham and Barton Fens (Broads Authority, 2013b).
S27 is characteristic of high water tables close to the surface but without regular or prolonged inundation, and where there is some throughput of water (Ecology Land & People, 2010). However, relatively low summer water tables (deeper than 10 cm below ground level) may be a natural feature of examples of the community in floodplain margins such as Catfield Fen (Environment Agency, 2010d).
The target identified through the Environmental Outcomes for The Broads SAC (Environment Agency, 2010b) indicated that where transition mire communities were located in non-floating situations, water levels should not fluctuate more than 30cm annually; additionally the water table should be continuously high with levels ranging between +1cm and +9cm above ground level for the transition mire communities. The target covers all three communities S27, M5 and M9 that contribute to this habitat (Environment Agency, 2010b).
An Assessment Cell has been located at the site of S27 within Catfield Fen, see Figure 4.1 and section 8.0 for further details.
4.3 H6410 SAC Feature: Molinia Meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae)
This habitat type comprises the most species-rich Molinia grasslands in the UK, in which purple moor-grass Molinia caerulea is accompanied by a wide range of associated species including rushes, sedges and tall-growing herbs. These grasslands are represented by two NVC types: M24 Molinia caerulea - Cirsium dissectum fen-meadow and M26 Molinia caerulea - Crepis paludosa mire (JNCC, 2014d).
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Molinia Meadows are widely but discontinuously distributed in the UK, with concentrations in south-west England, western and central Wales, East Anglia, northern England and the south-west of Northern Ireland. M24 fen-meadow is the more widespread and diverse, and in the fen systems of East Anglia comprises a form with tall herbs. It is a qualifying feature for the Broads SAC, but is not a primary reason for selection of this site (JNCC website).
Molinia Meadows on calcareous, peaty or clayey-silt-laden soils are a relatively minor feature of the Broads Valley. In the 2011 Ant Valley Fens Condition Assessment, the habitat was only recorded from a small area on Catfield Fen (Broads Authority, 2013b).
M24 Molinia caerulea – Cirsium dissectum (Fen Meadow)
M24 is widespread in Eastern England where it occurs in scattered, infrequent locations. It tends to occupy the zone between wetter fen communities and drier grassland and heath, but also occurs on some floodplains. Floristic composition of M24 varies considerably; it can be fairly species rich and supports a few rare mire species (Environment Agency, 2010d).
M24 is an uncommon community in the Broads, associated with low nutrient conditions and relatively low water tables. On wetter ground the effects of grazing (trampling and dung) seems to shift communities towards the more common M22 (Ecology Land & People, 2010). Persistently high summer water tables may be damaging to M24, and sites with relatively high water tables tend towards M13 (Environment Agency, 2010d).
The hydrological functioning supporting communities of M24 is described within the Ant Broads and Marshes Site Action Plan (Environment Agency, 2010b) as areas of permanent seepage and shallow water table supported by upward groundwater flow from the drift / Crag aquifers.
For the M24 community, the target identified is a water table of between 10 and 41cm below ground level in the summer months (July-September). This is the mean water level for M24 on a number of sites across East Anglia ±1 Standard Deviation (but curtailing the maximum water table to water at 10cm below ground level as measured). Winter water levels are to be nominally just sub-surface (Environment Agency, 2010b).
An Assessment Cell has been located at the site of M24 within Sutton Broad, see Figure 4.1 and section 8.0 for further details.
4.4 S1903 SAC and Ramsar Feature: Fen Orchid (Liparis loeselii)
Natural England have confirmed that the Fen Orchid is considered to be the most sensitive feature within the Ant Broads and Marshes SSSI. Natural England have also state that the presence and number of Fen Orchid plants within the Ant Broads and Marshes SSSI is integral to the Broads SAC (Natural England, 2008).
The Fen Orchid is a small green flowered orchid of fen and dune systems. There are two distinct morphological forms; the fenland form (Liparis loeselii) and the dune slack form (var ovata). With respect to the Ant Broads and Marshes SSSI, this assessment is concerned with effects on the fenland form (Liparis loeselii), and any further reference to the species in this document relates to the fenland form only.
The Fen Orchid (Liparis loeselii) is found in only 4 of the component SSSIs that make up The Broads SAC (Ant Broads and Marshes, Broad Fen, Bure Broads and Marshes and Upton Broads and Marshes). Figure 4.2 shows the distribution across The Broads SAC.
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The species inhabits wet calcareous or neutral fens, and is confined to species rich tall-herb fens that have experienced historic disturbance through peat-cutting.
The fenland form requires a base-rich water supply, being associated with pH values of 6.5 to 8.2, and it is understood that habitat loss through the cessation of peat cutting in the fens, as well as scrub encroachment are likely to be the most important contributory factors leading to the decline of the subspecies.
The Fen Orchid is associated with the Molinia Meadows and Calcareous Fen of Sutton Broad and Catfield Fen respectively, and the hydrological targets for these features (described in sections 4.1 and 4.3 above) are therefore applied to the Fen Orchid in these locations. (Environment Agency, 2010b)
The Ant Broads and Marshes SSSI Conservation Objectives v2.1 (Natural England, 2008) lists the presence/absence of the Fen Orchid as an indicator of favourable site condition. This indicates that single plants are of concern. As discussed above, due to the sensitivity and distribution of the species, it provides a good indication of whether there will be an effect on site integrity as a result of these renewal applications.
Groundwater model Cells I and E have been placed in the general location of the Fen Orchid within Catfield Fen and Sutton Broad respectively.
Figure 4.2. Known distribution of the Fen Orchid across The Broads SAC, Broadland SPA and Broadland Ramsar. (Environment Agency, 2010b)
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5.0 Previous Work
5.1 Reviews and Reports
As mentioned in section 2.0, where permissions are time limited, have been ongoing and applied to be renewed on the same terms, we would normally expect to renew15 time limited licences on those same terms (subject to three principles, one of which is environmental sustainability). Instances may be identified where the abstraction could result in a likely significant effect or adverse effect to site integrity of a European site, further action is then required. In such cases, it is normal for us to initially refer to the conclusions of the RoC for the site in question. In the case of the Ludham Road and Plumsgate Road applications, we have considered the RoC conclusions for the Ant Broads and Marshes SSSI (Environment Agency, 2010b).
Where there are some uncertainties with the environmental sustainability test associated with renewals (section 4.3 of Environment Agency, 2013d), it is the Environment Agency’s responsibility for establishing whether the licence meets this test.
The Ant Broads and Marshes SSSI is an extensively studied area of The Broads SAC, Broadland SPA and Broadland Ramsar, and there is a significant volume of information in the public domain particularly from the latter half of the twentieth century to present day. This information, along with the conclusions of the RoC and other reports produced specifically to support these renewal applications, has been used to assist us in assessing whether the applications could have an adverse effect on the site integrity of the Broads SAC, Broadland SPA and Broadland Ramsar.
The reports summarised in 5.1.2 – 5.1.7 have been produced specifically to assess the hydrology, hydrogeology and ecology, primarily of Catfield Fen but also the Ant Broads and Marshes SSSI to inform the impact assessment of abstraction. The predominant focus on Catfield Fen is a consequence of information provided by Natural England which reported a long-term trend of drying of Catfield Fen (Natural England et al., 2011) and updated with Natural England’s reports 1-7 (Natural England, 2013a-g). Within the Groundwater Summary Report (Environment Agency, 2014a) we also consider the potential impacts of abstraction on Sutton Fen, Sutton Broad and Sharp Street.
This section summarises the purpose and outcome of key documents for consideration as part of the Appropriate Assessment. This is not an exhaustive list of the information considered within this assessment. In addition to the reports listed below, we have also received ecological information from Parmenter, Barendregt, Mountford, the RSPB and Broads Authority. As Natural England is the Government’s advisor on ecological matters, these reports were sent to them to confirm whether they changed the advice they had given us to date. These have been included within their Reports 6 and 7 (Natural England, 2013f, g).
Where additional information has been taken into account (for example water level data and analysis from the RSPB and Broads Authority (RSPB, 2013b – and Natural England, 2013g)) it has been referenced and explained in sections 8 and 10 as appropriate.
15 Note, short duration licences do not carry a presumption of renewal.
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5.1.1 Habitats Directive Review of Consents (2010)
An extensive amount of work was undertaken in support of the Review of Consents (RoC) for the Ant Broads and Marshes SSSI under the Conservation of Habitats and Species Regulations 2010 (Regulation 63). This is described in further detail in section 2.2 of the Groundwater Summary Report (Environment Agency, 2014a).
At the time of undertaking the RoC16, Natural England were of the view that the ecology of the Ant Broads and Marshes SSSI was in favourable condition and existing abstraction was not believed to be generating an adverse effect on the site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar. In addition, as actual levels of abstraction had been steady since the early 1990s, it was deemed that the historical condition could be used as a baseline for judging acceptability of the fully licensed level of abstraction (and agreed at the time with Natural England (Environment Agency, 2014)). This work was supported by the Yare and North Norfolk Groundwater model and used Decision Tables to assess the risk posed by increasing abstraction to the fully licensed level. The use of the Decision Table is discussed further in section 9 of the Groundwater Summary Report and supported by a technical note (Amec, 2013c).
The work undertaken with the aid of the Yare and North Norfolk groundwater model during the RoC found that, for the Ant Broads and Marshes SSSI, fully licensed abstraction was not having a significant effect on the hydrological functioning (defined in section 8.5) of the site. The hydrological needs of the vegetation communities would be continued to be met and therefore it was concluded fully licensed level of abstraction had no adverse effect on site integrity.
For the Upper Thurne Broads and Marshes SSSI, while historical levels of abstraction were shown to not significantly alter the hydrological functioning of the site, fully licensed abstraction was potentially greater than the defined acceptable level of abstraction17 in drought summers. The Site Options Plan concluded that reductions in abstraction to two licences (7/34/09/*G/0091 Anglian Water Services and 7/34/10/*G/0111 Overton) were necessary to achieve the RoC Stage 4 Environmental Outcomes and ensure no adverse effect on site integrity. These abstractions are discussed further in section 8 and the reductions in licence quantity accounted for within the current fully licensed level of abstraction.
5.1.2 Ecological Compendium (Natural England et al, 2011)
Following concerns expressed by the landowner of Catfield Fen Units 11 and 35 that the site was experiencing low water levels, Natural England and the landowner prepared a compendium of ecological and eco-hydrological evidence which represented their agreed understanding of the available information.
In April 2011 we received notification from Natural England that it was now their view based on the ecological information available, that the evidence presented demonstrated a long- term trend of drying on the Catfield Fen hydrological sub area which appeared to be accelerating. There was also evidence of vegetation change consistent with drying of the wetland habitat. Further, Natural England concluded that local abstraction was potentially contributing to this drying and it would not be possible to conclude no adverse effect on the site integrity of The Broads SAC through an Appropriate Assessment of the Ludham Road and Plumsgate Road abstraction licence renewals.
16 For which the Appropriate Assessment for The Broads SAC, Broadland SPA and Ramsar was signed off by Natural England in 2006. 17 See the Groundwater Summary Report, Section 1.2.
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This information was subsequent to the Habitats Directive Review of Consents process for the Ant Broads and Marshes SSSI (described in 5.1.1) through which Natural England agreed there was a low risk to the site from abstraction.
The ecological compendium was therefore considered as new information further to our understanding of the site at the conclusions of the RoC process. The compendium formed the basis of the additional assessment work for the Ludham Road and Plumsgate Road applications. The evidence that informed the compendium has since been reviewed in Natural England’s Reports 1 and 2 (2013a-b).
5.1.3 Catfield Fen Investigation (Amec, 2012)
Amec were commissioned to undertake an independent investigation of Catfield Fen in response to the reported concerns of ‘drying out’ at Catfield Fen. A statement regarding the commissioning of this report can be found within the ‘March 2013 Update’ at the following link.
The report was commissioned to help evaluate these concerns and to increase understanding of fen complexity. The report had three key objectives:
• To assess how the fen functions hydrologically and hydrogeologically • To assess the fen’s sensitivity to water abstraction • To comment on the possible causes for the site drying out
The report examined all available monitoring data and concluded that the fen is a complex hydrological system which receives water via a number of routes including groundwater input via dykes, rainwater and groundwater via lateral flow. It concluded that the possible reasons for the fen drying out are varied and may involve several factors which are acting in- combination to produce the effects described in Natural England’s Ecological Compendium (Natural England et al, 2011). The potential contributing factors identified were groundwater abstraction, overflow of dyke water over the low lying bund at the southern end of the internal system, leakage through sluices, changes in water management, and the process of terrestrialisation which could lead both to the infilling of former pond areas and to the general rise in ground level.
Interested parties were invited to comment on the report and these comments were included in the final version.
A synopsis of the Amec (2012) report can be read in the accompanying Groundwater Summary Report, section 2.2 (Environment Agency, 2014a) and the complete report is available for viewing under “October 2012” at link.
5.1.4 Natural England Reports 1 - 4 (July - November 2013)
As the assessment of the applications to renew these abstraction licences has been refined, so the ecological evidence and advice as requested from Natural England has been integrated. A meeting was held between the Environment Agency and Natural England on 18 April 2013 to clarify Natural England’s position with regard to the condition of Catfield Fen. The notes from this meeting can be found at link.
Following the meeting, Natural England undertook a review of their existing evidence, which involved a number of site visits, including an update to their Condition Survey for the
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compartments within the interior system of Catfield Fen. This resulted in Natural England producing a series of reports to the Environment Agency (Natural England 2013a-d).
The Condition Survey, undertaken 02-03 July 2013, indicated that the ecology of the interior system of Catfield Fen is in favourable condition (Natural England, 2013d). Unit 11 was recorded as being in Favourable condition, and Unit 3 was recorded as being Unfavourable Recovering, due to actions taken to address excessive scrub across the site. Across both units, all ecological communities had good summer water levels consistent with their hydro- ecological requirements. The expansion of Sphagnum seen at Middle Marsh and the condition of the remainder of Unit 11 are not considered by NE as an indication that this unit is drying out and that drying out is accelerating (Natural England, 2013j). Note: although Unit 35 differs from Unit 11 in that it is an open water habitat, it is hydrologically connected with Unit 11 and so the condition status of Unit 35 was updated to reflect the improvement observed in Unit 11. The status of Unit 35 is however given as Unfavourable Recovering due to the ongoing recovery since mud pumping.
Natural England also there are changes to the species composition of the ecological communities across Catfield Fen, and have therefore given Unit 3 and Unit 11 Threat Categories of ‘changes in species distributions’ and ‘hydrological changes’ (Natural England, 2013d). This is considered further in section 8 of this document.
5.1.5 Natural England Reports 5 – 7 (September – November 2013)
Following Reports 1-4 (Natural England, 2013a-d), a meeting was held between the Environment Agency and Natural England on 05 September 2013 to clarify Natural England’s position with regard to the recent ecological survey work. The notes from this meeting can be found at link.
At the meeting the Environment Agency presented the following questions to Natural England:
• Can Natural England describe the reasons why it may not be appropriate to apply the RoC assessment principles, specifically in relation to condition status? • In addition, are the changes in vegetation recorded likely to lead to a deterioration of the condition in the medium to long term?
These questions were answered within Natural England’s Report 5 (2013e).
Two further reports followed. Natural England Reports 6 and 7 (2013f & g) provides comment on information submitted by the landowner of Units 11 and 35 of Catfield Fen and data supplied by the RSPB and the Broads Authority.
In response to Natural England Reports 1-7 (2013a-g), this assessment has focused on the potential impact on Catfield Fen, Sutton Broad, Sutton Fen and Sharp Street. We have been advised by Natural England that these areas are particularly sensitive to changes in groundwater input as they border the highland and may receive lateral groundwater input. In the case of Catfield Fen, ecological change has also been observed.
5.1.6 Environment Agency Groundwater Summary Report (March 2014)
This report sets out key findings from modelling work carried out between June to August 2013 (further refined September – November) undertaken in support of the review of these renewal applications. The modelling work involved use of the Northern East Anglia Chalk (NEAC) model which superseded the Yare and North Norfolk (YNN) model used during the
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Habitats Directive Review of Consents programme. The report has been prepared to provide:
• background information relating to the development and application of the NEAC model • an assessment of fully licensed in-combination abstraction within the Ludham-Catfield area • information about changes to water chemistry within the fringes of SSSI, of which particular concern has been raised over the Middle Marsh area of Catfield Fen (see Annex 1)
The report has been drafted by Environment Agency groundwater specialists using information supplied by Amec.
The report is accompanied by technical notes which give more information on certain aspects of the work. The subjects covered by the technical notes are:
• Review of pumping tests which have been undertaken on the main licensed sources within the Ludham-Catfield area (Amec, 2013a) • Soil moisture assessment (Amec, 2013b) • ‘Decision Table’ used to help quantify the differences between abstraction scenarios (Amec, 2013c) • Groundwater model grid cell size (Amec, 2013d).
5.1.7 Further Information
Under Section 61(4) of The Conservation of Habitats and Species Regulations 2010 we may if we believe it is appropriate consider any further information from the general public relating to the European site that may aid our decision. We made a request for any further information in November 2012 on our website (link). We received additional water level and water quality monitoring data along with anecdotal information from the RSPB and Butterfly Conservation who together manage SSSI Unit 3, shown in Figure 3.6. Additional information has been received from the applicant in relation to site management, local hydrology and hydrogeology and operation of the abstraction. This has included anecdotal and photographic evidence.
We have also received ecological and water level information from the RSPB, jointly with the Broads Authority (RSPB, 2013b) and information from the Broads Reed and Sedge Cutters Association (Brasca).
The landowner of Units 11 and 35 has provided a number of ecological reports. These were referred to Natural England as the Government’s advisor on the natural environment. These reports have been taken into consideration as part of Natural England’s advice to us, also see Natural England 2013f.
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6.0 Observed Monitoring Data
A comprehensive review of all available monitoring data in the vicinity of Catfield Fen was undertaken as part of the Amec report (2012). The report describes the known monitoring points considered as part the assessment of hydrological and hydrogeological functioning of Catfield Fen. The list of monitoring installations includes:
• 9 sites for surface water including gaugeboards. • 31 sites for groundwater (plus an additional 10 remote/regional observation points). • 5 sites providing electrical conductivity and related water level data (plus previously recorded chemistry data with additional chemistry data provided by Anglian Water Services and applicant). • 3 rainfall gauges (plus additional rainfall data provided by the landowner of Units 3 and 11 from the Catfield Hall Estate rain gauge. • Weekly MORECS evapotranspiration data. • Abstraction quantities, both daily and annual for 5 licences (including the two Alston licences). • Sluice records for the internal and external system. • Borehole lithological and construction logs for the installations listed above (including the licensed boreholes).
Monitoring in various forms has taken place since 1967 (Amec, 2012) however, data is sparse until the mid 1990’s when more consistent monitoring began. As part of abstraction renewal work, an internal review of recent monitoring data was undertaken by Sharpin (Environment Agency, 2010c). Since the report ‘Catfield Fen - An Assessment of Monitoring for Regulatory Purposes’, (Entec, 2010), no new monitoring points have been added to our knowledge. Some of the earlier monitoring points noted in the Amec report (2012) however have been removed from the monitoring round because the monitoring was manual and less frequent. The monitoring that remains is generally based on logger data of a frequency more suitable for finer detailed assessment.
Locations of monitoring points on Unit 3 are shown on Annex 1. Due to access issues we have been unable to install any additional monitoring within SSSI Units 11 and 35 of Catfield Fen.
Observation data also includes information from pumping tests of the Ludham Road and Plumsgate Road abstractions and those others of particular relevance in this assessment: 7/34/09/*G/0091 Anglian Water Services (AWS) and 7/34/10/*G/0111 Overton. The pumping test data is of variable quality with the best information being available for tests that were undertaken on the AWS Ludham source during 2002 and 2003. A technical note on the review of the pumping test (Amec, 2014a) information is submitted with the Groundwater Summary Report.
In addition the applicant has provided data through the monitoring addendum attached to both licences. The monitoring addendum requests that readings from local piezometers are collected daily during the abstraction season. The monitoring data up to October 2011 was included within the report by Amec (2012) see section 5.1. Data gathered from the applicant’s monitoring points more recently has been analysed, see section 8.0.
Water chemistry data has been collected as part of a number of investigations over the last 30 years (further information is available in Environment Agency, 2014b).
The Amec (2012) report presents raw data from the Collins, Atkins/ HSI and Ewan studies, and re-examines the sample analyses. The sample analyses are grouped into a number of
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hydrochemical groups. Further, maps are presented showing the location of monitoring points and thereby the locations of the samples falling into the hydrochemical groups.
The hydrochemical data and analysis is particularly useful for reinforcing the hydrological functioning of the Catfield Fen part of the Ant Broads and Marshes SSSI. It is believed that the behaviour of the floodplain margin at Catfield Fen is generally repeated along the eastern margin of the Ant Broads and Marshes including at Sutton Broad, Sutton Fen and Sharp Street.
The data from the monitoring installations provides information on the horizontal and vertical groundwater level gradients, and the fluctuations of water levels both seasonally and over longer periods of time. The Environment Agency’s assessment of the available hydrological data is that the data is extensive and of good quality. Many of the monitoring locations were constructed specifically to provide data to inform the Habitats Directive RoC assessment. Although some specific features are not monitored, the behaviour at these locations can be satisfactorily inferred from the monitoring points available. For further details of observed monitoring data see section 4 of the Groundwater Summary Report (Environment Agency, 2014a).
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7.0 Groundwater Modelling
There is agreement in that local abstractions capture groundwater flow that would otherwise have reached the Ant Broads and Marshes SSSI. The most appropriate tool we have available to assess the effect of fully licensed abstraction on the SSSI is groundwater modelling. The time-varying behaviour of the groundwater system can be accounted for using the groundwater model.
Natural England (meeting note of 18 April 2013, available at http://www.environment- agency.gov.uk/research/library/consultations/143536.aspx) agreed that groundwater modelling is the most appropriate framework to be using for the hydrological impact assessment for the two applications.
The numerical model is built and calibrated to replicate, as closely as possible field observations and our conceptual understanding of the Area of Interest, based on the best factual information available to us at the time of the assessment.
Our initial assessment of these applications referred to the Yare and North Norfolk (YNN) groundwater model. This model uses data from 1970 to 2005, covering several drought and non drought years, and was used to support the RoC assessment for the Ant Broads and Marshes SSSI. Whilst the YNN model has a robust data set, the data set stops at 2005, and as concerns regarding the drying out of Catfield Fen were expressed in 2008 and onwards, the more recent data was considered important for inclusion in the assessment. As a result of this, the Northern East Anglian Chalk (NEAC) groundwater model has been used to process these licence renewals. As well as using data sets that extend to the end of 2012, the NEAC model uses improved land use, soil and evaporation data compared to the YNN model and has also been refined in several areas to better represent hydrogeological concepts, conditions and observations.
7.1 Northern East Anglian Chalk (NEAC) Groundwater Model
The NEAC model is the result of a 15 year programme of model development and operation, and represents the cumulative knowledge of hydrogeologists and hydrologists working in East Anglia over a much longer period. External consultants have peer reviewed the NEAC model at all stages of its development, and it has been favourably received. There is no other tool which incorporates all the available information, and allows quantitative predictions of impact to be made. A model based methodology for assessing the impact of abstraction on wetland sites was developed with Natural England, which related the quantified requirements of wetland communities to quantitative model output. This is now the established method for assessing abstraction impact on wetlands in East Anglia.
The NEAC model has achieved an accurate representation at most of the water level monitoring points across the most sensitive hydrological sub areas. Examples of the model calibration are presented in section 7 of the Groundwater Summary Report (Environment Agency, 2014a) which shows that the model successfully captures the main features of water level behaviour, provides a good representation of the absolute water levels and successfully represents the hydrological functioning of the groundwater-surface water system. The configuration and calibration of the NEAC model have been refined with the aid of pumping test information from the AWS Ludham source. This has produced a good representation of the water levels and groundwater level gradients in the vicinity of the Ant Broads and Marshes and the Upper Thurne Broads and Marshes SSSIs and an accurate representation of the hydrological functioning of the groundwater-fed wetland areas. The
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Environment Agency has therefore used the model with confidence to assess the effects of the current licensed level of abstraction.
The model incorporates a wide range of quality assured data sets from a network of hydrometric installations (both surface water and groundwater). It also represents discharge volumes, quantities pumped by the IDB and pump test data. The opportunity to calibrate the model with new information has been taken. The level of detail built into the model in terms of the layering and grid size is such that it can effectively predict the changes in water levels that occur in response to abstraction. A more detailed account of the model representation and calibration is given in the Groundwater Summary Report (Environment Agency, 2014a).
As mentioned in section 7.2, our use of the NEAC model has focused on specific Assessment Cells which represent locations at which interest features are present. These are shown in Figure 4.1 and Table 4.2.
7.2 Abstraction Scenarios
Several abstraction scenarios have been investigated to assess the potential effect of abstraction on the Ant Broads and Marshes SSSI, and are described in detail in section 10 of the Groundwater Summary Report (Environment Agency, 2014a).
The key scenarios used within this assessment are as follows; • Naturalised: abstractions set to zero • Historical: uses historical actual abstraction, 1970 to 2012 • Current fully licensed: fully licensed abstraction including changes recommended as part of the conclusion of the Upper Thurne Broads and Marshes SSSI RoC (see section 5.1.1) • As current fully licensed but with Plumsgate Road set to zero • As current fully licensed but with Ludham Road set to zero.
We have confirmed with Natural England (meeting of 05 September 2013, notes available on our webpage at link) that we will present modelled results of the potential effect of the Ludham Road and Plumsgate Road abstractions against a naturalised scenario for all of the sensitive hydrological sub areas of the Ant Broads and Marshes SSSI, highlighted in section 3.5.
7.3 Water Chemistry: Water Balance Method
As a result of concerns raised by Natural England in relation to threats from potential changes to the base-rich to base-poor character of groundwater (Natural England, 2013e) a water balance method has been developed to assess water chemistry. This uses groundwater balance output from the NEAC groundwater model to calculate the proportion of water within the peat that has been derived from the Crag and how much from direct precipitation and shallow lateral inflows. Further explanation of the methodology of the water balance method is provided in section 8.2 of the Groundwater Summary Report (Environment Agency, 2014a) with the results discussed in section 8 of this report.
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8.0 Assessment of the Potential Effect of Abstraction
Of the nine hydrological sub areas of the Ant Broads and Marshes SSSI, this assessment focuses on the potential effects on Sutton Broad, Sutton Fen, Catfield Fen and Sharp Street, as discussed in section 3.5. The ecological evidence and advice from Natural England (2013a-g) indicates that these areas may be particularly sensitive to changes in groundwater. Any significant change to the hydrological functioning of the sub areas could result in an adverse effect on the sub area and therefore present an adverse effect on overall site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar. Our assessment takes into consideration the hazards listed in Table 8.1 as possible drivers for change to hydrological functioning, as well as the threat categories of changes in species distribution and hydrological changes, specifically at Catfield Fen.
We consider theses threat categories placed on Catfield Fen and whether the groundwater abstractions at Plumsgate Road and Ludham Road may be a causal factor, alone or in- combination.
The broader hydrological functioning is examined in the Groundwater Summary Report (Environment Agency, 2014a) and considered as part of our assessment of changes in flow/velocity regime, water level/table and water chemistry along with any subsequent habitat loss experienced as a result of these changes.
In accordance with internal guidance (Environment Agency, 2010a) the National Habitats Directive System has been used to generate the hazards which must be considered in the assessment of these permissions.
Nine potential hazards to which the European site features are potentially sensitive were identified. Five of these hazards, listed below, have been considered in the preceding assessment of likely significant effect through the Appendix 11 (Environment Agency, 2013a). Conclusions of no likely significant effect have been reached for each of the following hazards and therefore they are not considered further in this assessment:
• Changes in salinity regime • Changes in freshwater flow to estuary • Surface flooding • Entrapment • Reduced dilution capacity
Four potential hazards have been taken forward for consideration as part of this Appropriate Assessment, as a conclusion of no likely significant effect could not be reached for them. This section looks at the effect of abstraction with regards to each of the four hazards defined in Table 8.1. The potential effect of abstraction from each of the hazards is considered both alone and in-combination with other abstractions.
The cumulative effect is considered with other potential contributing factors (see section 10). Cumulative effect considers the influences on the site which have affected and are continuing to affect the condition of each European interest feature on the site. This term is commonly used to include all of the plans and projects (described in section 9) together with: completed plans or projects; activities for which no consent was given or required; and natural processes (by natural mechanism and at a natural rate) (Natural England, 2001). The current condition of the interest features may be a reflection of the cumulative effect on them.
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Hazard Description Changes in flow Changes in the flow or the velocity regime of a watercourse, which or velocity could result in damage to vegetation and/or other sensitive features. regime For example a discharge doubling a river volume to submerge or wash away sensitive species, or an abstraction halving a river flow to expose fish spawning habitat or reduce the humidity needed for some bryophyte species. Note, the changes in flow or velocity regime are assessed here as groundwater flow. Changes in Changes to water levels or groundwater tables which alter water levels or vegetation or other sensitive features. For example abstractions table lowering groundwater levels, causing water loving vegetation to die off or ponds and wetlands to dry out. Note, changes in surface water are discussed in section 9.1. Changes in Changes to the water chemistry resulting from additions of other water chemistry substances. For example, a sewage discharge containing chemicals or groundwater abstractions altering surface water chemistry. Habitats loss Changes to the protected site which could result in loss or damage to vegetation and/or other sensitive features. For example, physical damage caused by access or surface water erosion or areas of the protected site being removed in order to construct discharge headwalls. Table 8.1 Description of hazards
If it is shown that the hydrological functioning, in line with the Ecological Guidelines, is maintained, we conclude no adverse effect on site integrity from abstraction alone or in- combination. Such a conclusion will enable us to determine there is no link between the abstraction and the threats of hydrological change and species distribution.
The impact of all abstractions has been modelled for each of the Assessment Cells identified (section 4.0) against the various abstraction scenarios indicated in section 7.2. As agreed with Natural England (meeting 05 September 2013 link) we have focussed primarily on the naturalised scenario. This is the modelled groundwater conditions in the absence of all abstraction and discharges. Consideration of discharges is made in section 9.
Quantifying the potential impact (at the fully licensed quantities) from the Plumsgate Road and Ludham Road abstractions against the naturalised scenario will show the worst case drawdown from each of the two abstractions and the worst case drawdown in-combination with other abstractions.
The European site’s Conservation Objectives (Natural England, 2008) are used as the basis of our assessment. We have also considered the site citation (Natural England, 1974) and Views About Management (Natural England, 2005) for the component SSSI. In addition we have also referred to Natural England’s Ecological Reports (2013a-g). The impacts of the proposals on the European nature conservation interests for which the site was designated are assessed below.
8.1 Groundwater Abstraction In-combination
For the purposes of the in-combination assessment, all abstractions have been included and modelled using the NEAC groundwater model. In the Catfield area, there are five licensed groundwater abstractions and one licensed surface water abstraction as shown in Figure 8.1 and summarised in Table 8.2.
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These abstractions are also summarised within the Groundwater Summary Report (Environment Agency, 2014a). It should however be noted that, although the licence held by Simply Strawberries is considered to be small (9,100m3 per year) and the Harris licence has not been used historically, they are still considered as part of the in-combination assessment to ensure a worst case assessment for the European site.
Maximum annual Abstraction Source of Period of National Grid Purpose quantity Licence supply Abstraction Reference (cubic metres) AN/034/0009/009 Groundwater Spray Summer TG 38 20 22,700 (Ludham Road) irrigation AN/034/0009/008 Groundwater Spray Summer TG 3820 2230 68,000 (Plumsgate irrigation Road) 7/34/09/*G/0091 Groundwater Public All year TG 38 19 512,000 (Anglian Water water Services - source supply at Ludham only) 7/34/10/*G/0111 Groundwater Spray Summer TG 3968 2059 72,700 (Overton) irrigation 7/34/09/*G/0058 Groundwater General All year TG 3881 2240 9,100 (Simply agriculture Strawberries Ltd) 7/34/09/*S/0084 Surface Spray Summer TG 377 208 700 (Harris) water irrigation Total 685,200
Table 8.2 Summary of the licensed abstractions in the Catfield area.
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Figure 8.1 Location of licensed abstractions in the Catfield area.
The licences held by AWS and Overton required licence changes as a result of the RoC recommendations for the Upper Thurne Broads and Marshes SSSI (Environment Agency, 2010e). For AWS this led to a reduction in annual licensed quantity from 680,000m3 to 512,000m3 and a reduction in actual abstraction. For Overton, the recommendation from RoC for the Upper Thurne Broads and Marshes SSSI was to reduce the licensed annual quantity by 25% from 72,700m3 to 54,500m3 in drought years. The 2012 renewal of the time- limited part of the Overton licence has reduced the quantity which can be abstracted from the Crag borehole, the main operational source, to 54,500m3 in all years. Further changes to the Overton base licence which authorises abstraction from wellpoints are progressing with a Section 5218 Notice having been served in February 2014.
18 Water Resources Act 1991
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The quantity of water abstracted by the four largest abstractors in the area is shown in Figure 8.2. With the exception of the reduction in abstraction from AWS Ludham in the mid 1980s (due to a treatment works upgrade) abstraction since the early 1990s has been relatively consistent.
900
800
700
600
500 AWS Ludham Alston Ludham Road Alston Plumsgate Road 400 Overton
(TCMA) Abstraction
300 Note: The red line indicates the restriction of AWS Ludham to 512,000mᶟ/year in October 200 2012.
100
0 1967 1972 1977 1982 1987 1992 1997 2002 2007
Figure 8.2 Actual annual abstraction from the four largest groundwater abstractions in the Catfield area (Environment Agency, 2014) NB. In October 2012, AWS Ludham was restricted to 512,000m³ per year, this is shown by the horizontal red line.
Where it can be demonstrated that abstraction in-combination does not lead to an adverse effect on integrity, this conclusion can also be extended to the effect of the individual licence acting alone.
8.2 Hydrological Functioning and Decision Tables
Hydrological functioning is defined as the characterising of the hydrological regime based on the groundwater model and naturalised conditions and is key in establishing the starting point for any further assessment and ensuring that the Conservation Objectives for the site can be achieved. This characterisation is described in more detail in step 6 of the RoC Stage 4 summary note for the Norfolk Valley Fens (Environment Agency, 2009). By establishing what the general hydrological functioning is under naturalised conditions, this can then be compared against other model runs, including fully licensed levels of abstraction, to help establish whether there is any effect and if the hydrological functioning of the site is maintained.
Natural England’s European Sites Guidance (2004) advises that “the duration of any impact(s) and the potential for recovery/reversibility are important factors to consider when determining whether it is possible to demonstrate no adverse effect on integrity”. The Decision Tables consider the frequency of any breaches in water level thresholds, including the timing of when such breaches occur. The thresholds are set based on the tolerance ranges of the most sensitive features as set out in the Ecohydrological Guidelines (Environment Agency, 2010). A small number of breaches can be tolerated, while the overall
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hydrological functioning of the site is maintained. Note: maintenance of hydrological functioning, does not necessarily mean that there is no impact from abstraction on the site.
The Decision Tables consider the performance of the fully licensed abstraction against key thresholds and assigns a score to each. It includes a number of other criteria used for helping assess the effects of fully licensed levels of abstraction. For example, assessment is made of the level of abstraction compared to the long term average recharge input. Such criteria are explained in detail in the Decision Table Technical Note (Amec, 2014c). The Decision Table is scored over three sections:
1) Performance against model-based hydrological criteria 2) Appraisal of resources and abstraction scenarios 3) Uncertainties
Decision Tables have been produced for Cell C, Cell E, Cell G, Cell H and Cell I as part of this assessment. These are presented in the Groundwater Summary Report (Environment Agency, 2014a).
The decisions within this assessment focus on whether the hydrological functioning is maintained based on the fully licensed abstraction scenario against the naturalised scenario. Where we have established that the hydrological functioning is maintained, we are able to conclude that abstraction at fully licensed rates is insignificant and therefore no adverse effect on site integrity can be shown.
8.3 Baseline for assessment
In July 2013 the condition status of Catfield Fen SSSI units were updated with Units 3 and 35 changing from Unfavourable No Change to Unfavourable Recovering and Unit 11 from Unfavourable No Change to Favourable (Natural England, 2013d). Threat categories of changes in species distributions and hydrological changes were also attached. These threat categories reflect Natural England’s observations (Natural England, 2013d) that a number of species have changed in their composition and distribution in parts of the Catfield Fen hydrological sub area, and that this may be related to hydrological changes (either by natural processes or external influences).
With respect to species composition, Natural England have recorded that the occurrence of Sphagnum spp. has increased within Unit 3 and Unit 11 since the late 1980s. Natural England proposed that this may be due to a change in the balance of base-rich and base- poor water (Natural England, 2013d).
No similar significant changes have been recorded in recent survey work undertaken by the Broads Authority and the RSPB at Sutton Broad and Sutton Fen. We have received no reports of ecological change at Sharp Street which is currently assessed to be in favourable condition.
In view of the threat categories at Units 3 and 11 of Catfield Fen and advice from Natural England of changes in Sphagnum spp., it has only been possible to deem the historical level of abstraction as acceptable prior to 1986. This is based on Catfield Fen being in favourable condition at that time, and pre-dates the increase in Sphagnum spp. (Environment Agency, 2014). The historical time-series pre-1986 has therefore been used as the baseline for judging the acceptability of both the post-1986 historical abstraction and the fully licensed abstraction. This is in addition to the naturalised scenario.
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The technical assessment conducted within the Groundwater Summary Report (Environment Agency, 2014a) uses the following starting points for each of the hydrological sub areas of particular interest in our assessment:
• Sutton Broad and Sutton Fen – represented by model Cell E on Sutton Broad – the ecology is essentially viewed as being in an acceptable condition.
• Catfield Fen – represented by model Cells G, H and I – the ecology is viewed as being in an acceptable condition prior to 1986 – and historical levels of abstraction prior to 1986 have been deemed as acceptable.
• Sharp Street – represented by model Cells C and J – the ecology is viewed as being in an acceptable condition – and historical levels of abstraction have been deemed as acceptable across the whole time-series.
In terms of the duration of any impacts and potential for recovery, Natural England have confirmed that they do not consider that the changes recorded in Catfield Fen SSSI Units 11 and 3 to be contrary to the Conservation Objectives, and no losses of species or contributions from other species have been considered to be undesirable (Natural England, 2013e). However, the driver for the changes in species composition and distribution is unknown and the evidence shows that this change has been happening over the last 30 years (since 1986).
Whilst it is not possible to predict what changes may happen in the future, in assessing these renewal applications it is deemed that provided the hydrological functioning of the European site are maintained in line with the thresholds set out in the Ecohydrological Guidelines (Environment Agency, 2010d) for the most sensitive features on the site, and that fully licensed levels of abstraction are acceptable, a conclusion of no adverse effect on site integrity can be reached. If this is the case and vegetation trends on site are still observed, then it may be that other contributing factors are potential drivers of the trend. These are considered in section 10.
As part of this assessment, Natural England were asked what the outlook might be for these areas in the medium and long term19. For Sutton Broad, Sutton Fen and Sharp Street there is no clear evidence of ecological change, indicating that these sub areas should be assessed as Unfavourable Declining in the medium or long term. For Catfield Fen, Natural England notes that whilst they do not know the rate or trajectory of change, there is sufficient evidence to reasonably assume that the increase in abundance and distribution of Sphagnum spp. is an ongoing trend which is likely to continue should all or some of the potential drivers remain unchanged (Natural England, 2013e). If abstraction is shown not to be a potential driver of the trend, it is reasonable to consider time limiting the abstractions in the medium term and through to the longer term.
8.4 Conceptual Understanding of Groundwater Flow in the Area
The Groundwater Summary Report (Environment Agency, 2014a) presents a number of hydrogeological cross-sections to illustrate the conceptual understanding of the aquifer system in the vicinity of the Ant Broads and Marshes SSSI, particularly around Catfield Fen. This advances previous conceptual understandings developed for RoC and prepared by Amec (2012).
19 Defined by Natural England for this assessment, medium term is defined to 2015 and long term to 2027 (Natural England, 2013e)
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There is a broad consensus between interested parties with regard to the conceptual understanding of the groundwater-surface water system in relation to the Ant Broads and Marshes SSSI. The key features of the hydrological functioning are summarised in section 6 of Groundwater Summary Report (Environment Agency, 2014a).
Cross-sections presented in the Groundwater Summary Report (Figures. 6.4 to 6.6, Environment Agency, 2014a) show the shallow geology from the interfluve area to the east of Catfield Fen, through the Middle Marsh area of Unit 11, through Unit 3 and then through the exterior system to Barton Broad. The cross-sections also show the groundwater flow lines from the interfluve area into the discharge area. These figures suggest that Crag groundwater is able to flow directly into the peat at the eastern margin of Catfield Fen where the underlying clay layer is thought to be thin or not present, or even directly into watercourses that may have been dug into the top of the Crag. The cross-sections indicate that the arrangement underlying Unit 3 is slightly different in that the clay layer is believed to be thicker and more continuous. It is likely that such geological conditions allow base-rich Crag groundwater to more readily influence the chemistry of the shallow groundwater across Middle Marsh, and that a reduction in this influence may be responsible for the increase in the growth of Sphagnum spp. at Middle Marsh.
It is likely that the geological conditions allow base-rich Crag groundwater to more readily influence the chemistry of the shallow groundwater across the Middle Marsh area of SSSI Unit 11, shown as model Cell H in Figure 4.1.The hydrochemical data is consistent with an upward flow of base-rich groundwater to the fen. There is some evidence (Amec, 2012) that Crag water enters the dykes at the eastern margins of Catfield Fen. The fen compartments between the dykes appear to be largely rainfall-fed, with mixing of the rainfall recharge and upward flowing Crag groundwater taking place deeper within the peat deposits.
8.5 Changes in Flow or Velocity Regime
For the purpose of this assessment, the discussion of this hazard will focus on any potential changes in groundwater flow to the European site. The assessment of changes in surface water is captured in section 10.1.
The potential mechanism by which these abstractions could impact on groundwater flow is through the interception of lateral flow through the Crag which would otherwise help to support water levels both in the peat layer and ditches. This potential reduction in groundwater flow could affect the interest features discussed in section 4, which are deemed to be most sensitive.
Flow vector charts have also been produced for the wider area of north east Norfolk, on which the Area of Interest has been outlined. Charts have been produced showing vectors across the area under naturalised, historic and fully licensed scenarios and through the three different modelled layers. These charts have been produced for dry and wet condition time steps (Groundwater Summary Report Figure 8.6).
In response to the Amec report (2012), Professor Gilvear presented a quantification of the impacts of abstraction, specifically on Catfield Fen (Gilvear, 2012). The calculations presented in Gilvear’s paper have been referred to as the ‘Stockade Theory’ which is a reference to the understanding that abstractions in the vicinity of Catfield Fen will capture groundwater that would have otherwise flowed to the fen. The groundwater catchment of Catfield Fen presented by Gilvear, shown in Figure 8.3, broadly matches the vectors shown on the naturalised flow vector chart (Figure 8.7 of the Groundwater Summary Report).
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Figure 8.3 Groundwater catchment of Catfield Fen derived from known groundwater contours.
Abstraction In-combination
The fully licensed and historic scenario flow vector charts (Figure 8.7 of the Groundwater Summary Report) show the influence that the AWS Ludham abstraction has on groundwater immediately east of the Ant Broads and Marshes SSSI. This abstraction is an order of magnitude greater than all other abstractions in the area.
By comparing the flow vector plots between naturalised and historical abstraction scenarios, it can be seen that the AWS Ludham abstraction does slightly alter the groundwater flow direction under the Catfield Fen hydrological sub area, however groundwater does continue to flow under and upwards into the fen for the historical abstraction scenario. Comparing the plots for the historical and current fully licensed scenarios it can be seen that under the reduced licensed quantities implemented following the RoC solution for the Upper Thurne Broads and Marshes SSSI, the AWS Ludham source is predicted to have less of an impact on the groundwater flow vectors and that overall the hydrological functioning of the site is maintained.
Although there will be a degree of interaction between the Plumsgate Road and Ludham Road abstractions with AWS Ludham, no cumulative effect on flow regime is observed. Even with AWS operating at fully licensed level, groundwater modelling demonstrates that the
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level of in-combination drawdown does not compromise the hydrological functioning of the site.
Plumsgate Road Alone
Based on its location and the lateral flow from south east to north west, the Plumsgate Road abstraction could be expected to intercept groundwater which would otherwise help to support levels in Sutton Fen and Sutton Broad. However, as demonstrated by the groundwater modelling, the drawdown from Plumsgate Road alone (at the groundwater model Assessment Cell E on Sutton Broad) is considered insignificant. There is no significant effect from Plumsgate Road shown on both the fully licensed or historic scenario flow vector charts.
Ludham Road Alone
Based on its location and the lateral flow from east to west, the Ludham Road abstraction could be expected to intercept groundwater which would otherwise help to support levels in Catfield Fen. The Gilvear paper suggests that the Ludham Road abstraction point is located within the groundwater catchment of Catfield Fen. However, as demonstrated by the groundwater modelling, the drawdown from Ludham Road alone (at groundwater model Assessment Cells G, H and I on Catfield Fen) is considered insignificant. There is no significant effect from Ludham Road shown on both the fully licensed or historic scenario flow vector charts.
8.5.1 Conclusion
Changes in flow/velocity regime from the Plumsgate Road abstraction alone are considered insignificant as the hydrological functioning of the site is maintained.
Changes in flow/velocity regime from the Ludham Road abstraction alone are considered insignificant as the hydrological functioning of the site in maintained.
We can conclude no adverse effect on the site integrity of The Broads SAC, Broadland SPA, and Broadland Ramsar through changes in flow/velocity regime from either of the proposed abstractions either alone or in-combination with other abstractions.
8.6 Changes in Water Levels or Table
An extensive network of water level monitoring installations exists across the Area of Interest. These include dipwells monitoring the behaviour of the shallow water table and piezometers monitoring water level behaviour at different depths within the aquifer system.
The monitoring installations provide data on the horizontal and vertical groundwater level gradients, and the fluctuations in water levels both seasonally and over longer periods of time.
Examples of the groundwater level data collected for the Area of Interest are shown on Figures. 4.1, 4.2 and 4.3 of the Groundwater Summary Report (Environment Agency, 2014a). The data shows that groundwater gradients tend to be downwards in the interfluve areas, that these gradients are potentially increased by abstraction, and that groundwater gradients in the wetland areas tend to be upwards.
Dipwell readings at University of Birmingham dipwell 13 located on Middle Marsh (Figure 4.1, Environment Agency, 2014) show a water table fluctuation of just over 0.5m. The data
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was collected for a limited period of time but ran from 1988 into the drought year of 1990 and so potentially indicates almost a full range of fluctuation that could be observed from very wet years to very dry conditions. The readings for the line of dipwells on the Butterfly Conservation reserve (Figure. 4.2, Environment Agency, 2014) show a water table fluctuation of up to 0.6m. The period of data collection includes the very wet 2007 event and the very dry autumn of 2009. The data from the dipwells, and the vertical groundwater gradients are broadly in line with the hydrological conditions which have been reported in the Ecohydrological Guidelines (Environment Agency, 2010d) as supporting the ecological features found on the Catfield Fen part of the Ant Broads and Marshes SSSI.
The method of analysis used to assess effects on hydrological functioning takes into account pumping rates, although the quantities which tend to govern the overall hydrological impact of the abstractions are the licensed annual quantities, particularly in a high storage aquifer such as the Crag.
Table 3.1 of the Groundwater Summary Report shows that the abstraction reductions recommended under RoC for the Upper Thurne Broads and Marshes SSSI brings the fully licensed level of abstraction in line with the 2006-10 average level of abstraction. The effect of this reduction on licensed abstraction is that actual abstraction going forward is unlikely to exceed recent actual20 levels; assuming the pattern of spray irrigation use remains similar to recent years, the actual level of abstraction would be 92% of the total licensed quantity. For the period April 2012 to March 2013 the actual level of abstraction has been approximately 75% of the recent actual level due to the decision by AWS to restrict abstraction at its Ludham source to 408,300m³ per year.
We hold a significant amount of field data (also see section 6.0) for the Area of Interest, which includes pump tests carried out for each of the four largest groundwater abstractions in the area. Data from the pumping tests for Plumsgate Road and Ludham Road is of varying quality due to problems encountered during the tests such as pumping rate fluctuations, heavy rainfall and incomplete data records. Analysis of the data (Amec, 2014a, section 3) was only undertaken for tests where the data was considered to be reasonable and in most cases was limited to the recovery test data. The assessment of effects from the Plumsgate Road and Ludham Road abstractions is carried out primarily through the NEAC groundwater model (calibrated using the pump tests carried out at AWS Ludham). Further information on the pump tests is presented in the Pump Test Technical Note, (Amec, 2014a).
Monitoring data up to October 2011 was included within the report by Amec (2012) and the Groundwater Summary Report (Environment Agency, 2014a). Data gathered recently from the applicant’s monitoring points has been analysed and shows no drop in water levels over the summer of 2012, presumed to reflect the wet summer experienced across the area.
The impact of abstraction has been modelled against several scenarios (section 7.2). The model outputs show minimum, maximum, average and July 197621 drawdown. The full tables for each of the Assessment Cells are included in the Groundwater Summary Report (Environment Agency, 2014a).
For abstraction in-combination, the modelling indicates that the highest level of drawdown is predicted at Cell C (Sharp Street) and the lowest at Cell E (Sutton Broad). This reflects the proximity of Sharp Street and Sutton Broad to the AWS Ludham abstraction - locations are shown in Figure 8.1. Predicted drawdown at Cells G, H and I on Catfield Fen are similar as they are grouped closely together.
20 Recent actual is defined here as the average of actual abstraction over the period 2006 – 2010 inclusive. 21 Used as this was a very dry summer
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The overall scores have been calculated using the Decision Tables, see section 8.2. These relate to overall hydrological functioning for the Assessment Cells (C, E, G, H and I) for the fully licensed abstraction against the naturalised scenario. Table 8.3 summarises shows the Decision Tables for all cells, showing that a score of Low is reached, meaning hydrological functioning is maintained. The full Decision Tables for each Assessment Cell are presented in Appendix B of the Groundwater Summary Report (Environment Agency, 2014a).
Groundwater G (Catfield H (Catfield I (Catfield C (Sharp E (Sutton model cell: Fen) Fen) Fen) Street) Broad) Scale of breach 4.1cm 4.8cm 2.6cm 6cm <1cm for water levels in relation to the drought summer threshold (1976) Frequency of 3 out of 40 3 out of 40 2 out of 40 6 out of 40 1 out of 40 breaches for water levels in relation to drought summer threshold Number of None None None None None breaches to the non drought summer threshold for soil moisture Timing of any Droughts only Droughts only Droughts only Droughts only Droughts only breaches Impact on overall Upward Upward Upward Upward Upward hydrological vertical vertical vertical vertical vertical functioning gradient and gradient and gradient and gradient and gradient and upward flow upward flow upward flow upward flow upward flow remains remain maintained in not remain generally positive most drought maintained generally positive with years but generally positive or one period of consistent reduced to reversal to with zero downward naturalised consistent flow in 1973 with naturalised. Category: Low Low Low Low Low
Table 8.3. Summary of the Decision table results under naturalised conditions (Taken from Environment Agency, 2014 – Appendix B)
Natural England’s European Sites Guidance (2004) advises that “the duration of any impact(s) and the potential for recovery/reversibility are important factors to consider when determining whether it is possible to demonstrate no adverse effect on integrity”.
The modelling indicates that the Plumsgate Road abstraction is assessed as having the largest drawdown at Cell H (Catfield Fen North – Transition Mire), and smallest drawdown at Cell C (Sharp Street).
The modelling indicates that the Ludham Road abstraction is assessed as having the largest drawdown at Cell C (Sharp Street) and smallest drawdown at Cell E (Sutton Broad).
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For further information on drought and non drought conditions and for full cell tables which include Minimum, Maximum, Average and July 1976 drawdowns, see section 10 of the Groundwater Summary Report.
8.6.1 Conclusion
Changes in water levels or table from the Plumsgate Road abstraction alone are considered insignificant as the hydrological functioning of the site is maintained.
Changes in water levels or table from the Ludham Road abstraction alone are considered insignificant as the hydrological functioning of the site in maintained.
We can conclude no adverse effect on the site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar through changes in water levels or tables from either of the proposed abstractions either alone or in-combination with other abstraction.
8.7 Changes in Water Chemistry
Changes in water chemistry could manifest as a change in the balance or mixing of base- rich Crag groundwater with base-poor rainfall. Groundwater abstraction from the Crag could reduce the amount of groundwater reaching the site, and change this balance. This in turn could result in a change in species distribution on the site.
The Ecohydrological Guidelines, to which we refer to for the hydrological needs of the sensitive ecological features, do not give very specific information with regard to the water chemistry.
Natural England have recorded that the percentage of Sphagnum spp. has changed within SSSI Units 3 and 11 (particularly the Middle Marsh area of SSSI Unit 11) and propose that this may be due to a change in the balance of base-rich to base-poor water and that groundwater abstraction could not be ruled out as the cause for this change. It is not known what pH changes might be associated with the growth of Sphagnum spp within SSSI Unit 3 and Unit 11. However, from the point of view of abstraction, it is important to maintain the hydrological characteristics of the site, continuing to work to the water level ranges set out in the Ecohydrological Guidelines and to the particular water level ranges which are observed on the site.
With the aid of field data (presented in Amec, 2012) and the groundwater model, the hydrological functioning of the Ant Broads and Marshes SSSI has been characterised and quantified. The model produces a flow regime consistent with the field data and conceptual understanding, and indicates that a small upward flow from the Crag meets a downward flow from rainfall recharge leading to the potential for a mixing zone. It is this mixing zone, more prevalent at the fen edges where the upland meets the fen, which is particularly sensitive to any hydrological changes. The mixing zone is created by the upwelling of base rich groundwater mixing with base-poor rainfall. A potential reduction in base-rich upwelling would reduce the proportion of base-rich water in the mixing zone.
A water balance method has been developed, which represents the proportion of Crag groundwater flowing to the shallow groundwater system, and is able to indicate the changes to the base-richness under different abstraction scenarios. Threshold levels have been placed on the water balance method output to help judge the scale of any changes due to abstraction. See Groundwater Summary Report, section 8 (Environment Agency, 2014a) for further details.
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Groundwater balance information has been extracted for model Cell H covering Middle Marsh which is the focus of concern. Information has also been extracted for Cell E on Sutton Broad and Cell J on Sharp Street. Cell E and Cell J also represent floodplain margins although these areas are not showing the changes in Sphagnum spp which have been recorded in Unit 3 and Unit 11 of Catfield Fen. Note that Cell J has been introduced immediately to the west of Cell C as this location is more appropriate to use with the water balance method. As with Cell C, Cell J is also a location covering the S24 ecological feature where Agency dip-wells have been installed.
Abstraction In-combination
As the main concern in relation to water chemistry was raised for SSSI Unit 11, the following discussion focuses on groundwater model Cell H.
Results from the water balance method indicate that for the historical scenario, post-1986 data generally stays within the range set by the highest naturalised Crag proportion and the (pre-1986) lowest historical Crag proportion, and only falls out of this range in 2 out of the 42 years of simulation, these being 1998 and 1999. The historical time-series post-1986 does not fall below the threshold set by the ‘10% less than the lowest historical Crag proportion’22.
The results for the historical level of abstraction post-1986 for Cell H are shown on Figure 8.8.a of the Groundwater Summary Report. This shows that the historical time-series post- 1986 generally follows the seasonal behaviour of the naturalised time-series and that the Crag proportion is reduced by less than 10% from the naturalised.
The Crag proportion results for the current fully licensed level of abstraction are shown on Figure 8.8.b of the Groundwater Summary Report. Again, the fully licensed time-series follows the seasonal behaviour of the naturalised time-series and generally stays within the range set by the highest naturalised Crag proportion and the pre-1986 lowest historical Crag proportion. The fully licensed time-series falls out of this range in 6 out of the 42 years of simulation, however, the current fully licensed time-series falls below the threshold set by the ‘10% less than the lowest historical Crag proportion’ on just one occasion, at the end of 1974.
For the period 1993 to date, the current fully licensed time-series plots on top of (i.e., matches) the historical time-series. This illustrates the fact that the fully licensed level of abstraction, including the reductions made to the AWS Ludham licence following the RoC solution in relation to the Upper Thurne Broads and Marshes SSSI, has been brought in line with the recent actual level of abstraction.
In addition to the water balance method, the measured pH values from water samples (presented in Figure 4.5 of the Groundwater Summary Report) have a range from roughly pH 4.8 to pH 8.5. A potentially significant result is that Dyke Type 123 waters show a pH range of pH 6.5 to pH 7.3, similar to Shallow Groundwater, and somewhat higher than Shallow Crag. This suggests that there is not a simple connection between base-richness and pH, and questions the degree to which base-richness is determining pH in the peat layer. The chemical concentrations also indicate that the groundwater throughout the aquifer
22 Highest naturalised Crag proportion: set by the maximum naturalised proportion across the full time-series Lowest historical Crag proportion: set by the lowest historical proportion prior to the end of 1986 10% less than the lowest historical Crag proportion: set by reducing the lowest historical proportion by 10% of the range between the highest naturalised proportion and the lowest historical proportion 23 Type 1 waters have a significant rainwater component and could also be influenced by Crag and/or Broad water (Amec, 2012)
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system is highly buffered and that it would be difficult to change the pH of the groundwater through changes to the balance of groundwater flows.
Based on this assessment, due to the amount of buffering within the groundwater system and with the hydrological functioning being maintained, the in-combination effect of abstraction on changes in water chemistry are considered to be insignificant.
Plumsgate Road Alone
By comparing the fully licensed scenario with the same scenario but with the Plumsgate Road abstraction set to zero, we are able to determine what the alone effect is from this abstraction. Results from the water balance method showing the proportions of Crag water reaching Layer 1 of the model have been produced. These are shown in the Groundwater Summary Report, Figure 8.8c for model Cell C, 8.9c for Cell E and 8.10c for model Cell J. The Plumsgate Road alone abstraction scenarios plot very close to or directly on top of the time-series for the current fully licensed abstraction scenario. This indicates that the effect of the Plumsgate Road abstraction alone on water chemistry is insignificant, even at fully licensed levels.
Ludham Road Alone
By comparing the fully licensed scenario with the same scenario but with the Ludham Road abstraction set to zero, we are able to determine what the alone effect is from this abstraction. Results from the water balance method showing the proportions of Crag water reaching Layer 1 of the model have been produced. These are shown in the Groundwater Summary Report, Figure 8.8d for model Cell H, 8.9d for Cell E and 8.10d for model Cell J. The Ludham Road alone abstraction scenarios plot very close to or directly on top of the time-series for the current fully licensed abstraction scenario. This indicates that the effect of the Ludham Road abstraction alone on water chemistry is insignificant, even at fully licensed levels.
8.7.1 Conclusion
Changes in water chemistry from the Plumsgate Road abstraction alone are considered insignificant as the hydrological functioning of the site is maintained.
Changes in water chemistry from the Ludham Road abstraction alone are considered insignificant as the hydrological functioning of the site in maintained.
We can conclude no adverse effect on the site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar through changes in water chemistry from either of the proposed abstractions either alone or in-combination with other abstraction.
8.8 Habitat Loss
In the context of this assessment, habitat loss may occur as a result of significant changes in flow/velocity regime, water levels and/or water chemistry, particularly in relation to the most sensitive features on the site (section 4).
In July 2013 Natural England conducted a survey of Catfield Fen and reported that the range and quality of the vegetation communities on the site was impressive, and water levels were consistent with the hydrological needs of the communities (Natural England, 2013d). However, the species composition of the vegetation communities Natural England have recorded show the percentage of Sphagnum spp. has changed within Unit 3 and Unit 11
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since the late 1980s. Natural England suggest that a change to the hydrological functioning of the site may be the cause of this change.
No similar change was reported following recent survey work by the Broads Authority and the RSPB at Sutton Broad and Sutton Fen (Natural England, 2013g). No change has been reported at Sharp Street.
As part of our assessment, and in light of Natural England reporting that the observed ecological changes at Catfield Fen could be interpreted as a trend, Natural England were asked what might the outlook might be for Catfield Fen, Sutton Broad, Sutton Fen and Sharp Street in the medium and long term. For Sutton Broad, Sutton Fen and Sharp Street, Natural England noted that they do not have clear evidence of ecological change indicating that these hydrological sub areas should be assessed as Unfavourable Declining in the medium or long term (Natural England, 2013g). For Catfield Fen, Natural England noted that whilst they do not know the rate or trajectory of change, there is sufficient evidence to reasonably assume that this is an ongoing trend which is likely to continue should all or some of the potential drivers remain unchanged (Natural England, 2013e).
Plumsgate Road Alone
Habitat loss is considered here as a potential consequence of a change in flow regime, water levels and/or water chemistry. The effect from the Plumsgate Road abstraction on the hazards listed above (8.5 to 8.7) has been shown to be insignificant as the hydrological functioning is maintained. Therefore we conclude the effect from Plumsgate Road alone does not lead to habitat loss.
Ludham Road Alone
Habitat loss is considered here as a potential consequence of changes in flow/velocity regime, water levels/table and/or water chemistry. The effect from the Ludham Road abstraction on the hazards listed above (8.5 to 8.7) has been shown to be insignificant as the hydrological functioning is maintained. Therefore we conclude the effect from Ludham Road alone does not lead to habitat loss.
Abstraction In-combination
The effect of abstraction on the hazards listed above (8.5 to 8.7) has been shown to be insignificant as the hydrological functioning of the site is maintained under fully licensed abstraction (Environment Agency, 2014). We conclude that abstraction in-combination does not lead to habitat loss.
8.8.1 Conclusion
Habitat loss as a result of the effect of the Plumsgate Road abstraction alone is considered insignificant as the hydrological functioning of the site is maintained.
Habitat loss as a result of the effect of the Ludham Road abstraction alone is considered insignificant as the hydrological functioning of the site in maintained.
We can conclude no adverse effect on the site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar through habitat loss from either of the proposed abstractions either alone or in-combination with other abstraction.
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8.9 Summary of the Potential Effect of Abstraction
Abstraction has been assessed in relation to the identified hazards to determine potential adverse effect on site integrity of The Broads SAC, Broadland SPA and Broadland Ramsar.
The effects of fully licensed abstraction in-combination have been assessed through the use of Decision Tables (Environment Agency, 2014c). Overall scores calculated by the Decision Tables for Assessment Cells C, E, G, H and I, with comparisons based on naturalised and historical time-series baselines, are in the low range, indicating that the hydrological functioning of the site is maintained and in line with the Conservation Objectives.
Assessment of the abstractions against each of the hazards shows an insignificant effect alone and in-combination with other licensed abstractions. The Plumsgate Road and Ludham Road abstractions do not effect hydrological change, or changes in species distribution, alone or in-combination with other abstraction.
There are other external factors which could also influence the ecology and hydrological functioning of the hydrological sub areas. section 9 and 10 detail the potential in-combination effect from other external contributing factors.
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9.0 Other Plans, Permissions or Projects
9.1 Other Agency permissions
We have identified several other Agency permissions within the Area of Interest for the consideration of potential in-combination effect. There are no waste permits within this area, though there has been pre-application advice given for an intensive farming installation at NGR TG 3899 2450 (Reference CP3330UC); however our records indicate that that no formal application has been received.
In addition, there are nine discharge consents that have been identified as either soakaways or discharges into ditches that flow into the Ant Broads and Marshes SSSI.
Out of these nine consents; • Five private discharges to water are classed as small discharges (less than 5m³ per day) and as they are more than 50 metres away from the site can be ruled out as having an in-combination effect on the site (Environment Agency, 2006) • Two sewage (non water company) discharges were affirmed at Stage 3 of RoC as not having an adverse effect on site integrity
The remaining two consents are listed below in Table 9.1, however, for the reasons given in the table, these have been shown to not be having an in-combination adverse effect on the European site.
Type of Consent Location Purpose Assessment of likely significant Agency Number effect permission Discharge EPRHP3729XY TG 37025 Public NE were consulted at the time of Consent 24210 conveniences issue and agreed with our (discharged into conclusions of no likely significant Stalham Dyke) effect on the European site when considered alone and in- combination. Discharge AW4NF174X TG 37300 Sewerage During the RoC this consent was Consent 24700 Network deemed as revoked and therefore Pumping Station was not included within the (Water assessment. As the discharge is Company) intermittent and no concerns have been reported (Environment Agency, 2014b) it is not considered any further as part of this assessment.
Table 9.1 Discharge Consents previously not assessed during RoC within the Area of Interest
9.2 Other competent authority permissions
As part of assessing the potential in-combination effects we have consulted other competent authorities to establish whether, since completing our Appendix 11 assessment of likely significant effect (Environment Agency, 2013a), they have consented further activities which need to be considered in-combination with the Plumsgate Road and Ludham Road permissions.
The following competent authorities were consulted; • Broads Authority
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• North Norfolk District Council • Norfolk County Council • Natural England
There are three permissions that have been issued by Norfolk County Council around the Catfield area however none of these are considered to be relevant24 permissions (Norfolk County Council, 2014). The Broads Authority (2014), Natural England (2014b) and North Norfolk District Council (2014) have all confirmed they have not granted any relevant permissions since those included within the Appendix 11 proforma.
9.3 Other plans or projects
We are aware of several management plans that exist across Sutton Broad, Sutton Fen, Catfield Fen and Sharp Street, these are shown in Table 9.2 below.
Hydrological Owned Managed Management Plan Reference sub area Catfield Fen Butterfly Butterfly Ant Broads and RSPB (no date) (Unit 3) Conservation Conservation in Marshes National partnership with Nature Reserve RSPB Management Plan Butterfly Conservation Catfield Fen Section Catfield Fen Privately owned Privately HLS Agreement Not publicly (Units 11 and managed available 35) Sutton Broad Majority owned RSPB Sutton Fen, Sutton RSPB (2013a) and Sutton by the RSPB High Fen and Drakes Fen Fen Management Plan, April 2013 – March 2018. Sharp Street Privately owned Privately HLS Agreement Not publicly managed available
Table 9.2. Management Plans associated with the hydrological sub areas of focus for this assessment
These management plans have been implemented on the grounds that they are deemed ‘necessary for the management of the nature conversation site’.
24 It is the responsibility of the competent authority to decide whether a plan project or permission is relevant under the Habitats Regulations.
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10.0 Other Contributing Factors
Contributing factors are those which have affected and are continuing to affect the condition of each interest feature on the European site, they are considered as the cumulative effect. This term is commonly used to include all of the plans and projects (described in section 9) together with: completed plans or projects; activities for which no consent was given or required; and natural processes (by natural mechanism and at a natural rate) (Natural England, 2001). The current condition of the interest features may be a reflection of the cumulative effect on those features.
The scope of this Appropriate Assessment focuses on the Plumsgate Road and Ludham Road abstraction proposals, and does not include an individual assessment of each contributing factor. We have however, deemed it appropriate to note their presence at the European site, and acknowledge their potential to influence the character of the European site. In this assessment we note the following factors.
• Surface Water management • Land management • Rainfall • Air quality • Climate change
These factors are outside of the remit of the Environment Agency and may need to be considered by other relevant organisations.
10.1 Surface Water Management
Surface water level management is crucial to maintaining optimal reedbed conditions on the European site. Active management of surface water levels via the operation of water management structures, identified in section 3.4 for the hydrological sub areas, may be a contributory factor to the condition of fens and reedbeds.
SSSI Unit 3 is managed by the RSPB who maintain water levels within the fen through sluice operation. This is done to enable management work and harvesting of reed or sedge when water levels exceed 55cm (as measured at the northern sluice, shown in Figure 3.6). Water level data for 1996 – 2012 has been provided by the RSPB (Annex 3 of Natural England, 2013f). Natural England note that this data indicates a declining trend in water levels, supported by anecdotal information from the RSPB highlighting changes in both vegetation and surface wetness within Unit 3 (similar to the anecdotal changes noted in Unit 11).
Our analysis of the water level data shows that there appears to have been a change in the way measurements were recorded from the gaugeboards in 2003 (Environment Agency, 2013c). Prior to 2003, manual readings were recorded based on the water level position below the top of the gaugeboard or ‘dip’. From 2003 onwards, data were recorded more conventionally as ‘stage’ – this is the height above the bottom of the gaugeboard, gauged from zero. The data appears to have been displayed so that the data prior to 2003 is also ‘stage’ rather than as ‘dip’ which was actually measured. This error was discovered by comparing against logger data which has been measuring ‘stage’ since June 2006.
Once the data over the whole monitoring period of the gaugeboards has been corrected, as shown in Figure 10.1, there does not appear to be a declining trend in the water level data over the whole monitored period from 1996 to 2013. This agrees with the findings of the Amec (2012) report and has not changed with the addition of more recent data.
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Figure 10.1 A comparison of internal and external system water levels over the whole monitored period
The RSPB have analysed a set of observations from 2002 to 2013, along with level data. This data shows a small change in the difference between water level in the internal and external systems. The RSPB identify a decreasing trend in internal water level, which is due to a mistake in recording the data. Corrected data does not show this trend. There are a number of factors influencing water level in the internal system, including water level management, silting of the external system and a decreased ability of the Commissioner’s Rond to retain water within the internal system.
The historic practice of adjusting levels to allow in water from the external system by land owners and managers has ceased due to the poor water quality of Barton Broad. It is likely that this would have significantly influenced surface water levels, however the impact of the cessation of this practice is unclear.
Shorter term changes in water levels can be seen by examining manually recorded data from the current gaugeboards. The logger data, installed in 2006, show short-term water level rises and falls which appear to be related to rainfall events (Amec, 2012). These events can be very marked. For example at the end of March 2008, water levels rose by approximately 10 cm in five days, reaching a level of 0.71 mAOD, and then fell back within a week to the pre-rainfall event levels. The sudden falls in level indicates that water can be rapidly lost from the dyke system. This may be by infiltration into or inundation of fen compartments, or by leakage out of the internal system (Amec, 2012).
Butterfly Conservation (2012) confirmed that water can be released from the internal system into the external system via the northern sluice to enable reed/sedge cutting and other management work. This occurs when water levels in the internal system exceed a 0.55m level on the sluice/gaugeboard and when external water levels and water quality permit this lowering.
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Water levels across the fen were, until recently, frequently altered through operation of the northern sluice both to allow water in from the external system and to drain water out. The influence of this extends throughout the whole internal system at Catfield Fen. Butterfly Conservation note that the default water management policy is to leave the sluice closed throughout. In exceptional circumstances they reserve the right to apply for consent to open the sluice, but it is understood that agreement must be made with the adjoining land owner at Catfield Fen (RSPB, no date).
Amec (2014e) note that water level management has changed over time. Historically it had been traditionally managed for reedbeds, requiring constant and careful alteration of water levels to maintain optimal conditions for reed. Currently there is no active management occurring on site which results in high water levels in the winter and low water levels in the summer, and is considered to be undesirable for reedbed maintenance.
Both the Sutton Broad and Sutton Fen hydrological sub areas are also managed by the RSPB 2013a) however there is no water level data available for further analysis of these units.
There is little information regarding water level data at Sharp Street, however there is data for a gauge board (Reference TG31/790, located at NGR TG 3706 1994 and shown on Annex 1) indicating the level of the water table above ground. The gauge is read manually once a month by the Environment Agency and in addition there is also a data logger recording levels at 15 minute intervals. The data set currently available runs from the end of August 2006 to early September 2013. The logger data indicates that the water table regularly fluctuates by 10 to 20 mm whilst following a seasonal trend, rising in the winter and dropping in summer, and seasonal fluctuations can be up to 400 mm. Over the last 7 years the water table appears to be at a consistent level, with a very slight upward trend since September 2012.
There is a HLS agreement between the landowner of Sharp Street and Natural England. We understand that the site is managed for nature conservation purposes.
In addition to the above management of water, there are water inputs from surface water runoff into the four hydrological sub areas, including runoff from roads, built up areas and agricultural runoff from the surrounding arable fields. The DWPP for the Ant Broads and Marshes SSSI (Natural England & Environment Agency, 2010) identifies SSSI Units 33 and 36 (within the Barton Broad and Crome’s Broad hydrological sub areas respectively), as being under pressure from agricultural runoff. Remedies have been defined in the DWPP, with the condition status of the two SSSI units listed as Unfavourable Recovering, in part due to these remedies. There are no reported problems at the areas of particular interest to this assessment (Sutton Broad, Sutton Fen, Catfield Fen and Sharp Street). Any interaction between abstraction and surface runoff as a change to water chemistry is not considered to be significant.
10.2 Land Management
Land management within the Ant Broads and Marshes SSSI has the potential to contribute towards changes in species distribution. Land management practices can promote the onset of terrestrialisation which may result in the infilling of former pond areas and a general rise in the ground surface. Terrestrialisation has the effect of both lowering the water table and can lead to the spread of other species which are less sensitive to changes in water table.
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At Catfield Fen, and in particular SSSI Unit 11, both the historical and current management of the site has been detailed within Catfield Fen – Notes on the Management of Catfield Fen Amec, 2014e). This report indicates that over the past 200 years Catfield Fen has been subject to a range of different management techniques, including grazing, commercial reed and sedge cutting, and currently now managed for nature conservation under a HLS agreement between the owner and Natural England. As previously mentioned, changes in the distribution of Sphagnum spp. have been highlighted at Catfield Fen, along with threat category of ‘changes in species distributions’ following the July 2013 condition survey (Natural England, 2013d).
Although no similar trends have been highlighted on Sutton Broad, Sutton Fen and Sharp Street, there are management activities taking place on these hydrological sub areas (noted in section 3.4). On Sutton Fen and Sutton Broad the RSPB have a management plan in place for their reserve (RSPB, 2013a). In addition, the IDB also have a plan in place to resolve an ochre problem related to the Sutton Pump (Broads IDB, 2013b). At Sharp Street, the landowner has a HLS agreement in place with Natural England.
The change in management from the use of traditional methods for commercial reed production, which aims to reduce litter and in turn prevent the spread of Sphagnum spp., by a process of cutting and burning (see section 2.2 of Amec, 2014e), and minimising terrestrialisation by removing peat to improve water circulation and rejuvenate the fen surface (see section 2.3 of Amec, 2014e), to the current conservation management practice cannot be ruled out as a possible contributory factor in the establishment and spread of Sphagnum spp. across the fen.
10.3 Rainfall
The Environment Agency has undertaken rainfall analysis has to assess whether there have been any significant trends in rainfall patterns across the European site, and particularly since 1986 when vegetation changes were first noted within the Catfield Fen hydrological sub area. The analysis is based on rainfall data from Barton Turf and Hall (the closest gauge to the Ant Broads and Marshes SSSI, approximately 3km west of the abstraction points at NGR TG 354 223) which has records dating from 1966, and data from Woodgate House gauge (approximately 21km west of the abstraction points at NGR TG 181 260) which has a continuous record from 1955 with part records back to 1933. This longer record was used to support the baseline record from Barton Turf and Hall. In addition, the flow record for Honing Lock Gauging Station on the River Ant (approximately 5km upstream of the northern boundary of the Ant Broads and Marshes SSSI at NGR TG 3311 2704) has also been reviewed to affirm the findings from the rainfall record, demonstrating the river’s response to rainfall patterns (Environment Agency, 2013b).
Analysis of the data revealed the following: • Rainfall has consistently increased since 1986, compared to the 1951-1986 mean. This increase averaged 59 mm/year from 1987 to 2012 and 97 mm/year since 1998. • The most significant increase in rainfall has been during the 3 months of high summer (between June-August). Since 1998 increasing summer rainfall accounts for 64% of the overall annual increase.
The above analysis indicates that there has been an increase in the rainfall over the period since change has been identified within the ecology of Catfield Fen, and this is likely to be a contributing factor to any changes in water chemistry.
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10.4 Air Quality
We have considered the potential impacts from airborne pollutants at the Ant Broads and Marshes SSSI. The Air Pollution Information System (APIS) has been used to make an assessment of background acid deposition and nutrient nitrogen deposition at the SSSI, and in particular at Catfield Fen.
APIS indicates that fen, marsh and swamp habitats are not sensitive to acidification, and therefore we have not considered the potential for acidification any further within our assessment.
APIS notes that the critical load range for valley mire, poor fen and transition mire at NGR TG 3698 2101 is 10-15kgN/ha/yr. The grid reference was chosen as an NGR indicative of a main habitat component of Ant Broads and Marshes SSSI, and in particular Catfield Fen. Background nitrogen deposition at the specified NGR is 18.34kgN/ha/yr which indicates that nitrogen deposition at Catfield Fen is already exceeding the critical load range.
The precise changes in water chemistry over time are unlikely to be quantified without (unavailable) historical evidence, but we expect APIS data to be both up to date and without any other supporting evidence, relevant. There is clearly an element of generality both spatially and temporally with APIS data, but the system provides the best available data on background air quality levels at present. We have therefore based our conclusions of air quality effects upon this.
Due to the existing nitrogen deposition exceedence, we can assume that any effects on water chemistry by nitrogen deposition would already be occurring at the fen, and as such we can subsequently assume that any baseline data used in the water chemistry assessment (Environment Agency, 2014a) has already taken account of any nitrogen deposition from aerial sources at the European site.
There is also a generic assumption that the effect of nitrogen deposition from aerial sources on aquatic habitats is particularly limited. There may be some notable effects to small water bodies which have no flow within them, however in the case of the Ant Broads and Marshes SSSI, flow has clearly been established. Where flow is present water quality is generally maintained by other characteristics such as dissolved oxygen, to buffer any potential nitrogen deposition effects.
There are no extra process contributions of nitrogen from the proposed abstraction activities nor any additional sources that we are aware of; therefore nitrogen deposition is considered not to make a significant contribution to changes in water chemistry and is not considered any further as part of this assessment.
10.5 Climate Change
Warming of the global climate system is clear from temperature records around the world. It is extremely likely that the major cause of this is human activity, particularly the burning of fossil fuels. Continued emissions will cause further global warming and changes to other aspects of climate including rainfall. For the UK the most likely future is one of hotter, drier summers and warmer, wetter winters.
In the East of England, the UK Climate Projections 2009 show that by the 2050s, under a medium scenario of future greenhouse gas emissions, we will experience the following changes in climate, shown in Table 10.1.
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Central Likely range Change estimate Winter mean temperature 2.2 1.1 to 3.4 Summer mean temperature 2.5 1.2 to 4.3 Winter mean precipitation +14% +2 to +31% Summer mean precipitation -16% -37 to +6%
Table 10.1 Climate projections for 2050. NB. Temperature shown in degrees Celsius.
These changes will mean that it will be increasingly challenging to balance abstraction of water resources with the need to protect the environment.
We account for changing pressures from climate change by placing time limits on abstraction licences (Environment Agency, 2013c). On expiry of a licence, we have the opportunity to re-assess the long term sustainability of an abstraction, and where appropriate, make changes to the licence.
10.6 Summary of Other Contributing Factors
We have considered the potential cumulative effects from other contributing factors already known to be, or likely to be, existing at the European site. Whilst Natural England (2013e) consider it is unlikely that the Conservation Objectives for the European site will change significantly over the medium and long term, changes shown by vegetation surveys over the last 30 years at Catfield Fen appear to indicate an unknown rate or trajectory of change which could potentially continue. The driver for this is currently unknown but could be due to a number of factors discussed above. However we consider abstraction insignificant as we have shown that the hydrological functioning of the site is maintained.
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11.0 Environment Agency Conclusion
We have assessed the potential for abstraction from the Plumsgate Road and Ludham Road abstractions, considered both alone and in-combination with other projects, plans and permissions and prevailing environmental conditions.
Site integrity is defined in this context as “The coherence of its ecological structure and function, across its whole area, that enables it to sustain the habitat, complex of habitats and/or levels of populations of the species for which it was classified” (Natural England, 2004).
Whilst relatively small in spatial terms25 compared to the extent of the European site as a whole, the four hydrological sub areas identified in this assessment support the interest features for which the SAC, SPA and Ramsar are designated. Calcareous Fens with Cladium mariscus and species of the Caricion davallianae which comprises amongst others, S24 NVC communities, is considered to be particularly rare as its total extent in the United Kingdom is estimated to be less than 1,000 hectares. The areas within the Ant Broads and Marshes SSSI are considered to be one of the best in the United Kingdom.
The Fen Orchid is found at both Sutton Broad and Catfield Fen. These areas are two of only four known localities for the Fen Orchid in The Broads, and a feature for which The Broads SAC is designated.
Our assessment has focussed on the potential effect on three NVC communities (S24, S27 and M24) and the Fen Orchid (forming four of the European features; Calcareous Fens, Transition Mires and Quaking Bogs, Molinia Meadows and Fen Orchid). Natural England have confirmed these to be the most sensitive features for the European site, and protection of these features confers protection to all other features of The Broads SAC and Broadland SPA and Broadland Ramsar.
The following principles have applied in our assessment (in line with the Conservation Objectives for The Broads SAC, Broadland SPA and Broadland Ramsar):
• The Precautionary Principle26 • That failure against one feature will lead to the failure of the overall assessment • Failure of features would include changes in extent of communities, loss of a community, loss of key indicator species, increases or appearance of other species seen as negative • Where changes may be clearly linked to natural change then such change may not be considered to be negative
The evidence presented in this assessment and supporting technical documents shows that the hydrological functioning of the Ant Broads and Marshes SSSI, as a component part of The Broads SAC, Broadland SPA and Broadland Ramsar would not be compromised by the current licensed level of abstraction and that the hydrological and chemical requirements of the designated ecological features would continue to be met. The threat categories of changes in species distribution and hydrological changes included on the July 2013
25 The total surface area of the four hydrological sub areas of interest to these renewal applications represents 4.49% of the total area of The Broads SAC and 4.80% of the Broadland SPA & Broadland Ramsar.
26 The Precautionary Principle underpins the Habitats Directive and Regulations. When considering whether a plan or project will affect European designated sites, the competent authority must be certain that there will be no adverse effect and where doubt remains as to the absence of adverse effects, the plan or project must not be authorised. This is the known as the Precautionary Principle.
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condition status are accounted for within this assessment. As part of our assessment we have noted there is the potential for effects from other contributing factors already known to be, or likely to be, existing at the European site.
We consider that abstraction is sustainable in terms of maintaining the conservation status of the designated features, based on their Conservation Objectives.
The Environment Agency can conclude no adverse effect from abstraction licences AN/034/0009/008 Plumsgate Road and AN/034/0009/009 Ludham Road the on Ant Broads and Marshes SSSI – component of The Broads SAC, Broadland SPA and Broadland Ramsar.
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12.0 Glossary
Appropriate The Habitats Regulations do not specify how the assessment of adverse Assessment effect should be undertaken, but describe it simply as ‘an appropriate assessment’. We use the term to describe the assessment we make at Stage 3 of whether the permission will have an adverse effect on site integrity. The assessment is sent to Natural England for consultation.
Assessment Cell The NEAC groundwater model uses a grid comprising 200m x 200m squares. Each square is known as a ‘cell’.
Asset Every five years, each water company in England and Wales prepares an Management Plan AMP that sets out proposed spending plans for the next five years. (AMP)
Appendix 11 A form used at Stage 2 to record the likely significant effect of a permission alone and in-combination on a designated site and is sent to Natural England for consultation.
Area of Interest The Area of Interest is identified on the map of the Bure, Ant and Thurne catchments (Fig. 3.1 in the Groundwater Summary Report, Environment Agency, 2014a). The Area of Interest is bounded by the Ant Broads and Marshes to the west and north, the Upper Thurne Broads and Marshes to the east, and the Rivers Ant and Thurne to the south.
Broads Authority The Broads Authority is a statutory body with duty to manage the Broads for (BA) the purposes of: • conserving and enhancing the natural beauty, wildlife and cultural heritage of the Broads; • promoting opportunities for the understanding and enjoyment of the special qualities of the Broads by the public; and • protecting the interests of navigation. It must also consider the needs of agriculture and forestry, and economic and social interests of those in the Broads.
Condition status The condition of the SSSI land in England is assessed by Natural England, using categories across England, Scotland, Wales, and Northern Ireland through the Joint Nature Conservation Committee. There are six reportable condition categories (or statuses): Favourable; Unfavourable Recovering; Unfavourable No Change; Unfavourable Declining; Part Destroyed and Destroyed.
Conservation A statement of the nature conservation aspirations for the site, expressed in objective terms of the favourable condition that the species and/or habitats for which the site has been selected should attain.
Decision table This details the options that have come out the SOP in the form of a ‘risk- matrix’. The risk matrix is applied by assigning a ‘risk category’ to each site. The risk matrix takes into account the scale and frequency of breaches to primary criteria thresholds, in the context of changes to the overall hydrological functioning, the general level of fully licensed and historical abstraction in the catchment surrounding the site and uncertainties around the ecological ‘evidence’ available, the conceptual understanding or the
model representation. In addition, professional judgement will be applied to decide on the risk category as appropriate.
Destroyed A condition status category of a SSSI. Lasting damage has occurred to an entire designated feature on the unit such that the feature has been irretrievably lost (no amount of management will bring this feature back). This feature will never recover in the unit e.g. a finite mineralogical feature has been totally removed from its surroundings without consent and is therefore lost forever.
Diffuse water A plan to reduce the impact of diffuse water pollution where this is preventing pollution plan a SSSI from reaching Favourable condition status. It is produced by the Environment Agency and Natural England and identifies causes, remedial actions and monitoring.
Environmental The environmental outcome for the site can be regarded as realising the outcomes conservation objective of each of the designated features, which is to achieve favourable conservation status as detailed within the Conservation Objectives.
Environmental Environmental Stewardship is an agri-environmental scheme which offers Stewardship (ES) payments to farmers and land managers in England for effective land management to protect and enhance the environment and wildlife.
European The EC is the executive body of the European Union responsible for Commission (EC) proposing legislation, implementing decisions, upholding the Union’s treaties and day-to-day running of the EU. There are 28 Commissioners who are collectively responsible before the European Parliament.
European Sites Also known as Natura 2000 sites. This term has been used to describe all the sites that have been designated on a European scale. In this case it refers to The Broads SAC, Broadland SPA and Broadland Ramsar.
Favourable A condition status category of a SSSI. The designated feature(s) within the unit are being adequately conserved and the results from monitoring demonstrate that the feature(s) in the unit are meeting all the mandatory site specific monitoring targets set out in the FCT. The FCT sets the minimum standard for favourable condition for the designated features and there may be scope for the further (voluntary) enhancement of the features/unit. A unit can only be considered favourable when all the component designated features are favourable.
Habitats Directive The commonly used term for Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora.
Habitats The abbreviated term for the Conservation (Natural Habitats &c.) Regulations Regulations 1994, the legislation which transposes the requirements of the Habitat Directives into UK law.
Habitat A coarse screening exercise filtering out permissions that could not Regulations conceivably have an effect on the interest features of any Natura 2000 site. Assessment: Function-specific screening criteria (usually distance related) are used to Stage 1 determin whether a permission is relevant to a Natura 2000 site. If relevant, further assessment is required at Stage 2.
Habitat A second screening exercise and basic risk assessment identifying: potential Regulations hazards introduced by the permission, interest features that are sensitive to Assessment: these hazards, paths by which the sensitive interest features could be Stage 2 exposed to the hazards. The aim is to filter out permissions that are not likely to have a significant effect on a Natura 2000 site. If a permission may have a likely significant effect further assessment is required at Stage 3.
Habitat A site specific ‘appropriate assessment’ is undertaken to establish whether Regulations the permission could have an adverse effect on the integrity of a Natura Assessment: 2000 site. Stage 3
Habitat Dependent on the conclusions of Stage 3, new permissions are either Regulations granted, refused or referred to the Secretary of State or Welsh Minister. Assessment: Stage 4
HLS Higher Level Stewardship (HLS) is one element of the Environmental Stewardship (ES) scheme – a government scheme that is open to all farmers, land managers and tenants in England. It is a voluntary scheme, designed to deliver environmental benefits in high priority areas.
Hydrological sub A geographic area representing part of the Ant Broads and Marshes SSSI, area there are nine hydrological sub areas of the Ant Broads and Marshes SSSI.
IDB An Internal Drainage Board (IDB) is a local public authority established in areas of special drainage need in England and Wales. IDBs were established by the government under the Land Drainage Act 1930 and today operate under the Land Drainage Act 1991. An IDB’s primary role is to manage water levels and reduce the risk of flooding within their districts using their permissive powers. Much of their work involves the maintenance and improvement of watercourses and related infrastructure.
Interest Feature The Interest Features are the protected habitats and species, for which a Natura 2000 site has been designated as of European importance.
Joint Nature The statutory advisor to the UK Government on national and international Conservation nature conservation. Committee (JNCC)
Meteorological MORECS is used by the Meteorological Office to derive rainfall, evaporation Office Rainfall and and soil moisture information. MORECS can be used to: design and predict Evapotranspiration river flows; monitor and predict evaporation losses; plan and understand Calculation drainage, subsidence and drought issues. System (MORECS)
Northern East A numerical model of groundwater flow systems in the area of East Anglia. Anglian Chalk Groundwater model (NEAC)
Natura 2000 The European network of protected sites established under the Habitats Network Directive. This includes SACs and SPAs designated under the Birds Directive.
Natural England Natural England is the non-departmental public body of the UK government (NE) responsible for ensuring that England's natural environment, including its land, flora and fauna, freshwater and marine environments, geology and soils, are protected and improved. It is a statutory requirement that the Environment Agency consults Natural England when determining any licences which are relevant to a SSSI and/or European site.
Naturalised The baseline groundwater conditions in the absence of all abstraction and discharges.
National Grid The National Grid is the map reference system used on all Ordnance Survey Reference (NGR) maps to identify the position of any feature.
National Nature These sites often contain nationally important populations of flora and fauna. Reserve (NNR) They are managed to conserve their habitats or to provide special opportunities for scientific study of the habitats communities and species represented within them.
National The NVC is a comprehensive classification and description of the plant Vegetation communities of Britain, each systematically named and arranged and with Classification standardised descriptions for each. (NVC)
Part Destroyed A condition status category of a SSSI. Lasting damage has occurred to part of the designated feature on the unit such that it has been irretrievably lost and will never recover (no amount of management will allow the feature to ever reach favourable condition). Conservation work may be needed on the residual interest of the unit. If more than one feature occurs in a unit, but only one is considered part destroyed, consideration should be given to reunitising out the destroyed area.
Plans, Any activity requiring formal consent from the Environment Agency or Permissions or another competent authority. The Habitats Directive requires assessment of Project (PPP) the potential impacts or effects of PPPs on a designated site.
Precautionary The Precautionary Principle underpins the Habitats Directive and Principle Regulations. When considering whether a plan or project will affect European designated sites, the competent authority must be “convinced” that there will be no adverse effect and where doubt remains as to the absence of adverse effects, the plan or project must not be authorised. This is known as the Precautionary Principle.
Priority Feature Some of the natural habitats and species listed in the Habitats Directive and for which SACs have been selected are considered to be particular priorities for conservation at a European scale and are subject to special provisions in the Directive.
Pump test A pump test is a method of estimating borehole performance, yield, the sphere of influence of the borehole and the aquifer characteristics (i.e. the aquifer’s ability to store and transmit water, aquifer extent and possible hydraulic connection to surface water). A pumping test consists of pumping groundwater from a borehole, usually at a constant rate, and measuring water levels in the pumped borehole and monitoring the levels in any nearby boreholes (observation boreholes) and/or surface water features during and
after pumping. Pumping tests can last from hours, days or weeks in duration, depending on the purpose of the pumping test.
Public Water Provision of water to the public by a regulated water company. Abstraction Supply (PWS) licences for the purpose of PWS permit abstraction of comparatively large quantities of water.
Q95 The flow equalled or exceeded 95% of the time.
Ramsar Wetlands of international importance designated under the Convention on Wetlands of International Importance especially as Waterfowl Habitat, signed in Ramsar, Iran, 1971.
Recent Actual The groundwater conditions taking into account actual abstractions and discharges over the period 2006 - 2010.
Regulation 48 Under the Conservation (Natural Habitats &c) Regulations 1994 Reg 61 is (now Regulation an ‘assessment of implications for European sites and European Offshore 61) marine sites’. A competent authority, before deciding to undertake, or give any consent, permission or other authorisation for, a plan or project which – (a) is likely to have a significant effect on a European site or a European offshore marine site (either alone or in combination with other plans or projects), and (b) is not directly connected with or necessary to the magagement of that site, must make an appropriate assessment of the implications for that site in view of that site’s conservation objectives.
Regulation 50 Under the Conservation (Natural Habitats &c) Regulations 2010 Reg 63 is a (now Regulation ‘Review of existing decisions and consents’. Where a permission has been 63) granted before a site has become designated, a component authority must review the permission and affirm, modify or revoke it.
Real Fully The scenario in which all abstractors in the area take the legal maximum Licensed (RFL) quantities permitted by their licences.
Review of The term used for the programme, carried out between 2000 and 2010, to Consents (RoC) review the effects of all the existing permissions that had been granted without consideration of the Habitats Regulations.
Restoring A programme of work that identified, investigates and solves environmental Sustainable risks or problems caused by unsustainable licensed water abstraction Abstraction (RSA) throughout England and Wales.
Royal Society for A UK conservation charity which owns and manages a number of nature the Protection of reserves for birds and other wildlife. Birds (RSPB)
Special Area of A statutory European designated site (designated under the Habitats Conservation Directive), as a component of a protected areas network, known as ‘Natura (SAC) 2000’.
Site Action Plan A multi-functional document compiled at Stage 4 of the Review of Consents (SAP) process, it includes the following information;
• A summary of what is known; • The Environmental Outcome(s) to be achieved;
• The options available to achieve this; • An appraisal of options within the context of the principles underlying Stage 4; • And the preferred option.
This report provides the justification for Appendix 19 decisions.
Site Integrity This is the coherence of a site’s ecological structure and function, across its whole are that enables it to sustain the habitat, complex of habitats and/or the levels of populations of the species for which it was classified.
Site Option Plan Prepared at the start of Stage 4 of the RoC assessment process. A SOP (SOP) consists of a report with the purpose to confirm the predicted impacts of abstraction on the hydrological regime and to identify whether these impacts are acceptable or unacceptable in terms of their effects on the ecology of the site. The SOP also identifies any changes which the Agency believes are necessary to achieve the RoC Stage 4 Environmental Outcomes and to ensure no adverse effect on site integrity will make general proposal as to how the changes would be achieved.
Special Protection A statutory European designated site (designated under the European Birds Area (SPA) Directive 1979), as a component of a protected area network called Natura 2000.
Site of Special Protected areas which contain some of the finest wildlife and geology in Scientific Interest England and Wales they are protected under the Wildlife and Countryside (SSSI) Act 1981, as amended by the Countryside and Rights of Way (CRoW) Act 2000 and the Natural Environment and Rural Communities (NERC) Act 2006.
SSSI unit SSSI units are divisions of SSSIs used to record management and condition details. Units are the smallest areas for which Natural England gives a condition assessment. The size of units varies greatly depending on the types of management and the conservation interest.
Standard Deviation In statistics, the standard deviation shows how much variation or dispersion (SD) from the average exists. A low SD indicates that the data points tend to be close to the average, whereas a high SD indicates that the data points are spread out over a large range of values.
Stockade Theory A theory by Professor Gilvear of Stirling University to raise awareness of the hydrological significance of the licensed volumes of groundwater being abstracted nearby to Catfield Fen and the role of near surface catchment hydrology to the Fen water balance.
Condition threat/ Risks to a site’s condition status which could lead to a decline in quality are Threat category referred to as ‘Condition Threats’. Condition threats could include the impact of development, changes in land management regimes or invasion of non- native species. It is Natural England’s role to identify factors that have a reasonable chance of preventing the attainment, or maintenance of, favourable condition. Once identified, actions are implemented to address these factors either by Natural England or in agreement with other relevant organisations.
Unfavourable A condition status category of a SSSI. The unit/feature is not being Declining conserved and will not reach favourable condition unless there are changes to site management or external pressures. The site conditions is becoming progressively worse, and this is reflected in the results of monitoring over time, with at least one of the designated features mandatory attributes not meeting its target (as set out in the site specific FCT) with the results moving further away from the desired state. The longer the SSSI unit remains in this poor condition, the more difficult it will be, in general, to achieve recovery.
Unfavourable No A condition status category of a SSSI. An interest feature may be retained in Change a more-or-less steady state by repeated or continuing damage; it is unfavourable but neither declining nor recovering. In rare cases, an interest feature might not be able to regain its original condition following a damaging activity, but a new state might be achieved.
Unfavourable A condition status category of a SSSI. Often known simply as ‘recovering’. Recovering Units/features are no yet fully conserved but all the necessary management mechanisms are in place. At least one of the designated feature(s) mandatory attributes are not meeting their targets (as set out in the site specific FCT). Provided that the recovery work is sustained, the unit/feature will reach favourable condition in time.
Water Balance A hydrochemical mixing model, developed to assess the potential change in Method water chemistry under fully licensed abstraction.
Water Level An approach devised to manage river systems which impact upon SSSIs. Management Plan The plans are used to help determine the water levels required for a given (WLMP) area, so that SSSIs can be brought into favourable or unfavourable recovering condition. WLMPs are site specific, contain objectives and are reviewed periodically.
Yare and North A numerical model of groundwater flow systems in the area of north east Norfolk Norfolk. Groundwater Model (YNN)
13.0 References
Note: Redactions have been made to remove any information that would allow for the location of public water supply abstraction to be identified. This is in line with guidance issued by DEFRA. If you wish to view the un-redacted documents, these can be made available at either our Norwich or Ipswich offices. Please contact [email protected] to arrange an appointment.
Amec (2012) Catfield Fen Investigation – available at link under the heading ‘October 2012’.
Amec (2014a) Test Pumping Technical Note. Figure 1 has been redacted
Amec (2014b) Soil Moisture Technical Note. Figure 5.1 has been redacted
Amec (2014c) Decision Table Technical Note
Amec (2014d) Groundwater Model Grid Cell size Technical Note
Amec (2014e) Catfield Fen – Notes on the Management of Catfield Fen
Broads Authority, (2006) Barton Broad Water Space Management Plan 2006-2011 Available at: http://www.broads-authority.gov.uk/projects/barton-broad/barton-broad-water-space- management-plan.html
Broads Authority (2011) How Hill NNR Management Plan: 2011/12 -2015/16.
Broads Authority (2012) Cromes Broad query with Natural England. Email from The Broads Authority, dated 16 November 2012.
Broads Authority (2013a) Broads Authority comments to Natural England and the Environment Agency on the appropriate assessment on two licences AN/034/0009/008 and AN/034/0009/009 on Ant Broads and Marshes SSSI part of the Broadland SPA/Ramsar and The Broads SAC. 28 November 2013.
Broads Authority (2013b) Broadland Fens - Condition Assessment 2011 Ant Valley Fens.
Broads Authority (2014) Relevant permissions response. Email from the Broads Authority, dated 15 January 2014.
Broads Internal Drainage Board (2013a) Smallburgh IDB Sutton Pump. Email from the IDB, dated 31 January 2013.
Broads Internal Drainage Board (2013b) Broads IDB at Catfield. Email from the IDB, dated 01 May 2013.
Butterfly Conservation (2012) Catfield Unit 3 information. Email from Butterfly Conservation, dated 11 December 2012.
Ecology Land & People (2010) Fen Plant Communities of Broadland: Results of a comprehensive survey 2005-2009. Undertaken on behalf of the Broads Authority and Natural England.
Entec (2001). Hydro-ecological Review of European Sites within the Yare & North Norfolk Groundwater Resource Investigation Area: Ant Broads and Marshes. Final Report for the Environment Agency, Anglian Region, September 2001.
The following sections of this report have been redacted; p.65 Abstraction location removed p102/103 recommendations- abstraction location removed Table 5.1 Removed, shows abstraction location. Table 5.2 Removed, shows abstraction location. Table 5.3 Removed, shows abstraction location. Table 5.4 Removed, shows abstraction location. Figure 5.1 Removed, shows abstraction location. Appendix A p.14 piezometer location in relation to PWS abstraction location removed. Figure 14 Removed, shows abstraction location. Figure 15 Removed, shows abstraction location Figure 16 Removed, shows abstraction location ‘Appendix 2’ (Within Appendix A) Removed, abstraction location.
Entec (2006). Habitats Directive Review of Consents Stage 3 Hydrological Impact Assessment: Ant Broads and Marshes SSSI. Report for the Environment Agency, September 2006.
Entec (2010). Catfield Fen – An Assessment of Monitoring for Regulatory Purposes. Technical Note for the Environment Agency, July 2010.
The following sections of this report have been redacted; Section 5, Geology, page 4, reference to PWS abstraction removed P.6 location removed P.14 location removed Appendix A, figure A1- removed, shows abstraction location.
Environment Agency (2009) Summary Note - Technical approach, criteria and thresholds applied for inland sites – Norfolk Valley Fens. Prepared by U. Buss, January 2009.
Environment Agency (2010a) Operational Instruction 183_01, Habitats Directive: taking a new permission, plan or project through the Regulations
Environment Agency (2010b), Site Action Plan for Ant Broads and Marshes, Alderfen Broad and Broad Fen SSSI’s, January 2010
Environment Agency (2010c). Influence of abstraction under 7/34/09/*G/0144B on Crag groundwater levels. Unpublished report by the Environment Agency, Anglian Region, Eastern Area. Report prepared by G.Sharpin.
Environment Agency (2010d) Protecting the plant communities and rare species of fen and mire wetland systems - Ecohydrological guidelines for lowland wetland plant communities - Fens and Mires, update March 2010.
Environment Agency (2010e) Site Action Plan for the Upper Thurne Broads and Marshes, January 2010.
Environment Agency (2011) Environment Agency appropriate assessment: Pembroke Power Station Environmental Permit. November 2011, prepared by C. Rockliff.
Environment Agency (2013a) Appendix 11 – Habitats Directive: Form for recording likely significant effect (Stage 2) available at link under the heading ‘Late July 2013’.
Environment Agency (2013b) Recent Trends in Rainfall Patterns – Ant Broads and Marshes, North East Norfolk, 31 December 2013. Report prepared by P.J. Willett.
Environment Agency (2013c) RSPB water level analysis. Report prepared by M. Ramscar
Environment Agency (2013d) Managing water abstraction, May 2013.
Environment Agency (2014a) Groundwater Summary Report
The following sections of this report have been redacted; Figures 1.1, 1.2, 3.1, 6.1 and 7.3 as they all show the location of a public water supply abstraction.
Environment Agency (2014b) Discharge consent information. Internal email, dated 18 March 2014.
European Commission (2001) Assessment of Plans and projects Significantly Affecting Natura 2000 Sites: Methodological Guidance on the provisions of Article 6(3) and 6(4) of the Habitats Directive 92/43/EEC.
Gilvear D.G. (2012) Cones of depression and catchment water fluxes in the vicinity of Catfield fen – the impact of groundwater abstraction (the stockade theory) – method of assessment, 22 August 2012.
Joint Nature Conservation Committee (1998) Statement on Common Standards Monitoring Available at: http://jncc.defra.gov.uk/page-2323-theme=default [Accessed 18 March 2014]
Joint Nature Conservation Committee (2006) Common Standards Monitoring for Designated Sites: First Six Year Report. [Accessed 18 March 2014]
Joint Nature Conservation Committee (2011) – Standard Data Form for The Broads SAC. [Accessed 18 March 2014]
Joint Nature Conservation Committee (2014a) - The Broads SAC http://jncc.defra.gov.uk/protectedsites/sacselection/sac.asp?EUcode=UK0013577 [Accessed 18 March 2014]
Joint Nature Conservation Committee (2014b) – Habitat account - Raised bogs and mires and fens: 7210 Calcareous fens with Cladium mariscus and species of the Caricion davallianae http://jncc.defra.gov.uk/protectedsites/sacselection/habitat.asp?FeatureIntCode=H7210 [Accessed 18 March 2014]
Joint Nature Conservation Committee (2014c) – Habitat account - Raised bogs and mires and fens: 7140 Transition mires and quaking bogs http://jncc.defra.gov.uk/protectedsites/sacselection/habitat.asp?FeatureIntCode=H7140 [Accessed 18 March 2014]
Joint Nature Conservation Committee (2014d) – Habitat account - Natural and semi-natural grassland formations: 6410 Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae) http://jncc.defra.gov.uk/protectedsites/sacselection/habitat.asp?FeatureIntCode=H6410 [Accessed 18 March 2014]
Natural England (1974) Site Citation: Ant Broads and Marshes SSSI, Available at: http://www.sssi.naturalengland.org.uk/Special/sssi/sssi_details.cfm?sssi_id=1000501
Natural England (2001) Habitats regulations guidance note: Alone or in combination, May 2001.
Natural England (2004) European Sites Guidance: Internal Guidance to decisions on “site integrity”, May 2004
Natural England (2005) Views about Management
Natural England (2008) Individual designated interest features of the Ant Broads & Marshes SSSI of The Broads SAC, Broadland SPA and Ramsar Conservation Objectives v2.1 (Draft version).
Natural England (2009) RoC Stage 4 Summary Note. Email from Natural England, dated 09 March 2009.
Natural England & Environment Agency (2010) The Diffuse Water Pollution Plan for the Ant Broads & Marshes SSSI, dated 17 November 2010.
Natural England et al (2011) A compendium of ecological and eco-hydrological evidence from Catfield Fen, Norfolk, 31 January 2011.
Natural England (2013a) ‘Report 1’ - Natural England Report of Evidence and Advice to the Environment Agency for Ant Broads & Marshes SSSI, May 2013.
Natural England (2013b) ‘Report 2’ – Natural England Report of Evidence and Advice to the Environment Agency for Ant Broads & Marshes SSSI Part 2, June 2013.
Natural England (2013c) ‘Report 3’ – Natural England Report of Evidence and Advice to the Environment Agency for Ant Broads & Marshes SSSI Part 3, June 2013.
Natural England (2013d) ‘Report 4’ – Natural England Report of Evidence and Advice to the Environment Agency for Ant Broads & Marshes SSSI Part 4, July 2013.
Natural England (2013e) ‘Report 5’ – Natural England response to questions and points of clarification requested by EA September 5 2013, 13 September 2013.
Natural England (2013f) ‘Report 6’ – Natural England comments on recent information provided by Mr Harris to the Environment Agency, 03 October 2013.
Natural England (2013g) ‘Report 7’ – Natural England Ecological Report 7. Evidence and Advice to the Environment Agency for Ant Broads & Marshes SSSI.
Natural England (2013h) Sutton Broad and Fen information. Email from Natural England, dated 11 March 2013.
Natural England (2013i) Catfield sensitive features. Email from Natural England, dated 13 August 2013.
Natural England (2013j) Natural England response to EA questions of August 8 2013. Email from Natural England, dated 22 August 2013.
Natural England (2014a) Conservation objectives for Ant Broads and Marshes. Email from Natural England, dated 12 February 2014.
Natural England (2014b) Relevant permissions response. Email from Natural England, dated 26 February 2014.
Natural England (2014c) Condition of SSSI units Available at: http://www.sssi.naturalengland.org.uk/Special/sssi/reportAction.cfm?report=sdrt13&category=S &reference=1000501 [Accessed 18 March 2014]
Norfolk Wildlife Trust (2005), Management Plan for NWT Barton Broad and Catfield Fen: April 2003 – March 2008. Please note that a copy of this report is only available on request to Norfolk Wildlife Trust.
Norfolk County Council (2014) Relevant permissions response. Email from Norfolk County Council, dated 27 January 2014.
North Norfolk District Council (2014) Relevant permissions response. Email from Norfolk Norfolk District Council, dated 20 January 2014.
RSPB (no date) Ant Broads and Marshes National Nature Reserve Management Plan – Butterfly Conservation – Catfield Fen Section – 2013-2018. Prepared by the RSPB on behalf of Butterfly Conservation.
RSPB (2012) Additional evidence and information re. water abstraction near Catfield Fen. Prepared by Richard Mason, Sutton Fen Site Manager, RSPB dated, 07 December 2012.
RSPB (2013a) Sutton Fen, Sutton High Fen and Drakes Fen Management Plan, April 2013 – March 2018.
RPSB (2013b) Licence renewal applications to extract water from Plumsgate Lane and Ludham Road. Letter from the RSPB to Simon Barlow (Environment Agency), dated 06 December 2013.
Annex 2: Site Designation Hierarchy
European and Hydrological sub NEAC groundwater Nationally designated SSSI SSSI unit International Designation area model assessment cell The Broads SAC Alderfen Broad Unit 10 Cell E Sutton Broad Broadland SPA Ant Broads & Marshes Unit 30
Broadland Ramsar Barnby Broad & Marshes Sutton Fen Units 8, 10, 23, 24
Broad Fen, Dilham Units 2, 6, 8, 12, 13, 16, 18, Barton Broad Bure Broads & Marshes 20, 21, 25, 26, 27, 32, 33
Burgh Common & Muckfleet Marshes Unit 3 Cell I Calthorpe Broad Catfield Fen Unit 11 Cell H, Cell G Cantley Marshes Unit 35
Crostwick Marshes Unit 4 Cell C, Cell J Sharp Street Damgate Marshes, Acle Unit 6 Decoy Carr, Acle Crome's Broad Units 4, 5, 36 Ducan's Marsh, Claxton Barton Fen Units 1, 2, 9, 17, 23, 26, 29, 31 Geldeston Meadows Reedham Marshes Unit 22 Hall Farm Fen, Hemsby Hall Fen Units 5, 7, 16, 37 Halvergate Marshes
Hardley Flood
Limpenhoe Meadows
Ludham-Potter Heigham Marshes
Poplar Farm Meadows, Langley
Priory Meadows, Hickling
Shallam Dyke Marshes, Thurne
Smallburgh Fen
Sprat's Water & Marshes, Carlton
Colville Stanley & Alder Carrs, Aldeby
Trinity Broads
Upper Thurne Broads & Marshes
Upton Broad & Marshes
Yare Broads & Marshes
Annex 3: Distribution of SAC Features across the Ant Broads & Marshes SSSI
Ant Broads & Marshes SSSI Hydrological Sub Units Barton The Broads SAC – designated Barton Fen Reedham Sutton Sutton Fen Broad Catfield Fen Sharp Crome's features (Units 2, 6, 8, (Units 1, 2, 9, Marshes Hall Fen Broad (Units 8, 10, (Units 3, 11, Street Broad 12, 13, 16, 18, 17, 23, 26, 29, (Units 5, 7, 16, (Unit 22) (Units 10, 30) 23, 24) 35) (Units 4, 6) (Units 4, 5, 36) 20, 21, 25, 26, 31) 37) 27, 32, 33) H3140. Hard oligo-mesotrophic waters with benthic vegetation of - Present - - - Present Present - - Chara spp.; Calcium-rich nutrient- poor lakes, lochs and pools H3150. Natural eutrophic lakes with Magnopotamion or Hydrocharition-type vegetation; Present Present Present Present Present Present Present Present Present Naturally nutrient-rich lakes or lochs which are often dominated by pondweed H6410. Molinia meadows on calcareous, peaty or clayey-silt- Present - Present Present - Present Present - - laden soils (Molinion caeruleae); Purple moor-grass meadows H7140. Transition mires and quaking bogs; Very wet mires Present Present Present Present Present Present Present Present Present often identified by an unstable `quaking` surface H7210. Calcareous fens with Cladium mariscus and species of the Caricion davallianae; Calcium- Present Present Present Present Present Present Present Present Present rich fen dominated by great fen sedge (saw sedge) H7230. Alkaline fens; Calcium-rich Present ------springwater-fed fens H91E0. Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Present Present Present Present Present Present Present Present - Salicion albae); Alder woodland on floodplains S1016. Vertigo moulinsiana; Present - Present Present - - - - - Desmoulin`s whorl snail S1355. Lutra lutra; Otter Present Present Present Present Present Present Present Present Present S1903. Liparis loeselii; Fen orchid Present Present Present Present - Present - - - S4056. Anisus vorticulus; Little ------whorlpool ram's-horn snail
Distribution based on Natural England ENSIS records, 2013 for SSSI Units of the Ant Broads & Marshes SSSI. SSSI Units assigned to hydrological sub unit based on site hierarchy (Annex 2).