A Knowledge Base Supporting Decisions on SSSI River Flow Criteria

A knowledge base supporting decisions on SSSI river flow criteria

Judith Nutter, Matthew Holmes, Matthew Fry, Mike Acreman, Mike Dunbar, Jamie Hannaford, Jon Bass, Andy Young

2007

Natural England contract EIT36-05-027

Centre for Ecology and Hydrology Wallingford Hydro-solutions

Project title Developing a knowledge base supporting decisions on SSSI river flow criteria

Report title A knowledge base supporting decisions on SSSI river flow criteria

Natural England R&D no EIT36-05-027 Contractor Centre for Ecology and Hydrology (CEH) Sub-contractor Wallingford Hydro-solutions (WHS) CEH project no C02988

Principle researchers Judith Nutter (WHS), Matthew Holmes (WHS) Matthew Fry (WHS), Mike Acreman (CEH) Mike Dunbar (CEH), Jamie Hannaford (CEH) Jon Bass (CEH), Andy Young (WHS)

Period of study December 2005 – April 2006

Bibliographic reference Nutter, J., Holmes, M., Fry, M., Acreman, M,, Dunar, M.J., Hannford, J., Bass, J., Young, A. 2006 A knowledge base supporting decisions on SSSI river flow criteria. Report to Natural England. Centre for Ecology and Hydrology, Wallingford ?? pp

Dissemination status To be published as a Natural England Research Report.

Publishing organisations Natural England, Northminster House, Peterborough, PE1 1UA Tel: 01733 455000 website: http://www.english-nature.org.uk/ Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB Tel: 01491 838800 Website: www.ceh.ac.uk

All rights reserved. No part of this document may be produced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior permission of Natural England and the Centre for Ecology and Hydrology.

Disclaimer The content of this document does not necessarily represent the views of Natural England or the Centre for Ecology and Hydrology.

Executive Summary

Natural England is responsible for the definition of Conservation Objectives for Sites of Special Scientific Interest (SSSIs). These objectives, set for each site, determine how Natural England assess site condition and inform decisions over the management of the site. As part of conservation objectives for riverine SSSIs, targets for river flow are required, set in terms of levels of abstraction take deemed to be consistent with the Favourable Condition of the habitat. Generic guidance for setting flow targets for riverine SSSIs was produced by English Nature (one of Natural England’s predecessor bodies), based on a specific application of the Environment Agency’s Resource Assessment Methodology (RAM). This document is intended to assist local Natural England and Environment Agency in applying this guidance to specific SSSIs, providing a knowledge base to support decisions on river flow targets and generating tentative targets for each river that require local validation.

A considerable amount of evaluation work is already being undertaken on those riverine SSSIs that are additionally designated as Special Areas of Conservation under the EC Habitats Directive. The focus of this project was on those riverine SSSIs without SAC designation, where technical support was deemed to be most necessary. There are 23 SSSI rivers that are not designated as SAC within England, of which 15 were in Unfavourable Condition partly due to abstraction stress at the time this work was undertaken.. Priority was given in this project to those 15 rivers - those rivers not recorded as suffering from abstraction stress still require flow targets, in order to inform future condition assessments and decision-making, but these will be evaluated in a further study.

The information provided for each SSSI river within this report and associated MetaData Catalogues is as follows:

 SSSI Description  Catchment characteristics, including: o Catchment Summary o Deviations of topographic and groundwater catchment divides o Geology o Variation of HOSTBFI o Landuse o Flow gauging stations o Hydrological data o Macrophyte data o Macroinvertebrate data o Fisheries data  Catchment water use, including: o Artificial influences o Net Pressure of Artificial Influences o Catchment Abstraction Management Strategy (CAMS)  Environmental Weighting Units and River Flow Objectives  Bibliography

Each SSSI has been divided into a number of units based upon changes in the catchment physical characteristics. Each unit was assessed in relation to each of the four indicators (physical habitat, macrophytes, macro-invertebrates and fish) in the EA’s RAM Framework, and assigned an Environmental Weighting (EW) and River Flow target. The four indicators have been assigned RAM scores following the EA’s RAM Framework guidance, and then assigned an EW based upon English Nature Guidance. This guidance states that the EW is allocated primarily upon the physical assessment of river type, and then the biological assessment elements (macrophytes, macro-invertebrates and fish) can provide additional information to increase the sensitivity but not downgrade the assessment.

i 1 Introduction ...... 1 2 Identification of SSSI requiring River Flow Objectives ...... 1 3 Sources of Data ...... 3 3.1 SSSI Description ...... 3 3.2 Catchment characteristics ...... 3 3.3 Catchment water use ...... 5 3.4 Environmental Weighting Units and River Flow Objectives ...... 6 3.5 Bibliography ...... 6 4 Environmental Weighting and River Flow Objectives ...... 7 4.1 Physical Habitat ...... 8 4.2 Macrophytes ...... 11 4.3 Macro-Invertebrates ...... 13 4.4 Fish ...... 13 5 River Barle SSSI ...... 15 5.1 SSSI Description ...... 15 5.2 Catchment characteristics ...... 15 5.3 Catchment water use ...... 16 5.4 Environmental Weighting Units and River Flow Objectives ...... 17 6 River Beult SSSI ...... 18 6.1 SSSI Description ...... 18 6.2 Catchment characteristics ...... 18 6.3 Catchment water use ...... 19 6.4 Environmental Weighting Units and River Flow Objectives ...... 20 7 River Coquet And Coquet Valley Woodlands SSSI ...... 22 7.1 SSSI Description ...... 22 7.2 Catchment characteristics ...... 22 7.3 Catchment water use ...... 23 7.4 Environmental Weighting Units and River Flow Objectives ...... 24 8 River Eye SSSI ...... 26 8.1 SSSI Description ...... 26 8.2 Catchment characteristics ...... 26 8.3 Catchment water use ...... 27 8.4 Environmental Weighting Units and River Flow Objectives ...... 28 9 River Frome SSSI ...... 29 9.1 SSSI Description ...... 29 9.2 Catchment characteristics ...... 29 9.3 Catchment water use ...... 30 9.4 Environmental Weighting Units and River Flow Objectives ...... 31 10 Halsdon SSSI ...... 33 10.1 SSSI Description ...... 33 10.2 Catchment characteristics ...... 33 10.3 Catchment water use ...... 34 10.4 Environmental Weighting Units and River Flow Objectives ...... 35 11 River Hull Headwaters SSSI ...... 36 11.1 SSSI Description ...... 36 11.2 Catchment characteristics ...... 36 11.3 Catchment water use ...... 37 11.4 Environmental Weighting Units and River Flow Objectives ...... 38 12 River Ise and Meadows SSSI ...... 40 12.1 SSSI Description ...... 40 12.2 Catchment characteristics ...... 40 12.3 Catchment water use ...... 41 12.4 Environmental Weighting Units and River Flow Objectives ...... 41 13 River Kennett SSSI ...... 43 13.1 SSSI Description ...... 43 13.2 Catchment characteristics ...... 43 13.3 Catchment water use ...... 44 13.4 Environmental Weighting Units and River Flow Objectives ...... 46 14 River Lymington SSSI ...... 48

ii 14.1 SSSI Description ...... 48 14.2 Catchment characteristics ...... 48 14.3 Catchment water use ...... 49 14.4 Environmental Weighting Units and River Flow Objectives ...... 49 15 Moors River System SSSI ...... 51 15.1 SSSI Description ...... 51 15.2 Catchment characteristics ...... 51 15.3 Catchment water use ...... 52 15.4 Environmental Weighting Units and River Flow Objectives ...... 53 16 River Nar SSSI ...... 55 16.1 SSSI Description ...... 55 16.2 Catchment characteristics ...... 55 16.3 Catchment water use ...... 56 16.4 Environmental Weighting Units and River Flow Objectives ...... 57 17 River Ribble (Long Preston Deeps) SSSI ...... 59 17.1 SSSI Description ...... 59 17.2 Catchment characteristics ...... 59 17.3 Catchment water use ...... 60 17.4 Environmental Weighting Units and River Flow Objectives ...... 60 18 River Teme SSSI ...... 62 18.1 SSSI Description ...... 62 18.2 Catchment characteristics ...... 62 18.3 Catchment water use ...... 63 18.4 Environmental Weighting Units and River Flow Objectives ...... 65 19 River Test SSSI ...... 67 19.1 SSSI Description ...... 67 19.2 Catchment characteristics ...... 67 19.3 Catchment water use ...... 68 19.4 Environmental Weighting Units and River Flow Objectives ...... 70 20 References ...... 72 21 Annex 1 River Lugg SSSI ...... Error! Bookmark not defined. 21.1 SSSI Description ...... Error! Bookmark not defined. 21.2 Catchment characteristics ...... Error! Bookmark not defined. 21.3 Catchment water use ...... Error! Bookmark not defined. 21.4 Environmental Weighting Units and River Flow ObjectivesError! Bookmark not defined.

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1 Introduction

As the successor body to English Nature, Natural England is responsible fpr setting conservation objectives for all Sites of Special Scientific Interest (SSSIs). These objectives are used to assess whether a site is in ‘Favourable Condition’ and what changes in management regime may be necessary. For rivers, Favourable Condition is defined by a range of environmental targets relating to the hydrological, physical and chemical integrity of the habitat. These targets take account of variations in environmental conditions and ecological sensitivities between river types.

UK government has set itself a range of public service agreements (PSA targets) in England, of which one relates specifically to the SSSI network: 95%, of SSSIs (by area) should be in Favourable Condition (or in Unfavourable Condition but recovering) by 2010. Natural England is leading on the implementation of a programme that aims to deliver this target. To this effect, a programme has been developed (the ‘Remedies’ Project) to move SSSIs into Favourable Condition, which is currently being implemented. This involves identifying management measures, with partners such as the Environment Agency that allow the environmental targets in conservation objectives to be met.

Generic guidance on setting conservation objectives for SSSI rivers was issued in 2005, based on Common Standards recently agreed by the UK conservation agencies. This includes guidance on setting hydrological targets, based on deviations from naturalised flows, which are judged to be consistent with the Favourable Condition of the habitat for supporting the characteristic flora and fauna of the river. These targets, once set, are used to assess the appropriateness of the abstraction regimes and determine any necessary changes.

The guidance provides generic flow targets that vary according to river type, based on the sensitivity bands used in the Environment Agency’s Resource Assessment Methodology (RAM) Framework. A specific approach to the use of the techniques within the RAM framework is required, in order to ensure that the appropriate generic flow target is identified. The guidance allows for generic targets to be modified if robust local hydroecological information is available, according to defined criteria.

This project was commissioned to help local NE staff with setting flow targets for SSSI rivers. This report and associated MetaData Catalogues present a knowledge base on each of the SSSI rivers considered It is to be used as a tool to guide local Natural England staff in defining site-specific targets – tentative generic targets are suggested based on evaluation using the RAM Framework, but these may be over-ridden by local staff if this evaluation is thought to be inaccurate or if robust, local hydrolecological information on the river exists to set specific flow targets.

This knowledge base was developed over a number of phases, as follows:

 Phase 1 Prioritise rivers (see Section 2).  Phase 2 Identify sources of information (see Section 0).  Phase 3 Quality assurance (see Section 0).  Phase 4 Identify relevant generic flow criteria (see Section 4).  Phase 5 River assessments (See Sections 5 to 19 and associated MetaData Catalogues)  Phase 6 Dissemination

2 Prioritisation of river SSSIs

Whilst all river SSSIs require river flow targets as part of their conservation objectives, this project had to be restricted to a subset of river that most required assistance in target-setting. Firstly, river SSSIs that are additionally designated as Special Areas of Conservation under the EC Habitats Directive are receiving considerable attention under the Environment Agency Review of Consents programme, and are not in need of further assistance. Of the remaining

1 Final report November 2007 river SSSIs, those currently assessed as being (at least in part) in Unfavourable Condition due (at least in part) to abstraction stress are deemed to be in most urgent need, so that Remedies can be planned. For this reason, the work was restricted to this subset. Table 2.1 shows the condition status of each non-SAC SSSI river, and highlights those that have consequently been considered in this project. Natural England plans to undertake a similar exercise on the remaining rivers at a later date.

Table 2.1 Non-SAC river SSSI condition status (those shaded were recorded as 100% Favourable at the time of this evaluation and are not considered further in this report) % Area % Area % Area % Area % Area meeting % Area destroyed / SSSI River unfavourable unfavourable unfavourable PSA favourable part recovering no change declining target destroyed Barle 83% 36% 47% 11% 5% 0% Bere stream 100% 17% 83% 0% 0% 0% Beult 0% 0% 0% 100% 0% 0% Blythe 100% 0% 100% 0% 0% 0% Coquet 62% 60% 2% 38% 0% 0% Cornmill stream 100% 100% 0% 0% 0% 0% Eye 0% 0% 0% 67% 33% 0% Fray's 100% 0% 100% 0% 0% 0% Frome (lower) 16% 10% 6% 68% 16% 0% Halsdon 88% 0% 88% 12% 0% 0% Hull Headwaters 30% 30% 0% 66% 4% 0% Ise 46% 46% 0% 54% 0% 0% Kennet 0% 0% 0% 100% 0% 0% Loddon 100% 100% 0% 0% 0% 0% Lymington 0% 0% 0% 0% 100% 0% Moors 46% 30% 16% 39% 15% 0% Nar 59% 59% 0% 24% 17% 0% Ribble 0% 0% 0% 100% 0% 0% Teign/Bovey 100% 92% 8% 0% 0% 0% Teme 7% 3% 3% 93% 0% 0% Test 25% 20% 5% 47% 27% 0% Ure 100% 100% 0% 0% 0% 0% Wharfe 100% 2% 98% 0% 0% 0%

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3 Sources of Data A range of data was collated for each of the rivers considered. The datasets are described within this Section and the data is summarised within sections 5 to 19 of this report and presented within the associated MetaData Catalogue. The data for each SSSI is presented within the following broad headings:  SSSI Description  Catchment characteristics – Catchment summary, Deviations of topographic and groundwater catchment divides, Geology, Variation of HOSTBFI, Landuse, Flow gauging stations, Hydrological data, Macrophyte data, Macroinvertebrate data, and Fisheries data  Catchment water use - Artificial influences, Net Pressure of influences, and Catchment Abstraction Management Strategies (CAMS)  Bibliography

3.1 SSSI Description Information presented within the SSSI description section is based upon information provided for each SSSI on the then English Nature website, now available on the Natural England website (www.naturalengland.org.uk This section presents a summary physical description of the SSSI from the citation. The citation details the 'features of interest' for which a SSSI has been notified. Each citation shows details of the SSSI location, size and the date of notification. It also describes the general reasons for notification and the habitats, plants and animals that are found at the site. Links to further information held on the website is also presented.

3.2 Catchment characteristics

Catchment Summary The SSSI catchment is defined as all watercourses upstream of the SSSI outlet. The summary of the catchment presents the SSSI outlet location, catchment area (km2), average annual rainfall (1961-1990) (mm/yr), average annual potential evaporation (mm/yr), average annual runoff (mm/yr) and catchment average HOSTBFI (an estimate of Base Flow Index (BFI) derived from gridded data describing the fractional extents of Hydrology of Soil Types (HOST) classes). These variables are derived using the Low Flows 2000 water resource model (as utilised by the Environment Agency of England and Wales). In addition to these variable the natural mean flow (m3/s) and Q95 (flows exceeded for 95% of the time), derived using the Low Flows 2000 water resource model, are presented within the associated MetaData Catalogue.

Deviations of topographic and groundwater catchment divides Any well known deviations of the topographic and groundwater catchment divides are noted in this section.

Geology Descriptions of the solid and drift geology within the catchment are presented within this section based upon the British Geological Survey 1:625k bedrock geology and 1:625k superficial deposits maps (www.bgs.ac.uk). Two maps of the bedrock geology and superficial deposits within the catchment are presented within the associated MetaData Catalogue.

Variation of HOSTBFI The variation of HOSTBFI across the catchment are presented within this section. HOSTBFI is an estimate of Base Flow Index (BFI) which provides an indication of catchment permeability, Boorman et al. (1995). Values approaching zero indicate an impermeable catchment and values approaching unity indicate a highly permeable catchment. HOSTBFI is derived from gridded data describing the fractional extents of HOST classes on a 1km cell basis, see Boorman et al. (1995) for more details.

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Landuse Notes on the catchment major landuse and proportion of urban coverage is presented within this section. The full fractional extent of landuse classes is presented within the associated MetaData Catalogue. The landuse typology is based upon a 1 km aggregated grid of the CEH Land Cover Map 2000 Aggregate Class (LCM2000). The LCM2000 AC map was further aggregated into a nine dominant class 1 km grid using the mapping presented in Table 3.1.

Table 3.1 Mapping used to aggregate CEH Land Cover Map 2000 Aggregate Class into nine dominant classes Dominant Dominant LCM2000 AC LCM2000 AC Aggregate Grid Aggregate Grid Land Cover Description Number Description Number 1 Broadleaf 11 Broad-leaved/mixed woodland 2 Coniferous 21 Coniferous woodland 3 Arable 41 Arable cereals 42 Arable horticulture 43 Arable non-rotational 4 Grassland 51 Improved grassland 52 Setaside grass 61 Neutral grass 71 Calcareous grass 81 Acid grassland 91 Bracken 111 Fen, marsh, swamp 5 Upland 101 Dense dwarf shrub heath 102 Open dwarf shrub heath 121 Bog (deep peat) 151 Montane habitats 161 Inland bare ground 6 Urban 171 Suburban / rural development 172 Continuous urban 7 Inland Water 131 Water (inland) 8 Coastal 181 Supra-littoral rock 191 Supra-littoral sediment 201 Littoral rock 211 Littoral sediment 212 Saltmarsh 9 Seas 221 Sea / Estuary

Flow gauging stations Descriptions of National River Flow Archive (NRFA) gauging stations relevant to the SSSI catchment are presented in this section. Furthermore, the NRFA gauging station statistics, flow statistics, and NRFA comments regarding the gauging station and catchment are provided within the associated MetaData Catalogue. NRFA gauging station statistics presented are the station number and type, location, altitude, catchment area, record start and end dates (if applicable), average annual rainfall (1961-1990), flows at bank full and structure full, the sensitivity and artificial influence codes. NRFA flow statistics presented are the base flow index, mean flow, flows that are exceeded at 10%, 50% and 95% of the time, and the relationships between these flows. Full descriptions of all the statistics are given within the notes section of the MetaData Catalogue.

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Hydrological data Hydrological data for each of the SSSI catchments is provided through two different methods. Flow statistics based upon long term flow records at NRFA gauging stations within the SSSI catchments, are presented within the “Flow Data” sheet of the associated MetaData Catalogues. In addition estimates of the natural mean flow and flows exceeded for 95% of the time at the SSSI outlet, derived using the Low Flows 2000 water resource model, are presented within the “Catchment Information” sheet of the associated MetaData Catalogues.

Macrophyte data British rivers were classified using macrophyte communities following extensive surveys carried out throughout the 1980s and early 1990s at over 1500 sites (Holmes et al. 1998). The classification yielded ten River Community Types, varying from lowland, eutrophic rivers to torrential, oligotrophic streams. All macrophyte survey sites within the SSSI catchment were identified, noted in this section and presented in the associated MetaData Catalogue. General descriptive relations with some physical catchment characteristics are described. The surveys are based on two consecutive 500m reaches, the data from which is aggregated to define a typology. Basing a typology on ecological data collected over 1km is likely to be more robust and more related to catchment characteristics (as opposed to local site-scale variables) than for ecological data collected over shorter lengths of river (e.g. 100m) (SNIFFER, 2006).

Macroinvertebrate data Lotic-invertebrate Index for Flow Evaluation (LIFE) scores have been estimated for over 6000 General Quality Assessment (GQA) sites for Environment Agency of England and Wales, surveyed in either 1995 or 2000. All GQA sites within the SSSI catchment were identified, noted in this section and presented in the associated MetaData Catalogue. The presence of 3- season RIVPACS data within the catchment, which could also be used to determine the LIFE score expected under benchmark conditions, was also noted although the data was not available within the scope of this study.

Fisheries data The Database and Atlas of Freshwater Fishes published by CEH shows the surveyed locations of fish species within 1 km squares throughout Great Britain (Davis, 2004). Records of representative species of salmonids (salmon and trout), rheophilic cyprinids (dace, chub, and barbel) and eurytopic/ limnophilic cyprinids (roach and pike) were obtained from the National Biodiversity Network. The fish community of the highest vulnerability to adverse conditions is noted in this section, and the observed species within 1 km squares within the SSSI catchment are presented in the associated MetaData Catalogue.

3.3 Catchment water use

Artificial influences The presence of any major abstractions, discharges, impoundments, or canal systems within the SSSI catchment is noted in this section. This information was obtained from a number of sources including the NRFA catchment descriptors of factors affecting runoff, water resource studies and the Water Framework Directive (WFD) artificial influence data sets.

Net Pressure of Artificial Influences The Low Flows 2000 water resource model enables the natural flows at a point on a river to be estimated using UK best practice hydrological models. Low Flows 2000 also enables the impacts of seasonal water use to be simulated by including artificial influence data sets, describing the location and magnitude of water use features. As part of the Environment Agency’s Water Framework Directive National Screening Project a national data set of major artificial influences was developed. It should be noted that this data set has not yet been fully quality controlled, but does provide an indication of catchment wide water use.

Low Flows 2000 and the WFD artificial influence data set were used to estimate the current Net pressure at Q70 (Q70 is the flow that is equaled or exceeded 70% of the time). The Net Pressure is defined as follows;

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Net Pressure = 1 - Q70INF / Q70NAT

Where Q70INF is the Q70 flow including the impact of water use in the catchment; and Q70NAT is the expected natural Q70 flow assuming no water use in the catchment.

Hence negative Net Pressure values indicate that abstractions from the flow regime (such as public water supply abstractions) dominate, positive Net Pressure values indicate augmentations to the flow regime (such as sewerage treatment works discharges) dominate.

Catchment Abstraction Management Strategy (CAMS) Any existing Environment Agency CAMS assessment points (AP) within the SSSI catchment are noted within this section, along with their position relative to the SSSI. For each CAMS AP the location, assigned environmental sensitivity, reach low flow resource availability status, and Phase II comments are presented. The dataset used was provided by the Environment Agency and contained all CAMS completed by March 2006.

3.4 Environmental Weighting Units and River Flow Objectives This section presents the division of each SSSI into units based upon changes in the catchment physical characteristics. A map showing the SSSI boundary (downloaded from English Nature GIS Digital Boundary Datasets), and the hydrological catchment boundaries of each unit is also presented. Each unit is assigned an Environmental Weighting score based upon four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4) and an associated River Flow Objective. The datasets and calculated descriptors used to assign the Environmental Weighting are presented within the associated MetaData Catalogue.

3.5 Bibliography Literature searches were completed for each SSSI river, and the results are presented within the associated MetaData Catalogue. Searches for relevant literature were completed within the English Nature internal Library system, the Environment Agency internal library system (OLIB) and the Environment Agency publications direct. In addition relevant English Nature staff within local offices were contacted and details of reports containing ecology or river habitat data held by English Nature, Abstraction Management Plans (AMP) reports, Review of Consents (RoC) reports, or any public enquiry reports relating ecology to flow were requested which were relevant to the specific SSSI rivers. The information presented within the MetaData Catalogue contains the references to the specific reports, information regarding holdings and a quality assurance flag.

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4 Environmental Weighting and River Flow Objectives Environmental Weightings (EW) have been developed within the Environment Agency’s Water Resource Assessment and Management (RAM) Framework to assess the environmental sensitivity of a river to potential flow variability resulting from abstraction. This EW can then be used to derive appropriate Ecological River Flow Objectives (RFO). The RFO have been adjusted by Natural England for use as flow targets within SSSI Rivers, as shown in Table 4.1.

Within the RAM Framework (EA, 2002) environmental sensitivity is assessed in relation to each of the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (see sections 4.1 to 4.4). A five band scoring system is used for the individual indicators, ranging between 1 and 5. A RAM score of 1 relates to the lowest sensitivity to abstraction, whilst a RAM score of 5 relates to the highest sensitivity. Having defined the scores that would be expected under the benchmark conditions, for each of the four indicators, these are then combined to produce the overall Environmental Weighting. This ranges from ‘Very High (VH) Abstraction Sensitivity’ to ‘Very Low (VL) Abstraction Sensitivity’. In the context of setting flow targets for river SSSIs, the combination of this overall EW uses the following English Nature conditions.

1. The overall EW is allocated primarily upon the physical assessment of river type, and each reach should be categorised according to the most sensitive river type occurring within the reach. In this context, RAM scores of 2 are considered inappropriate for river SSSIs because it implies physical impacts that need to be addressed to restore characteristic habitat diversity (Favourable Condition). A RAM score of 1 may occasionally be appropriate in some limited circumstances, if a decision is made that artificial impoundments should not be removed on ecological grounds because they are vital in protecting floodplain habitats.

2. Biological assessment elements (macrophytes, macro-invertebrates and fish) can provide additional information to increase the sensitivity but should not downgrade the assessment. Importantly, there should be no decisions made on the basis of the current distribution of SSSI features on a river, since this may be impacted by a range of human influences.

For the assignment of EW to each SSSI, the rivers were divided into a number of environmental weighting units (EWU) based upon changes in the catchment physical characteristics. Each EWU was assessed in relation to each of the four ecological indicators and assigned a final EW. Note that these EWus do not equate to SSSI reporting units – some local interpretation will be required to resolve information into the SSSI reporting framework.

Table 4.1 Generic river flow thresholds for designated rivers, as defined within conservation objectives by Natural England

RAM Maximum % reduction from daily naturalised flow Environmental Flow >Qn50 Flow

Note: Qn50 = natural Q50 (ie the flow exceeded 50% of the time), and Qn95 = natural Q95 (ie the flow exceeded 95% of the time).

7 Final report November 2007 4.1 Physical Habitat Within the RAM framework (EA, 2002) a catchment is assigned a RAM Score based on the physical habitat, as shown by the general guidance notes in Table 4.2. The methodology used within RAM framework uses a combination of site visits and the RAM guidance on physical characterisation by reference to river channel properties (Appendix B, EA, 2002). These river channel properties are based upon a physical type illustration, gradient, altitude, width to depth ratio, width, depth, substratum, stream order and base flow index (BFI). The current project did not include a fieldwork survey component and hence an alternative approach to defining the physical habitat RAM score was developed. This involved the consideration of two physical habitat RAM scores.

 Firstly, a physical habitat RAM Score was derived for each EWU using the catchment characteristics of gradient, altitude, and BFI using the mapping shown on Table 4.3, following the RAM framework (Appendix B, EA, 2002) approach.

 Secondly, a river typology class was assigned to each EWU using a simplified version of the classification system developed by Holmes et al. (1998) and outlined in WFD48 Project (SNIFFER, 2006). The system of eight (8) typology classes was developed based on catchment area, average annual rainfall and the BFI as shown on Table 4.4. These eight categories were then mapped to a second physical habitat RAM Score, as shown in Table 4.5.

The required catchment characteristics of area, average annual rainfall and BFI were derived using the Low Flows 2000 water resource model. An estimate of gradient was derived from the Flood Estimation Handbook (FEH) variable DPSBAR, which is the mean of all the inter-nodal slopes for the catchment which characterizes the overall steepness within the catchment. Finally the altitude of each EWU was derived from the CEH Integrated hydrological digital terrain model (DTM), which is a 50m grid derived from OS contours, lake shores, coastlines, spot heights and rivers.

The two physical habitat RAM Scores were then both considered and a final single physical habitat RAM Score defined for each EWU using expert judgement. However, it should be noted that site visits may be required to verify the score.

Table 4.2 RAM Scores assigned to physical habitat (EA, 2002)

RAM Score Description 5 Rivers with steep gradients and / or wide shallow cross-sections 4 Moderate gradient rivers and streams High baseflow rivers & low gradient lowland rivers with diverse in-stream and 3 edge habitats 2 Low gradient rivers, streams and ditches with limited habitat diversity 1 Lowland river reaches, ditches and channels with minimal gradients.

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Table 4.3 RAM Guidance on physical characterisation by reference to gradient, altitude and BFI (based upon Appendix B, EA, 2002)

RAM Gradient Altitude Base Flow Score Index 1 5 h (m) h (any) vl 2 5 m - h h (any) l 3 5 m - h m (any) l 4 5 vh h (any) l - m 5 5 h (m) m l - m 6 4 l - m l (m) m 7 4 m - h l - m m 8 4 l - m l m (l) 9 3 l l vh 10 3 l l (m) m 12 2 l - m m l 13 2 l l l 14 1 vl l l (m)

9 Final report November 2007

Table 4.4 Generic river water reach types based on Holmes et al (1998) Type A Type B Type C Type D clay and/or Chalk hard limestone and sandstone non-calcareous shales, hard Granites and other hard rocks; low altitude; low-medium altitude, low-medium limestone and sandstone, medium low and high altitudes; low slope; slope; ?mesotrophic?; altitude, medium slope, oligo-meso- gentle and steep slopes; ultraoligo – eutrophic; gravel-boulder (predominantly trophic; pebble, cobble, boulder oligotrophic; cobble, boulder, silt-gravel bed; pebble-cobble), mostly smooth flow, bed, smooth flow with abundant bedrock, pebble; smooth flow; small turbulent areas riffles and rapids; smooth with turbulent areas – predominantly C and SE England SW, NW, NE England, E Scotland, C SW, NE England, Lake District, W torrential; and S. Wales Wales, Southern Uplands, C N and W Scotland, scattered in W Grampians Wales, SW, NW and S. England

Type A1 Type A2 Type B1 Type B2 Type C1 Type C2 Type D1 Type D2 Lowest gradients Slightly steeper gradient (4.1 shallower than gradient 5.4 +/- steeper than C1 medium gradient high gradient (0.8 +/- 0.4 (1.7 +/- 0.8 +/- 9.9 m/km), B1 (2.7 +/- 10.7 6.5 m/km; (7.3 +/- 10.8 (11.3 +/- 15.6 (25.5 +/- 33 m/km) and m/km), low altitude 93 +/- m/km); altitude altitude 101 +/- m/km); altitude m/km); low m/km); high altitudes (36 +/- altitude (55 +/- 69 m; . 71 +/- 58 m; 84 m; 130 +/- 90 m; altitude (93 +/- altitude (178 +/- 25 m), 38 m); Hard sandstone, predominantly hard limestone; non-calcareous 92 m), 131 m); predominantly Chalk calcareous NW England, E more silt and shales; pebble- oligotrophic, stream order 1 & clay catchments; shales; Scotland sand than C2; bedrock; substrate finer 2 SE England and predominantly predominantly mesotrophic oligo- than D2 (incl silt bed rock and East Anglia & gravel beds S. & SW England mesotrophic & sand); boulder; Cheshire plain base-rich; and SW Wales more slow flow ultra-oligo areas than D2 trophic torrential;. Example rivers where water body types (river reaches) can be found Wissey, Lark, Test, Piddle, Tamar, Torridge, Ribble, Wharfe, Scattered Lower Findhorn, English lowland Dartmoor, Nar, Wensum, Frome, Itchen, Exe, Teifi, Eden, Tweed, Spey, Dee, Esk, acid heaths Exmoor, Bure, Welland, Mimram, Hull, Monnow, Lugg, Lunan, Ythan Ure, Derwent, (New Forest), Brecons, Cherwell, Tame, headwaters of Dove Conwy, Dee, Scottish Flow Snowdonia, Evenlode East Anglian Cothi, Barle Country, Pennines, rivers Western Isles Cairngorms, NW Highlands

10 Final report November 2007

Table 4.5 RAM Scores assigned to the Holmes et al (1998) simplified generic river water body types

Simplified Generic River RAM Score Water Body Types 5 C2 & D2 4 B1, B2 & C1 3 A2 2/1 A1

4.2 Macrophytes British rivers were classified using macrophyte communities following extensive surveys carried out throughout the 1980s and early 1990s at over 1500 sites (Holmes et al. 1998). The classification yielded ten River Community Types, varying from lowland, eutrophic rivers to torrential, oligotrophic streams, as presented in Table 4.6. These river types have been integrated into the RAM framework, so that each River Community Type has been assigned a RAM score, based on the most flow-sensitive and dominant macrophytes associated with that river type (see Table 4.6). Therefore each EWU has been assigned a RAM score based upon the River Community Type assigned to the survey sites within that unit. If a survey site was not found within a EWU, a macrophyte RAM score was not assigned to the EWU.

Table 4.6 Classification of British rivers by macrophyte types (Holmes et al, 1999 cited within Annex 3, SNIFFER, 2006) and associated RAM Scores (EA, 2002)

River Type Description RAM Score

Non-flowering species - cladophera glomerata, Vacheria sp, Type I lowland low gradient Common species – carex riparia, Sparganium emersum, rivers e.g. Avon, Wissey, Potamogeton pectinatus, Sagittaria sagittifolia 1 Lark, Bure Less common – Pulicaria dysenterica, Berula erecta, Eupatorium cannabinum, Oenanthe fluviatilis, Iris pseudacorus, Phragmities australis Type II lowland clay- Assemblage similar to type 1, greater variety, more dominated rivers; low occurrence of common species Cladophora glomerata and gradient e.g. Devon, 2 Vaucheria sp, more occurrence of less common species Welland, Cherwell, Tame, Potamogeton natans, Juncus acutiflorus Evenlode Type III Chalk rivers and All rivers underlain by base-rich geology – 60% of type III other base-rich rivers with rivers are on Chalk with high base flow and stable flow 3 stable flows e.g. Frome, Test, regime. Piddle Itchen, Hull, Minram Type IV Impoverished lowland rivers; degraded Most typical species are all emergents or marginal species, Not used in through drainage and flood none of common submerged aquatics of Type I-III SSSI objective- defence, depleted flows or occurring in more than 35% of sites setting pollution

11 Final report November 2007

River Type Description RAM Score No submergent aquatics in over half type V sites, Sparganium erectum is the only emergent to occur. Submerged habitats dominated by mosses, most Type V Sandstone, mudstone important being Rhynchostegium riparioides, Fontinalis and hard limestone rivers of antipyretica and Amblystegium sp. Of common species England and Wales eg. 4 found in IV and V, Oenanthe crocata, Solanum dulcamara, Tamar, Exe, Teifi, Lugg, Conocephalum conicum and Vaucheria sp are more Dove frequent in type V. Of less common taxa, Apium nodiflorum, Eupatorium cannabinum, Lythrum salicaria and Carex remota are frequent. Of common species in V and VI, Myostosis scorpioides, Type VI Sandstone, Mentha aquatica, Mimulus guttatus, Equisetum arvense, mudstone and hard Caltha palustris, Elodea canadensis and filamentous algae limestone rivers of Scotland are more prevalent in Type VI. This also applies to less 4 and northern England. e.g. common occurring species Myriophyllum spicatum, Ribble, Wharfe, Eden, Tweed, Polygonum amphibium and moss Schistidium alpicola, Ythan Ranunculus fluitans and Eleocharis palustris. Wetland edge species characterise the assemblage with fewer bryophytes reflecting finer sediment. Of common Type VII Mesotrophic rivers species in VII and VIII, Phalaris arundinacea and Myosotis dominated by gravel, pebbles scorpioides are more common in type VII. Of less common 4 and cobbles. Sites well species, Callitriche stagnalis, C. hamulata, Equisetum scattered around Britain fluviatile, Myriophyllum alterniflorum, Juncus articulatus, Potamogeton natans and Rorippa nasturtium-aquaticum are far more prevalent Higher proportion of rocky substrate, less base rich means Type VIII Oligo-mesotrophic wide variety of bryophytes. Species more common in VIII rivers. Shales, hard than VII include: Rhynchostegium riparioides, limestone and hard Chiloscyphus polyanthus, Pellia epiphylla, Hygrohypnum sandstone dominate, ochraceum, Amblystegium fluviatile, Thamnobryum 5 gradients steeper than VII alopecurum, and Scapania undulate. Less common e.g. lower Findhorn, Spey, bryophytes and lichens occur five time more frequently in Dee, Esk, Ure, Derwent, VIII than VII including Dermatocarpon fluviatile, Conwy, Dee Cothi, Barle. Hyocomium amoricum, Dichodontium pellucidum and D. flavescens. Type IX Oligotrophic low altitude rivers. Rivers with Because of relative scarcity of rock Fontinais antipyretica gentler slopes than in type X and Sphagnum sp are the only mosses among top 30 and located at lower altitude, common species. Vascular plants Juncus bulbosus, more sand and silt, less Equisetum fluviatile, Myriophyllum alterniflorum, 3 cobbles, boulders. No single Potamogeton polygonifolius and P. Natans are all much large rivers; English lowland more common than in type X. acid heath (New Forest), Scottish Flow Country and Western Isles. Type X Ultra-oligotrophic Higher proportion of cobbles, boulders and bedrock and rivers. Type X communities presence of blanket bogs and acid heath means that on steeper gradients than IX bryophytes are a major component of the flora and very and at higher altitudes e.g. dominant in submerged habitats. Common species, Pellia upper reaches of rivers on epiphylla, Racomitrium aciculare, Scapania undulate, 5 Dartmoor, Exmoor, Brecon Hyocomium armoricum, Bryum pseudotriquetrum, Beacons, Plynlimon, Marupella emarginata and Jungermannia atrovirens are 10 Snowdonia, Pennines, North times more common in X than IX as are less frequently York Moors, Cairngorms and recorded Nardia compressa, Hygrohypnum ochraceum and north-west Highland. Schistidium alpicola

12 Final report November 2007

4.3 Macro-Invertebrates The macro-invertebrate component of the RAM framework (EA, 2002) is based on the Lotic- invertebrate Index for Flow Evaluation (LIFE). By responding positively to increased flow and current velocities (and negatively to declining flows and current velocities), LIFE provides a rational mechanism for incorporating key hydro-ecological data into the Environmental Weighting system. The RIVPACS software (Wright et al., 1984) provides an objective mechanism for determining the LIFE score that would be expected from a site under benchmark conditions. However, it should be noted that many sites within the RIVPACS database are physically impacted to a greater or lesser degree, and there is therefore the potential for some underestimation in the reference community and an overestimation of the observed/expected ratio. LIFE scores have been calculated for Environment Agency General Quality Assessment (GQA) sites, which consist of over 6000 sites surveyed in 1995 and over 130 sites surveyed in 2000. Therefore each EWU was assigned a RAM score based upon the Expected LIFE scores assigned to the survey sites within that unit. If a survey site was not found within a EWU, a macro-invertebrate RAM score was not assigned to the EWU.

Further biological information regarding the macro-invertebrates found during these surveys is available from the Environment Agency database. It should be noted that EW assigned based upon the predicted LIFE Scores should be reviewed in the light of site-specific observed Macroinvertebrate data in further studies.

Table 4.7 RAM Scores assigned to Expected LIFE Scores (EA, 2002)

RAM Score Expected LIFE Score 5 > 7.80 4 7.31 – 7.80 3 6.81 – 7.30 2 6.31 – 6.80 1 < 6.31

4.4 Fish Within the RAM framework (EA, 2002) RAM Scores are assigned based upon the fish communities present within a reach and their vulnerability to adverse conditions due to flow reduction. Table 4.8 presents the RAM scores assigned to each fish community. A fish atlas has been published by CEH which shows the surveyed locations of fish species within 1 km squares throughout Great Britain (Davis, 2004). Records of representative species of salmonids, rheophilic and eurytopic/ limnophilic cyprinids were obtained; however the atlas does not provide maps of the spawning or nursery areas. Therefore only three RAM Scores of 4, 3 and 2 where assigned to each EWU based upon the presence of the three communities within the SSSI catchment, as presented in Table 4.9.

Table 4.8 RAM Scores assigned to fish communities (EA, 2002)

RAM Score Description 5 Salmonid spawning / nursery areas Adult salmonid residents (wild) and / or rheophilic coarse fish – 4 barbel, grayling Salmonid passage (smolts and adults) and / or flowing water 3 cyprinids – dace, chub, gudgeon, bullhead and / or shad spawning / rearing / passage 2 Slow / still water cyprinids – roach, bream, tench, carp 1 Marginal fish community e.g. eels and sticklebacks, or no fish

13 Final report November 2007

Table 4.9 EW Scores assigned to fish communities and their representative species

Fish Community Species EW Score salmonids salmon and trout 4 rheophilic cyprinids dace, chub, and barbel 3 eurytopic/limnophilic cyprinids roach and pike 2

It should be noted that local Natural England staff or relevant experts should be consulted in further studies to characterise the fish communities of each river, with regards to the presence of the fish communities and locations of salmonid spawning / nursery areas.

14 5 River Barle SSSI 5.1 SSSI Description The Barle SSSI is wholly within Exmoor National Park and extends from just upstream of the town of Dulverton to Pinkery Pond, in the headwaters of the river Barle located in the Exmoor Forest. The total length of river included in the SSSI is approximately 30km. The flow regime of the river is unmodified by anthropogenic impacts.

SSSI Name River Barle County Somerset River Barle Natural England ID 2000143 Link River Barle SSSI Views About Management

5.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 45 Outlet location (290688,128973) Catchment area (km2) 117.1 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 1586 Average annual potential evaporation (mm/yr) 516 Average annual runoff (mm/yr) 1193 Catchment average HOSTBFI 0.44

More information about the catchment of this SSSI can be found on the River Barle SSSI MetaData Catalogue.

Deviations of topographic and groundwater catchment divides – None documented.

Geology – The upper catchment underlain by Upper Devonian slates and the lower catchment by sandstones. Drift deposits limited to small peat outcrops in headwaters.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from low permeability in the headwaters to higher values towards the bottom of the catchment. A catchment average value of 0.44 suggest a moderately permeable catchment. This reflects the underlying permeable geologies of sandstone.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is grassland with no urban areas. More information about land use within this SSSI catchment can be found on the River Barle SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 54011 (Barle at Brushford) is located downstream of the SSSI and has a catchment area of 128km2. This station is a full range velocity area station. The SSSI catchment represents 91% of the total catchment contributing to the flows at this gauging station. This gauged record is expected to be a good reflection of the flows in the lower portions of this SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Barle SSSI MetaData Catalogue.

15 Final report November 2007 Macrophyte data – Four (4) macrophyte survey points exist in the SSSI catchment, with major typologies varying from B1 to D2. Some replicate survey information is available. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Barle SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at four (4) sites, and estimated LIFE scores are also calculated for four (4) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Barle SSSI MetaData Catalogue.

Fisheries data – Salmonids have been surveyed within this SSSI. More information about sites in the vicinity of this SSSI can be found on the River Barle SSSI MetaData Catalogue.

5.3 Catchment water use Artificial influences – No major abstractions, discharges or impoundments exist in the SSSI catchment. No major canal systems exist.

Net Pressure at Q70 – The Environment Agency’s Water Framework Directive (WFD) Artificial Influences data set suggests that there are no influences (abstractions, discharges or impoundments) within this catchment and hence the Net Pressure is approximately zero, where Net Pressure is defined as;

Net Pressure = 1 - Q70INF / Q70NAT

And Q70INF is the actual Q70 flow including the impact of water use in the catchment; and Q70NAT is the expected natural Q70 flow assuming no water use in the catchment. Q70INF and Q70NAT are estimated using the Low Flows 2000 water resource model and the water use as characterised by the Environment Agency’s Water Framework Directive (WFD) Artificial Influences data set.

Analysis using the WFD Artificial Influences data set over 207 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

It should be noted that the WFD Artificial Influences data set has not yet been fully quality controlled and may contain errors affecting the estimation of Q70INF, there is uncertainty within the estimation of Q70NAT, hence these results should be regarded as indicative only.

Relationship with existing CAMS assessment points – The Brushford Bridge Assessment Point (AP) from the Exe CAMS is located downstream of the SSSI catchment, at the site of gauging station 45001. The information currently stored for this AP is summarised below.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Barle 5 BRUSHFORD VH 292700 125800 NWA No comments

16 5.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit Higher altitude, impermeable headwaters with peat and moorland. 1 272372, 140433 Rural. 2 279640, 136996 Impact of moorland reduced, impermeable flows from slates. Rural. 3 285059, 134450 River bank flooding common, change in morphology evident. Rural. Influence of underlying sandstones. Flows from Danes Brook 4 290662, 128992 influence regime.

270000 280000 290000

140000

2 Legend

3 Rivers EWU Boundary SSSI Boundary

130000

270000 280000 290000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Barle SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 5 5 none 4 VH 2 5 5 4 4 VH 3 5 5 none 4 VH 4 5 5 4 4 VH

17 6 River Beult SSSI 6.1 SSSI Description The River Beult SSSI consists of the stretch of river from Smarden to the River Medway confluence at Yalding, excluding the upper section of the river which is ditch-like with an impoverished fauna and flora. The river flows for most of its length over Weald clay which influences its ecology, and is one of the few clay rivers in England which retains a characteristic flora and fauna. The total length of river included in the SSSI is approximately 24.8km.

SSSI Name River Beult County Kent River Beult Natural England ID 1005993 Link River Beult SSSI Views About Management

6.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 40 Outlet location (569427,150147) Catchment area (km2) 478.3 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 728 Average annual potential evaporation (mm/yr) 551 Average annual runoff (mm/yr) 295 Catchment average HOSTBFI 0.40

It should be noted that at the SSSI catchment outlet two main rivers contribute to flows; the River Beult (flowing from east to west, catchment area 310km2) and the River Teise (flowing from south to north, catchment area 158km2). River Teise joins the River Beult near Benover, and impacts on flows for the lowest 3.5km of the SSSI.

Deviations of topographic and groundwater catchment divides – – None documented.

More information about the catchment of this SSSI can be found on the River Beult SSSI MetaData Catalogue.

Geology – The entire catchment of the River Beult is underlain by the impermeable Weald Clay formation. Drift deposits of alluvial sands and gravels occur in the main channel.

The upper portion of the River Teise is underlain by the Tunbridge Wells sandstones and the lower portion by the Weald Clay. Alluvial deposits of sand and gravel occur along the main river channel.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from very low permeability (in the order of 0.2 the Weald clay) to medium values on the sandstones (in the order of 0.5). The SSSI catchment average value of 0.40 suggest a lower permeable catchment.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable and grassland with 3.1% urban. More information about land use within this SSSI catchment can be found on the River Beult SSSI MetaData Catalogue.

18 Flow gauging stations –

 Gauging station 40005 (Beult at Stile Bridge) gauges flows from a catchment area of 277.1km2. The station is a flat vee weir and ultrasonic for high flows (pre 2002 a flume with broad crested flanking weirs). The flow regime recorded at this station is responsive to rainfall. This station measures flows from approximately 58% of the catchment contributing to flows at the downstream limit of the SSSI and 90% of the flows for the River Beult above the confluence with the River Teise. Flows measured at this station would be representative of the flow regime in the middle sections of the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Beult SSSI MetaData Catalogue.

Macrophyte data – Thirteen (13) macrophyte survey points exist in the SSSI catchment (including two on the River Teise), with major typologies varying from A1 to B2. Some replicate survey information is available. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Beult SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at five (5) sites, and estimated LIFE scores are also calculated for thirty two (32) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Beult SSSI MetaData Catalogue.

Fisheries data – Rheophilic cyprinid species have been observed, in addition to eurytopic/limnophilic cyprinid species. Trout were observed, but only at one site during one year (1969). More information about species found in the vicinity of this SSSI can be found on the River Beult SSSI MetaData Catalogue.

6.3 Catchment water use Artificial influences – No major canals exist in this SSSI catchment. River flows on the Beult are dependent on surface run-off from the impermeable catchment and stopboards are placed in spring to maintain levels of flow. The river restoration strategy is being developed for the SSSI, looking at restoring a more natural geomorphology including removal of impounding features. The catchment is predominantly rural in nature.

The Bewl Water Reservoir is located in the headwaters of the River Teise and many small weirs occur along this river’s course. Therefore the flows from the River Teise will be influenced by these features, which will in turn influence flows over the lowest 3.5km of the SSSI.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

Where Q70INF is the actual Q70 flow including the impact of water use in the catchment; and Q70NAT is the expected natural Q70 flow assuming no water use in the catchment. Q70INF and Q70NAT are estimated using the Low Flows 2000 water resource model and the water use as characterised by the Environment Agency’s Water Framework Directive (WFD) Artificial Influences data set.

For this SSSI catchment the Net Pressure at Q70 > +0.15, indicating that the net impact of water use in the catchment is more than 15% of the expected natural Q70 flow. This reflects the “discharges” from the Bewl Reservoir. Analysis using the WFD Artificial Influences data set over 140 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 50% of the observed Q70 values.

19 Final report November 2007 It should be noted that the WFD Artificial Influences data set has not yet been fully quality controlled and may contain errors affecting the estimation of Q70INF, there is uncertainty within the estimation of Q70NAT, hence these results should be regarded as indicative only. Furthermore, the inclusion of an impoundment in this catchment may introduce additional uncertainty into the estimation of Q70INF as the impacts of reservoirs have not yet been fully quality controlled in the Water Framework Artificial Influences data set.

Considering only the influences in the SSSI catchment of the River Beult prior to the confluence with the Teise, the 0.0 > Net Pressure at Q70 < +0.15 with the net addition to flow coming from sewerage treatment work discharges.

Relationship with existing CAMS assessment points – The Stile Bridge Assessment Point (AP) from the Medway CAMS is located at the site of gauging station 40005 on the River Beult. The information currently stored for this AP is summarised below.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Ecological Integrity Beult 5 Stile Bridge AP M 575800 147800 NWA Compromised

6.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit A head water stretch. Impermeable catchment. Generally 1 581810, 144212 rural Impermeable catchment, alluvial deposits influence. Impact 2 571649, 148213 of small STWs included. Flow from the River Teise included with higher base-flow 3 569447, 150130 component. Impacts of Bewl Water Reservoir. Increased urbanisation.

20 Final report November 2007

560000 570000 580000 590000 600000

160000

3 2

150000

1 Legend Rivers EWU Boundary

140000

140000 SSSI Boundary

130000

120000

120000 560000 570000 580000 590000 600000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Beult SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 2 [3] 2 1 3 M 2 3 2 2 3 M 3 3 2 1 3 M

21 7 River Coquet And Coquet Valley Woodlands SSSI 7.1 SSSI Description The River Coquet SSSI includes approximately 75km of the River Coquet from the headwaters in the Cheviot Hills to the mouth of at Amble. Also included are approximately 2km of the Rowhope and Trows Burns, the lower 7km of the River Alwin, and the entire 15km of the Wreigh Burn. The river is representative of a relatively natural upland river flow regime based non impermeable geologies. The riverside woodlands support a wide range of breeding habitats for birds, otter and red squirrels.

SSSI Name River Coquet And Coquet Valley Woodlands County Northumberland River Coquet Natural England ID 2000052 Link River Coquet And Coquet Valley Woodlands SSSI Views About Management

7.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 22 Outlet location (424928,605698) Catchment area (km2) 604.0 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 843 Average annual potential evaporation (mm/yr) 508 Average annual runoff (mm/yr) 447 Catchment average HOSTBFI 0.39

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Coquet SSSI MetaData Catalogue.

Geology – The headwaters of the Coquet and the River Alwin are founded on impermeable igneous rocks (Cheviot Lavas). Below Alwinton the geology changes to mudstones, cementstones and Carboniferous Limestones. The Millstone Grit Series underlies the catchment below Pauperhaugh. An east-west igneous intrusion runs almost the entire length of the catchment from Thirl Moor in the headwaters, to a discontinuity at Longframlington, and then on to Acklington in the lower catchment.

Peat deposits exist in the headwaters of the Coquet and the River Alwin. Upstream of Rothbury there are deposits of till and the main river channels are lined with alluvial clay, silt and sand. Downstream of Rothbury the coverage of till becomes extensive and glacial sands and gravels occur in the river channels that have been carved in the softer strata.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is grassland and arable with no urban areas. More information about land use within this SSSI catchment can be found on the River Coquet SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 22009 (Coquet at Rothbury) gauges flows in the middle reaches of the River Coquet with a catchment area of 346.0km2. The velocity-area station has an informal mill weir downstream providing a good control. This station measures flows from approximately 57% of the catchment contributing to flows at the downstream limit of the

22 Final report November 2007 SSSI. The flow regime recorded at this station would be a good reflection of flows in the middle part of the SSSI.

 Gauging station 22001 (Coquet at Morwick) gauges flows from the lower reaches of the River Coquet with a catchment area of 569.8km2. The station is a velocity-area arrangement with a concrete informal flat vee weir, and is impacted by the annual flushing of a dam on the upstream Duke of Northumberland estate. This station measures flows from approximately 94% of the catchment contributing to flows at the downstream limit of the SSSI. The flow regime recorded at this station would be a good reflection of flows in the lower part of the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Coquet SSSI MetaData Catalogue.

Macrophyte data – Five (5) macrophyte survey points exist in the SSSI catchment, with major types of C1, C2, B2 and D1 recorded. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Coquet SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at five (5) sites, and estimated LIFE scores are also calculated for fifteen (15) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Coquet SSSI MetaData Catalogue.

Fisheries data – Salmonid species have been observed, in addition to eurytopic/limnophilic cyprinid species. More information about species found in the vicinity of this SSSI can be found on the River Coquet SSSI MetaData Catalogue.

7.3 Catchment water use Artificial influences – Upstream of Rothbury is very natural with few influences on the flow regime. Below Rothbury a few minor groundwater and surface water abstractions exist. No significant impoundments exist and no major canal systems exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment -0.15 < Net Pressure at Q70 < 0.0 indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. Abstractions are predicted to dominate in this SSSI catchment. Analysis using the WFD Artificial Influences data set over 137 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

23 Final report November 2007 Relationship with existing CAMS assessment points – A total of two (2) assessment points (AP’s) from the Northumberland Rivers CAMS are relevant to this SSSI. AP2 is located at the downstream end of the SSSI and AP3 is located at Rothbury, in the middle of the SSSI.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Coquet 2 Lower Coquet H 423800 606050

Coquet 3 Upper Coquet VH 406650 601640

7.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit Headwater catchment, stable bedrock material, peat on ridge tops, 1 392025, 605687 steep, high energy river, igneous geology. Headwater catchment, stable igneous bedrock material, peat on 2 392151, 605741 ridge tops, steep, high energy river. Areas of alluvial clay, silt and sand occurring over underlying 3 402922, 601986 sandstones/cementstones. Upper portion on igneous, lower on sandstones/cementstones, 4 402970, 601978 alluvial clay, silt and sand occurring in main channel, till elsewhere. Sandstones and limestones underlying glacial deposits of sands and 5 408904, 600137 gravels, lower energy river developing meanders and a flood plain. Lower section of river, slower flowing, flood plain developed, steep 6 423704, 606087 sided channels cut into beds of till.

24 Final report November 2007

380000 390000 400000 410000 420000 430000

630000

620000

Legend

610000 2 6 610000 Rivers 1 4 EWU Boundary 5 SSSI Boundary 3

600000

590000

380000 390000 400000 410000 420000 430000 580000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Coquet SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 4 none 4 H 2 4 none none 4 H 3 4 3 4 4 H 4 4 none 4 4 H 5 4 4 none 4 H 6 4 4 4 4 H

25 8 River Eye SSSI 8.1 SSSI Description The River Eye SSSI consists of an 8km stretch above Melton Mowbray, is an exceptional example of a semi-natural lowland river on clay-based geologies which maintains a rich and diverse plant and animal communities.

SSSI Name River Eye County Leicestershire River Eye Natural England ID 1001178 Link River Eye SSSI Views About Management

8.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 28 Outlet location (476140,318820) Catchment area (km2) 182.7 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 638 Average annual potential evaporation (mm/yr) 587 Average annual runoff (mm/yr) 178 Catchment average HOSTBFI 0.38

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Eye SSSI MetaData Catalogue.

Geology – The geology of the SSSI catchment of the River Eye is comprised primarily of Jurassic and glacial Boulder Clays. The Whitby Mudstones overlay the Marlstone rock formation (sandstones) and Dyrham Formation (silty mudstones), which in turn overlay the Charmouth Mudstones (shales and bedded limestone). Lincolnshire Limestone outcrops in the northern section of the catchment. The catchment is bounded by the Inferior Oolite limestone to the east. Drift deposits in the catchment are dominated till with small deposits of glacial sands and gravels. Some alluvial clays, sands and gravel exist in the main river channel.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from very high permeability in the north of the catchment (in the order of 0.95 on the limestone) to very low values (in the order of 0.2) on the clays/mudstones/shales which dominate the catchment. The medium catchment average value of 0.38 reflects the low permeability solid geology of the catchment, but also the higher permeability of the large till deposits.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable with 0.5% urban. More information about land use within this SSSI catchment can be found on the River Eye SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 28024 (Wreake at Syston Mill) is located 25km downstream of the downstream limit of the SSSI, whereby the River Eye has turned into the River Wreake. This station gauges flows from a catchment area of 413.8km2. This electromagnetic gauging station (pre 1982 a Crump weir) is noted to be difficult to gauge with very low velocities at low flows and bypass at high flows. Very responsive flow regime. The SSSI catchment represents 44% of the total catchment contributing to the flows at this gauging station. Flows at this gauge are affected by the discharge from the Melton Mowbray

26 Final report November 2007 sewerage treatment works which is located downstream of the SSSI, and hence would not reflect the natural flow regime in the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Eye SSSI MetaData Catalogue.

Macrophyte data – Two (2) macrophyte survey points exist in the SSSI catchment, with an A1 major type. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Eye SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at one (1) site, and estimated LIFE scores are also calculated for sixteen (16) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Eye SSSI MetaData Catalogue.

Fisheries data – Rheophilic cyprinid species have been observed, in addition to eurytopic/limnophilic cyprinid species. More information about species found in the vicinity of this SSSI can be found on the River Eye SSSI MetaData Catalogue.

8.3 Catchment water use Artificial influences – Minor surface and groundwater abstractions occur in the SSSI catchment. Minor sewerage treatment works discharge above the SSSI but the major sewerage treatment works in the area (Melton Mowbray) discharges below the SSSI. No significant impoundments exist. Small sections of a disused canal system exist from Oakham to Stapleford but are unlikely to influence flows in the SSSI.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment 0.0 < Net Pressure at Q70 < +0.15, indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. Discharges are predicted to dominate in this SSSI catchment. Analysis using the WFD Artificial Influences data set over 70 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

Relationship with existing CAMS assessment points – The recently completed River Soar CAMS includes an Assessment Point (AP) at the Syston Mill (28024) gauging station (downstream of the SSSI). However, no data for this AP is currently available.

27 Final report November 2007 8.4 Environmental Weighting Units and River Flow Objectives Due to the short length of river included in the SSSI a single EWU has been adopted for the whole SSSI as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 476329, 318799 Whole SSSI catchment

480000 490000

1 Legend

320000

320000 Rivers EWU Boundary SSSI Boundary

310000

480000 490000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Eye SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 2 3 3 H

28 9 River Frome SSSI 9.1 SSSI Description The River Frome SSSI consists of the stretch of river from Dorchester to Wareham, including many of the main braided channels. The river is a major chalk stream, fed from the headwaters of South Wessex Downs, with a gradual transition to a lowland stream on mixed geologies in the lower reaches. The total length of river included in the SSSI is approximately 49km.

SSSI Name River Frome County Dorset River Frome Natural England ID 2000220 Link River Frome SSSI Views About Management

9.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 44 Outlet location (392195,87110) Catchment area (km2) 474.4 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 952 Average annual potential evaporation (mm/yr) 571 Average annual runoff (mm/yr) 502 Catchment average HOSTBFI 0.76

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Frome SSSI MetaData Catalogue.

Geology – The upper half of the SSSI catchment (upstream of Dorchester) is dominated by Chalk (including Red Chalk) with small outcrops of Gault, Upper Greensand formations and Oxford Clay occurring in the upper reaches. Clay with flints occur as drift deposits in the headwaters and alluvial deposits of sand and gravel occur along the main river in the middle to lower reaches.

The lower half of the SSSI catchment (from 3km downstream of Dorchester) includes varied geologies dominated by the Bagshot Beds (sands and clays) with smaller areas of London Clay (sandy, silty clay) and the Reading formation (clays). These geologies are less permeable than the chalk in the headwaters. Drift deposits of alluvial material become more widespread in the main river channel.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from high in the upper half of the catchment (over chalk), to areas of lower permeability in the lower catchment (over clays). The catchment average HOSTBFI value of 0.76 suggests a very permeable catchment, reflecting the dominant impact of the chalk geologies. The flow regime of the River Frome is noted to be more variable than other chalk rivers in southern England, due to the influence of the impermeable geologies in the lower half of the catchment.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable and grassland with 1.9% urban. More information about land use within this SSSI catchment can be found on the River Frome SSSI MetaData Catalogue.

Flow gauging stations –

29 Final report November 2007

 Gauging station 44004 (Frome at Dorchester Total) gauges flows from a catchment area of 206.0km2. This is a combined station consisting of; a) two Crump weirs at Louds Mill and b) a complimentary Crump weir at Stinsford (constructed in Oct 1971). This station measures flows from approximately 43% of the catchment contributing to flows at the downstream end of the SSSI, and approximately 100% of the flows at the upstream end of the SSSI. Flows recorded at this station would be representative of flows in the upper half of the SSSI.

 Gauging station 44001 (Frome at East Stoke Total) gauges flows from a catchment area of 414.4km2. This is a combined station consisting of; a) rectangular critical depth flume, bounded by two broad-crested weirs and b) a complementary Crump weir on bypass channel. The Crump weir is shown as gauging station 44811. This station measures flows from approximately 87% of the catchment contributing to flows at the downstream end of the SSSI. Flows recorded at this station would be representative of flows in the lower half of the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Frome SSSI MetaData Catalogue.

Macrophyte data – Six (6) macrophyte survey points exist in the SSSI catchment, with major typology varying from A1 to B1. Some replicate survey information is available. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Frome SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at eight (8) sites, and estimated LIFE scores are also calculated for thirty one (31) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Frome SSSI MetaData Catalogue.

Fisheries data – Salmonid species have been observed, in addition to rheophilic and eurytopic/limnophilic cyprinid species. More information about species found in the vicinity of this SSSI can be found on the River Frome SSSI MetaData Catalogue.

9.3 Catchment water use Artificial influences – No major reservoirs exist. No major canal systems exist. Groundwater abstractions occur in upper catchment. Sewerage treatment works discharge from major towns in the catchment.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

30 Final report November 2007 estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

Relationship with existing CAMS assessment points – The Frome, Piddle, Poole Harbour & Purbeck CAMS includes three (3) assessment points (AP’s) in the vicinity of this SSSI. AP1 is located near Stratton, approximately 7km upstream of the upstream limit of the SSSI, AP2 is located in the middle of the SSSI and AP3 is located at the downstream end of the SSSI.

ified ified

X Y

mod

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

AP1 Grimstone - Frome 1 H 363981 093906 WA No comment Frome

AP2 Tincleton - Frome 2 H 378256 091114 WA No comment Frome

Frome 3 AP3 Frome tidal limit H 392279 087142 WA No comment

9.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

31 Final report November 2007

Downstream EWU Notes Limit Impacts of the Upper Chalk as well as the Gault and Upper 1 384420, 87143 Greensand formations in the headwaters. Impact of urbanisation (Dorchester). Alluvial deposits and impacts of highly braided channels over 2 392196, 87111 Bagshot sandstones influence flow regime. Mainly rural.

350000 360000 370000 380000 390000

110000

100000

100000 Legend Rivers EWU Boundary 1 2 SSSI Boundary

90000 90000

80000

70000

350000 360000 370000 380000 390000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Frome SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 3 1[1] 3 4 H 2 3 3 3 4 H

[1] Potentially erroneous, based upon just one sample in 1995. All other surveys within this river system have higher communities.

32 10 Halsdon SSSI 10.1 SSSI Description The Halsdon SSSI is contained largely with a Devon Trust for Nature Conservation reserve between Lockshill and Ashwell, near Dolton, Devon. The sites consists of ancient oak woodlands and meadows adjacent to the River Torridge. The total length of river included in the SSSI is approximately 1.5km. This stretch of river is located approximately 6.5km below the confluence of the rivers Torridge and Okement.

SSSI Name Halsdon County Devon River Torridge (Halsdon) Natural England ID 1002148 Link Halsdon SSSI Views About Management

10.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 50 Outlet location (254940,113693) Catchment area (km2) 605.1 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 1215 Average annual potential evaporation (mm/yr) 560 Average annual runoff (mm/yr) 757 Catchment average HOSTBFI 0.42

Deviations of topographic and groundwater catchment divides – None

More information about the catchment of this SSSI can be found on the Halsdon SSSI MetaData Catalogue.

Geology – Entire catchment underlain by Upper Carboniferous measures of the Bude and Bideford formation and the Crackington formation (sandstone and argillaceous rocks). In the headwaters of the River Okement a small area of Exe Breccia (permeable) and also small area of peat overlying Granite exist. An small area of the Bovey formation (relatively impermeable) occurs in the River Torridge catchment. Drift deposits of alluvial material in main river channels of the River Okement and River Torridge. A small area of peat overlying granite exists in headwaters.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from low permeability (in the order of 0.2) in the areas of Granite and Bovey formation to high (in the order of 0.8) in the Exe Breccia. However, the catchment average value of 0.42 suggest a moderately permeable catchment.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is grassland with 0.5% urban. More information about land use within this SSSI catchment can be found on the Halsdon SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 50010 (Torridge at Rockhay Bridge) gauges flows from a 257.8km2 catchment. The station consists of an informal flat-vee low flow control between high angle, trapezoidal gabion wing walls. This station measures flows from approximately 42% of the catchment contributing to flows at the upstream end of the SSSI.

33 Final report November 2007  Gauging station 50008 (Lew at Gribbleford Bridge) gauges flows from a 71.1km2 catchment. The station consists of an informal flat-vee control between high angle, trapezoidal gabion wing walls. This station measures flows from approximately 12% of the catchment contributing to flows at the upstream end of the SSSI.

 Gauging station 50002 (Torridge at Torrington) gauges flows from a 663.0km2 catchment which includes the entire SSSI catchment. The station is a velocity area station. The SSSI catchment represents 91% of the total catchment contributing to the flows at this gauging station. Flows recorded at this gauge would be a good reflection of the flow regime in the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the Halsdon SSSI MetaData Catalogue.

Macrophyte data – Eleven (11) macrophyte survey points exist in the SSSI catchment, with the major type varying from B1 to C2. Some replicate survey information is available. More information about macrophyte survey data in the vicinity of this SSSI can be found on the Halsdon SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at six (6) sites, and estimated LIFE scores are also calculated for thirty nine (39) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the Halsdon SSSI MetaData Catalogue.

10.3 Catchment water use Artificial influences – No major abstractions or discharges exist in the SSSI catchment. No major canal systems exist. The Meldon reservoir (in the headwaters of the River Okement) is known to have some influence on flows in the SSSI.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment 0.0 < Net Pressure at Q70 < +0.15, indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. The “discharges” from Meldon reservoir are responsible for some of the net impact this SSSI catchment. Analysis using the WFD Artificial Influences data set over 70 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

34 Final report November 2007 uncertainty into the estimation of Q70INF as the impacts of reservoirs have not yet been fully quality controlled in the Water Framework Artificial Influences data set.

Relationship with existing CAMS assessment points – There are no CAMS completed in the vicinity of this SSSI.

10.4 Environmental Weighting Units and River Flow Objectives Due to the short (1.5km) length of river included in the SSSI a single EWU has been adopted for the whole SSSI as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 254957, 113621 Whole SSSI catchment

230000 240000 250000 260000

120000

110000

110000 Legend Rivers EWU Boundary SSSI Boundary

100000

90000

230000 240000 250000 260000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the Halsdon SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 4 none 4 H

35 11 River Hull Headwaters SSSI 11.1 SSSI Description The Hull Headwaters SSSI includes approximately 20km of the River Hull from Kirkburn (where the river is known as Eastburn Beck) downstream to the confluence of Kelk/Fodringham Beck and the River Hull at Emmotland. The section of Kelk/Fodringham Beck upstream of this confluence to Harpham is also included (approximately 15km). Also included is the 4km stretch of Elmswell Beck (near Little Driffield) to the confluence with the River Hull south of Driffield, and the marshes south of Kelleythorpe.

The headwaters of the River Hull are one of the most northerly examples of a chalk stream in England and includes a high diversity of habitats and corresponding species assemblages.

SSSI Name River Hull Headwaters County Humberside River Hull Natural England ID 1003424 Link River Hull Headwaters SSSI Views About Management

11.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 26 Outlet location (508213,451710) Catchment area (km2) 391 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 695 Average annual potential evaporation (mm/yr) 563 Average annual runoff (mm/yr) 240 Catchment average HOSTBFI 0.80

Deviations of topographic and groundwater catchment divides – None documented. The contributing catchment areas within this SSSI catchment are partially defined by the drainage network.

More information about the catchment of this SSSI can be found on the River Hull Headwaters SSSI MetaData Catalogue.

Geology – The SSSI catchment is underlain entirely by the Upper Cretaceous Chalk occurring on the north east coast of England. Drift deposits of glacial till occur in the south eastern half of the catchment. Alluvial sands and gravels line the main channel of the River Hull, while alluvial clays, silts and sands dominate the bed of the Kelk Beck.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from very high permeability on the north western half of the catchment (in the order of 0.95 on the chalk) to moderate values (in the order of 0.35) on the drift deposits in the south east. The high catchment average value of 0.80 reflects the dominance of the underlying chalk geologies.

Landuse - Based upon a 1 km aggregated grid, the majority of this catchment is arable with 0.5% urban. More information about land use within this SSSI catchment can be found on the River Hull Headwaters SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 26006 (Elmswell Brook at Lower Driffield) gauges flows from the upper catchment of the River Hull of approximately 136km2. The station consists of a thin-plate

36 Final report November 2007 weir. The baseflow dominated regime is known to included periods of zero flow during droughts. Flows from this station would provide a good representation of flows for the upper reaches of West Beck/River Hull portion of the SSSI.

 Gauging station 26001 (West Beck at Wansford Bridge) gauges flows from the middle of the River Hull, a catchment area of approximately 192km2. This station, a compound rectangular critical depth flume, was abandoned in 1974 and was effectively replaced by station 26009, in 1988.

 Gauging station 26003 (Foston Beck/Kelk Beck at Foston Mill) gauges flows from majority of the Kelk Beck, a catchment area of approximately 57km2. This station consists of a sharp-edged weir (sluice gate). Estimated natural flows have been generated by the Environment Agency for this station. Flows from this station would provide a good representation of flows for the Kelk Beck portion of the SSSI.

 Gauging station 26002 (Hull at Hempholme Lock) gauges flows a catchment area of approximately 378.1km2 and is located below the SSSI. This station consists of two tilting- gate weirs. The contributing area is known to be partially defined by the drainage network. Estimated natural flows have been generated by the Environment Agency for this station. Flows from this station would provide a good representation of flows for the most downstream section of the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Hull Headwaters SSSI MetaData Catalogue.

Macrophyte data – Five (5) macrophyte survey points exist in the SSSI catchment, with major types of A1 and A2. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Hull Headwaters SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at five (5) sites, and estimated LIFE scores are also calculated for ten (10) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Hull Headwaters SSSI MetaData Catalogue.

Fisheries data – Rheophilic cyprinid species have been observed, in addition to eurytopic/limnophilic cyprinid species. Salmon were observed, but only at one site during one year (1990). More information about sites in the vicinity of this SSSI can be found on the River Hull Headwaters SSSI MetaData Catalogue.

11.3 Catchment water use Artificial influences – The Driffield canal runs parallel to West Beck/River Hull downstream from Driffield, to the confluence of the Kelk Beck at Emmontland. The canal may effectively reduce the water recharging the River Hull by intercepting flows from the Chalk to the north of the river, however, no quantitative data is available to confirm this.

Minor surface water and some groundwater abstractions are noted in the catchment. No major impoundments are present. Discharges from sewerage treatment works exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

37 Final report November 2007 Hence negative Net Pressure values indicate that abstractions from the flow regime (such as public water supply abstractions) dominate, positive Net Pressure values indicate augmentations to the flow regime (such as sewerage treatment works discharges) dominate.

Relationship with existing CAMS assessment points – A total of four (4) assessment points (AP’s) from the River Hull Headwaters CAMS are relevant to this SSSI. AP3 is located downstream of the SSSI.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Ecological Kelk 1 Kelk Beck H 509360 454870 NWA Integrity Beck Maintained Ecological West 2 Upper West Beck H 506680 455550 NWA Integrity Beck Maintained Ecological River 3 Upper Hull L 507990 449890 OL/OA? Integrity Hull Maintained Ecological Driffield 4 Driffield Canal L 506730 455570 NWA Integrity Canal Maintained

11.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 502345, 456460 Headwater chalk catchment, narrow defined channel. Headwater chalk catchment, meandering river form in glacial 2 502310, 456510 sands and gravels. Headwater chalk stream with alluvial clays, silt and sand in 3 509043, 453957 bed material.

38 Final report November 2007

Low gradient, slower flowing river system on sands and 4 507962, 450033 gravels, increasing build up of fine sediments, includes impact of artificial drainage works.

Legend Rivers EWU Boundary SSSI Boundary

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Hull Headwaters SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 3 none 3 3 M 2 3 3 none 3 M 3 3 3 1 3 M 4 3 2 1 3 M

39 12 River Ise and Meadows SSSI 12.1 SSSI Description

The River Ise and Meadows SSSI consists of a 5km section of river between Barford Bridge railway viaduct and the village of Geddington. Flowing through a catchment of Oolite Limestone, the River Ise is the best example in the county of a lowland river on clay, fed by base-rich water. The channel displays a variety of semi-natural features increasingly uncommon in areas of intensive agriculture.

SSSI Name River Ise and Meadows County Northamptonshire River Ise Natural England ID 1004261 Link River Ise and Meadows SSSI Views About Management

12.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 32 Outlet location (489195,282962) Catchment area (km2) 70.9 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 655 Average annual potential evaporation (mm/yr) 590 Average annual runoff (mm/yr) 200 Catchment average HOSTBFI 0.45

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Ise SSSI MetaData Catalogue.

Geology – The upper SSSI catchment is underlain by the Whitby Mudstone formation which then changes to the Inferior Oolite Group (sandstones and calcareous mudstones) and finally, towards the lower sections of the catchment where the SSSI is located, to the Great Oolite Group (limestones and sandstones). Large deposits of till exist over the west and northern slopes of the catchment and alluvial clay, silt and sand are found in the upper catchment. Silts, clays and gravels are observed as substrate over the SSSI section of the river.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from very lower permeability in the western headwaters (mudstones) to medium/high values on the more permeable sandstones in the lower half of the catchment. The medium catchment average value of 0.45 reflects the relatively low permeability solid geology of the catchment.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable with 2.9% urban. More information about land use within this SSSI catchment can be found on the River Ise SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 32004 (Ise Brook at Harrowden Old Mill) is located 15km downstream of the downstream limit of the SSSI. This station gauges flows from a catchment area of 194.0km2. This station consists of a flat vee weir and crump weir (pre 1976 flume with low flow notch) The SSSI catchment represents 36% of the total catchment contributing to the flows at this gauging station. Flows at this gauge are affected by the discharges from the

40 Final report November 2007 Thorpe Malsor and Cransley reservoirs and sewerage treatment works discharges from Kettering.

More information about gauging stations in the vicinity of this SSSI can be found on the River Ise SSSI MetaData Catalogue.

Macrophyte data – No macrophyte survey points exist in this SSSI catchment.

Macroinvertebrate data –Estimated LIFE scores are calculated for two (2) GQA sites, but no 3-season RIVPACS exist within this catchment. More information about these sites in the vicinity of this SSSI can be found on the River Ise SSSI MetaData Catalogue.

Fisheries data – Salmonid species have been observed (at two sites during 1992), in addition to rheophilic and eurytopic/limnophilic cyprinid species observed over numerous years. More information about species found in the vicinity of this SSSI can be found on the River Ise SSSI MetaData Catalogue.

12.3 Catchment water use Artificial influences – The SSSI catchment is essentially natural with no significant abstractions noted, no impoundments and no canal systems. Minor discharges from sewerage treatment works exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

Relationship with existing CAMS assessment points – No CAMS assessment point (AP) information exists in the vicinity of this SSSI.

12.4 Environmental Weighting Units and River Flow Objectives Due to the short (5km) length of river included in the SSSI a single EWU has been adopted for the whole SSSI as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 489128, 282981 Whole SSSI catchment

41 Final report November 2007

470000 480000 490000

290000

Legend Rivers EWU Boundary SSSI Boundary

280000 280000

270000

470000 480000 490000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Ise SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 none 3 3 H

42 13 River Kennett SSSI 13.1 SSSI Description

The River Kennet SSSI is a 42km stretch dominated by chalk with the majority of the river bed being lined by gravels. Below Newbury the river traverses Tertiary sands and gravels, London Clay and silt, thus shows a downstream transition from the chalk to a lowland clay river. The flora of the River Kennet is species-rich and diverse, having the highest average number of species per site surveyed of any other lowland river in Britain.

SSSI Name River Kennet County Berkshire / Wiltshire River Kennet Natural England ID 2000164 Link River Kennett SSSI Views About Management

13.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 39 Outlet location (457174,166577) Catchment area (km2) 853.1 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 759 Average annual potential evaporation (mm/yr) 579 Average annual runoff (mm/yr) 289 Catchment average HOSTBFI 0.82

The main tributary to the River Kennet, the River Lambourn, joins the Kennet at Newbury. More information about the catchment of this SSSI can be found on the River Kennet SSSI MetaData Catalogue.

Deviations of topographic and groundwater catchment divides – Minor differences along the northern boundary where the topographic divide is thought to extend further than the groundwater catchment.

Geology – The majority of the upper half of this SSSI catchment consists of Upper Chalk overlain by alluvial deposits of sand and gravel in the river channels and Clay with Flints on the surrounding hills.

Near Kintbury the geology changes and the chalk is replaced by bands of impermeable stratum including the London Clay formation and sandstones/clays from the Lamberth Group and Bagshot beds.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from a very high permeability on the Chalk (in the order of 0.95) to low values (in the order of 0.25) on the impermeable London Clays and medium values on the sandstones of the lower part of the catchment. A catchment average value of 0.82 suggest a very permeable, base-flow dominated flow regime, reflecting the dominance of the chalk geology.

It is interesting to note that the catchment of the Enborne at Brimpton (147km2) is underlain by the impermeable geologies of London Clay and the sandstones/clays of the Bagshot beds. The observed base flow index (BFI) for this catchment is 0.53, while the Lambourn at Shaw (234.1km2) featuring almost entirely Upper Chalk, has an observed BFI of 0.97, one of the most base-flow dominated regimes in the UK.

43 Final report November 2007 Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable with 2.7% urban. More information about land use within this SSSI catchment can be found on the River Kennet SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 39037 (Kennet at Marlborough) gauges flows from a catchment area of 142.0km2. This station is a Crump weir. The hydrologic catchment (contributing to flows) is smaller than the topographic catchment. This station is 2.1km upstream of the upstream limit of the SSSI and hence flows recorded at this station would reflect the flow regime in the upper portion of the SSSI.

 Gauging station 39043 (Kennet at Knighton) gauges flows from a catchment area of 295.0km2. This station consists of two Crump weirs. This station is approximately 13km downstream of station 39037.

 Gauging station 39103 (Kennet at Newbury) gauges flows from the River Kennet before it’s confluence with the River Lambourn, with a catchment area of 548.1km2. This is an ultrasonic gauging station with six pairs of transducers. This station measures flows from approximately 64% of the catchment contributing to flows at the downstream end of the SSSI. Flows recorded at this station would reflect the flow regime in the lower portion of the SSSI.

 Gauging station 39019 (Lambourn at Shaw) gauges flows from a catchment area of 234.1km2. This station consists of a Crump weir with auxiliary downstream recorder. The flows at this station are augmented by the West Berkshire Groundwater Scheme during droughts. This station measures flows all the flows from the River Lambourn, a catchment area of approximately 30% of the catchment contributing to flows at the downstream end of the SSSI.

 Gauging station 39016 (Kennet at Theale), located 10km below the downstream limit of the SSSI, gauges flows from a catchment area of 1033.4km2. This station consists of a Crump weir. The flows at this station are augmented by the West Berkshire Groundwater Scheme during droughts. The SSSI catchment represents 83% of the total catchment contributing to the flows at this gauging station.

More information about gauging stations in the vicinity of this SSSI can be found on the River Kennet SSSI MetaData Catalogue.

Macrophyte data – Eleven (11) macrophyte survey points exist in the SSSI catchment, with a major type varying from A1 to B1. Some replicate survey information is available. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Kennet SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at one (1) site, and estimated LIFE scores are also calculated for fifteen (15) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Kennet SSSI MetaData Catalogue.

13.3 Catchment water use Artificial influences – Significant groundwater abstractions exist in the SSSI catchment. No major impoundments exist. Discharges from sewerage treatment works exist. A major canal system follows the River Kennet. The main impacts are summarised below;

44 Final report November 2007  West Berkshire Groundwater Scheme consists of 33 boreholes located mainly within the Lambourn and Pang catchments which were originally established to augment river flows during periods of drought. More recently plans have been developed to enable these boreholes to be used to alleviate “groundwater flooding” during winter periods when the water table is elevated. Flows in the bottom half of the SSSI may be affected by the operation of this scheme.

 Kennet and Avon Canal enters the SSSI catchment near the canal’s summit at Crofton Pumping Station. From the summit and Kintbury the canal is fed by the River Dun (a tributary of the Kennet); and between Kintbury and Reading by the River Kennet. In some places the canal joins with the river to form a single channel. There are also many carriers and channels formerly associated with water meadow systems.

 Significant Groundwater Abstractions occur within SSSI catchment, the largest single abstraction adjacent to the river is at Axford (between Marlborough and Hungerford), with 70% of the water abstracted here being exported out of the catchment. Studies have showed that this abstraction has a detrimental impact on flows in the River Kennet.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment -0.15 < Net Pressure at Q70 < 0.0 indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. Abstractions and discharges almost balance out in this SSSI catchment. Analysis using the WFD Artificial Influences data set over 137 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

It should be noted that the WFD Artificial Influences data set has not yet been fully quality controlled and may contain errors affecting the estimation of Q70INF and there is uncertainty within the estimation of Q70NAT. Furthermore, the operation of the Kennet and Avon canal and the West Berkshire Groundwater Scheme have not been included in the WFD Artificial Influences data set. In a complex catchment like the Kennet the Water Framework Directive data sets require further validation, and these result should be treated as indicative only.

Relationship with existing CAMS assessment points – The Kennet and Pang CAMS includes five (5) assessment points (AP’s) in the vicinity of this SSSI. AP7 is on the River Og, a tributary to Kennet, at the upstream limit of the SSSI as is AP7, which is located on the Kennet. AP6 is in the middle of the SSSI and AP4 (on the Lambourn) and AP5 (on the Kennet) are located towards the bottom of the SSSI.

45 Final report November 2007

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Lambourn 4 Lambourn VH 449000 167200 No comment No comment Lower Middle Kennet Kennet 5 H 448700 167200 No comment No comment (Newbury) Upper Middle Kennet Kennet 6 VH 434300 168600 No comment No comment (Hungerford) Upper Kennet Kennet 7 VH 419500 169500 No comment No comment (Marlborough) Og 11 Og VH 419600 169500 No comment No comment

13.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit Upstream section of chalk catchment. Influence of 1 Marlborough. Influence of the groundwater abstractions at 434232, 168698 Axford. Interaction of Kennet and Avon canal. Influence of 2 447160, 167169 impermeable geologies. Flows from Lambourn included. Influence of impermeable 3 457186, 166545 geologies more significant.

Legend Rivers EWU Boundary SSSI Boundary

46 Final report November 2007 Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Kennet SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 3 3 4 H 2 4 1 none 4 H 3 4 none 3 4 H

47 14 River Lymington SSSI 14.1 SSSI Description The River Lymington SSSI consists of Highland Water and Ober Water to their confluence to form the River Lymington and then from this confluence to the tidal limit at Lymington. The river supports a highly diverse range of habitats, reflecting the diversity of geologies encountered along it’s length. The total length of river within the SSSI, including the tributaries Highland and Ober Water, is approximately 32km.

SSSI Name River Lymington County Hampshire River Lymington Natural England ID 2000203 Link River Lymington SSSI Views About Management

14.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 42 Outlet location (432805,96018) Catchment area (km2) 123.1 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 844 Average annual potential evaporation (mm/yr) 600 Average annual runoff (mm/yr) 386 Catchment average HOSTBFI 0.42

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Lymington SSSI MetaData Catalogue.

Geology – The geology of this SSSI catchment is highly varied. The headwaters are underlain by the Barton Group (argillaceous) then sandstones from the same formation. Clays occur as surface deposits which are often overlain with peat, particularly in the Ober Water catchment. Downstream of Brockenhurst the Headon Beds and Osborne Beds (argillaceous and sandstones) occur.

Drift deposits consist of sands and gravels in the headwaters. Alluvial sands and gravels occur in a deposit at the confluence of the Blackwater, Ober Water and Highland Water (upstream of Brockenhurst), and then follow the Lymington river to the tidal limit.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from low permeability in the headwaters (in the order of 0.2) to higher values towards the bottom of the catchment (in the order of 0.6). A catchment average value of 0.42 suggest a moderately impermeable catchment, with catchment response affected by the areas of peat and bog in the headwaters.

Landuse - Based upon a 1 km aggregated grid, the majority of this catchment is woodland and grassland with 2.5% urban. More information about land use within this SSSI catchment can be found on the River Lymington SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 42003 (Lymington at Brockenhurst) gauges flows from a catchment area of 98.9km2. The station is a compound thin-plate weir (pre-1996: a thin-plate weir with V

48 Final report November 2007 notch). This station measures flows from approximately 80% of the catchment contributing to flows at the downstream limit of the SSSI, and all flows below the confluence of the Ober Water, Highland Water and Blackwater.

More information about gauging stations in the vicinity of this SSSI can be found on the River Lymington SSSI MetaData Catalogue.

Macrophyte data – Eight (8) macrophyte survey points exist in the SSSI catchment, with the major type varying from C1 to D2. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Lymington SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at two (2) sites, and estimated LIFE scores are also calculated for eight (8) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Lymington SSSI MetaData Catalogue.

14.3 Catchment water use Artificial influences – No major impoundments exist. No major canal systems exist. Minor groundwater abstractions and discharges from sewerage treatment works exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment 0.0 < Net Pressure at Q70 < +0.15, indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. A minor net discharge is predicted in this SSSI catchment. Analysis using the WFD Artificial Influences data set over 70 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

Relationship with existing CAMS assessment points – There are no CAMS completed in the vicinity of this SSSI.

14.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 427642, 106529 Headwater catchment of Highland Water upstream of drift

49 Final report November 2007

deposits. Rural. Headwater catchment of Ober Water upstream of drift 2 427796, 102951 deposits. Rural. Includes the contributions in flow from the Blackwater and 3 431514, 102392 Ober; impacts of the drift deposits associated with river confluences; impact of small urban areas (Brockenhurst). Impact of the Headon Beds and Osborne Beds (argillaceous 4 432785, 96098 and sandstones) geologies; increased urbanisation.

Legend Rivers EWU Boundary SSSI Boundary

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Lymington SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 4 none 4 H 2 3 3 3 4 H 3 3 none 3 4 H 4 3 none 3 4 H

50 15 Moors River System SSSI 15.1 SSSI Description The Moors River SSSI consists of the stretch of river from Cranbourne (where it is known as the River Crane) to the confluence with the River Stour just south of Hurn. The river supports a highly diverse range of aquatic and wetland plants, reflecting the diversity of geologies encountered along it’s course. The Moors River is noted for an abundance of dragonfly species. The total length of river included in the SSSI is approximately 32km.

SSSI Name Moors River System County Dorset River Moors Natural England ID 1004461 Link Moors River System SSSI Views About Management

15.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 43 Outlet location (413175,95915) Catchment area (km2) 148.8 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 820 Average annual potential evaporation (mm/yr) 597 Average annual runoff (mm/yr) 390 Catchment average HOSTBFI 0.63

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the Moors River System SSSI MetaData Catalogue.

Geology – The geology of this SSSI catchment is highly varied. The headwaters are underlain by the highly permeable Upper Chalk formation and springs are noted. Small drift deposits of clay with flints occur. The river then crosses a thin band of the impermeable Reading formation (clays and sandstone) and then London Clay. The remainder of the catchment is underlain by the Bagshot formation (sandstone) and the Bracklesham beds (clay and sandstone). Drift deposits of alluvial material occur along the course of the Moors River below Verwood, over the Bagshot and Bracklesham formations.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from high in the headwaters of the catchment (over chalk in the order of 0.95), to areas of lower permeability in the impermeable bands of the Reading formation and London Clay (in the order of 0.25). The catchment average HOSTBFI value of 0.63 suggests a relatively permeable catchment.

Landuse – Based upon a 1 km aggregated grid, land use in this catchment is a combination of grassland, arable and woodland, with 18.4% urban. More information about land use within this SSSI catchment can be found on the Moors River System SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 43022 (Moors River at Hurn Court) gauges flows from a catchment area of 143.3km2. This station was a Crump weir and gauged flows between 1992 and 1997. The gauging station was located at the downstream end of the SSSI and hence measured flows equal to the total flow at the downstream end of the SSSI.

51 Final report November 2007 As this gauging stations is not within the vicinity of this SSSI, no further information is provided.

Macrophyte data – Three (3) macrophyte survey points exist in the SSSI catchment. Point 1015201 is located on the Stour, downstream of the confluence of the Moors River and the River Stour. The major type on the moors river system is B1, and A1 of the Stour. More information about macrophyte survey data in the vicinity of this SSSI can be found on the Moors River System SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at twenty (20) sites, and estimated LIFE scores are also calculated for six (6) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the Moors River System SSSI MetaData Catalogue.

Fisheries data –Salmonid species have been observed, in addition to rheophilic and eurytopic/limnophilic cyprinid species. More information about species found in the vicinity of this SSSI can be found on the Moors River System SSSI MetaData Catalogue.

15.3 Catchment water use Artificial influences – No major impoundments exist. No major canal systems exist. Minor surface and groundwater abstractions exist. Medium size sewerage treatment works exist in the catchment.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

Relationship with existing CAMS assessment points – The Dorset Stour CAMS includes one (1) assessment points (AP) in the vicinity of this SSSI. AP9 is located at the downstream limit of the SSSI, on the Moors River, above the confluence with the Stour.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Moors 9 Moors River H 413100 095900 No comment No comment

15.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 407608, 110892 Pure chalk headwater catchment. Rural. Prior to main deposits of alluvial material. Influenced by 2 409989, 107416 geologies of impermeable London Clay and Reading formation. Rural. Formation of an alluvial floodplain impacts on flow regime. 3 409541, 101340 Drainage of heathland and conifer forests influences flows. Impact of the base-poor waters of Uddens Water. Increasing 4 413116, 95934 urbanisation.

Legend Rivers EWU Boundary SSSI Boundary

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the

53 Final report November 2007 methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the Moors River System SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 3 4 none 4 H 2 3 none 3 4 H 3 3 none 3 4 H 4 3 1 3 4 H

54 16 River Nar SSSI 16.1 SSSI Description The River Nar SSSI encompasses the entire 40km length of the River Nar from the source, springs in Chalk near Mileham in Norfolk, to the confluence with the Great Ouse at Kings Lynn. The river includes a diverse range of habitats from those associated with a chalk stream, in the upper reaches, to those associated with a sluggish East Anglian fen river with a wide floodplain in the lower reaches.

SSSI Name River Nar County Norfolk River Nar Natural England ID 1006323 Link River Nar SSSI Views About Management

16.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 33 Outlet location (562173,318734) Catchment area (km2) 248.3 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 668 Average annual potential evaporation (mm/yr) 605 Average annual runoff (mm/yr) 187 Catchment average HOSTBFI 0.81

Deviations of topographic and groundwater catchment divides – Minor differences possible due to low relief terrain and underlying permeable Chalk geology in upper catchment.

More information about the catchment of this SSSI can be found on the River Nar SSSI MetaData Catalogue.

Geology – The headwaters of this SSSI catchment lie on the permeable Upper, Middle and Lower Chalk formations. These overlie the less permeable Upper Greensands and Gault formations (sandstones and clays) which are exposed as a north-south band in the middle of the catchment. The lower reaches of the catchment are underlain by the impermeable Kimmeridge Clays. Extensive deposits of glacial till exist in the upper catchment and alluvial sands and gravels line the main river channel. The Middle chalk is noted to be exposed for a short length along the river, near Castle Acre. Alluvial clays, silts and sands then dominate the lower reaches and floodplain downstream of Blackborough.

The variation of HOSTBFI (an indicator of catchment permeability) ranges from high in the upper half of the catchment (over chalk), to areas of lower permeability in the lower catchment (over the sandstones and clay formations). The drift deposits of till in the upper catchment are less permeable than the underlying chalk. The catchment average HOSTBFI value of 0.81 suggests overall this SSSI catchment is very permeable, reflecting the dominant impact of the chalk geologies.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable with 0.4% urban. More information about land use within this SSSI catchment can be found on the River Nar SSSI MetaData Catalogue.

Flow gauging stations –

55 Final report November 2007  Gauging station 33007 (Nar at Marham) gauges flows from a catchment area of 153.3km2. The station is a critical depth flume (pre 1982 included a low flow notch). This station measures flows from approximately 62% of the catchment contributing to flows at the downstream end of the SSSI.

More information about gauging stations in the vicinity of this SSSI can be found on the River Nar SSSI MetaData Catalogue.

Macrophyte data – Three (3) macrophyte survey points exist in the SSSI catchment, with major types noted as A1, A2 and B2. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Nar SSSI MetaData Catalogue.

Macroinvertebrate data –Estimated LIFE scores are calculated for eight (8) GQA sites, and no 3-season RIVPACS sites exist within this catchment. More information about these sites in the vicinity of this SSSI can be found on the River Nar SSSI MetaData Catalogue.

16.3 Catchment water use Artificial influences – Small number of moderate surface water abstractions and groundwater abstractions exist. Discharges from sewerage treatment works exist. Riverside lakes exist but no major impoundments occur in this catchment. No major canal systems exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment Net Pressure at Q70 < -0.15, indicating that the net impact of water use in the catchment is more than 15% of the expected natural Q70 flow. Abstractions are predicted to dominate in this SSSI catchment. Analysis using the WFD Artificial Influences data set over 70 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 40% of the observed Q70 values.

Relationship with existing CAMS assessment points – Three (3) CAMS assessment points (AP’s) from the North West Norfolk CAMS exist in the vicinity of the SSSI. AP7 is located at the downstream end of the SSSI, AP9 is located approximately 1km downstream of AP7 at the confluence with the Great Ouse. AP8 is located at the Marham gauging station approximately in the middle of the SSSI.

56 Final report November 2007

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Ecological Middleton Stop (D/S) Nar 7 L 562300 318700 NWA Integrity (r & GWMU) Compromised Ecological Nar 8 Nar M/S (r & GWMU) H 572500 312100 OL/OA? Integrity Compromised Ecological Nar 9 Nar D/S (r & GWMU) L 561800 319300 OL/OA? Integrity Compromised

16.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit Headwater chalk stream, pool and riffle sequences, gravel 1 584239, 316924 bed.

2 578797, 315395 Includes section of exposed Middle Chalk.

3 574496, 313195 Increasing impacts of alluvial sands, silts and gravels in bed Clays and silts more common bed material. Steep banks with 4 566905, 313195 a floodplain developing. Underlying clay geologies and floodplain development 5 562123, 318278 changing river morphology

57 Final report November 2007

Legend Rivers EWU Boundary SSSI Boundary

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Nar SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 3 none 2 4 H 2 3 3 3 4 H 3 3 4 3 4 H 4 Need to discuss this – seems anomalous as there’s no way that 4 salmonids or H rheophilic cyprinids would inhabitat this stretch of well 3 1 1 canal basically

58 17 River Ribble (Long Preston Deeps) SSSI 17.1 SSSI Description The Long Preston Deeps SSSI includes approximately 8km of the River Ribble between Settle and Long Preston. The SSSI area includes a flat floodplain area unusually high up in the catchment providing breeding areas for many bird species. The base-rich waters derived from the limestone geology of the upper catchment, combine with fine alluvial sediments from the boulder clay in the SSSI area to create unique habitats.

SSSI Name River Ribble (Long Preston Deeps) County North Yorkshire River Ribble Natural England ID 1003025 Link River Ribble (Long Preston Deeps) SSSI Views About Management

17.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 71 Outlet location (382426,457313) Catchment area (km2) 170.0 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 1491 Average annual potential evaporation (mm/yr) 492 Average annual runoff (mm/yr) 1082 Catchment average HOSTBFI 0.37

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Ribble SSSI MetaData Catalogue.

Geology – The SSSI catchment is dominated by Carboniferous Limestone in the upper half of the catchment with the lower portion (including the SSSI) based on the Millstone Grit series (sandstones, siltstones, mudstones). The headwaters of the catchment include large areas of peat and till/glacial deposits are widespread throughout the main river valley. The main alluvial deposits of clay, silt and sand begin just upstream of the SSSI area and continue to the lower limit of the SSSI.

The variation of HOSTBFI (an indicator of catchment permeability) is relatively low throughout the SSSI catchment, with marginally increased permeability in the valley bottoms, due to the presence of glacial and alluvial deposits. The catchment average HOSTBFI value of 0.37 suggests overall this SSSI catchment is relatively impermeable.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is grassland with 0.6% urban. More information about land use within this SSSI catchment can be found on the River Ribble SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 71011 (Ribble at Arnford) gauges flows from a catchment area of 204.0km2. The station is a flat vee Crump weir (pre 1973 the Halton West gauging station (71802) was used). The SSSI catchment represents 83% of the total catchment contributing to the flows at this gauging station. Hence, the flows recorded at this gauge would be representative of the river flows in the SSSI.

59 Final report November 2007

More information about gauging stations in the vicinity of this SSSI can be found on the River Ribble SSSI MetaData Catalogue.

Macrophyte data – There are six (6) macrophyte survey points in the SSSI catchment, four are located in the upper catchment, with the other two located at the extremities of the SSSI. The latter two are noted to be B1 major type. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Ribble SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at seven (7) sites, and estimated LIFE scores are also calculated for five (5) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Ribble SSSI MetaData Catalogue.

Fisheries data – Salmonid species have been observed in this catchment, in addition to eurytopic/limnophilic cyprinid species observed at one site in 2000. More information about species found in the vicinity of this SSSI can be found on the River Ribble SSSI MetaData Catalogue.

17.3 Catchment water use Artificial influences – The SSSI catchment is essentially natural with no major abstractions, discharges or impoundments. No major canal systems exist.

Net Pressure at Q70 – The Environment Agency’s Water Framework Directive (WFD) Artificial Influences data set suggests that there are only a few very minor influences (abstractions, discharges or impoundments) within this catchment and the Net Pressure is approximately zero, where Net Pressure is defined as;

Net Pressure = 1 - Q70INF / Q70NAT

Relationship with existing CAMS assessment points – No existing CAMS information was available for assessment points (AP’s) in the vicinity of this SSSI.

17.4 Environmental Weighting Units and River Flow Objectives Due to the short (8 km) length of river included in the SSSI a single EWU has been adopted for the whole SSSI as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 382423, 457268 Whole SSSI catchment

60 Final report November 2007

370000 380000 390000

480000

Legend Rivers EWU Boundary

470000

470000 SSSI Boundary

460000

370000 380000 390000

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Ribble SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 5 4 4 4 VH

61 18 River Teme SSSI 18.1 SSSI Description The River Teme SSSI includes the full length of the River Teme from it’s source (Cilfaesty Hill in Wales) to the confluence with the River Severn south of Worcester. A total length of 134km (109.6km in England and 24.7km in Wales) of the River Teme in included in the SSSI, and the lowest 4.7km of the River Clun are also included. The SSSI is representative of a natural flow regime of a catchment based on sandstones and mudstones, and the associated habitats and species assemblages.

SSSI Name River Teme County Hereford And Worcester / Shropshire River Teme Natural England ID 2000102 Link River Teme SSSI Views About Management

18.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 54 Outlet location (384915,252260) Catchment area (km2) 1652.9 Boundary definition method DTM Average annual rainfall (1961-1990) (mm/yr) 801 Average annual potential evaporation (mm/yr) 555 Average annual runoff (mm/yr) 367 Catchment average HOSTBFI 0.59

Deviations of topographic and groundwater catchment divides – None documented.

More information about the catchment of this SSSI can be found on the River Teme SSSI MetaData Catalogue.

Geology – The SSSI catchment is underlain by the Ludlow and Wenlock formation and other siltstones/mudstones in the upper sections. Pools and riffles exist in this upper portion. Downstream of Downton Gorge (think band of limestone) the solid geology changes to the Lower Old Red Sandstone and then at Knightwick the Mercia Mudstone formation underlies the catchment until the river joins the River Severn at Worcester. Drift deposits of till occur in the upper reaches of the River Clun. Alluvial sand, silts and clay deposits occur in the main rivers upstream of Downton Gorge, and then again from Ludlow to Knightwick. Below Knightwick the river is of a lowland form with clays/silts forming the bed material.

The variation of HOSTBFI (an indicator of catchment permeability) is generally medium (values in the order of 0.5) for most of the catchment, with higher values on sanstones and lower values on mudstones/siltstones. The catchment average HOSTBFI value of 0.59 suggests overall this SSSI catchment is moderately permeable.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is grassland with 0.7% urban. More information about land use within this SSSI catchment can be found on the River Teme SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 54008 (Teme at Tenbury) gauges flows from a catchment area of 1134.4km2. The station is a velocity-area gauge with gravel control. This station measures

62 Final report November 2007 flows from approximately 69% of the catchment contributing to flows at the downstream end of the SSSI.

 Gauging station 54029 (Teme at Knightsford Bridge) gauges flows from a catchment area of 1480.0km2. The station is a velocity-area gauge with gravel control. This station measures flows from approximately 89% of the catchment contributing to flows at the downstream end of the SSSI.

 Gauging station 54056 (Clun at Clungunford) gauges flows from a catchment area of 195.0km2. The station is a rectangular notch with side contractions. This station measures flows from approximately 12% of the catchment contributing to flows at the downstream end of the SSSI, and approximately 70% of the River Clun catchment above it’s confluence with the River Teme.

More information about gauging stations in the vicinity of this SSSI can be found on the River Teme SSSI MetaData Catalogue.

Macrophyte data – Nineteen (19) macrophyte survey points exist in the SSSI catchment, with four (4) of these on the River Clun. The major types range from A1 to C1. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Teme SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at four (4) sites, and estimated LIFE scores are also calculated for thirty eight (38) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Teme SSSI MetaData Catalogue.

18.3 Catchment water use Artificial influences – The River Teme SSSI catchment contains very few artificial influences. Small groundwater and surface water abstractions exist, together with small discharges. No major impoundments exist, nor do any major canal systems.

Net Pressure = 1 - Q70INF / Q70NAT

63 Final report November 2007 Relationship with existing CAMS assessment points – A total of 15 assessment points (AP’s) from the River Teme CAMS are relevant to this SSSI. These include five (5) points on the River Teme (shaded) and ten (10) points on tributaries (including one on the River Clun).

X Y

modified modified

Name

Ref No Ref

erting A=VH, A=VH, erting

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Flow Flow Low Reach

conv

Availability Status Availability

Ecological Teme 1 Knighton VH 328985 272375 NWA Integrity Maintained Ecological Teme 2 Bromfield VH 348200 276700 WA Integrity Compromised Ecological Teme 3 Tenbury H 359777 268524 WA Integrity Maintained Ecological Teme 4 Knightsford H 373480 255733 WA Integrity Maintained Ecological Teme 5 Worcester H 384993 252184 WA Integrity Maintained Ecological Teme 6 Redlake VH 339351 274741 NWA Integrity Compromised Ecological Teme 7 Clun VH 340239 273916 NWA Integrity Maintained Ecological Teme 8 Quinney Bridge VH 342700 285200 WA Integrity Maintained Ecological Teme 9 Onibury H 345484 278978 WA Integrity Compromised Ecological Teme 10 Corve VH 350923 276080 NWA Integrity Maintained Ecological Teme 11 Ledwyche H 358152 267969 WA Integrity Maintained Ecological Teme 12 Rea VH 364392 269278 WA Integrity Maintained Ecological Teme 13 Sapey Bk H 372724 256053 WA Integrity Maintained Ecological Teme 14 Leigh Bk H 378390 253667 WA Integrity Maintained

64 Final report November 2007

Ecological Teme 15 Laughern Bk H 383383 252608 NWA Integrity Maintained

18.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit Headwater stretch, narrow steep-sided river channel, high 1 319040, 280243 energy, rocky. Impermeable geologies, sand/silt/clay becoming more 2 331197, 272853 common in bed material, shingle bars and pool and riffle sequences.

3 340357, 273885 Floodplain developing, shingle bars well developed. Includes impact of geology changing to calcareous/sandstone basis, Downton Gorge include. 4 348186, 276714 Upstream from this point has had different licensing policies for abstractions. Long section of river on Old Red Sandstone geology, 5 373679, 255565 submerged sandstone platforms present in river. Lowest reach of river, Mercia mudstone geologies, clays and 6 385004, 252210 silts in bed material, mature lowland river.

Legend Rivers EWU Boundary SSSI Boundary

65 Final report November 2007 assign the Environmental Weighting can be found in the River Teme SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 5 4 none 4 VH 2 5 4 4 4 VH 3 4 4 4 4 H 4 4 4 4 4 H 5 4 4 3 4 H 6 4 4 3 4 H

66 Final report November 2007

19 River Test SSSI 19.1 SSSI Description The River Test SSSI extends from the headwaters near Overton to the river’s tidal limit at Totton, some 50km to the south. The river is one of the most species rich lowland rivers in England and is a classic chalk stream, with winterbourne headwaters giving way to a succession of habitats as the morphology changes to a wider, gravel lined braided river.

SSSI Name River Test County Hampshire River Test Natural England ID 2000170 Link River Test SSSI Views About Management

19.2 Catchment characteristics The SSSI catchment is defined by the areas of land contributing to flow at the catchment outlet. A summary of the SSSI catchment is shown below.

Hydrometric Area 42 Outlet location (436129,114442) Catchment area (km2) 1165.9 Boundary definition method Analogue Average annual rainfall (1961-1990) (mm/yr) 798 Average annual potential evaporation (mm/yr) 586 Average annual runoff (mm/yr) 323 Catchment average HOSTBFI 0.84

Deviations of topographic and groundwater catchment divides – Minor overall differences in SSSI catchment boundary, however differences for tributary boundaries may be pronounced.

More information about the catchment of this SSSI can be found on the River Test SSSI MetaData Catalogue.

Geology – The portion of the SSSI catchment (approximately 865km2) upstream from Dunbridge and the confluence of the River Dun with the Rive Test, is underlain by Upper Chalk. The River Dun tributary and lower portion of the catchment are underlain by the less permeable London Clay (clays), Reading (clays) and Bagshot formations (clays and sandstone). Large areas of Clay with Flints exist over the Upper Chalk and the main river valley of the Test is lined with alluvial deposits of clay, silt and sand. More extensive deposits of sand and gravel occur in the lower reaches.

The variation of HOSTBFI (an indicator of catchment permeability) is very high (values in the order of 0.95) for most of the catchment over the chalk, while very low values (in the order of 0.15) are found on the London Clay and impermeable beds in the downstream section of the catchment. The catchment average HOSTBFI value of 0.84 suggest a very permeable catchment, due to the underlying chalk.

Landuse – Based upon a 1 km aggregated grid, the majority of this catchment is arable with 2.5% urban. More information about land use within this SSSI catchment can be found on the River Test SSSI MetaData Catalogue.

Flow gauging stations –

 Gauging station 42024 (Test at Chilbolton (Total)) gauges flows from a catchment area of 453.0km2 in the headwaters of the Test. The station consists of two electromagnetic

67 Final report November 2007 gauging stations (Chilbolton Main and Chilbolton Back Carrier) the flows from which are summed to give a total flow. This station measures flows from approximately 39% of the catchment contributing to flows at the downstream end of the SSSI and is representative of flows in the upper SSSI.

 Gauging station 42004 (Test at Broadlands) gauges flows from a catchment area of 1040.0km2 and is the most downstream gauge on the River Test. The station is a velocity- area gauge with control suffering from severe weed growth. Flows from 42013 are used to infill record. This station measures flows from approximately 89% of the catchment contributing to flows at the downstream end of the SSSI and is representative of flows in the lower SSSI.

 Gauging station 42013 (Test at Longbridge) gauges flows from a catchment area of 1040.0km2. This station was the first electromagnetic gauging station in the UK (pre 1982 Plessey device). Close to the Broadlands velocity-area site (42004).

More information about gauging stations in the vicinity of this SSSI can be found on the River Test SSSI MetaData Catalogue.

Macrophyte data – Ten (10) macrophyte survey points exist in the SSSI catchment, with major types range from A1 to B1. More information about macrophyte survey data in the vicinity of this SSSI can be found on the River Test SSSI MetaData Catalogue.

Macroinvertebrate data – 3-season RIVPACS exist at three (3) sites, and estimated LIFE scores are also calculated for thirty nine (39) GQA sites. More information about these sites in the vicinity of this SSSI can be found on the River Test SSSI MetaData Catalogue.

19.3 Catchment water use Artificial influences – Surface water and groundwater abstractions exist, primarily for public water supply but also for environmental flow conditions and fish farming enterprises. Sewerage treatment works exist. No significant canals or impoundments exist.

Net Pressure at Q70 – where Q70 is the flow that is equalled or exceeded 70% of the time, is defined as follows;

Net Pressure = 1 - Q70INF / Q70NAT

For this SSSI catchment -0.15 < Net Pressure at Q70 < 0.0, indicating that the net impact of water use in the catchment is less than 15% of the expected natural Q70 flow. This reflects the net impact of large public water supply abstractions (ground and surface waters) and return of water (less than that abstracted) by sewerage treatment works discharges. Analysis using the WFD Artificial Influences data set over 137 gauged catchments with Net Pressures in this range showed that the estimated Q70INF values were, on average, within approximately 30% of the observed Q70 values.

68 Final report November 2007 It should be noted that the WFD Artificial Influences data set has not yet been fully quality controlled and may contain errors affecting the estimation of Q70INF, there is uncertainty within the estimation of Q70NAT, hence these results should be regarded as indicative only.

Relationship with existing CAMS assessment points – A total of 12 assessment points (AP’s) from the River Test & Itchen CAMS are relevant to this SSSI. These include points which represent Ground Water management Units (GWMU) as well as surface water catchments.

X Y

modified modified

Name

Ref No Ref

B=H, etc B=H,

Resource Resource

PHASE II

River Name River

Band Band

Reach Low Fl Low Reach

converting A=VH, A=VH, converting

Availability Status Availability

Bourne GS (Bourne Test 8 M 444068 146310 NWA Rivulet AP & GWMU)

Bransbury GS (Dever Test 9 M 442137 142209 NWA AP & GWMU)

Chilbolton GS (upper Test 10 M 438485 139351 NWA Test AP & GWMU)

Fullerton GS (Anton Test 11 M 437877 139325 OL/OA? AP & GWMU)

Bossington GS Test 12 (Wallop Brook AP & M 433405 131361 NWA GWMU)

Dunbridge (Dun AP & Test 13 M 432585 126042 NWA GWMU)

Timsbury Bridge (mid Test 14 M 435146 123460 NWA Test AP & GWMU)

Test 15 Blackwater Total (AP) M 433911 117041 NWA

River Test Total AP Test 16 M 436796 113690 OL/OA? (Great + Little)

Testwood GS (Great Test 17 M 435887 115020 OL/OA? Test AP)

Ower GS (Blackwater Test 18 M 432828 117397 NWA AP)

Conagar Bridge GS Test 19 M 435520 115866 NWA (Little Test AP)

69 Final report November 2007 19.4 Environmental Weighting Units and River Flow Objectives The SSSI has been subdivided into EWU based upon changes in the catchment physical characteristics as specified below. The map below presents the SSSI boundary and the hydrological catchment boundaries of each unit.

Downstream EWU Notes Limit 1 443755, 144370 Headwater chalk catchment, including winterbourne section. Chalk catchment including contributions from the River 2 437734, 138528 Swift, large area of gravels and sands in main channel, clay with flints on surrounding hills. Section of chalk stream with less sand and gravel deposits 3 433156, 126642 on surrounding flood plain. Lower section of river on impermeable geologies, including flows from tributaries River Dun and River Blackwater 4 435965, 115106 (impermeable geologies, flashy response), more extensive areas of gravel and sand in floodplain, clay/silt/sand lining channel, extensive brading and floodplain developed.

Legend Rivers EWU Boundary SSSI Boundary

Each unit is assigned an Environmental Weighting score based upon the four ecological indicators – physical habitat, macrophytes, macro-invertebrates and fish (using the methodology described within Section 4). The datasets and calculated descriptors used to assign the Environmental Weighting can be found in the River Test SSSI MetaData Catalogue. The River Flow Objective associated with each EW can be found within Table 4.1.

70 Final report November 2007

Physical Macrophyte Macroinvert. Fisheries Environmental EWU Score Score Score Score Weighting 1 4 3 3 4 H 2 3 3 3 4 H 3 3 3 none 4 H 4 3 3 3 4 H

71 Final report November 2007

20 References

Boorman, D. B., Hollis, J. M. and Lilly, A. (1995). Hydrology of soil types: a hydrologically- based classification of the soils of the United Kingdom. Report 126. Institute of Hydrology. Wallingford.

Davis, C. (ed) 2004 Freshwater Fishes in Britain: The Species and Their Distribution. Harley Books 0946589763184 184 pp.

EA, 2002. Resource Assessment and Management Framework Report and User Manual (Version 3), R&D Technical Manual W6-066M.

Holmes, N. T. H., Boon, P. J. and Rowell, T. A. 1998. "A revised classification system for British Rivers based on their aquatic plant communities." Aquatic Conservation-Marine and Freshwater Ecosystems 8, 4, 555-578

Holmes N, Boon, P and Rowell T, 1999 Vegetation Communities of British Rivers: A Revised Classification. JNCC, Peterborough.

SNIFFER, 2006. Project WFD48 Development of Environmental Standards (Water Resources). Stage 3: Environmental Standards. Report authors: M C Acreman, M J Dunbar, J Hannaford (CEH), O M Bragg, A R Black and J S Rowan (Dundee University), J King (University of Cape Town)

72 Final report November 2007