Volume 1: Strategic Overview of Reports

Home , Mere (lake), Nene Washes, New Bedford River, Old Bedford River

OUSE WASHES LITERATURE REVIEW

VOLUME 1:

STRATEGIC OVERVIEW

OF REPORTS

May 2015

Mere Oak Ecology Mere Oak Farm Rowley Westbury Shrewsbury Shropshire SY5 9RY T. 01743 891492 [email protected]

OUSE WASHES LITERATURE REVIEW VOLUME 1 STRATEGIC OVERVIEW OF REPORTS May 2015

Mere Oak Ecology Mere Oak Farm Rowley Westbury Shrewsbury Shropshire SY5 9RY T. 01743 891492 [email protected]

CONTENTS

ACKNOWLEDGEMENTS ...... i 1. INTRODUCTION ...... 1 2. LIST OF DOCUMENTS INCLUDED IN THE REVIEW, IN CHRONOLOGICAL ORDER...... 4 3. THE STRATEGIC OVERVIEW OF REPORTS ...... 6 4. RECOMMENDATIONS FOR FUTURE WORK ARISING FROM THE REVIEW ...... 20 5. A SUMMARY OF INFORMATION RELATING TO BOTANICAL SURVEYS ON THE OUSE WASHES TAKEN FROM ENTEC, 2002...... 22 6. LIST OF BOTANICAL REPORTS AND PAPERS COLLECTED DURING THE REVIEW...... 25 7. REFERENCES NOT INCLUDED IN THE REVIEW ...... 27 8. TIMELINE OF EVENTS FOR THE OUSE WASHES ...... 28 Map 1. Location of the Ouse Washes ...... 30 Map 2. The Ouse Washes ...... 31 Map 3. The Upper and Bedford Ouse management catchment and the operational catchments within it, Diffuse Water Pollution Plan, 2010...... 32 Map 4. The different structures and drainage channels associated with the Ouse Washes, from the Water Level management Plan, 2002 ...... 33 Map 5. Diagram showing how water flows through the Ouse Washes and associated channels, from the Water Level management Plan, 2002...... 34 Map 6. Diagram showing the water level control structures associated with the Ouse Washes, from the Water Level management Plan, 2002...... 35

ACKNOWLEDGEMENTS

Thanks to staff at Natural England for commissioning this work and to Ruth Fish and Steve Brayshaw for their support and assistance. Others have also assisted in various ways.

1. INTRODUCTION Introduction from project specification document

The majority of the Ouse Washes are currently considered in unfavourable condition due to inappropriate water levels and water pollution:

 Units 1-15 are in unfavourable no change condition  Units 18 and 20 are in unfavourable recovering condition  Unit 19 and 21 to 23 are in favourable condition

Flooding throughout the year has increased in recent years and has a significant impact on notified interests, based on reports written by Black & Vetch – Monitoring of the Ouse Washes – National Environment Programme (Reports 1 to 7), the flooding on the Ouse Washes has increased yearly with flooding also occurring during the summer. The remedy for the inappropriate water levels includes creation of alternative habitat adjacent to the Washes and commitment to find other measures to control input of water onto the Washes and the release of water off the Washes, which have subsequently been subject to ongoing review by the Environment Agency, Natural England & partners. Remedy for point source water pollution consists of Environment Agency/Anglian Water control of discharges within the Great Ouse catchment. Remedy for diffuse water pollution includes creation and implementation of a Diffuse Water Pollution Plan (DWPP) by Natural England and partners, which has been ongoing since 2009. The DWPP identifies the need to review all available data & literature on water pollution and its impact on the Ouse Washes (5. Diffuse pollution actions needed to achieve favourable condition, Actions 2&3):

 Action 2 is a general literature review of previous scientific work to find evidence baseline/relevant information.  Action 3 is a specific literature search for documents cited in the Plan previously. Elaborate on information cited where relevant.

The purpose of the project is to review existing data & literature (held by Natural England & partners) with a focus on nutrient levels & sediment, but not withholding other pollutants and / or factors discovered to be impacting the Ouse Washes to assess what is known of the impact of those pollutants /other factors on the ecology of the site, particularly its notified interests. The literature review is expected to inform the Ouse Washes Diffuse Water Pollution Plan. The literature review should;

 summarise available information  where relevant, identify further survey/assessment which would improve our understanding of the impact of pollution on the Ouse Washes using the following resources provided by Natural England (listed in the ‘Invitation to Tender’ document).

Introduction to the Review

No guidance was received on what format the review should take. I have developed the work pragmatically with the aim of being as helpful as possible to the wide variety of people who

might be interested in learning more about the changes that have affected the site. Accordingly the review falls into three parts:

 Volume 1 is a fairly concise, more strategic review of the literature, with an introduction, recommendations for future work and a set of maps to aid understanding of how the site functions.  Volume 2 consists of the collected detailed reviews of the individual reports, some of which are lengthy.  Volume 3 contains the details relating to how the review was carried out.

The Ouse Washes, the largest functioning washland in Britain, located on a major river system, the Great Ouse, is probably one of the most complex designated conservation sites in the country. Furthermore the wildlife for which it was first designated sixty years ago now faces a very uncertain future.

The complexity is due to the fact that the site faces issues relating to:

 Water quantity – flooding and sediment deposition (water supply)  Water quality – point source and diffuse pollution  Changing environments on the Washes themselves, eg botanical, invertebrate and ornithological changes, as well as changes in the management that can be carried out on the site  The provision of compensatory or replacement habitats

These issues are of course all taking place under the overarching factor of climate change, which means that the future of the whole system is threatened by rising sea levels which could affect the ability of the Great Ouse to discharge to the sea.

Somewhat separate from the above there is also the issue of the changing resources available to the different agencies responsible for the site.

This complexity undoubtedly makes the site difficult for new agency staff to get to grips with and it is hoped that the ‘Review’ will help such individuals and others. Certainly many of the reports are unpublished ‘grey’ literature produced in limited numbers for the commissioning Agency and some are hard to find. For these reasons that some of the reviews are longer than might be expected – especially where they have set out the background issues clearly, eg Cathcart, 2002 & Entec, 2002. Quite a number of these reports form the basis for current work, especially as regards the apportionment of the nutrients entering the Washes to either point sources or diffuse pollution, the development of water and nutrient budgets for the Washes and the identification of which areas of the catchment contribute the most to nutrient enrichment, eg ENTEC Uk Ltd, 2002 & 2003, the current Diffuse Water Pollution Plan for the Ouse Washes and Portholme and various of the vegetation surveys carried out over the years.

The approach followed to undertake the review

The project started with a list of references being provided by Natural England. This was followed by scanned material being provided on memory sticks. It eventually became apparent that, within the time available, effort should be concentrated on the main reports and that other material would have to be set aside, unless it was particularly significant. Thus a few papers are included below which are not included in Volume 2, which contains the full reviews. Volume 3 gives more details of the actual approach followed. So much material was received from Natural England that it was not possible to seek contributions from partner organisations.

As stated above the Review was looking at a set of references provided by Natural England, most of which were dated prior to 2005, with a few in the period from 2005 to 2009. This means that little recent material was considered and that there were some relevant publications that were not looked at. A further difficulty is that much recent material is only available online. Although these limitations made producing a set of recommendations for future work difficult, a list is nevertheless included, some of which have been made previously in other reports.

NOTE – FRP at the end of the brief reviews below indicates that a Full Review has been Produced (hence FRP) and is included in Volume 2.

2. LIST OF DOCUMENTS INCLUDED IN THE REVIEW, IN CHRONOLOGICAL ORDER. Note that signifies Full Review Produced and included in Volume 2 of the Review.

English Nature, 1993. The Ouse Washes Management Strategy; Introductory Paper. Lambert,S.J.J.

English Nature, Undated (1994?). Ouse Washes Management Strategy – management of woody vegetation. Lambert, S.J.J.

Ramsar Advisory Mission (RAM), Ouse Washes Ramsar Site, United Kingdom, 5-8 November 2001, Report No. 49 by Roel Posthoorn, Eckhart Kuijken & Tobias Salathé.

Effects of Nutrient Loading on Ditch Flora and Fauna in the Ouse Washes: Current Impacts and Potential Mitigation. Interim Report - July, 2001, Rob Cathcart.

Cathcart, R. 2002. Effects of Nutrient Loading on the Ditch Flora of the Ouse Washes: Current Impacts and Potential Mitigation. University of Cambridge M. Phil. Thesis.

Ouse Washes Water Level Management Plan, prepared by Halcrow Group Ltd for the Environment Agency, 2002.

Environment Agency Anglian Region. Hydro-ecological Review of Selected European Sites. Ouse Washes cSAC/Ouse Washes SPA – Ouse Washes SSSI Conceptual Framework. Final 13 December 2002. Entec UK Ltd.

Environment Agency. Ouse Washes Strategic Studies. Slacker Monitoring Data Report – 2002. December 2002. Entec UK Ltd.

Entec UK Ltd. 2003 (a). Ouse Water / Nutrient Budgets Proposal.

Anglian Water Services. Assessment of the impact of Anglian Water Services abstractions on the Ouse and Nene Washes – Draft Final Report. December 2003. WRc.

Environment Agency. Ouse Washes Strategic Studies. Slacker Monitoring Data Report – 2003. December 2003 (b). Entec UK Ltd.

Environment Agency, Ouse and Nene Strategic Studies. Ouse Washes: Water and Nutrient Level Analysis. December 2003 (c), Entec UK Ltd.

Ouse Washes - Hydro-ecological Prescriptions for Favourable Condition. J. Graham, May 2003.

Black & Veatch. Investigations into solutions to water quantity problems affecting the special nature conservation interests of the Ouse Washes. English Nature, 2003.

Environment Agency. Ouse and Nene Strategic Studies. Ouse Washes: Water and Nutrient Level Analysis. March 2004. Entec UK Limited.

Environment Agency - Anglian Region. Ouse Washes Habitat Creation: Business Case for the next 5 Years of Investigations, Land Purchase and Permissions. March 2007.

Stella Bayliss, 2008. A summary of water quality information available in the Natural England Ouse Washes files, Ham Lane, Peterborough.

A Repeat transect vegetation survey of the Ouse Washes – A Report for the Environment Agency. Jonathan Graham, Fenland Botanical Surveys, 2008.

Great Ouse and Ouse Washes: Catchment Appraisal Refresh Proforma, 2009. DJLAgronomics, FuIstow Louth Lincolnshire LN11 OXR.

Ouse Washes Conservation Objectives botanicals, minute by Stella Bayliss, 10 December 2008 to Simon Leach.

Ouse Washes CSM compliant Condition Assessment, Stella Bayliss, January 2009.

Common Standards Monitoring Condition Assessments of the Ouse Washes SSSI, CSM Survey Report, October 2009. WWT Consulting.

Monitoring of the Wash and Ouse Washes in 2004 for the Natural Environment Programme. Second Annual Report. Black & Veatch for Essex and Suffolk Water, 2005.

Monitoring of the Wash and Ouse Washes in 2008; Sixth Annual Report. Black & Veatch, October 2010.

Monitoring of the Wash and Ouse Washes in 2009; Seventh Annual Report. Black & Veatch, October 2010.

Ouse Washes and Portholme Diffuse Water Pollution Plan, NE & EA, 2010. Note this document is still live and on at least Version 11, 31 March 2014.

Improvement programme for England’s Natura 2000 sites (IPENS). Natural England, 18 Dec 2012 & Diffuse Water Pollution Theme Workshop Note, Natural England, 5 Sept 2013.

Improvement Programme for England's Natura 2000 Sites (IPENS). Site Improvement Plan – Ouse Washes. Natural England, 19 December 2014.

signifies Full Review Produced and included in Volume 2 of the Review.

3. THE STRATEGIC OVERVIEW OF REPORTS English Nature, 1993. The Ouse Washes Management Strategy; Introductory Paper. Lambert,S.J.J.

This paper sets out the background to the production of a Management Strategy for the Ouse Washes by English Nature, in partnership with the National Rivers Authority and other organisations. The main aim was to ensure the continuation of the traditional, sustainable management and use of the Ouse Washes, to enable it fully to realise its value as a wildlife habitat and to maintain its flood defence capability. This paper was the first in a series of discussion papers which were to be produced during the coming year. It aimed to provide a statement of the conservation and flood defence value of the site, to identify the issues that needed to be addressed to ensure the long term maintenance of these values and to identify the partners who would have a significant role in this process. It was also to be the first stage in an ongoing consultation process.

The first stage in the management strategy process was to bring together all those bodies who had a major role in managing the Ouse Washes. In January 1992 a Management Strategy Group was established. Initially the group guided production of the management strategy. Subsequently it acted as a forum for communication and co-ordinated implementation of the strategy.

The paper is useful in explaining this background, which does not appear to have been documented elsewhere. In addition because of its early date, it references a lot of literature that would otherwise not be easy to track down. So far only this and the next paper are the only ones that have been seen out of what should have been a series of eight papers in total.

National Rivers Authority reports are referenced which recommend a range of solutions for reducing the problem of summer flooding on the Washes.

English Nature, Undated (1994?). Ouse Washes Management Strategy – management of woody vegetation. Lambert, S.J.J.

This report is a useful and thorough examination of the topic, however it is not really germane to the main objectives of this review. As with many references there appears to be no cover to the report giving the key details of production, such as the date of publication.

Ramsar Advisory Mission (RAM), Ouse Washes Ramsar Site, United Kingdom, 5-8 November 2001, Report No. 49 by Roel Posthoorn, Eckhart Kuijken & Tobias Salathé.

This is an important reference as the Habitat Conservation and Ramsar unit of the European Wildlife Division in the Department of the Environment, Transport and the Regions (DETR), the Ramsar Administrative Authority for the United Kingdom (now part of the Department for Environment, Food and Rural Affairs, DEFRA), requested the listing on the “Montreux Record” of the Ouse Washes Ramsar Site. The Montreux Record is a list of Ramsar Sites where changes in ecological character have occurred, are occurring or are likely to occur. A Contracting Party may request inclusion of a site in the Montreux Record in order to draw attention to the need for action or support, e.g. through a Ramsar Advisory Mission (RAM).

This RAM was significant as a group of distinguished continental ecologists were involved at the request of DETR and they produced a set of wide ranging ‘out of the box’ recommendations. These were certainly influential although it is not apparent that they have all been followed up and clear transparent decisions made on each one. As such the agenda for future action that they set out is still of relevance today.

Effects of Nutrient Loading on Ditch Flora and Fauna in the Ouse Washes: Current Impacts and Potential Mitigation. Interim Report - July, 2001, Rob Cathcart.

As the title suggests this Interim Report describes the work that is being undertaken but it is was written before the analysis of the results had been completed; it is recommended to simply look at the final report, 2002.

Cathcart, R. 2002. Effects of Nutrient Loading on the Ditch Flora of the Ouse Washes: Current Impacts and Potential Mitigation. University of Cambridge M. Phil. Thesis.

This study represents the first detailed and season-long investigation of water chemistry parameters within the Ouse Washes ditches. As such, it has been able to assess the trophic status of the system as a whole and to shed some light on the changes in the composition of aquatic plant communities that have been detected in periodic surveys from 1978 onwards (Cadbury et al, 2001).

Nutrient levels within the ditch system are very high, with total phosphorus showing a seasonal mean of 0.623 mg/I and a pattern of increase through the growing season. The latter indicates that phosphorus, normally the limiting nutrient in aquatic ecosystems, is not depleted or even reduced by plant and phytoplankton growth during the summer and remains in excess within the Ouse Washes' system as a whole. Levels of both total phosphorus and total nitrogen are highest at sites near the inlet sluices from the Hundred Foot River that supply the ditch network. It can be inferred that, while internal phosphorus loading from sediments may be playing a part, the ditches are being polluted primarily by water flowing in from the Great Ouse system.

The aquatic macrophyte species and communities present are, as a whole, further confirmation that the system is eutrophic. There can be little doubt that those species lost to the Ouse Washes in recent decades, such as Hydrocharis morsus-ranae and Utricularia vulgaris, have been out-competed by others more suited to higher nutrient levels. Certainly, historic data confirm that the mat-forming Lemna minor and Spirodela polyrhiza have increased considerably over time, and it is clear that few other plants can survive below these mats where they are extensive. Indeed a key finding of the study was that the mat-forming Lemna community represented the climax ditch vegetation given the high levels of nutrients. Other communities represented intermediate phases in a succession of community types along this nutrient gradient.

L. minor was present at over 80 per cent of the sites surveyed in the current study, and there must be concerns that it will only continue to extend its domination while nutrient levels remain high to the further cost of species of greater conservation value. At the time of the first comprehensive ditch survey in 1978, the Ouse Washes ditch system was viewed as supporting a

rich and diverse community of aquatic macrophytes. In 2002, it is difficult to claim that this is still the case.

Results showed that four distinct vegetation communities were present, identified by TWINSPAN classification and matching NVC community types, and that these groups exhibited significant differences in their water chemistry and were distributed along an environmental gradient with a clear zonation between groups:

 Group 4 ditches (NVC A16a Calitriche community) were associated entirely with the header drain and sites very close (<50m) to the header-ditch inlets,  Group 2 ditches (NVC A15 Elodea canadensis) were uniquely associated with clay substrates located in the area of the Mepal-Sutton clay incursion into the Washes' system and host all the nationally and locally scarce plants recorded in the survey, such as Nymphoides peltata and the rare stonewort Tolypella prolifera.  Group 1 ditches (NVC A5b Ceratophyllum demersum, Lemna minor) are associated with wide peat ditches that have an open aspect provided by gently sloping banks. This community tends to be located north of Mepal in the central and northern sections of the RSPB Washes and can be considerable distances (over 500m) from the slacker inlets toward the lower-lying areas of the Washes. They are, on average, some 300 metres further away from the slacker inlet than group 3 ditches.  Group 3 ditches (NVC A3 Spirodela polyrhiza-Hydrocharis morsus-ranae) have a number of similarities with Group 1 being also associated with the peat substrate of the central and northern sections of the RSPB reserve and have an average age since last slubbing of 7 to 8 years. These ditches are narrower and located closer to the slacker inlets than Groups 2 or 1. They have the highest average levels of total phosphorus and the lowest average pH.

Cathcart concluded that nutrient levels within the ditch system were very high, far above widely accepted criteria indicating polluted status (Vollenwieder 1968) and even in comparison with other eutrophic waterbodies (Moss 1987; Madgwick 1999). Total phosphorus was particularly high and showed a pattern of increase through the growing season. The latter indicated that phosphorus, normally the limiting nutrient in aquatic ecosystems, was not depleted or even reduced by plant and phytoplankton growth during the summer and remained in excess within the Ouse Washes' system as a whole. Levels of both total phosphorus and total nitrogen were highest at sites near the inlet sluices from the Hundred Foot River that supply the ditch network. It can be inferred that, while internal phosphorus loading from sediments may be playing a part, the ditches were being polluted primarily by water flowing in from the Great Ouse system.

He also concluded that there could be little doubt that those species recently lost to the Ouse Washes, such as Hydrocharis morsus-ranae and Utricularia vulgaris, were out-competed by others more suited to higher nutrient levels. Certainly, historic data confirm that the mat• forming Lemna minor and Spirodela polyrhiza have increased considerably over time (Cadbury et al. 2001), and it is clear that few other plants can survive below these mats where they are extensive.

He also pointed out that the loss of submerged plants beneath Lemna mats at the Ouse Washes must be having an impact on the ditch fauna and recommended that a comprehensive survey of invertebrates in the ditch system should be undertaken as a priority in order to establish baseline data for further monitoring.

It is probably true to say that the biomanipulation of ditches to reduce nutrient levels which he experimented with were not too successful as strategies that could be deployed on the site for various reasons, although he did point out that phosphorus levels can be buffered by binding with sediments in clay based ditches. Given that clay deposits extend beneath the whole site at a variety of depths beneath the overlying peat, total phosphorus levels could perhaps be reduced in selected areas by the expedient of digging ditches sufficiently deep to reach the clay stratum.

He finally concluded that a reduction in nutrient levels in the Great Ouse system was required before a subsequent decrease in the Ouse Washes ditch system could be achieved to the extent that restoration of ditch communities becomes feasible.

This was an extremely important study which really pinned down the causal factors driving deleterious changes in the flora of ditches on the Ouse Washes and raised concerns about changes that might be affecting the invertebrate fauna. It is required reading for anyone wanting to understand the changes in the aquatic flora that have taken place on the Washes. Now that phosphate levels have been significantly reduced in the River Ouse system it would be timely to investigate whether any recovery in the flora of ditches on the Washes has occurred.

Ouse Washes Water Level Management Plan, prepared by Halcrow Group Ltd for the Environment Agency,2002.

This version of the WLMP updates the original 1998 version. WLMPs are critical documents for large complex wetlands where a number of different organisations are involved in their management and their production and contents were determined generically by Defra. This document seems fine for its time, the most remarkable fact being that it was never updated subsequently. This is perhaps especially surprising given the concerns that have later involved the site. However possibly it is these very concerns that mitigated against such reviews being undertaken, as the search for solutions to the problems was seen as more important than updating a WLMP, especially when even after many studies were carried out, it was not clear what solutions would eventually be instituted.

This document was reviewed in detail as it offers an excellent summary of knowledge at the time concerning the functioning of all aspects of the Washes and of the context that they operate in within the Ouse River Basin. It also has some useful recommendations as to issues that should be investigated further.

The report was undertaken for EA by ENTEC as part of EA’s requirement as a ‘competent authority’ to review the effects of existing consents, permissions and authorisations that it (or its predecessor bodies) has granted on the European features of interest for which the site has been designated. It is particularly concerned to review the impact of abstraction licences on wetland sites.

It is based largely on desk-study and provides baseline hydro-ecological information that will be used to provide:

 A preliminary understanding of the key hydrological and hydrochemical processes affecting the wetland and the sensitivity of the site's European features to these processes.

 A preliminary assessment of whether there are likely to be any existing licensed surface water or groundwater abstractions that could adversely affect the wetland under study. The assessment is based on review of licensed abstraction quantities, rather than actual abstractions.

 An indication of where additional investigations may be required to fill shortfalls in knowledge for:

o improved strategic (catchment scaled) management;

o understanding appropriate conditions and/or management targets for the site.

For the Ouse Washes site it is considered that the principal water resources related factors which likely affect the site are primarily influenced by strategic catchment management rather than by impacts from consents. Therefore, in this assessment, due regard is given both to strategic issues as well as the standard requirements for the Review of Consents under the Habitats Directive.

Environment Agency. Ouse Washes Strategic Studies. Slacker Monitoring Data Report – 2002. December 2002. Entec UK Ltd.

Report not seen.

Entec UK Ltd. 2003 (a). Ouse Water / Nutrient Budgets Proposal.

This is essentially a seven page proposal by Entec to use the existing WRc model of the Ouse Washes system (produced for Anglian Water, under the Ouse and Nene Strategic Studies work programme), to combine the production of the water and nutrient budgets into a single project. This would enable the model produced to define adequately whether the Washes are currently outside their target regime in terms of annual water level and nutrient loadings, estimate the apportionment of nutrient sources from around the catchment and estimate the proportion of the current nutrient loadings that are derived from Anglian Water sources. The estimated cost was £23,914.50.

Anglian Water Services. Assessment of the impact of Anglian Water Services abstractions on the Ouse and Nene Washes – Draft Final Report, December 2003. WRc.

The Ouse and Nene Washes have been identified as at potential risk from the impact of abstraction in the Environment Agency National Environment Programme (NEP). These sites have also been identified as ‘High Priority’ under the Agency’s Review of Consents (RoC) project under the Habitats Regulations. The Agency is required to undertake an ‘appropriate assessment’ of these sites which seek to determine whether licences or consents are ‘likely to have a significant effect’ on these sites. Anglian Water Services (AWS) agreed to undertake an impact assessment under the NEP to feed into the RoC project.

The results of simulating the abstraction scenarios over 12 years and making the appropriate comparisons indicated that:

 AWS abstractions in combination are not likely to have a significant impact on the interest features of the Ouse Washes but that AWS effluents may have a significant impact on Birds Directive Annex I species (through the impact of phosphorus on the ditch flora) and on Habitats Directive Annex II species (through the impact of phosphorus on the spined loach in the Old Bedford/Delph.  AWS abstractions in combination are not likely to have a significant impact on the interest features of the Nene Washes. These findings coincide with those in Entec 2002. As the remit of this report was so restricted there is nothing further to add.

Environment Agency. Ouse Washes Strategic Studies. Slacker Monitoring Data Report – 2003. December 2003 (b). Entec UK Ltd.

In 2002 Entec was commissioned to monitor the summer flow of water onto the Washes through slackers from the Hundred Foot River. The information was needed to provide quantified information of the inflows to the Washes for use within water budget and water quality models. This programme took place between August and October, when the slackers were closed for the winter season after the first major flood event of the winter. Seven of the 17 slackers were gauged for this study.

In 2002 the study was extended to include all 17 slackers and covered the whole season from mid April to the end of September. Flow gauges were placed in the slacker pipes and records were kept of slacker opening and closing and of silt levels. The flows through the slackers were dominated by the spring/neap tidal cycle, especially at the northern end of the Hundred Foot River. In general there were no clear trends in slacker gate openings over the course of the irrigation season because the slackers are opened and closed manually on an ad-hoc basis in response to a number of factors. Flow was recorded when the slacker gate was recorded as closed on many of the slackers due to gate leakage, flow measurement error or unrecorded gate openings.

Environment Agency, Ouse and Nene Strategic Studies. Ouse Washes: Water and Nutrient Level Analysis. December 2003 (c), Entec UK Ltd.

This report is the most detailed piece of work examining the nutrient budgets for the Ouse River Basin and the likely impact of these budgets on the vegetation of the Ouse Washes designated sites. The approach to the study was wholly analytical, utilising a water quality and flow model

of the Great Ouse catchment and Washes system which was initially developed by WRc, on behalf of Anglian Water as part of the Ouse and Nene strategic studies, to investigate the impact of the effects of AWS operations (abstractions and discharges) on the Washes. Following discussions with WRc, the model was amended for this study and a set of new model scenarios were generated. Five scenarios of varying artificial abstractions and discharges, diffuse pollution (related to landuse) and sluice gate configuration were undertaken. One of the major outcomes of the study was the apportionment of nitrates and phosphates to point and diffuse sources and the consideration of general seasonal trends.

The report is complicated however because of the five scenarios used, the different nutrients involved, the different vegetation communities concerned and the effects of changing water levels. Nevertheless it remains a key reference for the Washes because it established the relative contribution of different sources for the nutrients entering the site.

The report is structured as follows:

 Section 2 details the ecohydrological prescriptions that were used to define the water level and nutrient requirements of the various sections of the Washes;  Section 3 discusses the modelling approach adopted, including model set-up and calibration, and introduces the five model scenarios undertaken;  Section 4 discusses the simple source apportionment that has been carried out on the model results to try to identify which areas of the catchment contribute to nutrient amounts entering the washes during different times of the year.  Section 5 introduces water and nutrient budgets for both the entire washes and for each individual field cell within the model. The budgets are looked at in terms of excess water, TIN or total-P and help to introduce the operation of the Washes as a flood storage facility, an agricultural area and a conservation site;  Section 6 discusses the water table depth results for each field cell within the model, and helps to identify whether different areas of the washes are currently within or outside the target water level regime;  Section 7 discusses total-P levels in the ditches and fields across the Washes relative to a target threshold;  Section 8 discusses TIN levels in the ditches and fields across the Washes relative to a target threshold;  Section 9 draws the results together to identify concluding remarks and to make suggestions for the future management of the washes to re-establish the target vegetation communities.

General Trends.

• Total P contributions are quite constant through the year, but point sources are relatively more important during summer months, when diffuse runoff decreases.

• Nitrate contributions decrease during summer months, but the contribution of point sources to overall load increases. This is also attributable to decreased runoff and diffuse pollution.

• Ammonia contributions and the importance of point and diffuse sources remain fairly constant during the year.

• The area of the catchment supplying the highest point source nutrient load to the Washes is between Buckingham and Bedford, with the catchment between Bedford and Offord supplying the lowest point source nutrient loadings.

Total-P

An examination of nutrient sources under the current scenario, at each of the four rainfall runoff sub catchments, reveals that the main source of phosphorus is point sources. Point sources at Brownshill account for 78.1% in January to 94.6% in July, compared to 5.4% in January to 21.8% in July from diffuse sources.

As is evident in the total phosphorus nutrient budget analysis, the monthly availability of phosphorus in each of the four catchments, due to point sources, gradually increases from its lowest point in January until it reaches a peak in July, after which it decreases. This is due to the decreased surface runoff during the summer, and therefore decreased diffuse pollution runoff, and hence a decreased relative contribution.

Diffuse contribution to total phosphorus loadings remains low throughout the year. There is a seasonal trend, as with all other diffuse pollution, of higher values during the winter in response to increased runoff rates. As with ammonia and nitrates, the lowest point source contributions, and hence highest relative contribution of diffuse sources, is in the sub-catchment with the lowest numbers of treatment works (Bedford to Offord).

Ouse Washes Special Protection Area (SPA) and Candidate Special Area of Conservation (cSAC): Hydro-ecological Prescriptions for Favourable Condition. J Graham, English Nature, 2003.

This paper is a valuable contribution to the hydro-ecological prescriptions required to return the site to Favourable Condition Status and draws on some of the best science carried out at the site, ie Prosser & Wallace (2002) and Cathcart (2002) and is often referred to by subsequent studies. It helpfully summarises the changes that have taken place on the site, both for the open wash vegetation (1972-2001) and for that of ditches and pools (drawing particularly on Cathcart’s 2002 work). It considers the role of both flooding and nutrient enrichment in driving these changes and sets out a ‘new ideal’ water regime which shows the required physical water regime for birds using the Ouse Washes (ie nests of spring waders not flooded, correct water levels for different species to feed in summer and winter) based on over 30 years of bird recording by RSPB.

The summary to the document states:

“The condition of the Ouse Washes is presently unfavourable declining due to the factors of water quantity (annual pattern of flooding) and water quality (notably phosphorus). To return the Ouse Washes SPA/ cSAC to favourable condition requires:

 The annual pattern of flooding to fall within the upper and lower limits of the regime defined in Figure 5 for three years out of every four years.

 The majority of the open washes to support NVC MG9 and MG13 wet grassland with the remaining areas supporting a mixture of S5, S19 and S28 swamp communities. The current regime does not favour these communities.

 The majority of internal ditches to support NVC A5 and A15 aquatic plant communities (Cathcart groups 1 and 2). These communities require concentrations of total phosphorus to remain consistently below 0.11 mg/l and total nitrogen below 1.5 mg/l.

Black & Veatch. Investigations into solutions to water quantity problems affecting the special nature conservation interests of the Ouse Washes. English Nature, 2003.

This is another significant report examining possible solutions to the flooding issues affecting the site and follows on from the Posford study in 2000. A Working Group, comprising of nominated officers in English Nature, the Environment Agency, the Royal Society for the Protection of Birds (RSPB) and the Middle Level Commissioners, was set up to help define hydro-ecological objectives against which options could be tested. The following hydro-ecological objectives were therefore agreed for the study:

Hydro-ecological objective 1: A flood frequency of I in 4 years for the spring period (April to June).

Hydro-ecological objective 2: A depth not greater than I.5m for longer than 3 consecutive days in the winter period (November to March).

As part of the hydrological analysis, the additional flood storage capacity or flood diversion capacity required to protect the Ouse Washes to a standard of I in 4 years was investigated, based on the flow records for 1978-2002. This analysis indicated that to achieve hydro- ecological objective I (HEO I), a storage volume (or equivalent flow diversion) of 37Mm3 of water would be required.

The Posford Duvivier report (October 2000) concluded that only larger schemes able to reduce the flow substantially should be considered further. As a review of previous studies indicated that none of the options considered previously were large enough to fulfil HEO I , this report focused on identifying 'larger' options of flood storage and flood diversion, using GJS methods to identify suitable locations.

The appraisal of flood storage and flood diversion channel options has indicated that there is no single solution that will achieve HEOI, i.e. a standard of protection of I in 4 years for the spring period April-June. However, a combination of these larger options - i.e. a flood storage option and flood diversion channel - could potentially achieve HEOI. Due to the reduction in storage volume required if the channel capacity in the system were increased, a combination option would also minimise the storage volume, and thus landtake for the storage area, required.

To reduce the land take associated with a combination solution, we recommend that conversion of the Old West River into a flood conveyance channel should be examined. However, as there are currently no details of the potential capacity of this river, this would need to be investigated in further detail. Such an examination should consider the potential capacity

of the Old West river and of its receiving waters. It also needs to address the potential impact of diversion on siltation within the Tidal River. The outcome of this detailed study could then provide the basis for identifying the overall solution to water quantity problems in the Ouse Washes, for example the volume of storage required to provide a standard of protection of I in 4 years for the period April• June. The cost of diversion to the Old West River with a storage area of approximately IO Mm3 was estimated at £47M.

The only option identified to address the problem of winter flooding (HE02) was that of ‘Reprofiling the Tidal River’. Although this option will not prevent flooding of the Washes, lowering of the bed levels will help remove flood waters off the Washes more rapidly. This would reduce the duration and depth of flooding in spring and winter.

The study recommended that identification of a preferred solution required further study on the capacity of the Old West River. From this, the storage capacity required to fulfil HEOI could be determined. In addition to this study, the effect of water entering the Washes from Welches Dam needs to be investigated.

Environment Agency. Ouse and Nene Strategic Studies. Ouse Washes: Water and Nutrient Level Analysis. March 2004. Entec UK Limited.

I could not access this scanned document but I believe that it is the final version of the 2003(c) report described above.

Environment Agency - Anglian Region. Ouse Washes Habitat Creation: Business Case for the next 5 Years of Investigations, Land Purchase and Permissions. March 2007.

This report is chiefly of interest in setting out the background to the Ouse Washes Habitat Creation Project in the summer of 2005 whereby Defra provided funding for the acquisition of 500ha of land close to the Ouse Washes to help compensate for the damage being caused to the interest of the site by flooding.

Stella Bayliss, 2008. A summary of water quality information available in the Natural England Ouse Washes files, Ham Lane, Peterborough.

This short paper sets out to establish that there is a significant amount of data available to make the case that diffuse pollution is a significant factor contributing to the ‘Unfavourable’ condition of the Ouse Washes and that this evidence helps make the case to progress the Catchment Sensitive Farming Project and the Strategic Partnership Catchment for the Great Ouse. It draws principally on the report “Environment Agency Ouse and Nene Strategic Studies, Ouse Washes: Water and Nutrient Level Analysis, December 2003, Entec UK Limited” and on “Monitoring of the Wash and Ouse Washes in 2007 for the National Environment Programme, Fifth Annual Report. Black and Veatch, 2008, report for Essex and Suffolk Water”.

Bayliss concludes from the Entec report that although point sources on average contribute 325 kg per day of phosphorus, there is approximately 75kg per day, on average entering the system from these parts of the catchment from diffuse sources. During the year, as for nitrates, this is heavily weighted towards the winter months, presumed to be due to agricultural run-off under increased rainfall conditions. Although the relative contribution of phosphates from diffuse

sources is small as compared to point sources (circa 22% in winter and 5% in summer), this modelling work does identify its presence and it cannot therefore be ignored. Furthermore as the planned improvements to STWs are implemented in the catchment (via AMP4), the relative significance of these diffuse phosphorus inputs will increase.

Bayliss also points out the difference in water quality between the Old Bedford River Delph and the Old Bedford Counter Drain, both part of the cSAC, using data from the Black and Veatch 5th Annual Report. In general, phosphate concentrations are higher in the Old Bedford/Delph and upstream at Brownshill, as compared to those readings in the Old Bedford/Counter Drain. It is noted that the converse seems to be true for N, where levels are higher in the ‘outer river’ fed from the pump-drained Middle Level catchment as compared to the ‘inner river’.

A Repeat transect vegetation survey of the Ouse Washes – A Report for the Environment Agency. Jonathan Graham, Fenland Botanical Surveys, 2008.

This is a key report, repeating as it does the transect vegetation survey of the Washes carried out by Prosser and Wallace in 2001, and extending a long established run of data. Unfortunately the EA funding did not extend to including an analysis of the data collected, other than to assign the vegetation of individual quadrats to NVC.

Great Ouse and Ouse Washes: Catchment Appraisal Refresh Proforma, 2009. DJLAgronomics, FuIstow Louth Lincolnshire LN11 OXR.

The lack of an introduction to the report does not help gain understanding of the context for the work. The report appears to be the first that looks at the diffuse pollution issues across the catchment as a whole, considers the different type of agriculture involved and sets out some recommendations for addressing these issues. It succeeds in pulling together some useful key facts about agriculture in the catchment but this process really needs to be continued by the Catchment Management Plan on an annual basis. The recommendations perhaps should not assume that the farming community is following NVZ, CoGAP and Good Agricultural and Environment Condition (GAEC) requirements and some of the seven recommendations made to reduce diffuse pollution seems rather simplistic. Generally the report seems to rely on the old nutrient modelling by AWS and ENTEC 2003 to identify the amounts and the apportionment of nutrients between point and diffuse sources, although there is new information included on pesticide levels.

Significantly the report notes that there is no sediment management plan in place for the catchment; as part of the catchment management process clear measures of success or milestones need to be agreed and set with all members of the partnership; management objectives in terms of catchment priorities would be a useful step in targeting improvements and the use of detailed GI mapping using IACS and census data would increase evidence base for targeting. A summary is provided:

1. Drinking Water failing to meet Article 7.3 2. Impacts on Ouse washes and Portholme Natura 2000 sites 3. High to very high levels of P and N within the majority of the rivers and tributaries within the catchment

4. Water Framework objectives to be delivered through River Basin Management Plan.

Ouse Washes Conservation Objectives botanicals, minute by Stella Bayliss, 10 December 2008 to Simon Leach.

This has a useful discussion re the presence of rare higher plants on the Ouse Washes.

Ouse Washes CSM compliant Condition Assessment, Stella Bayliss, January 2009.

This is a useful short note commenting on the monitoring of rare plants on the Ouse Washes and incorporates comments by Simon Leach, national specialist on higher plants.

Common Standards Monitoring Condition Assessments of the Ouse Washes SSSI, CSM Survey Report, October 2009. WWT Consulting.

This report, commissioned by Natural England was aimed at carrying out Common Standards Monitoring surveys of MG11, MG13 and related wet grassland habitat within 12 management units of the Ouse Washes SSSI. The grassland communities on the Ouse Washes have most recently been surveyed via a transect-based NVC methodology with aerial photography in 2001 (Prosser and Wallace, 2002) with these transects being repeated in 2008 (Graham, 2008). However, although these surveys will contribute to the SSSI Condition Assessment, the transects did not cover all the SSSI Units.’ The purpose of the current survey was, therefore to provide data to augment the existing survey data; specifically to provide Natural England with appropriate CSM survey data to allow them to undertake Condition Assessments of the MG11/MG13 and related grasslands of the Ouse Washes SSSI.

The work was undertaken using the standard ‘structured walk’ protocol as described in Robertson and Jefferson, 2000. The remit was to provide data to enable Natural England to produce up to date condition assessments of the SSSI units as part of their ongoing monitoring programme. As the report does not contain the condition assessments, it is of limited value to a general reader, although it does contain some useful commentary on the vegetation.

Monitoring of the Wash and Ouse Washes in 2004 for the Natural Environment Programme. Second Annual Report. Black & Veatch for Essex and Suffolk Water, 2005.

The temporary Denver Licence Variation was granted to the Environment Agency for a period of five years, which commenced on the 21 November 1997 and expired on the 20 November 2002. Within the Licence Variation application the Environment Agency, supported by Essex & Suffolk Water, proposed an extensive monitoring programme of the Great Ouse estuary and The Wash. When the Licence Variation expired, the licence reverted to the original conditions in place prior to 1998. A slight variation on the original licence conditions is that discharge of the MRF is now permitted through any sluice; this means that Denver Sluice can be used in preference to the Residual Flow Sluice. Essex & Suffolk Water agreed to continue monitoring of the Great Ouse estuary and The Wash in order to review the environmental effects of the Denver Licence upon these areas to inform stakeholders prior to the permanent variation proposed as part of the Abberton Scheme.

These reports provides a useful annual summary of water quantity and quality issues, as far as the Ouse Washes is concerned.

Monitoring of the Wash and Ouse Washes in 2008; Sixth Annual Report. Black & Veatch, October 2010.

As above. Water quality in the upper estuary was comparable with that of 2007, and reflected the relatively high freshwater flows experienced during both years. It should be noted, however, that as with 2007 the number of samples collected was notably reduced in comparison with the number collected in the previous years. This is a result of the Environment Agency's methodology for water quality sampling being modified to tie in with the requirements of the Water Framework Directive.

Monitoring of the Wash and Ouse Washes in 2009; Seventh Annual Report. Black & Veatch, October 2010.

This report is similar to the above. Some data for water quality measurements from EA monitoring are included. It should be noted that the number of sampling points and the frequency of sampling have gradually declined over the years. This is part of a transition in the monitoring programme to bring it in line with the requirements of the Water Framework Directive. Following these changes next year's study will only be able to report from five of the nine water quality sample points monitored in 2009 (as noted in Table 5.1). This is because the Environment Agency is in a transitional phase is response the requirements of the new Water Framework Directive methodologies set out for assessing river quality.

Importantly it was noted that the annual average concentration of orthophosphate in the Ely Ouse at Denver has been above 0.3mg/l since 2005 and was higher in earlier years. In 2009 the annual average concentration fell to 0.17mg/1 with only two samples during the year at this site containing 0.3mg/l or more orthophosphate; this is possibly as a result of increased phosphate stripping in recent years at water treatment works that discharge into the Ely Ouse system.

The Environment Agency has an automatic monitor for measuring conductivity at Salter's Lode in the Tidal Ouse Estuary. The Salter's Lode monitor is used to monitor the occurrence of saline intrusion to prevent saline water being abstracted from the Tidal River and taken into the Counter Drain on spring tides when freshwater flows are low. The water quality monitoring station at Salters Lode has not been functioning or recording since 2007 due to siltation problems. Any instrumentation installed here soon becomes buried. This station is next to the lock, which is a busy navigable section of the river. This therefore restricts the type of monitoring methods which could be used or installed at this location. As for last year the Environment Agency is currently reviewing this monitoring station to determine whether there is a solution, or whether it discontinues using this site.

Ouse Washes and Portholme Diffuse Water Pollution Plan, NE & EA, 2010. Note this document is still live and on at least Version 11, 31 March 2014.

Diffuse Water Pollution Plans (DWPPs) are, together with Water Level Management Plans, key building blocks for the conservation of important wetland conservation sites. The versions of this document that I have seen plunge straight into a landscape format Action Plan and lack any

introductory section that describes the framework that they are operating in. This is particularly unfortunate for such a complex site as the Ouse Washes. Any DWPP is going to have to work in tandem with efforts to reduce point source pollution from Sewage Treatment Works (STWs) through the five yearly Asset Management Programme (AMP) determined by the regulator OFWAT. The next five year programme, AMP 6, 2015 – 2020, starts soon.

More significantly is the question as to how successful many of the actions in the Plan will be, as they depend on voluntary positive action by the very many different types of landowners and farmers involved. It seems certain that a statutory approach would have more chance of success, however of course it may be necessary to invest in the voluntary approach first, to allow a statutory approach to be accepted later.

There are difficulties dating this document as I have Version 11, dated 31 March 2014. There is a signed version dated autumn 2010 (which was the version used for the Full Review in Volume 2 of the Ouse Washes Literature Review), but apparently this has been aborted and the current status of the document is unsigned, eg draft presumably, which is unfortunate.

This document has been one of the guiding documents for this review and more time would have been spent on diffuse water pollution matters if there had not also been crucial water quantity issues to consider, as well as the changes taking place on the Washes themselves.

It is noticeable from the Plan how important the various ENTEC reports still are as far as evidence about levels of point source and diffuse pollution in the catchment are concerned.

Improvement programme for England’s Natura 2000 sites (IPENS). Natural England, 18 Dec 2012 & Diffuse Water Pollution Theme Workshop Note, Natural England, 5 Sept 2013.

This documentation on Natural England’s website is very helpful in setting a national framework for diffuse water pollution affecting Natura 2000 sites in general and for Diffuse Water Pollution Plans in particular. IPENS is to produce a Theme Plan on Diffuse Water Pollution. It also recognises the need to set the direction of travel towards achieving often challenging water quality targets for individual Natura 2000 sites, whilst recognising the uncertainties involved and acknowledging the need to adopt an adaptive management approach in practice.

IPENS is to develop a Theme Plan on Diffuse Water Pollution.

Improvement Programme for England's Natura 2000 Sites (IPENS). Site Improvement Plan – Ouse Washes. Natural England, 19 December 2014.

This Site Improvement Plan (SIP) usefully brings together the current issues affecting the site but for anyone that knows the site there are no surprises or new information. Perhaps surprisingly Natural England is identified as the Delivery Lead Body for delivering a new Water Level Management Plan and again for the implementation of the current Diffuse Water Pollution Plan (DWPP). It is questionable whether there is a current agreed DWPP.

RK, 5 March 2015.

4. RECOMMENDATIONS FOR FUTURE WORK ARISING FROM THE REVIEW 1. Analyse existing vegetation survey data collected in 2008 (J. Graham) & 2009 (WWT consulting) and report on changes over time.

2. Repeat Rob Cathcart’s 2001 survey of the ditch flora to determine whether the reduction in P levels in the River Great Ouse and tributaries as a result of the introduction of P removal technology at Sewage Treatment Works has resulted in any beneficial effects on the flora of ditches on the Washes. If a full re-survey is too expensive, perhaps a section could be re- surveyed to see if there had been significant changes. There may be existing information that could complement such a re-survey, such as Amy Robinson’s PhD studies.

3. Perhaps in combination with 2 above, install sediment monitoring plates to investigate annual increases in sediment deposition and analyse such sediments to determine nutrient levels. I am not aware that such information has been previously so this would establish a useful baseline to monitor future change against.

4. Encourage the Environment Agency not to reduce their longstanding programme of water quality monitoring along the River Great Ouse for the Natural Environment Programme reported annually by Black and Veatch (this was indeed a recommendation of the 2002 WLMP).

5. Partners on the Ouse Washes Strategic Management Group should continue to meet regularly at a senior level to seek to resolve outstanding issues, agree future actions and monitor progress.

6. Partners on the Ouse Washes Strategic Management Group should produce regular reports of the situation on the Washes as far as flooding levels, nutrient levels, progress on measures to reduce flooding and on the Ouse Washes Habitat Creation Project are concerned. At present this information appears to occur mainly on fairly obscure websites.

7. The Environment Agency and Natural England should sign off the draft ‘Ouse Washes and Portholme Diffuse Water Pollution Plan’ to indicate publicly their commitment to implementing the Plan and to making progress on restoring the ecological condition of the Ouse Washes and Portholme Natura 2000 sites.

8. Work by partners towards the provision of replacement habitat for birds close to the Ouse Washes should continue. There is an urgency for progress to be made as the situation of the residual breeding bird populations is increasingly critical, especially for snipe. Delays in implementing the Ouse Washes Habitat Creation Project mean that there is a real danger of populations becoming too low to allow certainty over likelihood of successful colonisation of the replacement habitat.

9. Further analyses should be carried out to identify other areas of wetland creation that could be created elsewhere within the Great Ouse and other catchments that might also be able to take floodwater away from the Ouse Washes and would also contribute towards BAP targets and the Objectives of the Fens for the Future Partnership. This approach was also recommended by the Ramsar Advisory Mission (RAM) in 2001, which recommended

combining the integrated river basin planning for the Great Ouse with an ecosystem approach for the whole region of the Fens, notably also to define the functions of wet grasslands in this context. The time may be right for a re-appraisal of this approach as there is now greater knowledge and support for catchment-based solutions and the Natural Capital agenda. Also previous assessments did not consider the wider ecosystem services benefits of attenuating flows to the Washes in this way, nor indeed the ecosystem service benefits of the replacement habitat.

10. Re-evaluate whether floodwater could be diverted through the Old West River and Ely Ouse to reduce flood levels in the Ouse Washes, again as suggested by the Ramsar Advisory Mission and Black & Veatch, 2003.

11. Encourage a continued action programme to reduce diffuse water pollution from agriculture into the River Great Ouse and its tributaries. Maps should be produced showing areas most likely to be sources of diffuse pollution, perhaps as part of a review of Catchment Sensitive Farming work.

12. Consideration should be given to holding a further Ramsar Advisory Mission to the Ouse Washes, as a follow-up to their useful visit in 2001. This could be held 15 years after their initial visit.

5. A SUMMARY OF INFORMATION RELATING TO BOTANICAL SURVEYS ON THE OUSE WASHES TAKEN FROM ENTEC, 2002. It was felt that such a summary of botanical information might be of value to readers.

The plant communities recorded on site and listed below have been drawn from surveys undertaken by Sue Everett (1983), Burges, Evans & Thomas (1989) and Prosser & Wallace (January 2002).

Community maps and community descriptions from the Ouse Washes Grassland Management Topic Paper (1993) but based on those produced by Everett (1983) are presented in Appendix H of ENTEC, 2002.

Aquatic Flora

Dykes

A network of dykes drain the washes. The aquatic flora of the dykes in the Washes as a whole was last surveyed in 1992 and 2001 (Cadbury, Halshaw and Tidswell, 1993 and Cadbury, Prosser and Wallace, December 2001). 706 x 10m samples were recorded and 42 pool samples were also recorded.

The ditch flora was assigned to six main NYC communities as follows: A I Lemna gibba community;

 A2b Lemna trisulca sub-community of the A2 L. minor community;  A5b Lemna minor sub-community of the A5 Ceratophyllum demersum community;  S5a (G!yceria maxima) and S5b Alisma plantago-aquatica-Sparganium erectum sub- communities of the S5 G. maxima swamp;  SI4c Mentha aquatica sub-community of the Sl4 Sparganium erectum swamp.

The following communities were more local in their distribution:  A3 Spirodela polyrhiza - Hydrocharis morsus ranae community;  Sl2b (Mentha aquatica) and Sl2c (Aiisma plantago aquatica) sub-communities of the S12 Typha latofo!ia swamp;  S19a Eleocharis pa!ustris sub-community of the S19 (E. palustris) swamp;  S22b Sparganium erectum - Mentha aquatica sub-community of the Glyceria jluitans water-margin vegetation;  S28b Epilobium hirsutum - Urtica dioica sub-community of the Phalaris arundinacea swamp.

20 aquatic, 20 emergent and 50 bank-side species were recorded in 1992. Of the 31 vascular plants species recorded as associated with internal ditches during the 2001 survey, the most frequent (in order of decreasing frequency) were common duckweed (Lemna minor), reed sweet-grass (Glyceria maxima), rigid hornwort (Ceratophyl/um demersum), water mint (Mentha aquatica), blanket weed (Cladophora), water forget-me-not (Myosotis scmpioides), greater duckweed (Spirodela polyrhiza), common spike rush (Eleocharis palustris), water plantain

(Alisma plantago-aquatica), fat duckweed (Lemna gibba) and the trifid bur-marigold (Bidens triparlita).

16 species were recorded from the Ouse Washes between 1970 and 1992 that were considered nationally scarce at that time. Those that are still considered nationally scarce are listed below:

 Fringed water-lily (Nymphoides peltata);  Marsh sow-thistle (Sonchus palustris);  Whorled water-milfoil (Myriophyllum verticil/alum);  Hair-like pondweed (Potamogeton trichoides);  Large dodder (Cuscuta europaea);  Narrow-leaved water-dropwort (Oenanthe silaifolia);  Greater water-parsnip (Sium latifolium);  Tasteless water-pepper (Polygonum mitis);  Great tassel stonewort (Tolype/la prolifera);  Fen ragwort (Senecio paludosus).

Of these 16 species the following were not recorded by any of Perrow & Tomlinson, Prosser, Wallace and Cadbury and Prosser and Wallace in 2001:

 Marsh sow -thistle (population reported as sick in 1997);  Whorled water milfoil;  Narrow leaved water dropwort;  Tasteless water-pepper;  Fen ragwort.

It is worth noting that as far as the Counter Drain and Old Bedford Delph are concerned there is reference to the Environment Agency undertaking a macrophyte surveys of the these in 2000. At the time of reporting Entec has not seen these data. Anecdotal information for the Old Bedford Delph however indicates that the aquatic flora is dominated by macrophytes.

3.3.2 Previous and On-going Ecological Monitoring

Flora

The terrestrial flora of the whole of the Ouse Washes was surveyed in 1983 (Everett, 1983). The terrestrial flora of parts of the site has been surveyed since and a survey designed to determine/quantify the changes to the terrestrial flora of the Washes was commissioned in 2001 by English Nature, and has been reported (Prosser and Wallace, 2002).

The dyke flora of the Ouse Washes was surveyed by the RSPB in 1978 and it was surveyed again, for English Nature, RSPB and WWT, in 1992 (Cadbury, Halshaw and Tidswell). The RSPB has since undertaken work on their reserve with James Cadbury undertaking a ditch vegetation survey in 1997. The ditch flora of the Washes has also been included in the 2001 work commissioned by English Nature with the aim being to determine the changes taking place in the communities present.

The aquatic flora of the Old Bedford Delph and Counter Drain was surveyed by the Environment Agency in 1999.

A list of botanical reports and papers relating to the Washes and collected during the Review is given in the following section.

6. LIST OF BOTANICAL REPORTS AND PAPERS COLLECTED DURING THE REVIEW. Anonymous. Survey of aquatic macrophytes of the Ouse Washes Counter Drain (Old Bedford / Delph). Collected at ten named sites but undated and unauthored.

Burgess, N.D., Evans, C. & Carson, C. 1988. Vegetation changes on the Ouse Washes. (Mem stick 3).

Burges, N.D., Evans, C.E. & Thomas, G.J. 1989. Vegetation change on the Ouse Washes, England, 1972-88 and effects on their conservation importance. Report for RSPB, Biological Conservation.

Burgess, N.D., Evans, C.E., & Thomas, G.J. 1990. Vegetation change on the Ouse Washes, England, and their conservation importance. Biological conservation, 53, 173-189.

Cadbury, C.J. 1997. Ouse Washes Ditch Survey 1997. Unpublished Report, RSPB, Sandy, Bedfordshire.

Cadbury, C.J., Halshaw, L. & Tidswell, R. 1993. Status and management of the ditch and pool flora of the Ouse Washes 1992; Comparisons with 1978. Report for EN/RSPB/WWT.

Cadbury, J., Halshaw, L. & Tidswell, R. 1994. The Ditch Flora of the Ouse Washes (Cambridgeshire and West Norfolk): a Comparison between 1978 and 1992. Nature in Cambridgeshire, 36, 17-33.

Cadbury, C.J., Prosser, M.V. & Wallace, H.L. 2001. The ditch flora of the Ouse Washes, Comparisons with 1978. Report for EN/RSPB/WWT.

Cathcart, 2001. Effects of Nutrient Loading on the Ditch Flora of the Ouse Washes: Current Impacts and Potential Mitigation.

Sue Everett, 1983. Vegetation Map No. 2.

Graham, J., 2008. A repeat transect vegetation survey of the Ouse Washes – a report for the Environment Agency, Central Area, Anglian Region. Environment Agency.

Graham, J. J. 2011. A survey of the aquatic macrophytes associated with the drainage ditches of the Ouse Washes Site of Special Scientific Interest (SSSI). Unpublished report for Natural England.

Grose, M.P.B. & Allen, D.S. (1978). Survey of the Ouse Washes Ditch Plants, July-September, 1978. RSPB, Sandy.

Grose, M.P.B., Allen, D.S., Thomas, G.J.& Haslam, S.M (1978). Survey of Ouse Washes Flowering Plants July-September 1978. Anglian Water I RSPB unpublished report.

Lansdown, R.V. 2011. Ribbon-leaved Water Plantain (Alisma gramineum) monitoring at the Ouse Washes. Unpublished report for Natural England.

Newbold, C. 1999. Water quality and the aquatic flora of the Ouse Washes, Cambridgeshire – an historical perspective. English Nature (and included as an Appendix in ENTEC, 2002).

Prosser, M.V. & Wallace, H.L. 2002. Vegetation change on the Ouse Washes: 1972-2001. Report for EN/RSPB/WWT.

Thomas, G.J., Grose, M.P.B. and Allen, D.A. (1981). The Demography and Flora of the Ouse Washes, England. Biological Conservation, 21 (3), 197-229.

WWT Consulting, 2009. Common Standards Monitoring Condition Assessments of the OuseWashes SSSI.

7. REFERENCES NOT INCLUDED IN THE REVIEW Cottier, E.J. & Lea, D. (1969). Black-tailed godwits, ruffs and black terns breeding on the Ouse Washes. British Birds, 62, 259-270.

Cowley, C. (1990). Ouse Washes Environmental Statement. Mott MacDonald I NRA Anglian Region.

Environment Agency, 2004. Ecohydrological Guidelines for Lowland Wetland Plant Communities.

Environment Agency, 2008. Cranbrook/Counter Drain Flood Risk Management Strategy.

Environment Agency, 2009. The Great Ouse Tidal River Strategy.

Environment Agency, 2011. The Great Ouse Catchment Flood Management Plan.

Green, R.E., Cadbury, C.J. and Williams,G. (1987). Floods Threaten Black Tailed Godwits Breeding at the Ouse Washes. RSPB Conservation Review, 1, 14-16.

Mott Macdonald, (1991). Ouse Washes Flood Control Strategy Report. NRA Anglian Region.

Mott Macdonald, (1992). Ouse Washes Flood Control. Strategy Report for NRA Anglian Region.

National Rivers Authority, 1995. The Ouse Washes Flood Control Strategy.

Owen, M. & Cadbury, C.J., (1975). The ecology and mortality of swans at the Ouse Washes, England. Wildfowl, 26, 3 1 -42.

Posford Duvivier, 2000. Tidal River Great Ouse. Siltation and flood control: options past and present.

Posford Duvivier, Oct 2000. Overview of various measures to alleviate summer flooding. Ouse Washes Habitat Protection and Funding Group.

RSPB, 1999. Ouse Washes Cattle Grazing and Shepherding 1999 Season Summary. Unpublished Paper Presented to the Ouse Washes Management Review Meeting 1112199. RSPB, Ouse Washes Reserve.

Stroud, D. & Riley, H. (1992). Departmental brief the Ouse Washes Ramsar site extension and proposed Special Protection Area 1804A). International Designations Unit, Vertebrates & Landscape Ecology Branch, Joint Nature Conservation Committee, unpublished.

Thomas, G.J., (1980). The ecology of breeding waterfowl at the Ouse Washes, England. Wildfowl, 31, 733-788.

8. TIMELINE OF EVENTS FOR THE OUSE WASHES 1630 – The Adventurers engage Vermuijden to control flooding and he constructs a straight channel between Earith and Salters Lode, shortening the journey of highland water to the sea by 16 km, and creating the Ouse Washes. It was called the Bedford River in memory of the 4th Earl of Bedford who formed the Adventurers.

1650 - After the end of the Civil War in 1649, Cromwell set Vermuijden to work again. A second 30 km channel was dug parallel to the first, named the New Bedford River (or Hundred Foot River), running about 1 km east of the original Bedford River and creating a washland between the two channels. A flood storage reservoir of around 1900 ha was formed between the two new rivers, bounded on the West side by the Middle Level Barrier Bank and on the East by the South Level Barrier Bank. Thus the “Ouse Washes” were created.

1952 – Black-tailed godwit returns to breed at the Ouse Washes.

1955 – The site was first notified as a SSSI (Bedford Wash).

1967 – The Ouse Washes one of four sites included in an appeal launched by RSPB for acquisition.

1967 – The Wildfowl and Wetlands Trust acquires its first 100 acres on the Ouse Washes.

1971 - The Wildfowl and Wetlands Trust open the Welney visitors centre.

1976 – The Ouse Washes was included on the List of Wetlands of International Importance on 5 January 1976; it is Ramsar Site No. 77.

1984 – The site was re-notified under the wildlife and Countryside Act, 1981.

1991 – Ouse Washes Management Strategy Group formed (see WLMP, 2002).

1993 - The National Rivers Authority carry out major engineering works (grant-aided by MAFF) on the Barrier Banks to ensure that they are able to withstand a 1 in a 100 year flood. The works have a design projected life of 50 years.

1993 – Production of the Ouse Washes Management Strategy (Introductory Paper) started by English Nature.

1995 – Ouse Washes Flood Control Strategy produced.

1995 – Ouse Washes Site Management Statement produced.

1996 – The site was entered onto the Register of European Sites for Great Britain on 30 January 1996 as a Special Protection Area (SPA). Register Reference Number: UK000804. The site code is UK9008041. The SPA Citation is dated June 1992. At this time an average of 57 individual Black- tailed godwits were recorded lekking, a significant proportion of the British population.

1997 - The temporary Denver Licence Variation was granted to the Environment Agency for a period of five years, commencing on the 21 November 1997.

1999 - Reconstruction of the Welmore Lake Sluice.

2000 - In October the site was entered onto the Montreux Record, a list of failing Ramsar sites.

2004 - Defra set up a high-level Steering Group for the Ouse Washes, the Ouse Washes Strategy Group, with the membership made up of Directors from Defra, English Nature (now Natural England), the Royal Society for the Protection of Birds and the Environment Agency.

2005 - The sites was entered onto the Register of European Sites for Great Britain on 14 June 2005 as a Special Area of Conservation (SAC). Register Reference Number: UK0013011. The designation applies only to the Counter Drain and the qualifying species is Spined loach Cobitis taenia.

2005 - On 24th March Elliot Morley MP held a press conference on 'Making way for water' and within it he referred to the Ouse Washes:

"The Government is committed to ensuring that the flood risk management programme takes proper account of the environmental impacts of our interventions. As a practical example of this I am pleased to announce that we shall be taking measures to offset damage occurring to the Ouse Washes Natura 2000 site. This will allow the site to continue to protect people and property from flooding at the same time as addressing the environmental value it provides for birds."

2005 - In the summer the Ouse Washes Habitat Creation Project was set up to implement the decision and to deliver the replacement habitat. An Ecological Consultation group was set up to advise and make recommendations to the Project Board on a range of ecological issues within the project. A similar group has been used to explore Land Acquisition issues.

2006 – In November EA consulted on the Ouse Washes Habitat Creation Project. The aim was to deliver over 1000 ha of new wetland habitat in the Fens for a range of breeding and wintering birds that use the Ouse Washes in Cambridgeshire and Norfolk. It is hoped to have the site(s) completed and able to attract birds by 2015.

2007 - An overarching 'Implementation Strategy' was prepared for the Ouse Washes Habitat Creation Project which sets out how the project as a whole would be managed and implemented. This document was submitted to the National Review Group (NRG) in May, together with an accompanying non•statutory Strategic Environmental Assessment report.

2012 – Cambridge ACRE receives £90,500 development funding from the Heritage Lottery Fund (HLF) for a Landscape Partnership Scheme on the Washes.

2014 – In March the HLF granted the partnership £905,100 to deliver the Landscape Partnership Scheme.

RK, April 2015.

APPENDIX 1. MAPS

Map 1. Location of the Ouse Washes

Map 2. The Ouse Washes

Map 3. The Upper and Bedford Ouse management catchment and the operational catchments within it, Diffuse Water Pollution Plan, 2010.

Map 4. The different structures and drainage channels associated with the Ouse Washes, from the Water Level management Plan, 2002.

Map 5. Diagram showing how water flows through the Ouse Washes and associated channels, from the Water Level management Plan, 2002.

Map 6. Diagram showing the water level control structures associated with the Ouse Washes, from the Water Level management Plan, 2002.