River Darent Action Plan

Phase 2 – River Restoration Strategy

Nigel Holmes with Eddie Bradbrook, Richard Andrews, Chris Conroy, Ian Humpheryes, Dave Best, Bridget Thorn Where is the Darent? Problems: Historical Groundwater Abstraction Problems: 1976; 1984; 1989-91 Chalk Stream with a difference

Darent Daily Flow at

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10

5 Flow (cumecs) 0

Jan-87Jan-88Jan-89Jan-90Jan-91Jan-92Jan-93Jan-94Jan-95Jan-96Jan-97Jan-98Jan-99Jan-00Jan-01Jan-02 Date Hydrograph of a Real Chalk stream - Itchen

Daily Mean Flow on the River Itchen at Allbrook and Highbridge

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20

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10 Flow (cumecs) Flow

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0

01.10.198715.03.198828.08.198810.02.198926.07.198908.01.199023.06.199006.12.199021.05.199103.11.199117.04.199230.09.199215.03.199328.08.199310.02.199426.07.199408.01.199523.06.199506.12.199520.05.199602.11.199617.04.199730.09.199715.03.199828.08.199810.02.199926.07.199908.01.200022.06.200005.12.200020.05.200102.11.2001 Abstraction: effects on flow

Naturalised flow

Actual Flow Abstraction: effects on flow

Naturalised Flow

Actual Flow

Distance down the Darent Historical Channel Degradation

Water Quality

• Phosphates low – below EN’s SSSI Target • Nitrates OK – within WHO Drinking Water limits • Occasionally high BOD due to ‘weed growth’ in hot summers • Minor point-source small incidents • Silt is a problem • Around 1900 catastrophic pollution ‘killed every living thing in the river’ - previously considered one of finest trout rivers in the country The Darent Action Plan – Water Resources

• Two Phases • Phase I (1996) – Reduction of 20 Ml/d from upper catchment & augmentation in low-flow periods in vulnerable lower reaches • Phase II (2005) – Further reductions of 23.5 Ml/d from lower catchment sources • Modelling and other studies to determine an ‘Environmentally Acceptable Flow Regime’ (EAFR) The Darent Action Plan – Reduced Licences

Daily licensed abstraction accretion profile. Public water supply abstraction in the Darent Catchment upstream of in relation to the Darent Action Plan. Reductions in bold type.

200 Pre-Phase 1 (1994-97) quantities /yr Wilmington Current Quantities (2004) /yr 180 Proposed Quantities with phase 2 reductions (2007)/yr Darenth Augmentation Green St

160 Green Stansted Fawkham Ridley 140 Hartley Horton (aggregated) Kirby

120 Hartley (b)

100

Kemsing (Honeypot 80 Stream confluence)

Cramptons Rd Licencedabstraction (Ml/day) 60

40 Sundridge Oak Lane Westwood

Westerham Dartford

20

Eynsford Lullingstone 0 -2 4 10 16 22 28 Distance from start of main river (km) The Darent Action Plan – EAFR The Darent Action Plan – Restore flows and augment in extremes The Darent Action Plan – EAFR

• At What Cost? – c£75m+!! • Is it Enough (ecologically)? • How do we get best value for money? ………………HAVE A SUSTAINABLE AND ALL-EMBRACING CATCHMENT MANAGEMENT STRATEGY River Darent Restoration Strategy • Builds upon previous plans and actions. • Primarily building on improved flows. • Acknowledges more needed if environmental quality to be restored. • Two parallel studies required to progress a ‘River Restoration Strategy’.

River Darent Restoration Strategy – The 2 Studies

• Both essential to implement sustainable management and restoration. • Both provide concise outputs. • Outputs include consultation documents enabling the general public, and other project partners/stakeholders, to become involved in the most cost-effective manner. • The focus is the River’s ecology – through consultation this ‘backbone’ will be fleshed out with all interests fully integrated in the future River Restoration Strategy – Study 1

Assess, and report on, the ecological status of the river, its limitations and potential. review of all available ecological data;  assess the practices and pressures influencing ecology;  consideration of existing environmental responsibilities, and specifically assessments required under the Habitats Regulations (HR) and the Water Framework Directive (WFD).  output = ‘River Darent Environmental Appraisal’. Volume 2 ‘Draft River Darent Restoration Strategy; programme of Actions and Measures’

 reviews achievements of the Darent Action Plan (WR);  assesses how catchment land-use, water resources, flood defences and other activities could be managed in the future in an integrated and sustainable manner;  Preparation of a Strategy and Plan that will benefit the ecology of the river and its natural landscape assets, its resources for recreation and amenity, and provide cost-effective and sustainable water use and flood management. ‘Feature Interests’ Approach

• Include many key species/habitats of interest/responsibility (e.g. BAP) or of socio- economic importance (e.g. fish) • Can be used as ‘Barometers of health’; • If we get it right for these, everything else should be OK; • They are a basis to monitor – need to know progress being made, and possibly quantified; • Provides feed-back to functions and organisations that their actions have made a difference!! The ‘River Darent Environmental Appraisal’ – Data Review - Reporting • SIMPLE REPORTING FORMAT FOR EASE OF LOCAL INPUT TO DRAFT – What the current status of ‘feature interest’ is considered to be - (e.g. high, good, moderate, poor or bad) – How current status varies from year to year – e.g. upward/downward trends or stability. – The factors considered to be most influential in affecting the present ‘perceived’ status. Integrated Appraisal Approach – Key Factors – Assessing ‘Cause & Effect’

Also consider others – A. e.g. catchment effects Habitat (siltation), factors out of catchment (estuary Quality netting) Etc.

C. Feature B. Water Interest Water Quality being Quantity assessed D. Biological Interactions & Responses to Natural Change

The Darent Strategy – 1. ‘Feature Interests’

Feature Interest Otter Water vole Salmon

Lampreys Bullhead Trout and grayling

Other fish communities Invertebrate communities Crayfish Macrophyte community River Habitat The Darent Strategy – approach – 5-scale assessment of status

Colour code Natura 2000/EN definitions Water Framework Directive Additional Darent context for SSSIs Status

RED: Destroyed/Part Bad (severely degraded Destroyed/At risk Destroyed/Unfavourable and [HMWB]) Declining

ORANGE: Unfavourable and Poor (significantly changed Poor condition – has been Maintained from pristine) much better in past

YELLOW: Unfavourable and Moderate (moderately Also includes Naturally Recovering changed from pristine) moderate or worse

GREEN: Good (slightly departing near-favourable or close to from pristine) maximum potential

BLUE: Favourable. High (pristine or near- Healthy and not at risk natural) The Darent Strategy – approach – 5-scale assessment of factors affecting status

Score Description of extent of influence on status 5 Probably key influence

4 Major influence

3 Important influence

2 Moderate influence

1 Minor influence

Blank or not cited None or not known The Darent Strategy – Standard approach to reporting

• Data Sources. • Expert Opinion Sources. • Status between Otford & Dartford. • Basis for Status Category. • Comparison of Present Status with Historical Status. • Key Factors Affecting Status. • Actions.

The Darent Strategy – Results of Environmental Status using surrogates

Feature Interest Status

Otter Unfavourable (no significant change in past 20 years)

Water vole Unfavourable and maintained (no significant change in past 20 years)

Salmon Naturally Unfavourable?? (no significant change in past 20 years) – May be naturally unfavourable, or historically impacted

Lampreys Probably Naturally Unfavourable (no significant change in past 20 years) Bullhead Favourable - Not adequately known - probably recovered in past 10 years

Trout and grayling TROUT: Unfavourable (V. slight recovery) GRAYLING: Unfavourable

Other fish communities Moderate except in, and after, major drought years

Invertebrate communities Unfavourable (recovering)

Crayfish Unfavourable (declining [destroyed])

Macrophyte community Near-favourable or close to maximum potential

River Habitat Full range from Unfavourable to locally Near-Favourable The Darent Strategy –Factors affecting Ecological status – Matrix Approach

Feature Interests/Factors O WV S L B TG O I C M H F Historic changes to channel form and present character 2/2 5 2 2 2/2 2 5 Flood defence management 1/1 2/2 2 2 2 3 3 2 2/2 4

Channel and other fisheries management actions 1/1 1/1 1 1/1 1/1 1/2 1/3 1/1 2/2 1 Siltation of gravels 4 ? 1 3 2 2 2 2 Periodic drying 4 4 4 4 5 5 5 4 5 1 Extreme low flows - 2 4 2 4 4 4 3 3 3 Present general water quality 1 1 1 2 Historic catastrophic pollution ? 4 4 1? ? 2? Estuary quality 2 Alien species – e.g. fish stocking 5 2 5 Catchment/floodplain land-use 3/2 Distant effects (sea/estuary- salmon) 2 Specific effects 5 5 5 5 The Darent Strategy –Factors affecting Ecological status

Type of Impacts Historic changes to channel – Severe for Salmon and River Habitat Flood defence management – Moderate for Many things Fisheries management actions – positive or negative for most Siltation of gravels – Fish and invertebrates especially Periodic drying – catastrophic for fish and inverts, and macrophytes?? Extreme regular low flows – bad for everything Present/recent water quality – not an issue Historic catastrophic pollution event – legacy difficult to quantify Alien species – catastrophic for crayfish - Catchment/floodplain Land-use – otter (roads)

Outside catchment effects – salmon – probably not an issue Species-specific effects – crayfish, water vole, salmon, native Darent fish

The Darent Strategy – Ecological Status and Factors Determines Strategy - Headlines Key Impacts Proposals to Reverse Impacts

A. Historic changes to channel Developing a catchment-wide river restoration strategy. Addressed through a comprehensive programme of river restoration/rehabilitation (Actions). At local ‘hotspots’ in urban areas this may require significant engineering; in others, gentle actions only to kick-start natural recovery.

B. Flood defence management Establishing, and adopting, a strategy of carrying out necessary maintenance in >99% of the river using only environmental best practices which will enable the river to help repair itself.

C. Fisheries management actions Through the FAP, develop and adopt a strategy for self-sustaining fish populations and fisheries. Actions will include any river enhancements that use best practice options only that optimize how river processes can be harnessed to restore desired habitat structure for fishery and other interests (assisted natural recovery). It also includes re-establishing Darent progeny and enabling them to be self-sustaining (e.g. EA/DVTF incubator introductions from upstream of Chipstead).

D. Siltation of gravels Addressed through strategies and actions regarding catchment and channel management strategies and actions cited for A, B, C and K.

E. Periodic drying Being addressed through DAP. A strategy needs to be in place to address problems if the perceived improvements do not materialize. Specific actions to await this appraisal through CAMS and response of river to next major drought (due soon). F. Extreme low flows

G. Present/recent water quality Continued vigilance of EA in their consenting and regulatory roles. No new strategy or actions required.

H. Historic catastrophic pollution event Legacy; outside the Scope of the RDRS.

I. Estuary quality Outside the Scope of the RDRS.

J. Alien species Strategies to be developed on how to respond most effectively to individual threats. Addressed then through targeted actions for each one, on a priority basis, but only hope of success is through an integrated catchment approach.

K. Catchment/floodplain land-use Requires both ‘catchment-wide’ and ‘reach’ problems addressing through a coordinated programme of actions. Priority actions addressing the major problem areas to be determined through a whole catchment strategy to silt reduction.

L. Outside catchment effects Outside the Scope of the RDRS.

M. Species-specific effects Addressed through specific actions. There will be an over-arching strategy to undertake actions that will address specific, and reversible, factors that adversely impact key interests. The individual actions to be very limited as the thrust of the RDRS is to undertake integrated management activities that benefits all interest, negating the priority for actions for specific species except where they alone are seriously impacted (e.g. otter, crayfish). The Darent Strategy – Ecological Status and Factors Determines Strategy - Headlines

Key Impacts Proposals to Reverse Impacts

A. Historic Developing a catchment-wide river restoration changes to strategy. Addressed through a comprehensive channel programme of river restoration/rehabilitation (Actions). At local ‘hotspots’ in urban areas this may require significant engineering; in others, gentle actions only to kick-start natural recovery. B. Flood Establishing, and adopting, a strategy of defence carrying out necessary maintenance in >99% management of the river using only environmental best practices which will enable the river to help repair itself. The Darent Strategy – Ecological Status and Factors Determines Strategy - Headlines

M. Species- Addressed through specific actions. specific There will be an over-arching strategy effects to undertake actions that will address specific, and reversible, factors that adversely impact key interests. The individual actions to be very limited as the thrust of the RDRS is to undertake integrated management activities that benefit all interest, negating the priority for actions for specific species except where they alone are seriously impacted (e.g. otter, crayfish). The Darent Strategy – Ecological Status and Factors Determines Strategy

Strategy Description Developing consensus, partnership involvement, and adequate funding to implement the RDRS over a >10 year period. Reduce/control abstractions to a level that approaches the EAFR. Improve channel habitat, landscape and broad ecological quality. This should reflect the improved flows due to the DAP I & II measures, and assist the river to become self-sustaining in the future and ultimately require minimal intervention.

Develop a long-term, catchment-wide, strategy for river rehabilitation in partnership with local communities, riparian owners, fishery associations etc. See 7.14. Implement a phased programme of river rehabilitation, addressing improvements to totally degraded sections, blighted urban areas with high aesthetic and public recreational potential and generally improving habitat throughout the river. Develop a FAP, that has at its heart, measures to create a sustainable fishery that maximises the biodiversity, recreation and socio-economic value of the mixed fishery potential. Everything should be delivered through the FAP, which also needs to link closely to the whole RDRS. Continue/extend re-introduction of Darent progeny fish in line with the EA Trout & Grayling Strategy. Implement limited actions to benefit individual species interests. The focus of the RDRS is to protect the good habitat and improve the rest for the benefit of all environmental interests of the Darent. However, some measures the help recovery of key species of chalk rivers may be required. Develop, a strategy for silt management and implement measures required to address the problems. Review and monitor achievements against targets. The Darent Strategy – Ecological Status & Factor Assessment leads to Actions Set within a Strategy

ACTION 3a. Establish, and issue, a clear policy statement on river maintenance that meets flood defence needs but minimises intervention.

This is the means whereby potentially good reaches get better for free, and some improvement occurs elsewhere. Implement immediately, but in consultation with interested groups and a series of public meetings/leaflet productions etc. to maximise acceptance and encourage good river management by owners and occupiers.

Contribution to National Chalk River BAP: 2.2, 2.3, 5, 13.1. Contribution to Area Chalk River BAP: Priority: imperative The Darent Strategy – river maintenance The Darent Strategy – Ecological Status & Factor Assessment leads to Actions Set within a Strategy ACTION 4a. Prepare a long-term, catchment-wide, programme of river rehabilitation in partnership with local communities, riparian owners, fishery associations etc.

Programme to address how, and where, phased improvements to urban and rural sections should be tackled, and set priorities. All improvements (e.g. for fisheries – see 7h-7j) would be included within this integrated programme. The programme would set measurable targets. Demonstration reaches are recommended to help build confidence, including ones in urban areas for full public enjoyment.

A key need is to develop a programme that includes both significant intervention for severely degraded sites that cannot recover naturally, and sites where minimal intervention is needed to assist natural recovery.

Contribution to National Chalk River BAP: 2.2. Contribution to Kent Area Chalk River BAP: Priority: imperative. The Darent Strategy – Ecological Status & Factor Assessment leads to Actions Set within a Strategy

ACTION 5a. Implement river rehabilitation according to the programme developed in 4a.

A rolling annual programme of works to be in place for 10 years, addressing highest priority, full consensus, areas first, and then areas where partner confidence required before support given.

Contribution to National Chalk River BAP: 2.3, 5. Contribution to Kent Area Chalk River BAP: Priority: very high. The Darent Strategy – RestorationExamples Prepared