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Southern Water and South East Water Tasks

Southern Water and South East Water Tasks

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Southern Water and South East Water Tasks

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  1. Southern Water and South East Water Tasks Conor Linstead

  2. Southern WaterWater Resource Investigations Two key elements: Little Stour and Wingham River Environmental Appraisal Report Kent and Sussex Hastings Water Resources Management Regional Studies evaluating desalination, effluent re-use & demand management options

  3. Little Stour & Wingham River Environmental Appraisal Report © Southern Water

  4. July 2006 March 2007 Nailbourne at Bourne Park (Photos: Alfred Gay. Made available under GNU Free Documentation License)

  5. Little Stour & Wingham River Environmental Appraisal Report Determined ecological status of each river reach Link status to factors that influence the ecology (flow, channel form, water quality, river management, abstraction etc…) Put into perspective the influence of flow and abstraction Suggest priorities for further investigation and inclusion in possible Action Plan

  6. Key Conclusions Natural flow characteristics are still the key determinant of the ecological communities Historic changes to channel morphology greatest impact on ecological communities esp. upper & lower Little Stour Wingham River Siltation has a significant effect on fish and invertebrates

  7. Key Conclusions Abstraction-induced low flows: Most sensitive reaches to abstraction are the lower Nailbourne and upper Little Stour reaches Abstraction-induced impacts are relatively minor on the Wingham because of very degraded physical habitat and the enriched water quality No impact on the ecology in the middle Nailbourne Abstraction reduces flows in the lower Little Stour reach, but probably has minor influence on the ecology Little is known about the flow regime of the upper Nailbourne.

  8. Kent and Sussex Hastings Water Resources Management Kent Thanet WRZ Kent Medway WRZ Sussex Hastings WRZ © Southern Water

  9. New water supply option appraisals Three broad categories of options: Desalination (marine and tidal) Effluent re-use Demand management and water efficiency options Phase 1: Option identification (61) & screening Phase 2: More detailed appraisal Phase 3: In-depth appraisal (ongoing)

  10. Desalination Options – Kent Thanet One option within Stour carried forward from Phase 1 Tidal site adjacent to a WWTW Use existing outfall (21Ml/d licenced) Phase 2 considered Evaluation of the yield improvement Engineering description of potential operation Technical risks Environmental designations Aquatic environmental impacts Planning assessment

  11. Effluent reuse – Kent Thanet One option with the Stour carried forward from Phase 1 Transfer of 18Ml/d outflow from WWTW to support flows within the Stour upstream of water supply works Phase 2 considered: Aquatic environmental impacts Environmental and planning assessment Technical and engineering issues Additional tertiary treatment New pipework

  12. Demand management – Kent Thanet Phase 2 options considered: Increased household metering Rising block tariff Leakage reduction Combined household water efficiency options Combined non-household water efficiency options

  13. Demand management © Southern Water

  14. New water supply option appraisals Phase 3 In-depth appraisal of these options on-going Evaluating the Kent Thanet WRZ options in the context of the other WRZs

  15. South East Water investigations Two major studies running from 2005 to 2010: Great Stour and Upper Great Stour Upper Great Stour Abstraction focused on small number of major sources Can larger number of smaller sources deliver the same abstraction levels with reduced impact? Consider future demand and climate change Great Stour explore the possibility that abstraction is impacting on the flow regime in the reach between Wye and Thanington Phase 1 scoping studies, Phase 2 investigations

  16. Upper Great Stour Investigations – Phase 2 Focus on understanding hydrology of the Hothfield Bogs Period of monitoring groundwater levels against rainfall and PWS abstractions Geological modelling Surveys of hydrochemistry of headwater springs, sites around Hothfield Common SSSI Ground truthing of the soils and geology data for the Hothfield Bog NVC surveys of Bogs 1-4 and margins

  17. Upper Great Stour Investigations – Phase 2 Conclusions Geological modelling confirmed the site is underlain by the Folkestone Formation which provides groundwater seepages Bog 4 within Hothfield common confirmed to rely on ground water input (fen habitat) The areas of influence associated with groundwater abstractions are not considered likely to impact on Hothfield Common SSSI Suggest that there is sufficient recharge to the aquifer to feed the demands of Bog 4 as well as fully licenced abstraction

  18. Great Stour Investigations – Phase 2 Review of groundwater level monitoring network and equipping key wells with water level recording equipment Use geological maps and air photographs to reduce uncertainty of gravel distribution Monitor groundwater levels and recorded flows against abstraction rates over a 12 month period Develop conceptual understanding and report results and interpretation Study ongoing

  19. Putting the Work into Context Confirms importance of simultaneously pursuing water quality and water quantity approaches to improving ecological status While current impacts of abstractions are limited, protecting future abstractions requires water quality and habitat to be addressed WFD targets on ecological status may limit volume of abstractions in situations of poor water quality Limitations imposed by climate change Evidence base for choosing top-down vs. bottom-up (catchment-based) solutions Targeted water efficiency advice vs. capital projects (effluent reuse etc) On-farm advice vs. End-of-pipe water treatment