Draft SE Plan Examination in Public Data Session Water

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Draft SE Plan Examination in PublicData Session
- Water

• October 17th
• David Howarth
• Strategic Environmental Planning Manager
• Environment Agency

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Water Resources

• Water Resources Planning
• Some concepts
• The scenarios
• Conclusions

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Water Resources Planning in England and Wales

• Environment Agency Water Resources Strategies -
  high level framework (1994, 2001)
• Water Company Water Resources Plans 1999, 2004,
  2009
• Investment needs identified in WRP part of
  Periodic Review submission to Ofwat

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Demand Forecasting
Leakage
Non-household
Household
T1
T2
2026
2006
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Headroom
Demand headroom
Water volume
Demand
Deployable Output
T1
T2
T2
T1
Time
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Water Resources Zones
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Water Resources Modelling

• Is there enough water to support growth?
• Water Resources in the South East Group -
  Environment Agency with water companies (x 8),
  English Nature, Ofwat, Assembly
• Contribution throughout preparation of Plan
• Scenarios developed and modelled - using water
  company demand forecasts as base data

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Water Resources Modelling

• Housing
• Scale and distribution in SE Plan - 28,900 p.a.
• Up to 40,000 dwellings p.a. pro rata
• Water Efficiency
• 8, 21 and 47 above standard build
• Resources
• No new water resources beyond 2010 baseline
• Continued development of resources to 2030
  further
• Integrated better use of existing resources
• At 2016 and 2026

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Water Resources Modelling

• Context
• Regional demand 2509 Ml/d (inc. target
  headroom)
• Per capita consumption 160-170 l/h/day (highest
  in UK)
• Current reliable supplies 2703 Ml/d
• SE Plan growth adds 299 Ml/d to demand 2025/26
• Sustainability Reductions
• To protect environment assumed at 112 Ml/d
• Climate Change
• Allowance of 80-100 Ml/d

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The Modelling

• Simple spreadsheet model
• Set the growth rate (retain water co. occupancy
  and per capita consumption)
• Set the level of water efficiency
• Baseline, Further or Integrated Resources

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Climate change
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Water Resources supply-demand balance Baseline
2006
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Water resources Supply-demand balance 2016
baseline resources, no extra efficiency, 28,900
dwellings pa
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Water resources supply-demand balance 2026
baseline resources, no extra efficiency, 28,900
dwellings pa
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Water resources supply-demand balance 2016
Further resources, 8 efficiency, 28,900
dwellings pa
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Water resources supply-demand balance
2026 Further resources, 8 efficiency, 28,900
dwellings pa
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Water resources supply-demand balance
2016 Further resources, 8 efficiency, 40,000
dwellings pa
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Water resources supply-demand balance
2026 Further resources, 8 efficiency, 40,000
dwellings pa
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Water resources supply-demand balance
2026 Integrated approach, 47 efficiency new
homes 21 in 20 existing stock
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Illustrative water savings (21) Source EA and
Southern Water, 2004

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Conclusions

• Scale and distribution of growth in South East
  Plan can be accommodated by a combination of
  water efficiency and resource development
• Risks associated with efficiency and new
  resources
• Higher housing numbers cause deficits in some
  areas from 2016 unless higher water efficiency
  achieved (21)
• Need for long-term planning and enabling
  mechanisms

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Water Quality

• Current WQ in the South East
• Water Quality and growth
• Water Quality and planning
• The Modelling
• Conclusions

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General Quality Assessment water quality
chemistry for SE rivers
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The Challenge

• More houses more sewage effluent
• Need to protect sensitive receiving waters
• Sewage treatment to the highest standards can
  still produce a high polluting load if the volume
  is high enough and there is insufficient dilution

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Why is this important?

• River Quality Objectives
• EU Directives
• Drinking water supplies
• Ecology/biodiversity
• Amenity/recreation

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Water Quality and Planning
PPG 23 (Pollution Control) states Planning
Authorities should work on the assumption that
the relevant pollution control regime will be
properly applied and enforced
The planning and pollution control systems are
considered to be complementary and close
co-operation can help ensure that the common
objective of sustainable development is met
effectively and efficiently Environment Overview
and Scrutiny Committee 2002
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The Process

• 523 Sewage Treatment Works - initial screening -
  67 for further analysis
• Mathematical models (SIMCAT) to examine impact of
  projected housing numbers (based on Policy H1)
• Will standards required be in excess of Best
  Available Techniques (BAT) to achieve the
  Environmental Quality Standard (EQS)?
• If so, how many houses can be built within that
  constraint?
• For constrained works assess likelihood of that
  constraint being reached by 2026

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Environmental Quality Standards (EQS)
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Best Available Techniques

• Best Available Techniques (BAT) are defined by EC
  Directive 96/61 as 'the most effective and
  advanced stage in the development of activities
  and their methods of operation which indicates
  the practicable suitability of particular
  techniques for providing the basis for emission
  limit values designed to prevent, and where that
  is not practicable, generally to reduce the
  emissions and the impact on the environment as a
  whole'.

In other words..Best Practice
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Best available techniques emission standards

• BOD5 5mg/l (95ile)
• Ammonia N 1 mg/l (95ile)
• Total Nitrogen N 10mg/l (annual average)
• Total phosphorus P 1mg/l (annual average)

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Environmental Quality Standards (EQS) below BAT
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Limited extra development
Discharge at BAT
quality EQS Target
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Limited extra development
Discharge at BAT
quality EQS Target
Current Consent
Maximum
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Limited extra development
Discharge at BAT
quality EQS Target
Current Consent
Maximum
Actual
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Limited extra development
Discharge at BAT
quality EQS Target
Current Consent
Consent
Maximum
Actual
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Limited extra development
Discharge at BAT
quality EQS Target
Current Consent
Consent
Maximum
Actual
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Limited extra development
Discharge at BAT
quality EQS Target
Current Consent
Actual
Maximum
Consent
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(No Transcript)
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STWs - limits on additional housing
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Next phase of work

• Assess whether there may be engineering solutions
  in the 7 catchments, e.g. discharge effluent to
  another river or to ground, and at what cost
• Further studies for Blackwater catchment
  (unidentified ammonia)
• Integrated water cycle studies at Basingstoke
  and Aylesbury - results in time for EiP
  sub-regional studies

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Future uncertainties

• Water Framework Directive
• Habitats Directive
• Government action on water efficiency
• Behaviour change
• Best Available Techniques