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Water Demand Management

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Water Demand Management UNIT 3 WDM Options and benefits Course map Outcomes By the end of this unit, you should be able to explain the costs and benefits of WDM, in ... – PowerPoint PPT presentation

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Title: Water Demand Management


1
Water Demand Management UNIT 3
WDM Options and benefits
2
Course map
3
Outcomes
  • By the end of this unit, you should be able to
  • explain the costs and benefits of WDM, in
    financial and social contexts
  • understand various demand projection methods, and
    the advantages and disadvantages of each
  • analyse to what extent WDM measures have been
    incorporated into demand scenarios

4
Outcomes
  • By the end of this unit, you should be able to
  • give a broad overview of various WDM measures
  • discuss each measure in detail and be able to
    select the most appropriate WDM measures for your
    MWSA
  • understand the need for measures to reduce UAL

5
Options and benefits
  • How does an MWSA decide on a way forward?
  • What means are available for evaluating WDM
    interventions against other strategies?
  • An MWSAs decision to opt for a particular WDM
    strategy or measure wont be a clear-cut choice

6
Options and benefits
  • Our focus
  • The costs and benefits of WDM
  • Ways of evaluating the future demand for water
  • Ways of deciding between the range of WDM options
    that are available

7
3.1 Costs and benefits
  • Consider the options for your MWSA
  • What are the costs and benefits?
  • What time horizon should be adopted?
  • Do organisations know about the WDM
    opportunities?
  • Which constraints need to be addressed before WDM
    is implemented?
  • WDM should be implemented when the benefits
    exceed the costs

8
3.1.1 Financial costs and benefits
  • Your MWSAs financial costs and revenues
  • determine economic performance
  • determine its degree of cost recovery
  • are key concerns

9
3.1.1 Financial costs and benefits
  • Categorise financial costs by
  • source of supply
  • type of demand intervention (e.g. WDM)
  • Determine net financial benefits or costs of WDM
    interventions compared to others
  • Financial cost-benefit analysis is required as
    part of a broader multi-criteria analysis

10
3.1.1 Financial costs and benefits
11
3.1.2 Social environmental costs and benefits
  • Government must consider social and environmental
    costs
  • Government and MWSA costs may differ, e.g.
  • UAL may not be a MWSA cost but is always a social
    cost
  • Water subsidies provide MWSA revenue but are a
    transfer cost in society

12
3.1.2 Social environmental costs and benefits
13
3.1.2 Social environmental costs and benefits
  • Comparing financial, social and environmental
    costs and benefits may show
  • Financial and social benefits. The WDM measure
    should be implemented immediately without
    government support.
  • Social benefit only. The WDM measure needs to be
    implemented with government support or
    regulation.
  • No social or financial benefit. Such a measure
    would normally not be implemented.

14
Example Standpipes and private connections
  • compares communal standpipes dispensing free
    water with the provision of private paid
    connections
  • examines social cost-benefit issues of equity,
    sustainability and water use efficiency
  • attempts to provide objective solutions that
    provide optimal social benefits at least cost

15
3.2 Demand projections and analysis
  • Projecting future water demand is part of regular
    planning activities
  • THEN demand projections were to ensure that a
    given quantity and quality of water was available
    over a specified period
  • NOWdemand projections become integral components
    of the decision-making cycle

16
3.2 Demand projections and analysis
  • Analyse
  • past/present water consumption
  • how this consumption might develop in future
  • when existing sources of supply may be exhausted
  • potential of WDM to reduce future demand

17
3.2.1.1 Urban users
  • Urban water users are
  • the largest sector of the customer base of many
    MWSAs
  • a mixture of domestic and productive users
  • described in Table 3

18
3.2.1.1 Urban users
  • Domestic users
  • Households using standpipes
  • Low-income households with own water connection
  • Medium-income households with own water
    connection
  • High-income households with own water connection

19
3.2.2 Demand monitoring and projections
  • Key determinants of domestic water consumption
  • Household income and size
  • Living conditions
  • Household plot size

20
3.2.2 Demand monitoring and projections
  • Key determinants of productive uses
  • Type of product and production process
  • Expected output
  • Employment/manpower levels
  • Technology employed

21
3.2.2 Demand monitoring and projections -
forecasting
  • Different methods
  • Different levels of accuracy
  • Require differing logistical inputs
  • These include
  • Judgemental analysis
  • Trend analysis
  • Component analysis
  • Regression analysis

22
3.2.2 Demand monitoring and projections -
forecasting
  • Suggested criteria for selection of method
    include
  • Consistency and transparency
  • Quality of the method
  • Incorporation and explanation of historical
    trends
  • Inclusion of historically neglected factors
  • Empirical validation
  • Acceptance of method

23
3.2.2 Demand monitoring and projections -
forecasting
Trend analysis results Figure 1 example
24
3.2.3 Demand monitoring and projections -
uncertainties
  • Any forecasting method is prone to uncertainty
    e.g.
  • Droughts/floods
  • Changes in macroeconomic conditions
  • Changes in health conditions (HIV/AIDS)
  • Changes in settlement patterns and migration
  • Projected impacts of new policies and programmes

25
3.2.3 Demand monitoring and projections -
uncertainties
  • Steps to be taken
  • Identify and incorporate into the forecasting
    process
  • Develop scenarios based on major uncertainties
  • Perform sensitivity analysis (e.g. Low, Medium
    and High population growth)
  • Validate forecasts or adjust them over time
  • Remember ignorance of uncertainties can lead to
    major inaccuracies

26
3.2.3 Demand monitoring and projections -
scenarios
27
3.2.3 Demand monitoring projections -
forecasting in Masvingo
28
3.2.3 Demand monitoring and projections - impacts
on timing
29
3.2.3 Demand monitoring and projections - impacts
on timing
30
3.2.3 Demand monitoring and projections - impacts
on timing
  • Important message
  • Use of demand forecasting and monitoring is of
    paramount importance to MWSAs
  • WDM measures have the potential to significantly
    defer augmentation schemes
  • Deferred schemes have other benefits like
  • Less wastewater is produced and therefore less
    treatment is needed
  • Less energy is used
  • Reduced alteration of natural water flow patterns

31
Activity
  • Can you think of any examples where dams or well
    fields have been prematurely built?
  • Which ones?
  • Why were they built, and what have the
    implications been?

32
3.3 Selecting the right WDM intervention
  • Broad spectrum of WDM interventions
  • Careful and consistent application
  • Maximise benefits
  • Phased approach to WDM
  • WDM plan and strategy

33
3.3.1 In selecting the right WDM intervention -
remember
  • Complementary and integrated measures are
    preferable
  • Awareness raising, training and campaigns are
    vital
  • Evaluation of WDM interventions
  • Choice of intervention must be informed by
    sustainability indicators and criteria

34
3.3.2 Selecting the right WDM intervention -
selection tools, methods, rules
  • Tools
  • Benefit-Cost Analysis (BCA)
  • Economic efficiency evaluation
  • Common indicators are the NPV, B/C ratio
  • Decision-making is based on WDM measures with
    positive NPVs

35
3.3.2 Selecting the right WDM intervention -
selection tools, methods, rules
  • Tools
  • Multi-Criteria Analysis (MCA)
  • Broader
  • Identification of positive and negative impacts
  • Quantification and ranking of impacts
  • Identification of selection criteria
  • Allocation of weights to criteria
  • Ranking of performance or scoring
  • Decision-making based on best performing measure

36
3.3.2.2 Selecting the right WDM intervention - US
EPA method
  • Recommended criteria
  • Economic
  • Social
  • Environmental
  • Contextual

37
3.3.2.3 Selecting the right WDM intervention -
DWAF RSA method
  • Integrated Least Cost Planning criteria
  • Social impacts
  • Economic impacts
  • Institutional impacts
  • Technical impacts
  • Environmental impacts
  • Risks

38
3.3.2.4 Selecting the right WDM intervention -
pragmatism
  • The 8020 Rule
  • Picking the low hanging fruit
  • WDM interventions that yield 80 of the desired
    results e.g. water savings, with 20 of the
    investment
  • Largest results with lowest effort, capacity,
    burden
  • Tangible immediate results (Watch out!)

39
3.4 WDM measures/options
  • 3.4.1 Technical options
  • 3.4.2 Financial options
  • 3.4.3 Policies, legislation and regulations
  • 3.4.4 Consumer service and public awareness

40
3.4.1 WDM measures/options -technical measures
  • Among the most tangible efforts to reduce
    inefficiencies
  • Easily appreciated by engineers and planners and
    understood by consumers
  • Results generally measurable and quantifiable
    (water and money saved)

41
3.4.1 WDM measures/options -technical measures
  • Aim to reduce UAL or UAW
  • Water losses due to leaks
  • Wastage among end-users
  • Illegal abstractions
  • UAL represents loss of revenue
  • Technical measures are not all about fixing
    leaking taps (Watch out!)

42
3.4.1 WDM measures/options -technical measures
levels of UAL
43
3.4.1 WDM measures/options -technical measures
  • Leak detection and repair
  • Passive and active leakage management
  • Pressure management
  • Metering all uses
  • Demarcation of supply area into zones and
    districts
  • Supply through one point?
  • Measuring Minimum Night Flows (MNF)

44
3.4.1 WDM measures/options -technical measures
  • Water audits
  • Water balances at zone boundaries
  • Water reaching end user
  • For inexplicable high losses, conduct MNF
    exercise
  • Supply through one point?
  • Measuring MNF

45
3.4.1 WDM measures/options -technical measures
  • Installation and maintenance of water meters
  • To promote effective billing
  • An essential requirement for water resources
    management
  • Provides an idea of the potential for WDM
  • Benefit-Cost analysis of metering is essential

46
3.4.1 WDM measures/options -technical measures
  • Water supply system maintenance
  • Anticipating failures
  • Predicting failures
  • Preventing failures
  • Detecting and correcting failures
  • Requires excellent record keeping, preferably an
    Engineering Infrastructure Management System
    (EIMS)

47
3.4.1 WDM measures/options -technical measures
  • Features of most EIMSs
  • Water loss and meter management
  • Customer service requests
  • Notification of pipe leaks
  • Hydraulic pressure and hydrant database
  • Work scheduling and maintenance
  • Asset register and stock inventor
  • Time keeping and cost accounting
  • NOT All EIMSs contribute to WDM (Watch out!)

48
3.4.1 WDM measures/options -technical measures
  • Types of maintenance
  • Routine preventative maintenance
  • Corrective preventative maintenance
  • Breakdown maintenance
  • Project maintenance

49
3.4.1 WDM measures/options -technical measures
  • Pressure management
  • Reduces water loss
  • Prolongs life span of pipe work
  • Recommended in areas with high losses
  • Recommendation 300 to 600 kPa, 150 kPa in
    low-cost areas
  • Consider fire fighting and peak demands

50
3.4.1 WDM measures/options -technical measures
Khayelitsha
  • Objective
  • Reduction of excessive pressure
  • Situation
  • 70 000 stands
  • Pressure 600 to 800 kPa
  • Very high losses
  • 80 sewage return flow

51
3.4.1 WDM measures/options -technical measures
Khayelitsha
  • Action
  • Installation of two pressure control points
  • Result
  • Flow reduction from
  • 2 500 to 1 800 m3/hour
  • 42 water savings
  • 27 Million Rands per year at a cost of 2.5
    Million Rands

52
Activity
  • Do you know the water pressure used by your MWSA?
  • What would be the water-saving potential of
    pressure reduction?
  • Record you answers for later use in your WDM
    implementation plan (Unit 4).

53
3.4.1.6 End user appliances, faucets and
retrofitting devices
  • Water saving devices
  • Low volume urinals
  • Waterless urinals and toilets
  • Low volume shower heads
  • Self-closing public taps
  • Size of toilet cisterns
  • Size of bath tubs
  • Water and energy efficient appliances
  • Washing machines
  • Dish washers
  • Water boilers

54
3.4.1.6 End user appliances, faucets and
retrofitting devices
  • Efficient garden irrigation systems
  • Micro sprinklers
  • Wise gardening (Xeriscape)
  • Indigenous versus exotic plants
  • Timing of garden irrigation

55
3.4.1.6 End user appliances, faucets and
retrofitting devices
  • Meter appliances
  • Prepayment meters
  • Use of sub-potable water
  • Reuse of grey water
  • Rain water harvesting

56
Summary
  • Technical options reduce inefficiencies
  • Increase best possible use of water
  • Have measurable and quantifiable results
  • BUT
  • MWSAs need to inform end users
  • Standards Associations need to regulate fittings
    and fixtures
  • Manufacturers and designers of fittings and
    fixtures must be aware of WDM

57
3.4.2 Financial options for WDM
  • Water as a public and economic good
  • Market forces in water supply
  • Types of financial incentives
  • Water subsidies
  • Water pricing or tariffs

58
3.4.2 Financial options for WDM
  • Water historically treated as a public good
  • No exclusion use of one does not adversely
    affect others
  • Paid from general tax revenues
  • Economic good
  • Proper pricing based on true costs (e.g. MOC)
  • What about social aspects?
  • Problems affordability and access to all
  • Solutions cross subsidisation, free lifeline
    entitlement

59
3.4.2 Financial options for WDM
  • Four issues in market forces and water
  • Competition among suppliers (including self
    providers)
  • Demand allocation
  • Price determination
  • Privatisation of suppliers
  • Water markets?

60
3.4.2 Financial options for WDM
  • Types of financial incentives
  • Water subsidies
  • Water tariffs
  • Others
  • Tax incentives
  • Property rights
  • Effluent charges
  • Special surcharges

61
3.4.2.1 Financial options for WDM - water
subsidies
  • Subsidies are common, but decreasing adoption
  • MWSA perspective
  • Subsidies are revenues and permit lower water
    tariffs
  • Decrease in subsidies forces MWSA to decrease
    revenues from end users

62
3.4.2.1 Financial options for WDM - water
subsidies
  • National perspective
  • Rising water costs require rising subsidies
  • Subsidies are justified on social grounds
    (affordability and access)
  • Growing opportunity costs of water subsidies
    (e.g. health care)

63
3.4.2.1 Financial options for WDM - water
subsidies
  • Environmental perspective
  • Encourage water wastage
  • Examples
  • A leakage in the yard of 20 m3/month would cost
    the end-user nothing if the water is free, 20 if
    the water costs 1/m3 but 100 if the water costs
    5/m3

64
3.4.2.1 Financial options for WDM - water
subsidies
  • Examples
  • Botswana (Selebi-Phikwe) A household with an
    income of P3 000/month that does not receive a
    water subsidy will consume 22 m3/month. However,
    water consumption for a household with the same
    income and access to a water subsidy will
    increase by 41 m3 to 63 m3/month.

65
3.4.2.1 Financial options for WDM - water tariffs
  • Common foundations for tariffs
  • Average historical supply costs
  • Replacement costs
  • Marginal supply costs
  • Marginal opportunity costs
  • Water tariff systems
  • Flat rate for certain period
  • Constant unit charge (e.g. 1000 Kwacha/m3)
  • Block or band unit system

66
3.4.2.2 Financial options for WDM -banded water
tariff example
67
3.4.2.2 Financial options for WDM - variations in
water tariffs
  • Tariff variations are found among
  • User groups
  • Areas
  • User bands
  • Issues
  • User groups productive compared to consumptive
    use
  • Areas how effective are water tariffs as a
    locational factor?
  • User bands free water? Cross-subsidisation

68
3.4.2.2 Financial options for WDM - impacts of
water tariffs as a WDM tool
  • MWSA
  • Direct water consumption and total revenues
  • Future delayed capital investments
  • Key variable price elasticity of demand for
    water or the slope of the demand curve

69
3.4.2.2 Financial options for WDM - impact of 10
tariff increase
  • Original consumption 100 m3 Price 1/m3

Water consumption Revenues/ costs
Pr. El -0.5 Price 1.1/m3 Cons 95 m3 Revenues 104.5
Pr. El. 1 Price 1.1/m3 Cons. 110 m3 Revenues 121
Pr. El. -2.0 Price 1.1/m3 Cons. 80 m3 Revenues 88
70
Activity
  • Update and correct pricing details for your
    country and MWSA
  • Discuss and determine required changes in pricing
    mechanisms for your MWSA

71
3.4.2.2 Financial options for WDM - effect of
rising tariffs on consumption
72
3.4.2 Financial options for WDM - price
elasticity of demand
  • According to HR Wallingford Handbook (2003)
  • The elasticity of water consumption is generally
    low.
  • The price elasticity is greater when the price is
    higher.
  • In the household sector, the price elasticity
    varies between -0.15 and -0.70.
  • With respect to drinking water the demand-price
    relation will never be elastic (E lt-1).
  • In the industrial sector, the majority of
    estimates are in the range of -0.45 to -1.37.

73
3.4.2 Remarks
  • The effectiveness of tariffs for WDM depend on
    price elasticity
  • Subsidies lower tariffs and may discourage WDM
  • Other economic instruments need to be used (e.g.
    tax relief, property rights)

74
3.4.3 Policies, legislation and regulations
  • IWRM and WDM policies
  • Local plans and bylaws
  • Regional/town planning
  • Municipal economic development

75
3.4.3 Policies, legislation and regulations -
policy reforms and WDM
76
3.4.3 Policies, legislation and regulations -
local plans, bylaws and development
  • Bylaws for e.g. gardening, swimming pools, alien
    species
  • Regulation against wastage
  • Drought measures
  • Plot size regulations
  • Regulations for industrial development in line
    with water conditions

77
3.4.4 Consumer service and public awareness
  • 3.4.4.1 WDM and participation of end users
  • 3.4.4.2 Service related measures

78
3.4.4 Consumer service and public awareness -
participation of end users
  • WDM is 50 social engineering?
  • It is about behavior change
  • Involvement of users from planning through to
    implementation stage
  • Effective communication with users is essential

79
3.4.4 Consumer service and public awareness -
participation of end users
  • Example
  • Recent work on price elasticity in Gaborone
    showed that most domestic users have a general
    perception that water is expensive, but
  • they do not know that the MWSAs have annually
    increased the tariffs by an average of 17  over
    the last five years, and
  • they do not know how much they pay per month.
  • It is not surprising therefore that such users do
    not respond to price changes!

80
3.4.4 Consumer service and public awareness -
innovative and informative water billing
  • Water bills are the most important communication
    tool between an MWSA and the end-user
  • They need to be
  • Accurate
  • Sent out timely and regularly
  • Need for innovation and sophistication
  • Presentation of information
  • Management Information System

81
3.4.4 Consumer service and public awareness -
innovative and informative water billing, EDAMs
and Hermanus example
82
3.4.4 Consumer service and public awareness -
campaigns
  • Target specific audiences
  • Boost public support
  • Continuous
  • Require a sizable budget
  • These may include
  • International/National Water Weeks
  • Competitions on water use efficiency
  • Articles or advertisements in newspapers or
    popular magazines
  • Water-wise posters

83
3.4.4 Consumer service and public awareness -
campaigns
  • These may include
  • Pamphlets
  • Stickers, T-shirts, caps
  • Sponsorship of appropriate events
  • More examples and guidelines are provided in two
    GWP publications

84
3.4.4 Consumer service and public awareness
campaigns examples of material
85
3.4.5 Education and training in WDM
  • Target specific audiences
  • Might not necessarily be on WDM but containing
    relevant aspects
  • This may include
  • Incorporation of WDM in schools curricula
    (primary and secondary education)
  • Tailor-made tertiary training courses (e.g.
    IUCNs Guideline Training Module for MWSAs and
    IUCN-WaterNet Module)
  • Education at home
  • Education in the workplace

86
3.4.5 Education and training in WDM
  • Some remarks
  • Training and education can be costly
  • Public and private funding
  • Partnerships and co-operation between training
    institutes, donors, employers and employees is
    essential
  • It must be continuous, provide feedback and be
    easily replicated
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