Course 5
Water Demand Measures
Teacher
Saroj Sharma
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s.sharma@unesco-ihe.org
About Saroj Sharma
Saroj Kumar Sharma graduated in Civil Engineering with distinction in
1988 (M.R.Engineering College, University of Rajasthan, India),
completed his MSc in Sanitary Engineering with distinction in 1997
(IHE Delft, The Netherlands) and PhD in Groundwater Treatment in
2001 (Wageningen University and IHE Delft, The Netherlands). He is
specialized in water supply engineering - water quality, treatment and
distribution.
He has 19 years of professional and academic experience in planning,
design, implementation, and operation and maintenance of urban,
semi-urban and community-based rural water supply projects. He has
worked with several government agencies, international consultants
and donors (UNICEF, WHO, ADB, WB) in various water supply
projects in different parts of the world.
His teaching and research interests are in the field of physicochemical
treatment processes (filtration and adsorption based processes),
natural treatment systems (bank filtration and soil aquifer treatment),
water transport and distribution (water loss management, urban water
demand management, corrosion of water pipes) and decentralized
water supply systems for small towns and urban poor areas.
http://www.unesco-ihe.org/iu/staffmember/roj
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Contents
 Introduction
 Urban water demand management measures
 Case studies
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Part A
INTRODUCTION
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Traditional Water Supply Management



Traditional supply driven water management
- Water needs are “requirements” that must be met
and not the “demands” that are changeable.
- New facilities and structures are developed using
available sources to meet perceived “increasing”
water needs.
Traditional approach has led to over-use of the
resources, over-capitalization, pollution and other
problems of varying severity.
Old paradigm of designing water supply with little
attention to demand determinants, pricing structures
and financial policies is not sustainable.
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From water supply management (WSM)
to water demand management (WDM)
 WDM approach places water demands themselves, not
structural solutions, at the centre of concern.
 WDM recommends the development of large, capital
intensive structures only after other possible options for
lowering or mitigating the proposed demands have been
fully analyzed.
 WDM and conservation represent the cheapest form of
easily available water. Particularly in the areas where
additional demands are being placed on water resources
which are already stretched to their limit.
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What is Water Demand Management?
Water demand management (WDM) refers to any socially
beneficial action that reduces or modifies average or peak
water withdrawals or consumption consistent with protection or
enhancement of water quality.
WDM can be defined as a strategy to improve efficiency and
sustainable use of water resources taking into account
economic, social and environmental considerations.
WDM corresponds to use of price, quantitative restrictions and
other devices to limit the demand of water.
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Benefits of WDM
 Reduces water demands (30% - 50%) with no deterioration in life
style or service level.
 Significantly reduces capital requirements for expansion of water
supply and lowers operating costs (particularly chemicals and
energy)
 Reduces generation of pollutants, and therefore the requirements
for new or expanded wastewater treatment systems.
 Facilitates expansion of the coverage of available fund
 Enhances the development and adoption of new technologies.
 Leads to financially sustainable water systems
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Part B
WATER DEMAND MEASURES
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Water Demand Management Measures
WDM relies upon a range of measures (tools and techniques)
which can be divided into



Economic
Socio-political, and
Structural and operational
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Economic Measures
Economic techniques depend on

Incentives such as rebates, tax credits and

Disincentives such as real cost, penalties, fines
Example: Realistic Water Pricing

A direct means of controlling water demand and
generating revenues to cover costs

Should be complementary to other measures of
water demand management
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Socio-political Measures
 Policies and Laws
 Economic policies, government regulations, standards on
appliance redesign and marketing:
− policy to promote water saving devices
− encouraging water savings in industries
 Effective public/stakeholder education and awareness measures
 Wise use of water; direct restrictions on use
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Structural and Operational Measures
Structural and operational measures are used to achieve
better control over water demand.
- metering, retrofitting, controlling flow (rationing)
and recycling
- reduction of UFW, leakage detection and repair
- use of water efficient devices
- water use restrictions during periods of water
shortages
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Approaches for Water Demand Management





Increase system efficiency
Increase end use efficiency
Promoting distributed sources of supply
Substitute resource use
Improve the market on resource usage
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Demand Management Measures
 Increase system efficiency
 No change in usage, but change in system operation
 Leak detection and repair, pressure reduction
 Increase end use efficiency
 Less resource use by consumers by using water
advertising, education and use of water efficient devices (low
volume flush, shower heads, dish washer, washing machine etc)
 More efficient watering of public open spaces
 Water efficiency in the planning, design and construction of
homes and buildings
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Demand Management Measures
 Promoting distributed sources of supply
 Provide service via local resource not being used
 encourage rainwater use and grey-water reuse
 Substitute resource use
 Provide same service without resource use
 Waterless sanitation, low water- use garden plants and shrubs,
plants adapted to local rain fall
 Improve the market on resource usage
 inform consumers about full cost of resource
 full cost pricing, universal metering, information on impact of
excessive water use
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Reduction and Control of Unaccountedfor Water
Reduction and Control of UFW

Substantial savings can be achieved and requirement
of extension water supply facilities can be avoided or
minimised by reducing unaccounted-for water.
(specifically leakage detection and control)

By reducing UFW water agency will be in better
financial situation and will be stronger position to
achieve its financial self-sufficiency and long term
sustainability.

A low rate of unaccounted-for water is one of the
best overall indicators that a water utility is successful.
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What is Unaccounted-For-Water?
Definition
Unaccounted-for water (UFW) represents the difference
between "net production" (the volume of water delivered into
a network) and "consumption" (the volume of water that can
be accounted for by legitimate consumption, whether
metered or not).
UFW = “net production” – “legitimate consumption”
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Non-Revenue Water
Non-revenue water (NRW) represents the difference between
the volume of water delivered into a network and billed
authorized consumption.
NRW = “Net production” – “Revenue water”
= UFW + water which is accounted for, but no revenue is
collected (unbilled authorized consumption).
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Components of Unaccounted-For Water
Unaccounted-for water
Physical loss
(Real loss)
Commercial loss
(Apparent loss)
Pipe breaks and leaks
Metering Errors
Storage overflows
Water Theft
House connection leaks
Billing Anomalies
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Standard Terminologies
Authorised
Consumption
System
Input
Volume
Billed
Authorised
Consumption
Unbilled
Authorised
Consumptiion
Apparent
Losses
Water Losses
Real Losses
Source: IWA (2000)
Billed Metered
Consumption (including
water exported)
Revenue
Water
Billed Unmetered
consumption
Unbilled Metered
Consumption
Unbilled Unmetered
Consumption
Unauthorised
Consumption
Metering Inaccuracies
Leakage on Transmission
and/or Distribution Mains
Leakage and Overflows at
Utility’s Storage Tank
NonRevenue
Water
Leakage on Service
Connections up to point of
Customer Metering
All quantities in m3/year
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Four components of an active real loss management program
More efficient
leak detection
Existing real losses
Economic
Improved
response time
for leak repair
level
Unavoidable
real losses
Improved system
maintenance,
replacement,
rehabilitation
Pressure
management
and level control
Source: Thornton (2002)
Four components of an active apparent loss management program
Reduction of
meter error by
 Testing,
 Sizing
 Replacement
Existing apparent losses
Reduction of theft by
 Education
 Legal action
 Prepay measures
 Pressure limitation
 Flow control
Economic
level
Unavoidable
apparent
losses
Reduction of
computer error by
 Auditing
 Checking
 Routine analysis
 Upgrade
Reduction of
human error
 Training
 Standardizing
 Reporting
 Auditing
Source: Thornton (2002)
Part c
CASE STUDIES
Case Study: Singapore (1)
Limited water resources, importing water from Malaysia
Strong emphasis on Water Conservation as well as
Management of Water Distribution System
Water Demand Management Approach

Keeping unaccounted-for water low

Conservation in customers’ premises

Tariffs and use of economic incentives and
disincentives
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Case Study: Singapore (2)

Keeping unaccounted-for water low
leak detection and repair, mains replacement
and rehabilitation, minimising illegal connection

Conservation in customers’ premises
water saving devices, promoting use of other sources
(rain water, sea water), encouraging water reuse,
consumer education

Tariffs and use of economic incentives and
disincentives
- rates reviewed periodically, rate structured to
encourage conservation
only approved pipe and fittings are allowed to be used
in water supply system
water service works are done by licensed workers only
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Evolution of UFW in Singapore (1989-1999)
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10.6
10
9.5
UFW (%)
7.7
8
6
6.7
6.4
6.0
6.2
5.9
4.9
4.7
5.1
4
2
0
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Source: Yepes (1995); PUB Singapore (2001)
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Singapore - Volume of Water Sold and Revenues (1994)
Consumer
Percent of
Percent of Sales
Relative Tariff
Volume
Residential
47.3
40.3
0.85
Commercial and
Industrial
32.0
47.1
1.47
Government
19.9
10.6
0.53
Shipping
0.8
2.0
2.50
100%
100%
1.00
= 456 Mm3
= $US 237 million
= $US 0.52/m3
Total
Source: Yepes (1995)
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Case Study: Rous Regional WDM Program
New South Wales, Australia – Population 70000
Demand management program included the following

Pricing and billing reform

Leakage detection and repair

Rebates & give-aways for water efficient shower heads

Point of sale rebate for front loading washing machines

Discounted residential retrofit

Free water audit for non-residential customers

A water efficient demonstration house and garden

Effluent reuse in a new village

A school education program
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Case Study: Brittany, France
 A major pilot project in 7 cities of Brittany, France
[Brest, Lorient, Pontivy, Quinter, Rennes, Morlaix (St-
Martin-des-Champs) and Vannes] (total population – 800,
000)
 Project activities
- Information campaign (users and professionals);
- Letters to domestic users;
- Tests & installation of various water-saving devices
- Investigations of leakage in the public distribution
system and in private households.
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Water Savings in Seven Pilot Cities in Brittany, France
Source: Sustainable Water Use in Europe (EEA 2001)
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Case Study: Decreasing Network Losses in Zurich,
Switzerland
 Network monitoring and leakage control
- Annual inspection of at least 40 % of the network
 Regular network flushings & hydrant controls
- Around 10,000 hydrants are checked, flushed and
repaired biannually.
 Periodic area-wise network maintenance
- Valves, street surface boxes, signs, etc., are locally
inspected, cleaned, made accessible or restored.
 Periodic pressure surge measurements and stray current
measurements
- To maintain the up-to-date situation of performance
analysis
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Decreasing Network Losses in Zurich
 Specific water loss decreased from 0.57 m3/h/km in
1985 to 0.22 m3/h/km in 1995.
 Cost of maintenance operation
Component
Repairs
Man-hour
/km/year
5
Swiss Frank/
km/year
5000
Preventive
Maintenance
25
3000
Renewal
Total
25
55
15000
23000
Source: Sustainable Water Use in Europe (EEA 2001)
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Decreasing Network Losses in Zurich
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Losses (%)
10
8
6
4
2
0
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
Year
Source: Sustainable Water Use in Europe (EEA 2001)
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Case study – WDM in Boston, USA
 In Boston, impending costs of supplying water to the city led officials
to implement a Long Range Water Supply Program (LRWSP) to cut
down on water use.
 Between 1988 and 1993, LRWSP reduced the average daily
demand for water from 1.2 million to 0.9 million m3.
 The program focused on
- detecting and repairing leaks, metering, retrofitting
showerheads and toilets with more efficient technologies,
protecting water sources from pollution, and building support for the
program among city, residents through outreach and education.
 These reductions eliminated the need to develop new supplies -saving hundreds of millions of dollars--and the water system is
operating within its safe yield for the first time in 20 years (40).
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Reducing water demand in Sydney
364
329
http://www.sydneywater.com.au/html/AER2000/html/imp_water/demand_manag.htm
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Water Supply and Demand with and without Demand
Management
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Bibliography

ADB (1997) Second Water Utilities Data Book: Asian and Pacific
Region. Edited by McIntosh, A.C. and Yniguez, C.E. Asian
Development Bank.

Baumann, D. D., Boland, J.J. and Hanemann, W.M. (1998) Urban
Demand Management and Planning. McGraw-Hill Inc.

EEA (2001) Sustainable Water Use in Europe. European Environmental
Agency. www.eea.eu.int

OECD (1999) Household water pricing in OECD Countries.

Prasifka, D.W. (1994) Water Supply Planning. Krieger Publishing
Company, Florida, USA.

UK (1994) UK Water Industry: Managing Leakage. Interpreting
Measured Night Flows.

Yepes, G. (1995) Reduction of Unaccounted-for water: The job can be
done! ESD, World Bank.
Water
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Web Resources on Water Conservation
1.
Environmental agency UK – Save water
www.environment-agency.gov.uk
2.
Conserve Water – Melbourne Water Australia
http://conservewater.melbournewater.com.au
3.
Water Efficiency Clearing House - AWWA
www.waterwiser.org
4.
USEPA – Water Use Efficiency Program
www.epa.gov/owm/water-efficiency/
5.
Environment Canada
www.ec.gc.ca/water/en/manage/effic/e_weff.htm
6.
Public Utilities Board
http://www.pub.gov.sg
7.
Water Demand Management Forum
http://www.idrc.ca/waterdemand/
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