PI’s Targets for Water Distribution€¦ · Coherence in Setting Water Loss PI’s Targets for Water Distribution Alexandru ALDEA, Anton ANTON Technical University of Civil Engineering,

Coherence in Setting Water Loss

PI’s Targets for Water Distribution

A l e x a n d r u A L D E A , A n t o n A N TO N

Te c h n i c a l U n i ve r s i t y o f C i v i l

E n g i n e e r i n g , B u c h a r e s t

Performance Indicators

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INTRODUCTION

IWA Water Balance Terminology

Non-Revenue Water

Billed Authorized

ConsumptionRevenue Water

Billed Metered Consumption

Billed Unmetered Consumption

Unauthorized Consumption

System Input

Volume

Authorized

Consumption

Water Losses

Apparent losses

Real Losses

Meters error and data handling

Unbilled Authorized

Consumption

Unbilled Metered Consumption

Unbilled Unmetered

Consumption


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INTRODUCTION

SIV System Input Volume

NRW Non-Revenue Water

LKN Real Losses per network length

ILI Infrastructure Leakage Index

𝑈𝐴𝑅𝐿 = 18𝑥𝐿𝑚

𝑁𝑐+ 0.8 + 0.025 ∗ 𝐿𝑝 ∗ 𝑃


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WATER SUPPLY PERFORMANCE INDICATORS

Choosing KPIs Careful process, there are common misuse cases

• the overconfidence in the available data can result in severe over- or

underestimations of the variables

• the NRW indicator proved to be inadequate as a target PI because doesn’t offer

detailed information on the real problems

• the choice of different benchmarking matrix can yields different strategies, so it is

recommended to carefully chose the benchmarking matrix and then restrain to change it

• the choice of assessing the performance indicators should follow this simple rule:

financial indicators when dealing with a water utility / subsidiary and operational indicators

when dealing with the actual distribution network.

Aldea, A., Anton, A.,”On water loss performance indicators –

relevance and inconsistencies”, WaterLoss 2016

PERFORMANCE INDICATORS – Overconfidence of data and forecast

CASE STUDY – UTILITY C

The difference between the initial data and the actual data was quite huge:

• 3400 connections wrongly estimated in the initial data and only 405 connections in reality.

• One more remark for this case: the system input volume dropped by 40% and the billed consumption

dropped by 25% compared to the initial situation in 2008.

FS IWA Performance indicator UM Initial Actual Target

2.5.1 A21 Total non-revenue water m3/day 2500 316.55 1400

2.5.2 Fi46 Non-revenue water % 54% 30.18% 45%

2.5.3 A19 Real losses in the network m3/day 1700 172.91 1000

2.5.5 Op27 Real losses per connection l/conn./day 114 426.94 103

2.5.8 Op29 ILI 3 7.84 3

PERFORMANCE INDICATORS - UTILITY C

PERFORMANCE INDICATORS – ILI vs. NRW as % of SIV

Romania has 42 large water utilities designated as Regional Water Operators

• Each Regional Operator comprises several administrative branches, varying from 1 to approx. 50 small utilities (depending on each individual branch)

• Every Regional Operator is administered by the local county council which owns 51% to 100% of the shares

Case study – the Regional Operator manage 5 separate water supply systems

• the largest supply systems consists of 76 water networks

CASE STUDY – REGIONAL OPERATOR


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•As expected, no correlation between ILI and NRW (% of SIV)

• low ILI values and high NRW(%) values for small new networks (due to

low connection rate)

• very high ILI values for the larger networks (mainly due to high number

of blocs of flats)

• Inaccuracies due to rough estimations of the Average Pressure

•Need for more reliable data and measurements in order to explain all the

anomalies


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Case of % of SIV for new small water networks

•Very low connection rate

• Very low consumption per capita (or connection)

• Need of purging because of low velocities and consequently greater

water age in pipes

•All these suggests that the figures for NRW as % of SIV could be very

high, but perfectly acceptable due to the specific situation


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Case of ILI for networks with high extension length

•The network doesn’t benefits from rehabilitation works (or only in very

small % of existing pipe length)

• The network is heavily extended in order to supply a larger area

•All these will indicates very low figures for ILI, but in reality little or

no measures were taken in order to reduce the physical losses


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COMPARISON CRITERIA – Are we comparing the “right” entities?

“Similar” systems In this respect the following information was assessed for

more than 30 water supply systems in Romania

• the density of connections (connections/network length)

• the ratio between inactive and active connections

• the ratio between mains length and distribution length

• the annual authorized consumption profile (only were multi-

annual data was available)

• the consumption per capita (in order to compensate for

different connection diameters)


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EXAMPLES

Water network

before and after

EU funded

projects

Initial

network

Initial

network

Can be applied also for the same system over a

period of time, in order to determine if the network

characteristics and behavior changed significantly.

COMPARISON CRITERIA – Are we comparing the “right” entities?


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COMPARISON CRITERIA

Density of connections

Double purpose :

-Grouping criteria

- “Red flag”

indicator

0

5000

10000

15000

20000

25000

30000

0 100 200 300 400 500 600 700 800

No.

of c

onne

ctio

ns

Network Length (km)

Overview : density of No. of connections / km

61

59

101

47101

46

46

29

43

14

2728

223033

2663

34

171117

3722

31

2433

0

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70 80

No.

of c

onne

ctio

ns

Network Length (km)


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COMPARISON CRITERIA

Consumption per capita

Outcome:

- different grouping

-Another “Red flag”

indicator

- Comparison with

standard values of

110 l/p/d and 80

l/p/d

0

50

100

150

200

250

300

0

20

40

60

80

100

120

Co

nsu

mp

tio

n p

er

cap

ita

(l/p

/day

)

De

nsi

ty o

f co

nn

ect

ion

s

Supply system grouping : density of connections vs. consumption per capita criteria

Density of connections Consumption per capita


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COMPARISON CRITERIA

Further investigations Generally speaking, the very low values (around 40 – 50

l/person/day) characterize the new small networks, where either not

all citizens were connected to the water supply or they still had an

alternative water source from private wells.

This situation emphasizes the need to clearly estimate the ratio

between inactive and active connections and also to

differentiate between an “urban” and a “rural” system.

The detailed investigations also revealed a very low degree of

accuracy of the billed consumption records, which had a direct

impact on the water balance itself and consequently on the PIs.


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CONCLUSIONS

Only two primary criteria where actually used in the end for the grouping of

the systems: density of connections and the consumption per capita.

The other three criteria served as secondary information in order to validate

or explain the results.

All of the criteria served in the end two purposes:

• a primary purpose for objectively choosing the system to be compared

•a secondary purpose of warning against corrupt or dubious data.


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THANK YOU FOR YOUR ATTENTION

Documents

PI’s Targets for Water Distribution€¦ · Coherence in Setting Water Loss PI’s Targets for Water Distribution Alexandru ALDEA, Anton ANTON Technical University of Civil Engineering,