Abstract
Water is a scarce natural resource and is predominantly involved in the day to day activities of
human life. Water losses in Water Distribution Systems (WDS) are the major challenge faced
by water utilities around the globe. According to the World Bank, about 40% of the world’s
population survives in areas with moderate to high water stress conditions and further
estimations are that by 2025, two-thirds of the world’s population - about 5.5 billion people
will live in areas facing water stress, therefore, integrated initiatives on water loss control are
key to sustaining the future generations. Water losses has an adverse effect on public health
and safety, economic viability and sustainable development. Various literature sources proves
that it cots global water utilities scales of billions of dollars to provide water to various endusers,
therefore it is imperative that this scares limited resources is economically managed in
an integrated manner. Scientifically, it has be proven that water leakage often leads to customer
service interruption and results in customer service complaints to water managers. Some of the
compounding problems of water losses are due to ageing water supply infrastructure, low
infrastructure investment, rapid population growth, poor speed and quality of repairs, poor
institutional governance, water theft through illegal connection, and even the dire consequence
of exponential climate change. These unprecedented conditions makes enough contention for
urban water managers to seriously implement without failure water loss reduction strategies.
While the above preliminary abstract findings exist, various approaches are being practiced
world-wide to curb water losses, including amongst others, pressure management, pipe
upgrades, meter management, operations and maintenance and etc. The present research
proposes an Integrated water loss management model (IWLMM) to manage water losses and
sustain the supply of water thereof. The sub-objectives involved in the study comprises of basic
hydraulic modelling on the conservation of mass and conservation of energy, where the
following activities were performed; (i) quantifying the transient flows in to DMAs or water
supply zones, (ii) assessment of infrastructural losses for both apparent and real losses as well
as (iii) domestic background leakages. Further, the scientific principles of conservation of
energy and mass in this study were based on the following hydraulic techniques of (i) the
Orifice method, (ii) Background and burst estimate (BABE) method, (iii) Fixed and Variable
Area Discharge (FAVAD) and (iv) Minimum Night Flow (MNF) techniques.
In order to integrate the economic level of water losses (ELWL), the socio-economic analysis
in the urban township in Alexandra- of Johannesburg, in South Africa was performed as a case
PhD: RP Mathye: 809901464 i i i
study. The ELWL methodology meant the application of a socio-technical water loss control
approach based on cost-benefit analysis (CBA) with the inclusion of developed; (i) Social
Capital Investment Intervention Strategy (SCIIS), (ii) Capital Expenditure on Infrastructure
renewal (CAPEX) and (iii) Operations and Maintenance costs. The socio-economic approach
used financial modelling such as (i) marginal cost of capital (MCC), (ii) net present value ratio
(NPV), (iii) weighted average cost of capital (WACC) as well as risk parameter of coefficient
of variance (CV). Further, the outranking preference system through PROMETHEE II and DSight
software was used to evaluate the strategic divergence of decision makers (DMs)’
preference of water loss objectives in water loss reduction. A Multi Criteria Decision Analysis
(MCDA) method used the decision maker’s strategic preference outcome whereby to develop
an integrated water loss management improvement project (IWLMIP), which was later used as
a model for pre-testing on site for final IWLMM solution.
Finally, the IWLMIP was practically tested in a real case setting where (i) visual condition
assessment was done to households, (ii) questionnaire data sampling of 61 professional in the
water utility’s water loss management as well as 361 public participants. Analysis for public
and professional respondents and their water loss practical perceptivity was validated through
the qualitative statistical package for the social sciences (SPSS) tool which is an integrated
principal component analysis (PCA) technique and verified through a MATLAB algorithm
process. The results of the Integrated Water Loss Management model (IWLMM) through
multi-criteria decision support tool for operations and maintenance MCSDT-OM implies that
sound (i) technical capability, (ii) financial objective, (iii) socio-economic outcomes along with
(iv) institutional governance are necessary to curb water losses in a socio-economic urban
township. The outcomes will assist water managers, policy makers and water utility
departments of developing countries to frame optimal water management strategies. In
summary the following were achieved through each sub-objective of the study.
1. The existing challenges in Alexandra are high population, high water consumption
exacerbated by ageing infrastructure and exponential background domestic leakages
from households (HH). The results showed that against the SIV, MNF was measured
at 14.01 % while NRW was 95.21% measured at a flow rate of 196.39 l/s and a linear
regression value (R2) of 0.096. Results further show that with no change in behavior of
the customers and non-improvement of current water loss reduction strategy, NRW will
100% by 2025, equaling the annual SIV at a population growth rate of 2.5% per annual.
PhD: RP Mathye: 809901464 i v
2. With application of optimal pressure management in WDS, the results showed that
significant reduction in average zonal pressure (AZP) was directly proportional to
reduction in the system input volume (SIV) from 26,272,579 m3 to 21,915,943 m3 per
annum as well as MNF from 14.01% to 12.50%. The annual estimated nodal system
output (NSO) on 20 critical nodal points (CNP) of the district metered areas (DMAs)
was reduced from 14,774.62 m3 to 12,787.85 m3. While the monthly average linear
system repairs were reduced from 246 to 177. The volumetric index analysis showed
that the percentages of leakage frequency/km/pressure decreased from 8.31% to 5.98%
year on year. Further, the total compound cost of leakages declined from $4,009,315.54
to $2,862,053.10 per month, while average monthly consumption (AMC) reduced from
36.33 m3 to 24.56 m3.
3. The CBA results through a sensitivity analysis methodologies showed the following
findings (i) the socio-domestic retrofitting capital investment at an average investment
cost of $USD 5 735 per household reduced the average high consumptions from 1369.4
m3/year to 301.99 m3/year, at a projected savings of 521.05 m3/household/year. Results
further show that the integrated socio-technical strategy ELWL achieved at a WACC
of 16.2, a CV of 0.66, and the NPV ratio or Net Capital Risk of 0.246, which summarily
proved that addressing HH background leakages beyond the metering device has longterm
benefit compared to huge infrastructure investment.
4. Further, the PROMETHEE II’ MCDA outcome showed that four sub-element of
IWLMIP namely (i) Financial objectives, (ii) technical capacity, (iii) institutional
governance, and (iv) socio-economic objectives are key for a matrix IWLMM.
5. Finally, the practical application of IWLMIP on site in Alexandra into a final IWLMM
resulted in a Y-Shaped IWLMM with three strategies options and 14 sub-strategies
integrated together.
This thesis provides a comprehensive water loss control tools and socio-technical methods
needed required by water managers, policy makers, academic researchers and financial
institutional bodies working together to reduce losses in water distribution systems particularly
for the developing countries
Keywords: Water Loss Management Strategies, Decision Support Tool, Developing Countries,
Institutional Governance, Water Conservation and Demand, Revenue Management