Assessing Water Conservation and Demand Management Option for Addis Ababa City
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Date
2010-12
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Addis Ababa University
Abstract
This research develops water demand (end-use) modelling and forecasting, and assesses water
conservation and demand management potential for the city of Addis Ababa. The research
methodology consists of four steps: 1) data collection, 2) assessing and reducing water distribution
system leakage, 3) developing water demand (end-use) modelling and forecasting, 4) water
conservation and demand management analysis. International Water Association (IWA)/American
Water Work Association (AWWA)’s water loss analysis software and economical leakage reduction
model is used for assessing and reducing water distribution system leakage. The Demand Side
Management Least Cost Planning Decision Support System or DSS model is developed and used for
water demand forecasting and assessing water conservation and demand management measures. DSS
model is Microsoft Excel application model. The non-revenue water (NRW) level in the water
distribution system in the city of Addis Ababa is found to be 38.2Million m3/year (39.5% system input
volume). The real or physical losses are 26.2Million m3/year (27%) of the total NRW, the commercial/
apparent losses are 10.1Million m3/year (10.5%) and unbilled authorized consumptions are1.9 Million
m3/year (2%). The economical leakage reduction model result indicated that 5.7Milion m3/year or
about 10% of the water losses is an ‘’economical leakage level’. This show about a 29.5% of water
losses can be saved through implementation of the recommended water loss reduction programs for the
city of Addis Ababa. The water demand (end-use) modeling and forecasting has identified the city
average water use in liter per capita per day is 117 and the projected water demand will be 840, 1,502
and 2,735 Million of liter per day by 2020, 2030, and 2040 respectively. With adaption and
implementation of the recommended water conservation and demand management program B in the city of
Addis Ababa would reduce the future water demand by 66%. This would postpone up to 2020 and
downsize of the need for developing new water sources and infrastructures. Furthermore, the benefitcost
analysis result of adapting and implementing the recommended water conservation and demand
management program B provides present value benefit of 106,550 million birr and costs present value of
862 million birr to Water and Sewerage Authority of Addis Ababa (AAWSA). The benefit-cost ratio is
found to be 120. The cost of water saved is found to be 8,145birr/Million litre which is less than the cost of
developing new deep wells and operation and maintenance cost of 300,000birr/Million litres by AAWSA.
Therefore, water conservation and demand management provides economically feasible and
environmentally sustainable solution for meeting the shortfall supply and projected future water demand in
the city of Addis Ababa. The environmental sustainability of water conservation and demand management
option is reducing the waste water generated from household and buildings to sewerage system or to the
environment.
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Keywords
Planning Decision Support System