Botswana has had water accounts since 2000, but the earlier accounts were restricted to surface
and groundwater. Growing concerns about water scarcity and growing amounts of wastewater
due to improvements in sewerage and wastewater treatment works offer opportunities for re-use
and recycling that are hardly exploited to-date. Incorporating wastewater into the water accounts
would contribute towards integrated water and wastewater planning within the IWRM
perspective. Wastewater would be considered as an economic good instead of a waste product.
The specific objectives of the study are to:
• Identify and quantify stocks and flows of wastewater in Botswana;
• Develop Natural Resource Accounting (NRA) as a planning tool that integrates fresh
water resources and wastewater; and
• Explore economic, social and environmental benefits of using wastewater.
The planned study’s activities include a review of Botswana’s policies and programmes towards
water management and sanitation; a review of treatment of wastewater under the SEEA structure
and in water accounts of other countries; re-design of Botswana’s water accounts to
accommodate wastewater stocks and flows as comprehensively as currently possible; collection
of wastewater data and construction of amended water accounts; and exploration of the
environmental and economic impacts of different uses of wastewater (scenarios). The activities
were all carried out and have led to the construction of modified and up-dated accounts. In
addition, a survey was held among collectors of wastewater from the Gaborone WWTW’s
maturation ponds. This emerged during the study in response to the water crisis faced by
Gaborone in 2004/05. It was expected that a survey of small scale re-use hold important lessons
for re-use in future.
The Water Research Fund for Southern Africa (WARFSA) provided funding for the study. While
the study focuses on Botswana, its findings are considered relevant to other countries in southern
Africa.
The water use accounts show that water consumption amounts to 170 Mm3 in 2003. An estimated
29.2 Mm3
of that consumption was returned to WWTW in cities, towns and major villages (16%
of water consumption) with an estimated outflow of 14.5 Mm3
(8.5% of water consumption).
The estimated amount of re-use is 3.0 Mm3 in 2003, representing 11% of the outflow of WWTW
and less than 1% of total water consumption. The survey of small scale re-use in Gaborone
indicated that 0.1 Mm3
may be collected, currently posing no threat to planned large irrigation
schemes. The amount of ‘new water’ will increase in future because of introduction of treatment
technologies with considerably lower water losses than the pond technology, construction of
more WWTWs and more connections to the sewerage system of households and businesses.