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Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area 24
Those operations which appeared to be obvious non-starters were flagged. Comment was also made as to
the extent of available information and whether the technology had been successfully utilised previously or
elsewhere in the country or internationally.
7.5.2 Costing
Where possible, capital costs were based on costs available from previous studies. These costs were
then escalated based on Contract Price Adjustment (CPA) indices to be representative of the base year
costs (June 2009).
An evaluation period of 50 years was selected for all water augmentation schemes, for determination of
URVs. Discount rates of 6%, 8%, and 10% were used in URV calculations, to cater for funding by both
MLM and the DWA. Multiplication factors were applied to allow for additional costs as follows:
Preliminary and General costs of 20% were first added to the capital costs;
A 10% Contingency sum was then added to the previous sub-total;
A 15% Professional fees/site supervision sum was further added to the previous sub-total, to get the
total construction cost estimate;
The total construction cost estimate was spread over the first two financial years in the URV
calculation; and
VAT is excluded in URV calculations
Equipment replacement periods for pumps (mechanical and electrical), pipelines, etc and desalination
membranes were not considered.
Capital costing and determination of URVs was undertaken at a conceptual level. Potential future electricity
increases were not allowed for in URV calculations. Demand profile was assumed to be constant. Cost of
electricity was assumed to be 35c/kWh for Eskom and 58c/kWh for Centlec (the local distributer). The
Centlec supply was assumed for the water re-use options.
7.5.3 Outcomes of Preliminary Screening Workshop
The proceedings of the Preliminary Screening Workshop are bound into this document as Appendix 1. The
comments and recommendations made at the workshop were taken into account when refining proposed
interventions and developing reconciliation scenarios during the remainder of the study.
7.5.4 Refinement of Selected Potential Interventions
After the Preliminary Screening Workshop, selected interventions were refined by improving cost estimates
and carrying out more detailed determinations of the effects that the interventions would have on the yield
of the water resources system if implemented. The refined interventions, as used for the final scenarios, are
described in the remainder of this document. Details of estimates of capital and operating and maintenance
costs for the interventions are contained in Appendix 2 and the calculation of unit reference values is shown
in Appendix 3.
Interventions Report June 2012