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This presentation explores alternative water resources to supplement surface and groundwater supplies. It discusses options like iceberg towing, shipping water from Zambezi/Congo, canal transfer from the Zambezi, rainfall stimulation, improved water use efficiency, removal of invasive alien plants, use of treated effluent, desalination, and groundwater development. The importance of integrated planning and proper investigation of all options is emphasized to ensure the best solution is implemented.
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Alternative water resources Presentation to Portfolio Committee 14 September 2005
Alternative water resources • Alternative to what? – Surface and groundwater most used currently • Let us consider all options • Most options technically feasible but the costs of some is prohibitive • Water is not the issue, affordability is • Some options will work better along the coast
Improbable for near future • Towing of icebergs • Huge logistical challenge • Feasibility not proven • More expensive than to ship fresh water from Zambezi/Congo • Let others try it first
Improbable (continued) • Shipping water from Zambezi/Congo • Possible • Large tanker operation • Reconnaissance costing showed it to be more expensive than desalination
Improbable (continued) • Canal transfer from the Zambezi • Large transfer has been studied • 8 basin states, RSA is not • All 8 have ambitions to use the water to develop their own countries • Use own resources more efficiently before thinking about neighbours’ resources
In the middle there is • Rainfall stimulation through cloud seeding • Research has proven that it can be done • Implementation will be costly • Potential legal issues may make it difficult • Huge potential and should be taken further • Government will have to take the lead in
More likely options • Improved water use efficiency (WCDM) • Removal of Invasive Alien Plants (IAPs) • Use of treated effluent • Desalination • Groundwater • Surface water including Inter Basin Transfers (IBT)
Water use efficiency (WCDM) • Recent presentation to Portfolio Committee • Too much water being used inefficiently • Savings could in many cases delay augmentation with years • Municipalities will have to be supported to achieve practical implementation
Removal of Invasive Alien Plants (IAPs) Removal of IAPs makes more water available • Consider quantities and costs in all cases where water is required • Implement if this is best option
Use of treated effluent • Treated effluent being re-used indirectly and directly in inland areas for many years and on large scale in some cases • Biggest future potential at coastal cities
Indirectly • Municipalities treat effluent in sewage works and discharge to river • Users down stream use it for irrigation and domestic • Large scale in Vaal River system • Rand Water re-uses effluent from southern Gauteng • Pretoria from Kempton Park through Rietvlei Dam
Directly • In SA often for industrial use • Municipalities treat effluent in sewage works and supply directly to next user • Kelvin power station in Johannesburg • Mines near Mokopane from Mokopane and Polokwane • Mines near Rustenburg from Rustenburg • Durban to industries
Coastal areas Effluent mostly discharged to the ocean (treated or untreated) • Huge potential resource • Cape Town is discharging nearly 160 mill m3/a • If all of this could be re-used it would sustain Cape Town for 13 years • If fully recycled, some desalination will be required • This is currently being investigated
Desalination Already being done on small scale • Albany Coast Water Board – Bushmans River/Kenton-on-Sea • West Coast – desalination of brackish ground water • Huge potential for coastal towns and cities • At present much more expensive than we got used to for surface resources • Desalination takes place on huge scale overseas • Very energy intensive – cost and impacts of energy generation will increase • Becoming most economical option in specific cases • Is being and will be investigated for large towns and cities
Ground water • Very important resource • Often the only resource for small towns and communities • Must be properly developed and managed • Artificial recharge must get proper attention • Conjunctive use where possible will give more in total
Way forward • Aim – ensure best solution is implemented • Proper investigation of all options • Integrated planning essential • Example of strategic planning for W-Cape
Reconciliation strategy for Western Cape system • Cape Town area currently under restrictions • Berg River dam will only supply up to 2010 • Urgent action required to prevent problems after that • DWAF strategy study with CCT active participant • Western Cape Province also involved • Public participation programme
Options • Increase of water use efficiency (WC/DM) • Removal of IAPs • Effluent re-use • Desalination • Groundwater e.g. Cape Flats, West Coast, TMG • Artificial recharge • Conjunctive use • Surface water development (various small and bigger schemes) including IBTs • Answer will be a combination of the above, strung together in a plan that will be affordable and flexible
Summary • Basic research not required before implementing feasible options • Investigate all options properly • Align strategies (CMS, PGDS, IDP) • Western Cape Reconciliation Strategy as example