Alternative

1

• Alternative
• Water Supply -
• A Water Services
• Perspective
• Portfolio
• Committee
• 14 September 2005

DEPARTMENT WATER AFFAIRS AND FORESTRY
2
MIG Grant
Why Alternative supply?

• At the retail or WS level, WSAs are increasing
  facing financial difficulties.
• Affordability of alternative supply mechanisms,
  rather than technical limitations are usually the
  problem.
• Grants and improved cost recovery can only
  provide so much there is thus a need to improve
  the efficiency of schemes.
• This includes utilising alternative sources of
  water or means of accessing it and also the
  efficient use of water.

3
Desalination

• Although there are a number of methods, only two
  have really been used in SA.
• Solar distillation
• Requires much sunshine.
• Has been done successfully at 2 schools
  (Kerkplaas and Algerynskraal)
• Can be implemented in modules.
• Appropriate only in very water scarce areas.
• Reverse Osmosis
• Expensive, but becoming affordable where
  electricity is available

4
Desalination

• Reverse Osmosis (continued)
• WRC study due for completion November 2005
• This system is used at Bushmans River Mouth,
  Kenton-on-Sea and on Robben Island.
• Where diesel generators are used for power, this
  method becomes very expensive and solar
  distillation is more appropriate.
• There is a huge potential as sea water is
  unlimited.

5
Rainwater harvesting

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Rainwater harvesting

• Rainwater is collected from impermeable
  surfaces, usually a roof, and led to a storage
  tank.
• Water can be passed through a screen and
  charcoal to purify it.
• This technology is simple, there is a sense of
  ownership and no need to transport the water.
• Rain is however unpredictable and large storage
  tanks may be necessary where the dry season is
  long.
• Although widely used internationally, there has
  been little use in SA. Genadendal and
  Kammiesburg are examples.
• This is a secondary supply of water, but can
  substantially reduce the stress on supplies.

7
Cloud/Mist harvesting

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Cloud/Mist harvesting

• Water droplets are intercepted and collected on
  vertical panels of shade cloth or nylon mesh
  placed perpendicularly to the wind.
• The droplets fall into gutters at the bottom and
  are fed into a storage tank.
• This system is only suitable for mist prone
  areas such as mountains or coastlines with cold
  water.
• Easy to construct and maintain
• Unfortunately only small amounts of water are
  produced and the formation of mist is uncertain.
• Pilots in SA on W. Coast, at Lepelfontein and in
  mountainous areas of Limpopo E. Cape.
• There is limited potential for this.

9
Grey water recycling
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Grey water recycling

• Grey water is water used for washing self,
  clothes dishes.
• Approximately 1500 households have been fitted
  with recycled mechanisms to irrigate their
  gardens. Genadendal is an example.
• Whilst this will reduces the demand for
  irrigation water, there will be less returned
  into the system for downstream users, which may
  be problematic.
• There can be social customs that prevent the use
  of washing water for gardens.

11
Water Conservation and Demand Management

• Good WCDM practices can substantially reduce the
  water requirements with relatively little
  expense, (as was recently presented to you).
  More importantly they can be self funding.
• WCDM deals with issues such as
• Technical aspects (Active Passive Leakage
  Control, Water Audit Mass Balance, Network
  Audit, Pressure Reduction etc)
• Social aspects (Education Awareness programs,
  etc)
• Financial Aspects and
• Institutional Legislative aspects (Bylaws,
  including WC/WDM in WSDP).

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Other

• Virtual Water
• This entails growing crops in another country and
  then importing them back to SA. In essence we
  are using the other countrys water.
• Reduction in evaporation from water in storage
• This has been used in Namibia and although tested
  in SA, with mixed results, has not yet been
  applied.

13
Sanitation

• Without going into details of sanitation, suffice
  to say that there are various water saving
  sanitation technologies.
• Systems such as LOFLOS, urine diversion etc.
• This can reduce water demand substantially,
  bearing in mind that one flush of a waterborne
  toilet can use 10 15 liters per flush.

14
Involvement of WSAs

• DWAF is engaging with WSAs through the IDP/WSDP
  process.
• This affords an opportunity to inform Council
  and officials of the various alternative options,
  so that they can make informed decisions.
• This requires them to consider technical,
  social, financial and political imperatives.
• It is essential that before implementing other
  options, that they have the capital and operating
  funds required, and can make allowance for
  replacement costs.

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Involvement of WSAs

• Most importantly the WSAs must have the
  capacity to operate and manage the systems.
• What could also assist municipalities is to
  provide appropriate user-friendly guidelines. In
  this regard the Guideline on small scale
  productive uses currently being drafted will be
  of assistance.
• Benchmarking and lesson sharing between
  municipalities will be valuable.
• THANKS