Download Managing Water Resources for Climate Change

CHAPTER 10
MANAGING WATER RESOURCES
FOR CLIMATE CHANGE
10.1 Context and current challenges
Climate change is expected to have a major impact on South Africa, with
resulting consequences for people, the economy and ecosystems.
Water is the primary medium through which the impact of climate
change is going to be felt in South Africa.
Climate change in South Africa will result in changing rainfall patterns,
the intensity of storms and the extremes of droughts and floods;
increasing evaporation; changes in soil moisture and runoff and thus
water availability; changing water quality conditions (including
temperature of aquatic systems) and increasing climate variability.
10.1.2 Alignment with DEA
The Department of Environment Affairs (DEA) is
designated to lead the country’s climate change
agenda with responding and adapting to climate
change as one of several strategic national
objectives. The recently released White Paper on
National Climate Change (2011) provides the
framework for South Africa’s response to climate
change and requires the development of sector
strategies. One of the intended outcomes is to
develop the skills base required to deal with the
consequences of climate change. The DEA is
currently developing Long Term Adaptation
Scenarios (LTAS) for South Africa, which will also be
useful in assisting other sectors to develop their
adaptation strategies. Improving the capability of
developing countries to adapt to climate change was
one of the key outcomes of the COP 17 held in
Durban in 2011.
10.1.1 Climate Change and development challenges
Climate change is one of five critical trends noted in the National
Development Plan, which recognises that “South Africa is not only a
contributor to greenhouse gas emissions – it is also particularly
vulnerable to the effects of climate change on health, livelihoods, water
and food, with a disproportionate impact on the poor, especially women
and children. While adapting to these changes, industries and
households have to reduce their negative impact on the environment.
This will require far-reaching changes to the way people live and work.”
(NDP, 2012)
The NDP recognises that the impacts of climate change will be felt
substantially in the water arena, and reflects the need to build economic
sustainability and resilience to “enhance the resilience of people and the
economy to climate change.”
South Africa has low rainfall and high evaporation rates, while rainfall
varies significantly from year to year and across the country. This poses
major challenges to economic development and livelihoods.
Both agriculture and urban-industrial areas in many parts of the country
have experience floods and droughts in the past. While South Africa’s
water infrastructure and management capacity assist in adapting and
responding to this variable climate, climate change is expected to
exacerbate this variability with significant hydrological, ecological, social
and economic consequences.
Climate variability refers to natural variability in the climate in a
particular region over time. Some areas, such as South Africa, have
highly variable climates, with frequent droughts and floods being
experienced as part of the natural climate cycle.
Climate change, on the other hand, refers to long-term changes in the
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climate experienced in a particular region. While climate change occurs
naturally over long periods of time, in the context of this document,
climate change refers to the rapid climate change currently being
experienced as a result of human activities and the increased production
of greenhouse gases.
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Managing in uncertainty
The uncertainty in projected water-related climate
change impacts is one of the biggest challenges
facing water managers. These managers must
understand how this uncertainty influences the
management decisions to be made and that
decisions must be appropriate to a possible range of
scenarios. A critical tool in this regard is adaptive
management, in which water resource systems are
carefully monitored and management actions are
tailored and revised in relation to the measured
changes on the ground.
It is against this background that the DWA is
developing a Climate Change Response Strategy for
Water Resources in South Africa. This strategy will
provide guidance on adaptation to the water-related
impacts of climate change and to maximise any
beneficial impacts. The strategy will include the
approach to be taken to climate and water
adaptation, as well as measures and actions, where
possible, focusing on actions that support both
adaptation and mitigation.
10.1.3 Climate change and models to
calculate impact
The impacts of climate change are calculated
through the use of scientific models called Global
Circulation Models (GCM). There are a number of
such models, and each is based on slightly different
assumptions or rules. Because of the number of
different factors affecting the global climate, it is very
difficult to create a model that can exactly replicate
the real world. As a result, the models all give
different results in terms of what the climate change
impacts will be and over what period. Some of the
models give extremely different results for particular
areas, with some, for example, predicting increased
rainfall and others predicting decreased rainfall in
particular areas. While some models reflect a trend of
wetting in the eastern parts and some drying in the
west of the country, some models reflect a strong
drying trend across the country. This shows the
uncertainty of South Africa’s possible climate futures,
and means that the water and climate strategy
must consider the possibilities of a very
challenging climate scenario.
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As a result, one cannot predict climate change impacts with any certainty, and the recognition of this uncertainty must be built into all
climate change response strategies.
Changed rainfall results in amplified hydrological impacts. Thus, a reduction of 10% in rainfall results in a much greater reduction in water
availability.
There is much greater agreement between the various GCMs about temperature increase. Surface air temperature in South Africa is
expected to warm everywhere, but most strongly in the interior (as indicated in Figure 16). In the intermediate future, annual temperature
will increase by 1.5 to 2.5°C along the coastline and by 3.0 to 3.5°C in the far interior. Temperature change will accelerate towards the end
of the century with increases of 3.0 to 5.0°C along the coast and more than 6.0 °C in the interior. This increase in temperature is likely to
result in increased water demands and increased evapotranspiration.
To assess the water-related impacts of climate change in the Climate Change Response Strategy, the country has been divided into six
hydro-climatic zones, as represented in Figure 17. A high level assessment of the possible climate change impacts in each of these
zones has been examined and is contained in the Climate Change Response Strategy for Water Resources in South Africa.
Average of Changes
January Maximum Temperature
Intermediate to Present
Muliple GCMs
0
C
<2.0
2.0 - 2.5
2.5 - 3.0
3.0 - 4.0
4.0 - 5.0
5.0 - 6.0
>6.0
GCMs:
CGCM3.1 (T47)
CNRM-CM3
ECHAM5/MPI-OM
GISS-ER
IPSL-CM4
Intermediate:
2046 - 2065
Present:
1971 - 1990
Figure 16: Downscaled seasonal temperature increase for January (Schulze, 2011)
Proposed New Water Management
Areas & Catchment Management
Agencies April 2012
Description:
Map depicting the new proposed Water
Management Area and Catchment Management
Agency Boundaries
Zone 1
Data sources:
Water Management Areas: Dept. Water Affairs
(DWA), Directorate Catchment Management.
Zone 3
Zone 2
Legend
Proposed New WMA & CMA Boundaries
Existing Water Management Area Boundaries
Quarternary Drainage Region Boundaries
International Boundaries
Zone 4
Proposed New WMA’s & CMA’s
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Zone 5
IN
CE
O
IC
AN
O
NT
CE
AN
A
ATL
Zone 6
Figure 17: Six hydroclimatic zones
1
2
3
4
5
6
7
8
9
Limpopo
Olifants
Inkomati-Usuthu
Pongola-Mzimkulu
Vaal
Orange
Mzimvubu-Tsitsikamma
Breede-Gouritz
Berg-Olifants
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Arising from the assessment of the water and climate scenarios for
South Africa, several key issues need to be addressed, as follows:
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There is a need to build the capacity of water sector institutions to
function in a context of high levels of uncertainty.
There is a need to build the water sector’s climate response
capability and commitment to timeous action, to be able to avoid
inappropriate responses, and to ensure that the sector is able to
manage water in a context of high levels of uncertainty.
Improved collaboration between all agencies to address climate
change, in particular those that are likely to have overlapping and or
similar objectives.
There is a need to adjust the water resources planning and
management processes in the country to build the required
resilience and adaptive capacity in society and ecosystems. A key
element of this is improved water conservation and water demand
management across the country.
There is an urgent need to strengthen the present rainfall,
environmental, hydrological and hydro-geological monitoring
systems to support effective climate change detection and effective
adaptation.
The available human capacity relating to climate change impact
assessments and adaptation within the water sector is very limited
and needs to be strengthened.
There is a need to address research gaps in current water sector
climate change programmes and water and climate change
knowledge.
10.2 Principles
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A sound scientific foundation is the basis of all recommendations and
actions.
A balanced approach between preparedness and over reaction must
be maintained.
There is integration of potential climate change impacts into water
resources and water services planning and supply at all levels.
Leadership is provided by the DWA with strategic partners to drive
appropriate strategic responses to minimise the impacts of climate
change.
Existing initiatives and institutions are aligned to improve the
effectiveness of the national response.
Climate and water is elevated onto appropriate agendas to ensure
that this relatively new field is incorporated into the national agenda
and managed adequately.
Knowledge of the climate-water relationship and how this will impact
on society is improved.
Critical natural infrastructure (ecosystems) are protected and
enhanced.
Physical infrastructure is planned for a changing future using a noregrets/low regrets approach.
No-regret measures are ones that will prove worthwhile doing even if no
(further) climate change occurs or if the climate change impacts are different
from those expected.
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Low-regret measures are ones that will only require small additional
expenditures to cater for the negative effects of climate change.
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10.3 Objectives
The key objectives of a climate change strategy for
the water sector include:
• Reduce the vulnerability and enhance the
resilience of communities, people, enterprises
and ecosystems, to water-related impacts of
climate change, particularly for those groups most
at risk.
• Improve and enhance water resources
management processes to build the required
resilience and adaptive capacity.
• Integrate climate change considerations into
short-, medium- and long-term water planning
processes for water resources and water
services.
• Implement the best catchment and water
management practices to maximise the degree of
water security and resource protection under
changing climatic conditions.
• Enhance the human, legal, regulatory,
institutional, governance and financial resources
and capacity to assist with the effects of climate
change on water.
• Undertake focused monitoring and research to
ensure the efficacy of water adaptation
approaches over the long term.
• Ensure inter-linked climate and hydrological
modelling tools that represent the complex interrelated natural systems.
10.4 Strategic actions
Many of the strategic actions outlined below are
parallel to, and build on strategic actions in several
other chapters in this Strategy. They are highlighted
here in relation to their specific importance for
responding to climate change.
10.4.1 Water governance
10.4.1.1 Adaptive approach
In implementing the adaptation strategy, the
approach will combine the traditional approach of
down-scaling the GCMs with a bottom-up approach
based on monitoring and assessment of actual
trends. In this way, defendable climate-water
scenarios that show clear signals will be developed
and updated to enable robust decision-making.
Responses to climate change will be addressed via
existing programmes, and investment will be made in
skills development and resource allocation for
dealing with the long-term effects of climate change.
10.4.1.2 Building adaptive institutions
The DWA will work to ensure that the institutions
responsible for water management and governance
are able to adapt timeously and effectively to
changing climatic conditions. This requires that
management institutions such as municipalities,
water boards, CMAs, international bodies and the
DWA are designed and operate as adaptive, learning
institutions.
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10.4.1.3 Intergovernmental relations and collaboration
To manage water-related adaptation and mitigation effectively, the DWA
will put in place the necessary co-operation and co-ordination
mechanisms in the water sector and between vulnerable sectors.
Activities such as research, water planning, infrastructure investment,
and risk and disaster management will be better coordinated, robust and
focused, under the leadership of the DWA.
10.4.1.4 Awareness and communication
The DWA, with the WRC and other water institutions, will run awareness
and communication campaigns to ensure that all water institutions and
water users understand the water-related climate change issues and
how to respond to them. The DWA will also seek to consult widely with
stakeholders on appropriate climate change response strategies.
10.4.1.5 Building resilience and reducing vulnerability
The poor, particularly the rural poor, are the most vulnerable to climate
change. Therefore, there is a particular imperative on water institutions
to ensure the protection of the poor in relation to water, both through
management systems and through appropriate infrastructure choices. It
is also important to recognise, however, that poor communities have
complex coping strategies to cope with climate variability, and it is
important to understand and build on these coping strategies as a way of
building resilience and reducing vulnerability.
10.4.1.6 Research and development
Research into existing gaps in scientific understanding such as impact
studies on land-use, sedimentation, groundwater, water quality, dam
safety, flooding, infrastructure sustainability, and evaporation, the socioeconomic costs, and new elements of the process such as stilling and its
effect on evaporation will be initiated.
Impact studies will be conducted for all catchments, and the relative
importance of climate change on water resources versus other stressors
will be assessed.
The Water Research Commission will continue its current research into
the potential impacts of climate change on water. This should include
looking at water quality issues as well as research into the social
elements of adapting to climate change.
Further research will be supported to increase the accuracy of possible
future climate change predictions by improving their scientific basis and
initiating additional research into climate and water models to develop
more robust and dependable results.
10.4.1.7 Regional engagement
The DWA will work with the National Planning Commission in developing
shared water solutions as part of the SADC economic integration
process.
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10.4.1.8 Climate financing
The DWA will ensure that climate change resilience for water
infrastructure is factored into the National Water Investment Framework.
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10.4.2 Infrastructure development,
operation and maintenance
10.4.2.1 Increasing water supply
The DWA will use the no-regrets/low regrets
approach to making decisions on future
infrastructure development and will communicate
this approach to all water sector institutions. The
DWA will consider all appropriate sources of water for
increasing water supply, including groundwater and
alternative water supply sources. The use of these
will be tested against the climate change scenarios.
10.4.2.2 Water supply and sanitation
Water Services Authorities must develop climate
response strategies in the WSDPs, implement water
conservation and water demand management and
reduce levels of non-revenue water.
10.4.2.3 Flood protection measures
The DWA will put in place improved flood early
warning systems in critical catchments and will work
with municipalities to improve their flood early
warning systems.
10.4.2.4 Infrastructure safety
Increased rainfall intensity in certain areas may result
in increased flood pressures on dams and other
infrastructure with concerns regarding the safety and
resilience of such infrastructure. This includes urban
infrastructure such as treatment works and
wastewater treatment works as well as industrial
infrastructure such as tailings dams. All water
institutions managing infrastructure must address
the issue of climate change impacts in their asset
management plans.
10.4.2.5 Hydro-geo-meteorological monitoring
systems
With the uncertainties arising from the downscaling
of the GCMs, monitoring is critical to being able to
assess actual water-related climate change impacts
and trends on the ground. Therefore, the monitoring
and evaluation of water and climate data must be
prioritised under the coordination and leadership of
the DWA and the adequacy of the weather,
environmental, hydrological and hydro-geological
monitoring systems must be substantially improved,
Equally, standardised reporting protocols must be
agreed on, and implemented, under the leadership of
the DWA and DEA.
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10.4.3 Water management
10.4.3.1 Scenarios, climate modelling and water availability
The DWA will work with the WRC and relevant experts to improve climate change modelling for South Africa, with a particular focus on
understanding the hydrological impacts. Arising from this, the DWA will determine the availability of water under conditions of climate
change.
10.4.3.2 Vulnerability assessment
The DWA will conduct a vulnerability assessment for the country to assess the most critical areas for the implementation of water and
climate change adaptation measures.
10.4.3.3 Planning and strategies
The DWA will finalise the Climate Change Response Strategy for Water Resources in South Africa. This document will form the
framework for all of the other strategic actions listed here, and will serve as the guideline for climate change response in the water
sector in particular. Following from the Climate Change Response Strategy for Water Resources in South Africa, all catchment
management strategies, Reconciliation Strategies and investment planning must address the issue of climate change adaptation and
mitigation.
Responses to the water-related impacts of climate change must be addressed in the programmes and strategies of all water sector and
water dependent entities, and must be addressed by all spheres of government to ensure resilience in their own areas.
Water-related climate change adaptation and mitigation planning should be incorporated into all water services development plans
and IDPs.
In looking at strategies to address climate change in the water sector, the full range of adaptation options, including protecting and
developing natural capital or taking an ecosystems-based approach should be assessed.
Equally, all initiatives should have an increased focus on integrated scenario planning and flexible adaptation plans, which are key to
managing uncertainty.
10.4.3.4 Water allocation and authorisation
The tools for allocation of water will need to be able to adapt to intra- and inter-annual changes in water availability. The current tools
available to the DWA are adaptive in nature, but the mechanisms for applying them will need to be refined.
10.4.3.5 Water conservation and water demand management
The implementation of water conservation and water demand management is a critical element of adapting to climate change. This
must be implemented by all water sector institutions and water users, and should include the optimisation of dam and groundwater
operation, as well as the reduction of physical water losses and the introduction of water-efficient appliances, processes and crops.
10.4.3.6 Water quality management
Climate change will affect water quality but in many areas the impacts may be masked by changes in land use, or compliance to effluent
standards. Some of the impacts can be foreseen and mitigated by careful planning to include potential climate change in water quality
management strategies.
10.4.3.7 Resource management and protection
Aquatic ecosystems will change substantially over time as a result of climate change. These changes will need to be factored into
Reserve determination processes, and the protection of aquatic ecosystems. This will be supported by increased research in this area.
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10.4.3.8 Disaster management
The potential impacts of water-related climate change will be integrated into disaster management systems and processes and the
ability to respond to unforeseen events through, for example, early warning systems and effective planning for incidences of flooding
and drought will be enhanced.
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