Water and Water Pollution

Author: Hanlie Hattingh, Anthony Turton, Christine Colvin, Marius Claassen & Peter Ashton; and statistics provided by Peter Ashton & Linda Godfrey – CSIR

( Article Type: Overview )

Water supply and use

Surface water and groundwater are the two components of our water supply sources:

Surface water sources (water in rivers, lakes, pans and dams), constitute the main sources of water supply in South Africa – meeting about 66% of our water needs. Of the approximately 10% of all rain that ends up in rivers or underground aquifers, only about 60% can be economically captured in dams, and South Africa is rapidly approaching the limit of economically viable water capture in dams.

Groundwater sources (water in underground aquifers and streams) provides only about 10% of South Africa’s water requirements but plays an important role especially in rural areas and drier areas with little or no perennial surface water sources. Effective management of groundwater supplies, given the growing demand for agricultural, industrial and urban supplies, is needed to ensure the sustainability of the resource. Key challenges in this regard are to achieve a balance between abstraction and recharge and to prevent contamination of groundwater resources through pollution.

 

Water uses

According to the World Health Organisation, 50 litres water per day of suitable quality is required for a person to sustain life. The Department of Water and Sanitation notes the basic human need requirement as 25 litres per person per day. While the available stored water in South Africa is sufficient to supply this basic human need, this supply relates to drinking and cooking water only. However, water is also required for personal hygiene, agricultural, industrial activities and the environment. Added to this, the population of South Africa is growing by an estimated 3% per year, which is escalating the water demand by at least a further 6.8 million litres per year.

Water to meet basic human needs and water required to sustain the ecology are legally recognised as water rights in South Africa. These two water uses are, specifically provided for in the National Water Act. All other domestic uses of water such as gardening, laundering and swimming pools are regarded as secondary water uses’ and are not included in the figure above which shows the breakdown of the other water use per major sector in South Africa. While agriculture (both subsistence and commercial) is the biggest water use activity, accounting for about 62% of the national water budget, its contribution to the national GDP is relatively low.

Subsistence farming requires relatively low quantities of water, as water is carried manually from the water source. The volume of water used in commercial farming however is far higher, due to mechanised irrigation systems. Comparing water use to productivity, primary agriculture accounts for 4.5% of the national Gross Domestic Product (GDP) of South Africa while the larger agro-food complex accounts for a further 9%. Industry and mining are the second largest water users, but their contribution to South Africa’s GDP is approximately 6%. Interestingly, water for industrial use creates more jobs and is more efficient, as it can be recycled an almost infinite number of times (technology and cost permitting). This implies that moving water from agriculture to industrial uses over time in a controlled and managed way may be a viable approach to sustaining economic growth while also managing the water deficit caused by the growth in human population.

Scarcity

The western parts of the country receive a lower rainfall than the eastern and southern part of the country (see Figure 2). Even though the population in the western part of the country is significantly sparser, the available water is not always sufficient to provide an adequate basic water supply.

In the eastern and southern parts of the country, irresponsible and excessive uses of water also leads to shortages. Examples include the watering of gardens in dry seasons, the uncontrolled pollution of water by industry and mining and the reliance on highly irrigated agriculture methods to achieve a national selfsufficiency in food. If South Africa achieved a 10% saving in water used by the agricultural sector, we would – at least in the short term – no longer be a ‘water scarce’ country. The solution therefore lies in a policy of regional food security rather than national selfsufficiency. The implementation of new strategies for the pricing of water is an attempt, to force bulk water users to move their water from low efficiency to higher efficiency methods and uses.

Integrated Water Resource Management

A water source is a where water is obtained from, such as a river, dam or tap. A water resource is a water course, surface water, groundwater or estuary. A wider definition of a water resource is ‘an ecosystem, which includes the physical or structural aquatic habitats (in stream or on the river banks), the water, the aquatic biota, and the physical, chemical and ecological processes which links the habitats, water and biota’. Biota are living organisms including plants, bacteria and animals. These systems are inextricably linked.

Water Resource Management

In the past, water management focused primarily on managing (reducing) the contaminants that flow into the water resources. This focus did not look at the water as a whole resource, but rather at water as a source of supply. The result of this previous thinking was the setting of effluent standards, to control the quality of the wastewater being put back into the resource. This strategy made use of hydrologists and engineers, with a primary focus on water supply. Key concepts reflecting this focus are: supply; the polluter pays principle and the precautionary approach.

Since 1998, the focus has changed to recognise water as a resource and a necessary precondition to sustainable development. As long as the resource is in a sound condition, it can supply the required goods and services we need, but the integrity of the resource has to be protected. This includes the understanding that a healthy resource will be able to absorb some level of pollution loads and still retain its functional capacity. This capacity to absorb and cleanse is referred to as an environmental sink and is utilised as part of our modern water management process. To implement this new focus, a number of new terms and concepts have been developed. Terms such as:

Reserve
Resource Directed Measures
Resource Quality Objectives
Integrated Water Resource Management
Catchment Management
Catchment Assessment and
Catchment Visioning

are all expressions of this new management approach. Principles such as the polluter pays principle and precautionary approach have not been abandoned; these are still applicable, but the goal and standards that are strived for have changed dramatically.

Integrated Water Resource Management
Managing water resources is not a matter of separately managing the rivers, lakes, wetlands, groundwater and estuaries, but rather dealing with the landscape, including the water uses and users, human impacts and its drainage as one interrelated system.

Integrated water resource management involves water quality and quantity, surface and groundwater, rivers, lakes, wetlands and estuaries and is based on the hydrological cycle. It also involves stakeholder requirements and the integration of various scientific disciplines in the management of water resources, including social sciences, anthropology, ecology, and geomorphology. The main aim of integrated water resource management is to achieve a balance between protection and use of the water resources.

Catchment Management

A catchment is an area of land from which water collects into a common water body. The boundary between one catchment and another is known as the watershed. Within catchments water runs off and infiltrates through the landscape into rivers, lakes, wetlands, estuaries and groundwater; all of these are connected, hydraulically, by water. Through catchment processes of rainfall, infiltration and run off, water ends up in rivers, wetlands, groundwater and estuaries. The amount of water available for beneficial use is related to how human activities modify these natural processes. The condition of the water is directly affected by, and in turn affects, the health of the associated ecosystems and consequently the ecological processes. A catchment assessment study determines all the water sources, land uses, water uses and users, the quality of the water and the water available, as well as the ecological status of the water resources. A catchment visioning process involves people living in a particular catchment determining their water usage requirements and then translating this into objectives reflecting those requirements.

Resource Directed Measures

• Basic water to all the people living in that area (Basic Human Needs Reserve); and
• To sustain the ecological processes within the water resources (Ecological Reserve).

The Classification of water resources involves looking at the state of the water resources in terms of the Reserve requirements and the catchment vision and then classifying the water resources according to how these states reflect the capability of that water resource to sustainably provide the services required. Examples of water resource classifications include ‘work horse’ and ‘natural’. The National Water Act calls for a classification system, which is currently being developed but has not yet been implemented. This is a complex process because it involves a scientific understanding of inter-related systems, but also takes high-level strategic trade-offs into consideration. Science informs the policy-maker about the limits or thresholds of given systems.

• Resource quality objectives refer to all the aspects of the water resource, including:
• Quantity, pattern, timing, water level and assurance of in stream flow;
• Water quality – chemical, physical and biological characteristics of water;
• The character and condition of the in-stream and riparian (banks of watercourse) habitat;
• The characteristics, conditions and distribution of aquatic biota.

The purpose of Resource quality objectives is to set clear goals, balancing the need to protect and sustain water resources against the need to develop and use the same water resources. The Resource quality objectives are numeric or narrative descriptors of the conditions required to achieve the desired management scenario.

Water Governance

Water Governance can be generally defined as:

‘the process of informed decision-making that enables trade-offs between competing users of a given resource so as to balance protection and use in such a way as to mitigate conflict, enhance security, ensure sustainability and hold government officials accountable for their actions’.

In simpler terms, water governance is the process through which all stakeholders talk to each other with the purpose of raising the concerns and issues relating to water and discussing different ways of meeting the objectives and addressing the concerns. The governance process is based on specific principles, namely:

• Buy-in
• Accountability
• Trust
• Transparency
• Consensus
• Predictability
• Adaptability
• Equity.

Discussions between stakeholders on specific issues provides the platform to achieve a shared (common) understanding, identify a shared (common) goal, and finally reach agreement on how to work together to achieve the identified shared goal.

This is where trade-offs are made, and conflict arising from possible competing uses is mitigated. A trade-off is when one party agrees to give some benefit or use up, to enable another party to use that portion of the water. For governance to work, this must be an informed and a negotiated process, wherein all stakeholders have taken part. Normally, negotiation will take place between three parties, which we refer to as a trialogue. The governance trialogue model explains relationships between government, science and society as seen in the figure above. A trialogue may take place between any of the following stakeholders: a community; the municipality; local, provincial or national government departments; scientists or civil society. Governance enables participatory decision-making and supports a true democracy.

Overcoming future water challenges

The issues that we should be facing now include:

How to ensure that we develop the necessary mechanisms to create a situation of structurally induced water abundance?

What do we require in order build the necessary social adaptability to meet our future water challenges?

There are a number of different aspects to developing social adaptability: the first is the enhancement of our current knowledge and science. We need, for example, a better understanding of the hydrology of our catchments, more sophisticated modelling capacity, better data, and longer time sequences of data. We need a better understanding of ecosystem functioning and resilience; we need a better understanding of what constitutes efficient water use in the different sectors; we need an enhanced capacity for monitoring, evaluation and critical analysis of the situation; we need a better understanding of pollution issues and of the management and mitigation of pollution problems.

Secondly and of equal importance is the need to achieve greater knowledge and understanding of the social dynamics required to develop a society with the necessary social adaptability to overcome physical water scarcity. Interrelated with this is the need for improved education. We need a better-educated population in terms of general awareness, literacy and understanding of water scarcity issues and the efficient and effective use of water. Social adaptability cannot be achieved by any minority – it requires the commitment and understanding of all South Africans, and also requires very specific enhancement of our science and technology capacity in the country – at schools, at universities, and in previously disadvantaged communities.