Chapter 10: WATER RESOURCES

Authors: Mike Howard(1), Stuart Mangold(2) and Sandile Mpambane(2)

1.WSP Walmsley, Cape Town
2.North West Dept. Agriculture, Conservation and Environment, Mafikeng


CONTENTS
  1. Surface Water Resources
  2. Groundwater Resources
  3. Indicators for water resource management
    4.
References

Maps:

Primary drainage regions of the North West Province (Map 7)
Secondary drainage regions of the North West Province (Map 8)
Tertiary drainage regions of the North West Province (Map 9)
Quaternary drainage regions of the North West Province (Map 10)
Rivers and dams in the North West Province (Map 11)
Wetlands and pans in the North West Province (Map 12)
Groundwater storage rock types of the North West Province (Map 13)
Groundwater mean recharge rate of the North West Province (Map 14)
Water management areas in the North West Province (Map 49)
Mean groundwater depths in the North West Province (Map 50)
Groundwater dominant cation type in the North West Province (Map 51)
Groundwater dominant anion type in the North West Province (Map 52)
Groundwater total dissolved solids concentrations in the North West Province (Map 53)
Groundwater nitrate concentrations in the North West Province (Map 54)
Groundwater fluoride concentrations in the North West Province (Map 55)


Appendices:

Appendix 1: Extract from DWAF water quality guidelines for aquatic ecosystems, domestic, recreation, industry and agriculture.

10.1 Surface Water Resources

10.1.1 Introduction

Due to South Africa's unpredictable rainfall, high evaporation rates and low conversion of rainfall to runoff, South Africa is a water stressed country, where demand is fast approaching available supply. This, coupled with rising water consumption, is placing increasing demands on the Nation's existing water resources. The North West Province, being generally an arid province has all of these water resource constraints.

The general objective of the Rio declaration, applicable to the North West provincial government, is "…to make certain that adequate supplies of water of good quality are maintained for the entire population… while preserving the hydrological, biological and chemical functions of ecosystems, adapting human activities within the capacity limits of nature and combating vectors of water-related diseases."

The declaration states that the "widespread scarcity, gradual destruction and aggravated pollution of freshwater resources", all of which apply to the North West Province, "demand integrated water resources planning and management. Such integration must cover all types of inter-related freshwater bodies, including both surface water and groundwater and duly consider water quantity and quality aspects."

The North West's surface water comprises rivers, dams, pans, wetlands and dolomitic eyes fed by underground water sources. In the North West, ground and surface water are integrated and interdependent as dolomitic eyes or springs are the sources of several major rivers which rise within the boundaries of the Province, such as Groot Marico, Mooi and Molopo Rivers. Therefore, water quality and quantity issues affecting groundwater also have implications for surface waters.

10.1.2 Driving forces

There are four main driving forces affecting surface water resources in the North West Province, namely climatic conditions, increased population growth, industrial demand, and policy and legislation.

Climate

The riverine systems within the North West are susceptible to a range of climatic conditions, particularly rainfall and evaporation. Rainfall is highly variable, both in space and time, often resulting in severe droughts and extreme flooding. In the eastern part of the Province, rainfall varies from 500 to 700 mm per annum. In the central regions, this drops to between 400 and 600mm. In the western part of the Province, annual rainfall varies between 100 and 400 mm. Coupled to these figures is a corresponding increase in evaporation from east to west. The net effect is a reduction in runoff of 5-50 mm in the east and 0-2,5mm in the west. In all catchments in the North West Province, evaporation exceeds rainfall.

Population

The fact that water is a basic need makes the Province's population one of the main driving forces influencing the state of water resources. The rising population numbers and increasing wealth and standard of living exerts pressure on almost every conceivable aspect of the environment. The growing population (see Chapter 3) who are increasingly migrating to urban areas, results in an incremental increase in demand for water resources. For South Africa as a whole, the expected increase in demand for urban and domestic water over the next thirty years is 219 % Walmsley et al. 1999).

Higher standards of living and raised expectations of rural communities, who are becoming more developed and economically empowered than in the past, means that greater volumes of water are required to assure basic supply of portable water available "on tap" within 200 m of their homes.

Industrial demand

In addition, to feed the ever-increasing population, an increase in agricultural production can be anticipated, also resulting in an increase in irrigation demand. For South Africa as a whole, the expected increase in demand for irrigation water over the next thirty years is 28 %, while mining and industrial growth is estimated at 111 % (Walmsley et al. 1999).

Policy and legislation

Policy and legislation such as the National Water Act (Act 36 of 1998) is central to the management of water resources from national to water management area level. Legislation therefore influences the pressures, state, impact and responses pertaining to the water resources (Walmsley et al., 1999).

However, historical legislation and policy has influenced the deterioration of water quality in surface water systems. In South Africa, the uniform effluent standards (UES) were in place for over 20 years. The approach was to regulate the input of effluents to the river system by way of uniform standards. It did not, however, reflect the requirements of the receiving waters, nor the assimilation capacity of the rivers. While the effect of the UES was to decrease the rate of water quality deterioration, they did little to attenuate water quality deterioration.

10.1.3 Pressures

An increase in the population exerts pressure on the environmental quality and quantity of the water resource through greater demand as well as the discharge of used water through sewerage and other effluents. These pressures exerted on the water resources are manifested as: changed hydrology; mining; agriculture; industry; and tourism.

Changed hydrology in major rivers

The volumes of water required for domestic use, industry, mining and agriculture have prompted the construction of many impoundments in the rivers of our country. The Vaal is one of the most important rivers in the Province. The construction of many large dams in the Vaal River system, as well as the transfer of water from other catchments into the Vaal River system, has had a profound effect on the natural hydrology of these rivers. The natural and seasonal cycle of floods and periods of low flow has been significantly altered.

Regulation of river systems, including the Vaal, has had other, more subtle environmental effects. Many aquatic organisms depend on cyclical and seasonal floods for survival. The reduction of floods has significantly affected the ecosystem functioning of many rivers. In addition, inter-basin transfers have resulted in altered flow regimes and the translocation of aquatic fauna and flora between previously separated catchments.

Mining

Mining places significant negative pressure on the Province's water resources. Most mines need large volumes of water for production and also dispose of waste products into the used water, which is discharged as effluents into rivers and other surface waters. Mining wastes, such as overburden, waste rock or slimes all have a negative impact on the aquatic environment. Mining at depth cannot be conducted safely below dolomite aquifers, and the standard practice of the industry is to dewater such aquifers for safe operations. Many local aquifers have become depleted because of this.

Mining and associated industries also have an impact on the water resource through employees' usage. Often the mines have associated "mining villages" with own sewage and water provision infrastructure. These associated services are not part of a mining entity's core business and may operate under severe budgetary constraints.

Depletion of surface water resources within the Province as a result of mining activities is difficult to differentiate from the depletion of the ground water, as information on the individual components of a mine's water balance are generally not measured. An example of the depletion of the aquifers in the vicinity of deep mining operations is in the Klerksdorp area.

Agriculture

A well-developed agricultural industry is essential to provide food for the population, raw materials for industry, and to earn needed foreign exchange by exporting surplus production. The irrigation industry is the biggest single water user in the North West Province. The pressure on the water supply from dry-land crop production, as well as stock and game farming, is insignificant compared with the demand for irrigation water. Irrigation farming depends on two factors: a supply of irrigation water and the availability of good arable soil, which means that in many of the dolomitic water-rich areas the overlaying soil is not only arable but also fertile. This further drives the demand to use ground water for irrigation. Even today a significant proportion of the total area under irrigation uses very water-wasteful flood irrigation methods. Another negative effect of irrigation is the washout of fertiliser and agrochemicals into the receiving watercourse.

Industry

Industrial activities in the Province largely support the mining, agriculture and foodstuffs industries (see Chapter 7). These industries exert an influence through the demand for water, the requirement for labour living close to the place of work and through discharging a variety of waste products into the environment. The result is a greater impact on the aquatic and terrestrial environment.

Tourism

Tourism and game ranching rely on a healthy environment. The tourism sector places pressure on the surface water resources of the Province through the need for sanitation and water-supply services; increased water consumption and pollution from domestic sewage. These are, however, far outweighed by the positive aspects such as increased wetland creation and protection, and the general uplifting of workers in the industry.

10.1.4 State

Surface water resources include rivers, reservoirs, springs and wetlands. In the North West Province there is an overall scarcity as many surface water systems are non-perennial. The amount of available surface water decreases from east to west in the Province, with significantly higher flows in the east.

Rivers

Of the six major catchments in South Africa, the Limpopo, Orange and the Vaal partly fall within the boundaries of the Province (Table 10.1.1 & Map 7). The secondary, tertiary and quaternary drainage regions of the North West Province are depicted by Map 8, Map 9 and Map 10 respectively.

With the exception of the Vaal River, the highly variable runoff from the non-perennial water sources prohibits direct utilization by runoff-river abstraction on a large scale from major rivers in the Province. See chapter 2 for more information on the hydrology and hydrography of the Province's river systems.

Table 10.1.1: Major river catchments within the boundaries of the North West Province (source: Midgley et.al. 1994a,b,c).

MAIN RIVER PRIMARY SECONDARY TERTIARY
Limpopo River Catchment
Crocodile Pienaars Apies  
Elands Selons Koster
Brakfonteinspruit
Hex Waterkloofspruit
Sterkstroom
Magalies Scheerpoort Nouklip-oog
Maloneys-oog
Swartspruit
Hennops Rietspruit
Jukskei Klein Jukskei
Bloubankspruit
Limpopo Groot Marico Klein Marico
Vaal River Catchment
Vaal Harts Dry Harts  
Groot Harts  
Klein Harts  
Schoonspruit Taaiboschspruit
Rietspruit
Mooi Loopspruit
Molopo Ramatlabamaspruit
Setlagolespruit
Ganyesaspruit
Pepanespruit


Mean annual runoff in major river catchments - The mean annual runoff (MAR) in the North West Province is reported to be very low. Average MAR as a percentage of the precipitation is 6% for the entire Province, which is below the average of 9% for southern Africa. The MAR varies significantly from east to west ranging from approximately 7% in the eastern region to less than 1% in the far western region (Shulze, 1997). Table 10.1.2 presents the mean annual runoff (MAR) for the major catchments in the Province.

With the exception of the Vaal River and perennial streams which arise from springs, the rivers and streams of the North West Province are characterized by highly variable runoff, which increases from east to west. The high variability in runoff makes direct utilization by runoff-river abstraction unfeasible, with the exception of small consumers abstracting water from major rivers (Nel et al., 1995).


Table 10.1.2: North West Province catchment MAR (Source: Midgley et al. 1994a,b,c).

River MAR (106m3)
Crocodile River 209.5
Elands / Hex River 112.3
Marico River 125.5
Molopo River 49.2
Mooi River 238.9
Vaal River 50.1
Harts River 147.7


Impoundments and Inter-basin Transfers

There are 28 large impoundments within the North West Province (Map 11). Water from these is mainly used for: domestic supply, industry, agriculture and recreation.

Because of the variability in supply from natural sources, several inter-basin transfers (IBT's) have been developed. These are: Water quality

Water quality information is available for the major impoundments of the North West. The parameters being measured are Total Dissolved Solids (TDS), sulphates (SO4), fluorides (F), Chlorides (Cl), total aluminium (TAL), sodium (Na), Potassium (K), magnesium (Mg) and calcium (Ca). Table 10.1.3 presents a summary of the water quality of the major reservoirs in the North West Province for the period 1990 to 2000.

Table 10.1.3: Summary water quality (mg/l) of reservoirs within the North West Province (Source: DWAF HIS QualDB).

Station Description TDS SO4 F Cl TAL Na K Mg Ca
A2R001Q01 Hartbeespoort Dam 366 66 0.47 47.7 113.9 42.7 9.4 16.7 32.8
A2R003Q01 Olifantsnek Dam 172.066 23.7 0.2 5 76.877 7.253 3.095 11.76 16.211
A2R005Q01 Buffelspoort Dam 42.5 5.9 0.12 4.9 18.2 1.7 1.38 3.1 3.4
A2R006Q01 Bospoort Dam 496 79.4 0.27 99.6 126.4 81.5 13.44 22.5 32.8
A2R007Q01 Lindleyspoort Dam 128 12.6 0.22 5.2 65.693 5.7 3.54 8.1 11.786
A2R011Q01 Kosterrivier Dam 149 11.3 0.26 5.5 79 6 3.69 9.8 14.8
A2R012Q01 Klipvoor Dam 488 65.75 0.57 70.75 166.79 73.15 13.145 18.102 35.793
A2R013Q01 Swartruggens Dam 95.071 8.4 0.175 5 49.206 5.9 1.71 5.5 7.65
A2R014Q01 Vaalkop Dam 346 46.7 0.95 38.3 131.4 36.4 7.28 18.4 29.4
A2R015Q01 Roodekopjes Dam 622 128.95 0.69 94.2 174.7 86.5 9.12 32.65 44.75
16Q01 Leeukraal Dam 555 77.55 0.39 70.6 182.8 78.15 12.85 19.7 42.75
A3R001Q01 Marico-Bosveld Dam 223 9.5 0.21 5 130.8 5.8 1.701 16.8 22.95
A3R002Q01 Klein Maricopoort Dam 317.5 26.8 0.54 13.9 165.7 10.8 6.23 23.1 34.1
A3R003Q01 Kromellen-boog Dam 126 11.8 0.29 5 65.7 5.4 2.34 6.881 14.3
A3R004Q01 Molatedi Dam 191 8.3 0.31 4.7 109.3 5.616 5.67 14.6 17.1
C2R001Q01 Boskop Dam 489 112.7 0.156 21.4 195 22.2 2.165 43.1 51.25
C2R002Q01 Johan Neser Dam 392 54.2 0.32 11.1 187.5 16.3 6.4 30.5 36
C2R003Q01 Klerkskraal Dam 392.5 5.9 0.15 4.35 244.35 4.35 1.44 31.75 44.922
C2R004Q01 Potchefstroom Dam 512 101.5 0.16 21.3 220.4 20.5 2.28 45.1 53
C2R005Q01 Klipdrift Dam 456 98.85 0.35 55.3 134.45 54 7.955 24.5 36.3
C2R006Q01 Elandskuil Dam 346 4.25 0.183 6.85 205.9 4.6 1.4 31.2 31


Station Description TDS SO4 F Cl TAL Na K Mg Ca
A2R001Q01 Hartbeespoort Dam 366 66 0.47 47.7 113.9 42.7 9.4 16.7 32.8
A2R003Q01 Olifantsnek Dam 172.066 23.7 0.2 5 76.877 7.253 3.095 11.76 16.211
A2R005Q01 Buffelspoort Dam 42.5 5.9 0.12 4.9 18.2 1.7 1.38 3.1 3.4
A2R006Q01 Bospoort Dam 496 79.4 0.27 99.6 126.4 81.5 13.44 22.5 32.8
A2R007Q01 Lindleyspoort Dam 128 12.6 0.22 5.2 65.693 5.7 3.54 8.1 11.786
A2R011Q01 Kosterrivier Dam 149 11.3 0.26 5.5 79 6 3.69 9.8 14.8
A2R012Q01 Klipvoor Dam 488 65.75 0.57 70.75 166.79 73.15 13.145 18.102 35.793
A2R013Q01 Swartruggens Dam 95.071 8.4 0.175 5 49.206 5.9 1.71 5.5 7.65
A2R014Q01 Vaalkop Dam 346 46.7 0.95 38.3 131.4 36.4 7.28 18.4 29.4
A2R015Q01 Roodekopjes Dam 622 128.95 0.69 94.2 174.7 86.5 9.12 32.65 44.75
A2R016Q01 Leeukraal Dam 555 77.55 0.39 70.6 182.8 78.15 12.85 19.7 42.75
A3R001Q01 Marico-Bosveld Dam 223 9.5 0.21 5 130.8 5.8 1.701 16.8 22.95
A3R002Q01 Klein Maricopoort Dam 317.5 26.8 0.54 13.9 165.7 10.8 6.23 23.1 34.1
A3R003Q01 Kromellen-boog Dam 126 11.8 0.29 5 65.7 5.4 2.34 6.881 14.3
A3R004Q01 Molatedi Dam 191 8.3 0.31 4.7 109.3 5.616 5.67 14.6 17.1
C2R001Q01 Boskop Dam 489 112.7 0.156 21.4 195 22.2 2.165 43.1 51.25
C2R002Q01 Johan Neser Dam 392 54.2 0.32 11.1 187.5 16.3 6.4 30.5 36
C2R003Q01 Klerkskraal Dam 392.5 5.9 0.15 4.35 244.35 4.35 1.44 31.75 44.922
C2R004Q01 Potchefstroom Dam 512 101.5 0.16 21.3 220.4 20.5 2.28 45.1 53
C2R005Q01 Klipdrift Dam 456 98.85 0.35 55.3 134.45 54 7.955 24.5 36.3
C2R006Q01 Elandskuil Dam 346 4.25 0.183 6.85 205.9 4.6 1.4 31.2 31
C2R007Q01 Rietspruit Dam 415 4 0.16 5.7 251.8 4.1 1.19 32.5 54
C3R001Q01 Schweizer-Reneke Dam 291 14.3 0.49 15 156.3 26.5 12.99 15.1 20.3
C3R003Q01 Barbers Pan 1004 18.8 0.58 215.7 386.3 206.7 34.32 39.2 17.1
C3R006Q01 Taung Dam 182.322 6.6 0.22 5.55 100.75 12.6 4.69 7.15 19.15
D4H026Q01 Cooke's Lake (Molopo River) 595 38.8 0.16 52.5 304.2 29.1 3.3 55 53.4
D4R003Q01 Disaneng Dam 354.443 16.4 0.33 25.8 184.4 31.3 6.272 24.3 23.525
D4R004Q01 Setumo Dam 451 22.9 0.26 38.7 226.3 38 6.22 35.9 28.1


Total dissolved solids - are a reflection of the total dissolved inorganic compounds, also known as total dissolved solids (TDS). These indicate current levels of salinity of water. High TDS levels in surface waters may be due to natural causes (from leaching from the underlying bedrock or soils) or more frequently from human induced pollution (such as irrigation return-flows, industrial and mining effluents. For a number of dams listed in table 10.1.3 TDS concentrations exceed the upper limits of the Target Water Quality Ranges of 200 mg/l for domestic use as stipulated in South African Water Quality Guidelines (see appendix 1). These are the following: Bospoort Dam, Klipvoor Dam, Roodekopjes Dam, Leeukraal Dam, Boskop Dam, Potchefstroom Dam and Barbers Pan. Apart from Barbers Pan and Leeukraal Dam, all the dams are downstream of mining areas or large urban centres.

Sulphates - excessive sulphate concentrations are frequently linked to acid mine drainage (AMD) problems. Roodekopjes Dam, on the Crocodile River catchment draining the Gauteng region was found to have the highest sulphate concentrations. However, these do not exceed the DWAF TWQR for human consumption.

The ecological status and sensitivity of catchments and impoundments is a system of grading which uses four main categories (see table 10.1.4). The ecological status of the main reservoirs and their catchments within the North West Province is presented in table 10.1.5.

Table 10.1.4: Ecological importance and sensitivity categories (Source: Kleynhans 1999).

Ecological Importance And Sensitivity Category
Very high
Quaternary catchments that are considered unique on a national or even international level based on unique biodiversity (habitat diversity, species diversity, unique species, rare and endangered species). These rivers (in terms of biota and habitat) are usually very sensitive to flow modifications and have no or only a small capacity for use.
High
Quaternary catchments that are considered to be unique on a national scale due to biodiversity (habitat diversity, species diversity, unique species, rare and endangered species). These rivers (in terms of biota and habitat) may be sensitive to flow modifications but may have a substantial capacity for use.
Moderate
Quaternary catchments that are considered to be unique on a provincial or local scale due to biodiversity (habitat diversity, species diversity, unique species, rare and endangered species). These rivers (in terms of biota and habitat) are usually not very sensitive to flow modifications and often have a substantial capacity for use.
Low/marginal
Quaternary catchments that are not unique at any scale. These rivers (in terms of biota and habitat) are generally not very sensitive to flow modifications and usually have a substantial capacity for use.


TABLE 10.1.5: Ecological status of selected reservoirs in the North West Province (Source: Kleynhans 1999).

Name Ecological status
Eastern District Council
Hartebeespoort Dam Moderate
Klipvoor Dam Moderate
Vaalkop Dam Moderate
Roodekopjes Dam Moderate
Koster River Dam Moderate
Rustenburg District Council
Bospoort Dam Moderate
Molatedi Dam Moderate
Olifantsnek Dam Moderate
Buffelspoort Dam Moderate
Lindleyspoort Dam Moderate
Central District Council
Kromellenboog Dam Low/Marginal
Marico-Bosveld Dam Low/Marginal
Lehurutshe Dam Low/Marginal
Setumo Dam No data
Disaneng Dam No data
Cookes Lake No data
Southern District Council
Klerkskraal Dam N/D
Boskop Dam Moderate
Klipdrift Dam Moderate
Bloemhof Dam Moderate
Rietspruit Dam Moderate
Johan Neser Dam Moderate
Schweizer-Reneke Dam Moderate
Potchefstroom Dam Moderate
Elandskuil Dam Moderate
Huhudi District Council
Spitskop Dam Moderate
Taung Dam Moderate
N/D - Not Determined

The majority of dams and their catchments are categorised as moderate.
The trophic status (e.g. eutrophic or mesotrophic) is a reflection of the nutrient input flowing into an impoundment. The trophic status of selected reservoirs in the North West Province is presented in Table 10.1.6. The trophic status of certain of the dams has not been determined because of a lack of monitoring data.

Table 10.1.6: Status of selected reservoirs in the North West Province (Source: DWAF 2001).



Name Trophic Status Limitation Toxic incidents Dominant Algae Other Problems
Eastern District Council
Hartebeespoort Dam Eutrophic - Hypertrophic P limited Yes Cyanobacteria (Microcystis & Anabaena) Water Hyacinth Fish kills
Klipvoor Dam Hypertrophic N Limited Potentially Cyanobacteria (Microcystis & Anabaena) Fish kills
Vaalkop Dam Meso- trophic P limited Potentially Cycolotella TrachelomonasCeratium
Roodekopjes Dam Mesotrophic / Eutrophic P limited No CycolotellaTrachelomonasOocystis Water hyacinth
Koster River Dam N/D N/D N/D
Rustenburg District Council
Bospoort Dam Hypertrophic N/D N/D Microcystis scum (January 1999) and fish kill (October 1999)
Molatedi Dam N/D N/D N/D
Olifantsnek Dam N/D N/D N/D Fish kill (September 2000)
Buffelspoort Dam N/D N/D N/D
Lindleyspoort Dam Mesotrophic / Eutrophic N/D Potentially Cyanobacteria (Microcystis & Anabaena) Water primrose
Central District Council
Kromellenboog Dam N/D N/D N/D
Marico-Bosveld Dam N/D N/D N/D
Lehurutshe Dam N/D N/D N/D
Barbers Pan N/D N/D N/D
Setumo Dam Eutrophic N/D Potentially Coelastrum OocystisAnabaena
Disaneng Dam Mesotrophic N/D No Cosmarium / Oocystis
Cookes Lake Eutrophic N/D Potentially Cyclotella Mircocystis
Klerkskraal Dam N/D N/D N/D
Boskop Dam Mesotrophic N/d No Chrysophyta Chlorophyta
Klipdrift Dam N/D N/D N/D
Bloemhof Dam Highly enriched Light limited Yes Cyanobacteria (Microcystis & Anabaena) Fish kills
Rietspruit Dam N/D N/D N/D
Johan Neser Dam N/D N/D N/D
Schweizer-Reneke Dam N/D N/D N/D
Potchefstroom Dam N/D N/D N/D
Elandskuil Dam N/D N/D N/D
Huhudi District Council
Spitskop Dam N/D N/D N/D Incubation point for Cylindrospermopsis raciborskii
Taung Dam N/D N/D N/D Incubation point for Cylindrospermopsis raciborskii
N/D - not determined

Hypertrophic conditions have been reported from Hartebeespoort Dam, Klipvoor Dam, Bospoort Dam, Setumo Dam, Cookes Lake and Bloemhof Dam with the latter being recorded as the most severe. Fish kills caused by the development of toxic conditions arising from hypertrophication have been reported from Hartebeeespoort and Bloemhof Dams.

Water quality information for rivers of the Province is unavailable at present.

Wetlands

There are approximately 40 major wetland areas within the North West Province (Walmsley et al. 1999). They are composed of riverine wetlands, dolomitic eyes, palustrine wetlands and endorheic wetlands or pans (Map 12) of which Barbers Pan, a Ramsar site, is the Province's largest. Barbers Pan, situated 15 km north-east of Delareyville, is a large permanent shallow alkaline lake. The pan is approximately 2 000 ha in area and has an average depth of 10 m with a catchment area of 30 km2. The pan is considered to have a high ecological status and is especially important for waterfowl for breeding and feeding. When surrounding pans dry up, Barbers Pan becomes a significant habitat in the region. Many wetlands have been lost or seriously degraded world-wide, with some 50% of known wetlands have been lost to agricultural and urban "reclamation" during the twentieth century. The remaining wetlands in North West Province are considered to be ecologically sensitive areas, particularly the dolomitic eyes. Refer to Chapter 2 for further information on the wetlands of the Province.

10.1.5 Impact

The main impacts on the freshwater systems of the North West Province are water quantity and a quality impacts which result in ecological impacts.

Impacts on water quantity

Abstraction of groundwater from dolomitic compartments for irrigation for agriculture affects the water quantity flowing from dolomitic eyes, which are the sources of several important rivers in the Province, such as the Molopo and Groot Marico Rivers. Significant reductions in flow from several dolomitic eyes and springs in the Province have been reported. These include the Molopo, Polfontein and Dinokana Rivers.

Although indispensable as reservoirs for water storage, dams, weirs and other barriers disrupt the natural flow regimes of rivers. The construction of Disaneng and Setumo Dams on the Molopo River has resulted in this river becoming non-perennial. The construction of dams also results in changes in conditions from riverine (flowing waters) to lacustrine (standing waters) (Walmsley et. al, 1999). All major rivers in the North West have been dammed and transformed as mentioned above.

Interbasin transfers (IBTs) - Interbasin transfers (IBTs) of water from one catchment to another has major water quantity ramifications for rivers. The donor river inevitably incurs a reduction in flow, while the receiving river experiences an increase in flow (Snaddon & Davies, 1997). The river regulation through dams as well as IBTs also affects the natural flow variability of the receiving river, particularly in semi-arid environments. Such is the case of the international water transfer scheme from the Groot Marico River to the Ngotwane River in Botswana.

Water quality impacts

Impoundments - Dams also affect the thermal and dissolved oxygen conditions as well as nutrient levels in the water, with the water contained within the impoundment differing in quality from both downstream and upstream conditions (Snaddon, 1999). This is particularly evident in the Hartebeespoort Dam on the Crocodile River.

Pollution of surface water resources - The scarcity of water is compounded by the deterioration in quality as a result of water pollution. Typical point-source pollution in the North West Province includes domestic sewage, industrial effluents and acid mine drainage (table 10.1.7). Non-point source (or diffuse) pollution, reported to comprise up to 80% of the pollution entering major river systems, includes agricultural runoff of fertilizers, insecticides and herbicides from agricultural land and stormwater runoff from urban surfaces such as roads. Non-point source pollution is the most difficult to manage due to its diffuse nature.

As the headwaters of the Crocodile River are located in the highly industrialised urban area of Gauteng, return flows are predominantly treated sewage and industrial effluents. As a result, the river is subject to high levels of pollution as well as increases in flow, largely due to return flows from the Vaal River. This impacts upon the water quality downstream of Gauteng including Hartebeespoort Dam where eutrophication frequently occurs (Walmsley et al. 1999).

Table 10.1.7: Pollution type per major catchment in the North West Province (source: Midgley et al. 1994 a,b,c).

Catchment Description Dominant Pollution type
Crocodile / Elands Rivers Eastern District Council
  • Treated and untreated domestic sewage
  • Industrial effluent
Marico / Heks Rivers Rustenburg District Council
  • Treated and untreated domestic sewage,
  • Industrial and mining effluent
Marico / Molopo Rivers Central District Council
  • Treated and untreated domestic sewage
Mooi / Vaal Rivers Southern District Council
  • Treated and untreated domestic sewage,
  • Industrial and mining effluent
  • Agricultural return flows
Harts River Huhudi District Council
  • Treated and untreated domestic sewage, Agricultural return flows


Salinisation - is the progressive increase in the concentration of salts in water. It can be measured by means of total dissolved solids (TDS) levels. It occurs in both surface and ground water. Salinisation of rivers occurs primarily as a result of mining and industrial activities and agricultural return flows. Table 10.1.8 presents summary salinisation sources for the major catchments in the North West Province (Walmsley et. al 1999). Several dams in the Province have shown high TDS levels, viz. Bospoort Dam, Klipvoor Dam, Roodekopjes Dam, Leeukraal Dam, Boskop Dam, Potchefstroom Dam.

Table 10.1.8: Salinisation sources in the North West Province.

Catchment Description Dominant salinisation source
Crocodile / Elands Rivers Eastern District Council Industrial / Agriculture
Marico / Heks Rivers Rustenburg District Council Geology
Marico / Molopo Rivers Central District Council Geology
Mooi / Vaal Rivers Southern District Council Mining
Harts River Huhudi District Council Agriculture / Geology


Acidification - refers to changes in the acidity of water, reflected in the pH measurements. The acidity of natural waters is determined largely by geological and atmospheric conditions. However, human-induced acidification of surface waters has occurred due to industrial effluents, acid mine drainage and acid rain. This can lead to the mobilization of cadmium, cobalt, copper, lead, zinc and other heavy metals as well as radioactive elements such as uranium in the water column and sediments. This could impact on the suitability of the water for domestic consumption as well as the aquatic biota (Walmsley et. al 1999).

Physical impacts on river channels and impoundments

Sedimentation and silt migration - of watercourses is another significant surface water impact. This is due to land degradation (such as overgrazing and poor agricultural practices), soil erosion, construction activities and destruction of the riparian vegetation in the catchment. The result is highly suspended solid loads in the water, which may cause sedimentation affecting the hydrological characteristics of the catchment. High sediment loads often become trapped in impoundments, reducing their storage capacity (Walmsley et. al 1999).

Ecological impacts

Habitat integrity - ecological sensitivity (or fragility) refers to the system's ability to resist disturbance and its capability to recover from disturbance once it has occurred (resilience). Negative ecological changes to freshwater systems can occur as a result of influences such as flow regulation, water abstraction, pollution and nutrient enrichment. These may impact directly on the habitat integrity of aquatic or riparian fauna and flora (such as peat harvesting in the riparian zone of the Schoonspruit River) or the water quality such as dissolved oxygen levels in the water, heavy metals and other toxic substances.

Aquatic biodiversity - in general, South African riverine biota (plants, reptiles, amphibians, fish and invertebrates) are considered to be naturally well adapted to changing hydrological conditions. It has also meant that many species have become highly tolerant of environmental extremes as well as being reproductively opportunistic. However, anthropogenic stress on aquatic ecosystems may result in the tolerance ranges of the more sensitive species being exceeded and localized extinctions of these species.

The construction of dams, weirs and other barriers has major ecological implications for the biota inhabiting rivers. Dams and weirs disrupt the longitudinal continuity of rivers, preventing the movement of migratory species such as eels as well as fragmenting populations of fish and invertebrates making them more vulnerable (Skelton 2001). Dams also affect the flow conditions of rivers, which may have a negative impact on those species which rely on the natural water flow regime of the river or which require seasonal increases in water flow for breeding purposes. Several impoundments in the North West have been invaded by aquatic alien plants particularly water hyacinth. Noticeable infestations of these occur during favourable climatic conditions at both Hartebeespoort and Bloemhof Dams.

IBTs have an impact on the natural cycle of rivers and can result in the encroachment of reeds and affect seasonal flooding of floodplains and wetlands. The net result is that flow conditions in both the donor and the receiving rivers are drastically altered, affecting the habitat integrity of the resident biota downstream. Several fish species as well as other alien and pest species may be transferred from one catchment to another through IBTs (Walmsley et. al 1999).

Siltation and sedimentation of watercourses from poor land use practices in the catchment also results in a negative ecological impact. This includes smothering breeding sites and organisms, decreased light penetration affecting natural productivity and visibility (Walmsley et. al 1999). Refer to chapter 11 for more information on aquatic ecological and biodiversity effects.

Water quality also affects the microbiology of surface water resources, such as the presence and abundance of disease causing bacteria, viruses and parasites. These are often associated with sewage effluents and measurements of the bacteria Eschereshia coli in the water are used to assess whether the water is safe to drink. High E.coli counts were recorded at a monitoring site in the Seshabele River downstream of Mogwase sewerage works in 1999, corroborating the fact that this sewerage works was overloaded and not functioning properly at the time (Rustenburg District Council pers. comm.).

Enrichment of surface water and eutrophication

Eutrophication has been defined as the process whereby nutrients accumulate in a body of water. This process is often accelerated by nutrient-rich discharges from agriculture or sewerage, leading to a rapid and excessive growth of algae and water plants and undesirable changes in water quality. In most lakes and dams, plant production is regulated mainly by the availability of nutrients, principally nitrogen and phosphorous compounds. The manifestation of eutrophic conditions due to the proliferation of algal scums sometimes accompanied by toxic events resulting in fish kills. Eutrophication is a serious water quality impact in the Province and may in fact be the most serious problem in the future. Some of the effects of eutrophication in the Province are: 10.1.6 Responses

Legislative Responses

International Conventions

The Helsinki Rules on shared watercourses - each basin state has a right to the reasonable and equitable share of the water in the basin and that the greatest benefit should be achieved with the least disadvantage to other states. This applies to the the Limpopo River, which is shared by North West and Botswana.

SADC Protocol on Shared Watercourse Systems - ratified by South Africa, Lesotho, Botswana and Mauritius and of relevance to the management of the Limpopo and Molopo Rivers, shared by North West and Botswana.

The cooperation in the management of shared water resources between South Africa and Botswana is formalised by the Limpopo Basin Technical Committee at national level. Decisions made by this committee affect the North West Province.

Convention on Wetlands of International Importance - Ramsar Convention is applicable to Barbers Pan, the Province's only Ramsar site - see chapter 11 for details.

National legislation

The vital nature of water as a developmental resource has prompted the government for many years to pass laws and regulations aimed at protecting the resource (e.g. the Water Act, Act No. 54 of 1956). In the last five years, South Africa's water policy has undergone significant developments, with the promulgation of the National Water Act (Act No. 36 of 1998) and the Water Services Act (Act No. 108 of 1997). National legislation and policies concerned with water management is presented in Table 10.1.9.

Table 10.1.9: Policies and legislation relevant to the management of water resources of the North West Province.

Act/Guideline/Policy Description
White Paper on Environmental Management Policy The goals of this policy are:
  • effective institutional framework and legislation
  • sustainable resource use and impact management,
  • holistic and integrated planning,
  • participation and partnerships in environmental governance,
  • empowerment and environmental education, and
  • information management and international co-operation.
White Paper on the Conservation and Sustainable use of SA Biological Diversity (GN 1095, 28 July 1997) The goals of this policy are inter alia:
  • sustainability,
  • minimising impact on biological diversity,
  • application of the precautionary principle, and
  • ensuring that benefits from use of resources serves the national interest.
White Paper on Integrated Pollution and Waste Management for South Africa. (GN 227, 17 March 2000) The vision for this policy is to develop and maintain an integrated pollution and waste management system that contributes to sustainable development and measurable improvement of the quality of life, by harnessing the energy and commitment of all South Africans for the effective prevention, minimisation and control of pollution and waste.
General Policy in terms of the Environment Conservation Act 73 of 1989 (GN 51, 21 Jan 1994) This policy has amongst its aims:
  • environmental rights for all,
  • sustainable use of resources,
  • the maintenance of natural systems,
  • sustainable development, and
  • the establishment of a partnership between the State and the community (including private sector, industry and the international community) to pursue environmental goals.
White Paper: A Minerals and Mining Policy for South Africa (GN 2359 20 October 1998) This policy strives to facilitate the establishment of a balance between a cost effective and competitive mining industry and the imperative to protect the environment. The Policy calls for inter alia:
  • the employment of environmentally competent staff in government,
  • a co-ordinated and integrated environmental management approach to the planning, management and use of all natural resources,
  • increased public involvement, and
  • ongoing research into environmental management and pollution control.
Minerals Act 50 of 1991 Sections 38 and 39 of this Act require the holder of a mining authorisation to compile and submit an Environmental Management Programme Report, and undertake rehabilitation of the land surface. The Regulation describes the required processes for environmental management on the site, pecuniary provision in terms of the EMP, performance assessment and monitoring of the provisions of the EMP.
National Water Act (36 of 1998) This Act makes provision for the sustainable and equitable protection, use, development, conservation, and management and control of water resources.Reg 704 relates to the use of water for mining and associated activities. Any person intending to open a new mine must notify DWAF not less than 14 days before commencement of the activity, submit their EMP, notify them of cessation of activity and report any emergency incident (or potential incident) relating to water to DWAF.
National Environmental Management Act (107 of 1998) This Act deals with the prevention and remediation of soil erosion, stocking rates and prohibits the destruction of wetlands.NEMA also deals with Integrated Environmental Management (IEM) - including:
  • identification, prediction and evaluation of the actual and potential impacts on the environment;
  • risks, consequences and alternatives and options for mitigation of activities;
  • monitoring and management of environmental impacts, and the effectiveness of the implementation of mitigating measures.
Water Services Act (Act 108 of 1997)
  • Is chiefly concerned with the provision of water supply and sanitation to the people of South Africa (see chapter 13 on water supply and sanitation).


National Water Act (Act No. 36 of 1998) - It is important to note that South Africa's water policy does not aim to, at all costs, prevent impacts to the water environment as this will not allow the country to achieve much-needed social and economic growth. However, the National Water Act (NWA) states that the key, is "to balance long-term protection of water resources with short- and medium-term demands for using them." The challenge is to obtain the right balance with respect to equity and sustainability.

The NWA stipulates that "the protection of water resources is fundamentally related to their use, development, conservation, management and control". The protection of water resources rests on a classification system for water resources which provides guidelines and procedures for determining different classes of water resources. Currently the classification system for rivers is based on the ecological integrity status of rivers and six different classes are proposed (A-F) (Table 10.1.10).

Table 10.1.10: Classification system for the assessment of the ecological integrity status of surface water resources (Source: DWAF 1997).

Class Ecological Integrity Status
A Unmodified, natural; the resource base reserve has not been decreased - the resource capability has not been exploited.
B Largely natural with few modifications; the resource base reserve has been decreased to a small extent. A small change of natural habitats and biota may have taken place but the ecosystem functions are essentially unchanged.
C Moderately modified; the resource base reserve has been decreased to a moderate extent. A change of natural habitat and biota have occurred but the basic ecosystem functions are still predominantly unchanged.
D Largely modified; the resource base reserve has been decreased to a large extent. Large changes in natural habitat, biota and basic ecosystem functions have occurred.
E Seriously modified; the resource base reserve has been seriously decreased and regularly exceeds the resource base. The loss of natural habitat, biota and basic ecosystem functions is extensive.
F Critically modified; the resource base reserve has been critically decreased and permanently exceeds the resource base. Modifications have reached a critical level and the resource has been modified completely with an almost total loss of natural habitat and biota. In the worst instances the basic ecosystem functions have been destroyed and the changes are irreversible.


The determination of the classes of water resources is essential to formulate the resource quality objectives for important rivers. The resource quality objectives should take cognizance of the following components: The Reserve, which is the only right specified in the National Water Act, consists of two parts: The Reserve must specify the quantity of water that must be present in the water resource, as well as the quality of the water for the resource to remain ecologically healthy, and to be able to provide the basic human needs for water.

All water uses under the National Water Act, which have an impact on the Reserve, are subject to the requirements of the Reserve. Thus, licenses cannot be issued for these different types of water use without the Reserve having been determined. It is important that the North West DACE develop the capacity to engage in the debate on water resource allocation in order to ensure compliance with the National Water Act requirements.

Other important aspects covered by the NWA include: Institutional Responses

Catchment Management Strategy (CMS) - the National Water Act is the legal instrument that gives effect to the country's water policy and embodies the principles of equity, efficiency and sustainability. In order to effectively manage these considerations, the Act provides for a National Water Resource Strategy (NWRS) and a Catchment Management Strategy (CMS). The NWRS provides a framework for protection, use, development, conservation, management and control of water resources for the country as a whole. The CMS should facilitate the management of the water resources within a catchment by: Catchment Management Agency (CMA) - DWAF is in the process of establishing a catchment management agency (CMA) for the Crocodile (West) and Marico Water Management Area (WMA), to give effect to Integrated Water Resource Management (IWRM) as stated in the NWA. This CMA is one of three pilot scale CMA's in South Africa. The Crocodile (West) and Marico CMA falls largely within the North West Province and also straddles the Limpopo and Gauteng Provinces. The Crocodile (West) and Marico CMA comprises a number of river forums and water user associations, which are charged with managing their respective sections of the catchments within the WMA. These are the following:
  1. Molopo River Forum (NWP)
  2. Marico River Forum (NWP)
  3. Thabazimbi River Forum (LP)
  4. Elands River Forum (NWP)
  5. Magalies River Forum (GP)
  6. Jukskei River Forum (GP)
  7. Hennops River Forum (GP)
  8. Apies-Pienaars River Forum (NWP & GP)
  9. Kwena River Forum (NWP)
The CMA is responsible for developing and implementing its Catchment Management Strategy, which is basically an integrated water management plan for the catchment. There are, however, still some challenges ahead. Other WMA's which fall partially within the boundaries of the North West Province are the Upper, Middle and Lower Vaal River WMA's (Map 49).

North West Province First Order Strategy - the DWAF formulated First Order Strategy for each of the provinces, which was published in July 1998. This publication details the demographics, economic profile and depicts some environmental conditions such as climate, topography, land-use and water resources. The First Order Strategy was produced at a provincial scale as well as at the District Council level and is used for planning purposes for the provision of water and sanitation services by the regional offices of DWAF.

Water quality monitoring for flowing and standing water bodies - is another important response. The River Health Programme which is a national programme implemented provincially, uses indices of "ecosystem health" which are used to monitor the status of the aquatic invertebrate fauna, fish, riparian vegetation. A number of sites on several key rivers in the North West have been surveyed, such as the Elands, Hex, Groot Marico and Schoonspruit Rivers (see chapter 15).

DWAF regularly monitors a number of impoundments in the North West Province for key chemical constituents. See table 10.1.3. for details.

National Working for Water (WfW) Programme - The WfW's main objective is to eradicate thirsty alien invasive trees from South Africa's river courses. The WfW is active in the North West, and is currently concentrating on alien infestations of wetlands and dolomitic eyes particularly in the Mafikeng and Rustenburg districts. The clearing of alien vegetation at these sensitive areas will ultimately have a positive effect on the ecological integrity of these water resources (see chapters 11 and 16 for more information).

Research - this is important for the acquisition of essential information for decision makers and resource managers. There is a need to provide relevant information timeously to underpin sound environmental decision making concerning the Province's water resources. The Water Research Commission (WRC) is the official funding body for water research in South Africa, and over half of the research funded is directed to water resource management.

Environmental education and capacity building - There are several environmental education programmes focusing on water which are currently being run in the North West. The NWDACE is involved with some of these, while others are being run by DWAF, universities, schools and other institutions. The NWDACE environmental education and empowerment sub-directorate recently were involved in promoting DWAF's 20/20 Vision to educators and schools in the Province (see chapter 14).

10.1.7 Outcomes

There can be no doubt that the economic and population development forces from within the Province will exert an ever-increasing demand on the quantity and quality of the water resource. As the population becomes economically empowered and adopts a more sophisticated life style, so the demand for more water and water of better quality will increase. To meet these demands in time with their development will call for careful and well coordinated planning.

On a national level, the outcomes of the responses are not known although Walmsley et al. 1999 has suggested that certain outcomes can be expected at national level (Table 10.1.11) and these can also be expected at a provincial level.

Table 10.1.11: Probable outcomes of South African policy and legislation on water resources (Walmsley et al. 1999).

Response Negative Outcomes Positive Outcomes
National Water Act 36 of 1998
Development of a national water strategy Time and finances used to complete the job may exceed its use. Neglects local strategies. If the strategy is implemented properly, the sustainability of water resources in South Africa may be assured.
Development of catchment management strategies This may be unsuccessful without the co-operation of other government departments and local authorities. Smaller management units (i.e. catchments are easier to manage, and more control over development and land-use planning is possible).
Development of a classification system and setting resource quality objectives Difficulties in determining a classification system that will suit all needs. In conjunction with catchment management, this could become a good integrative management tool.
Determination of the Reserve Even if the environmental reserve is determined, basic human needs will still have priority Will provide information essential to supply planning and water resource development.
Integrated Pollution Control through Receiving Water Quality Objectives and Pollution Prevention Monitoring and enforcement will still be required. Requires the co-operation of all water users. Will ensure an integrated approach to pollution control.
Establishment of CMAs and integrated catchment management Establishment of CMAs is a long-term project that requires substantial institutional change. If effective, CMAs will have greater power to ensure sustainable use of water in each catchment in a socially-acceptable and integrative way.
Demand management through water pricing Has substantial economic repercussions for the food-producing sector. Will create an ethic of awareness of water conservation and the value of water.
Water Services Act 108 of 1997 Increased access to water will increase demand - human need will always take preference over environmental need. Abstraction easier to manage and control.


10.1.8 Linkages

Water is intricately linked to virtually every aspect of human economic, social and other activity. Not only does the impact of man's activities affect the use of water, but the volume and quality of available water has an impact on man's activities. Thus, water is linked to all other chapters of this report. Some specific linkages are provided in Table 10.1.12.

Table 10.1.12: Water resource linkages.

Driving Forces Pressures State Impacts Responses
Social Population growth Mean annual runoff

Impoundments

Water Quality

Wetlands		 Positive impact Institutional legislation and policy
Climate Changed hydrology Negative impact
Mining Mining activities
Agriculture Population growth
Industry Population growth Ecological impact
Tourism Population growth Human impact


Issues surrounding water resources are cross-cutting and as a result this section is linked to almost all other sections in this report. However, important linkages are the following: 10.1.9 Data Issues

The DWAF has been solely responsible for the management of ground and surface water resources in the Province. Much of the data drawn from National and other databases regarding water, have some inadequacies, such as information gaps and un-calibrated data.

Water quality data is available from the Hydrological Information System Quality Database (HIS QualDB) from DWAF. Hydrological data is available from the Hydrological Information System of DWAF. The data accuracy of these databases requires investigation. Some studies have highlighted problems with data and gauging stations, while data from industry, mining and water treatment works is not always captured. A complete review of data within the Province is required.

Of the 28 large dams in the North West Province, 17 are monitored on a weekly basis by the Department of Water Affairs and Forestry (for regular updates see http://www-dwaf.pwv.gov.za/directorate/waters/damlevels). Records of the total volume of each dam and current capacity as well as the previous week and previous year's records are also kept.

A large number of flow gauging stations are not in good condition. A review is required to assess these stations and make the necessary repairs or calibration to ensure that accurate data is generated. The projected water requirements and the distribution of the resources of the North West Province needs to be established as a matter of priority, in order to balance the available supply with the future demand. The development of settlements and agriculture depends on accurate information being readily available.

Some other data issues include: An inventory of the North West Province's water resources is therefore required as a matter of urgency.

In order to use the information generated from indicators, a comprehensive data management system is required. This has already been developed to some extent, but has not yet been implemented in the whole of the North West Province. The Water Management System is a computer programme developed specifically for DWAF to support decision-making and to provide the necessary information needed to manage water resources, sources and monitoring in South Africa.

The system comprises of the following core components: The goals of the Water Management System (WMS) include: 10.1.10 Environmental Indicators

The following national inland water indicators have been identified by the National Indicators initiative of DEAT and the CSIR.

Limited Freshwater Resources: Changing Freshwater Quality: Degradation & Loss of Freshwater Ecosystem Integrity: See section 10.3 for more details.

10.1.11 Conclusions and recommendations

The North West Province is classified as a water-scarce province. There is presently insufficient water for all, and what water there is, is not equitably distributed.

The water resources of the Province are becoming increasingly stressed, largely due to population growth, development, agriculture and mining. The attention by managers of environmental matters at all levels is urgently required to ensure sustainability of the water resources in the Province.

Aquatic systems in the Province are susceptible to a wide range of extreme climatic conditions (e.g. droughts and floods). In all catchments evaporation exceeds rainfall and few river systems are perennial.

There are 40 major wetland areas and one international Ramsar site (Barbers Pan).

There are 28 major impoundments most of which were constructed for irrigation purposes. Most of the impoundments have been classified as being of moderate ecological status.

There is a substantial import of water from outside the Province and most of the surface waters in the Province are polluted to varying extent from mining (through acid mine drainage), effluent discharges, urban and agricultural runoff and from sources outside the Province (particularly Gauteng).

There are two major water quality problems within the North West Province, notably eutrophication and salinisation. Both of these arise because of excessive loads of chemicals from industrial and domestic sources.

Eutrophication is probably the most serious of the Province's water quality problems. It has led to nuisance algal blooms and plant growths in rivers and dams throughout the Province. This has a negative effect on the tourism value of these water bodies, particularly Hartebeespoort Dam.

Several impoundments in the North West have been invaded by aquatic alien plants particularly water hyacinth. Noticeable infestations of these occur during favourable climatic conditions at both Hartebeespoort and Bloemhof Dams.

In order to maintain the long-term sustainability of the Province's water resources, DWAF's Water Management System needs to be implemented. The system should be designed so that important parameters are measured, recorded, stored and analysed on a regular basis. The data can then be used to establish baseline trends in water quantity and quality. Changes in the quality or available quantity of the resource can then be identified and managed accordingly.

The North West has four Water Management Areas (WMAs) within its provincial boundaries: Crocodile (West) and Marico, Upper, Middle and Lower Vaal WMAs. The establishment of the former has been prioritised as one of three national pilot CMAs. The water management strategy for important catchments within these WMAs needs to be developed and needs to be supported by the accurate collection of surface and groundwater data.

The classification, the Reserve and Resource Quality Objectives need to be determined for important rivers in the Province, such as the Elands, Hex and Marico Rivers.

Training in water management responsibilities at the levels of District/Regional Councils, Water Services Authorities and Catchment Management Agencies should be an on-going process. This could either be done through formal training sessions with regular back-up support, or, where consultants are used to analyse data or any other project, they could be used to transfer management skills.

It is recommended that NWDACE develops capacity to participate in the issuing of water use licences by DWAF. This will ensure integration of this process and the consideration of environmental aspects in terms of the NWA and NEMA. NWDACE should also engage in the public participation process related to the issuing of significant water use licences.

Health services should be improved in rural areas in order to assist in managing the effects of water quality problems and other water borne diseases.

10.2 Groundwater Resources

10.2.1 Introduction

Groundwater or subterranean water resources occur in openings in the rock material in the subsurface. These openings could be pores, cracks, fractures and dissolution cavities. In carbonate rocks (i.e. dolomite) large volumes of rock material could have been dissolved forming subterranean caverns that could even threaten the geotechnical stability of the terrain. Groundwater is recharged by rainfall (mostly on annual basis) and stream infiltration. Groundwater can discharge in the form of springs or form a baseflow to surface water bodies. In the North West Province, ground and surface water are integrated and interdependent as dolomitic eyes or springs are the sources of several major rivers which rise within the boundaries of the Province, such as Groot Marico, Mooi and Molopo Rivers. Groundwater can also discharge through evaporation in pans.

Groundwater is of vital importance in the North-West Province. Predominantly rural and underdeveloped groundwater is in many instances the only source of water for many rural people, particularly in the arid western region of the Province. More than 80% of rural communities in the Province depend on groundwater as a sole source of domestic water. Despite its importance, groundwater resources remain under threat of quantitative and qualitative degradation due to various anthropogenic pressures. This is not unique for the Province, however, due to the limited surface water resources (especially in the western half of the Province), it is imperative to attenuate further degradation of this vital resource.

10.2.2 Driving forces



General driving forces include natural factors and human activities that impact on groundwater quality and quantity. The impact may also affect other indirect environmental changes. For example, compromising the recharge source may have environmental implications for large areas as a result of deepening of groundwater levels.

Climate

Rainfall is the most significant driving force with respect to groundwater recharge. The frequency and occurrence of wet and dry periods play a major role in the groundwater recharge rate and ultimately the quantity and quality of the resource. Climatic conditions (see Section 10.1) affect other environmental factors such as vegetation, soil cover etc., which affect the groundwater quality and occurrence. Permeability of the surface and percolation of surface water into aquifers and other groundwater features are also influenced by climatic conditions.

Population

Population growth and urbanisation place additional demands on groundwater resources. Because the groundwater reserves are not exactly specified, demands may in many instances exceed supply. The influence of other major driving forces is expected to intensify in the future mainly due to expected population growth. However, population growth projections have to be gauged against the on-going AIDS epidemic. Corrected population estimates are important in determining the demand on groundwater resources and quality protection measures.

Urbanisation

Residential areas and especially informal settlements influence both groundwater quantity and quality. The magnitude of this impact is very site-specific and cannot be overly generalised. However, some indications from groundwater quality point to a potentially significant impact resulting from poorly managed and serviced residential areas.

Large, urbanised residential areas are generally serviced with acceptable technologies to reduce pollution of groundwater resources. Even so intermittent sewer blockages and pipe leaks cause occasional pollution even in well-managed centres such as Klerksdorp, Potchefstroom and Vryburg.

Policy and legislation

Policy and legislation such as the National Water Act (Act 36 of 1998) is central to the management of water resources from national to catchment level. Legislation therefore influences the pressures, state, impacts and responses pertaining to the water resources (Walmsley et al. 1999). See section 10.1 for more details.

10.2.3 Pressures

Groundwater resources are affected by two main factors: groundwater depletion and quality deterioration. Groundwater depletion is associated with: These depletion factors, in combination with beneficial users, define groundwater demand versus groundwater availability pressure for the North-West Province. The effect of demand/availability pressures is cumulative and may require interventions in areas where rapid growth in population occurs in a region with limited groundwater resources. The western section of the Province on the edge of Kalahari is especially vulnerable in this regard. The expected trend is towards increasing pressure in the demand for water, especially in the context of the National Water Act (Act No. 36 of 1998), which mandates safe water provision to all citizens.

Mining

Mining exerts significant pressures on groundwater quality. Although the overall mineralisation of groundwater resources is not extremely high, the variability is, especially in the eastern section of the Province (due to combined effects of mining and residential pollution). In some areas (especially non-dolomitic areas), low pHs may occur at mines affected by acid mine drainage (AMD).

Mining in the north-eastern side of the Province (platinum and other rare metals) and Potchefstroom and its eastern surroundings (e.g. Klerksdorp, Orkney) does not only affect groundwater quality, but also the water balance (quantity), as there are large-scale transfers occurring at some mines.

From a water quality point of view, platinum mines can affect the surrounding environment more substantially due to acid mine drainage (AMD) problems from mine residue and waste dumps. Although carbonate buffering in dolomite regions is quite effective in reducing AMD problems at gold-producing mines, the sheer size of gold-mining operations exert significant pressure on groundwater resources. Large-scale withdrawals of groundwater from mined areas also affect hydrology of both surface and subsurface systems. Surface streams often act as recharge source for underlying aquifers and groundwater transfers are sometimes severely compromised.

Industrial development

Various industries in the predominantly eastern section of the Province exert pressure on the groundwater resources in several ways. Most industries in this region support mining activities in the area, but also provide processed food and agricultural products. Locally the subsurface release of harmful chemicals from oil industries and retailers may adversely affect groundwater resources, because organic chemicals tend to be dangerous in minute concentrations (e.g. benzene derivates in fuels, industrial solvents).

Agriculture

Agriculture is relatively well developed and is an important provider of earnings for the Province. Agriculture is also the largest sector user of water in the North West Province. Pressures on ground water resources are largely due to large quantities of water required for irrigation by central pivot systems of crops such as maize and sunflowers. Return flows containing fertilizer and pesticide residues exert pressure on the quality of the affected groundwater.

Domestic requirements

Large areas of the North West Province are dependent on groundwater for domestic consumption, particularly in the arid western region. This region has a paucity of reliable surface water resources with few permanent river courses with sufficient flows. As over 60% of the population of the Province resides in rural areas, many people are dependent on groundwater resources, for domestic and stock watering. This exerts both water quality and quantity pressures on available groundwater reserves.

Altered surface water hydrology

As ground and surface water resources are interdependent, pressures on surface water may be felt on groundwater hydrology. As with large-scale transfers due to mining, artificial influence on streamflows have immediate and medium-term impact on groundwater and the surrounding environment.

10.2.4 State

Groundwater quantity

The North West Province is considered to have substantial groundwater reserves most of which are of a reasonable quality. Groundwater is located in a number of different types of aquifers. These include dolomitic (karstic) aquifers, intergranular aquifers and fractured aquifers (Map 13). The major groundwater storage regions in the Province are the following (Nel, et al. 1995):
  1. Ghaap plateau Dolomites
  2. Western Transvaal Dolomite
  3. Coetzersdam-Louwna Granite-Gneiss region
  4. Vryburg Basin
  5. Kalahari Basin: Penrith-Radnor
  6. Other regions in the Province
Karst (dolomite) aquifers - are regarded the most significant groundwater resources due to relatively large amounts of good quality water they store. Karstic dolomites are prevalent in both the Ghaap Plateau dolomites in the western region of the Province and the Western Transvaal dolomite in the central region of the Province.

The Ghaap plateau can be divided into 3 regions namely :
  1. Tosca-Vergelee area - Large yields of groundwater occur in this area. There are at least 21 centre pivots extracting ground water for agricultural purposes in this region. The current rate of extraction of groundwater may lead to the exhaustion of the aquifer, as the natural recharge rate of the ground water may not be able to balance the present rate of extraction.
  2. Pomfret-Lykso area - This area has a large groundwater potential. Currently the ground water in this area is used only for domestic and stock-watering purposes.
  3. Lykso-Reivilo-Boetsap area - Ground water in this area is primarily used for irrigation and domestic uses.
The ground water found within the Western Transvaal Dolomite occurs in the top cast zone of the rock formation. Several large springs, termed eyes, issue from dolomite aquifers, many of which are sources of important rivers in the Province. They can have large yields, although some of them are affected by groundwater abstraction for irrigation and domestic purposes. Several springs occur in the area called Bo Molopo. There, the dolomite aquifer is compartmentalised by numerous impermeable intrusive dykes, with springs issuing on the dyke contacts. Some of them have been commercially used for water supply (e.g. Grootfontein). Other springs occur in the Potchefstroom area (Turffontein, Gerhardminnebron), Ventersdorp (Schoonspruit) and elsewhere. The reported typical flow rates for selected dolomite springs vary quite significantly. Different authors report inconsistent values. We therefore use the work by Fleisher (1981) to present the following long-term flow rates: Turffontein: minimum 247 l/s - maximum 492 l/s (1912-1978); Gerhardminnebron: minimum 666 l/s - maximum 920 l/s (1906-1978); Schoonspruit: minimum 824 l/s - maximum 1998 l/s.

More recent estimates cite consistently lower values. For example Kotze et. al (1994) quote 761 l/s for the Schoonspruit Spring. In the Bo Molopo area the springs that are known to continue flowing include Buffelshoek, Doornfontein, Dinokane, Doornplaat, Molopo, Olievendraai, Paardevallei, Rietgat, Rhenosterfontein, Stinkhoutboom, Tweefontein, Welgedacht and others. In general, the flows range from 7 l/s (Olievendraai) to 19-146 l/s (Buffelshoek) or 19-309 l/s (Malmane) (Bredenkamp, 2000) (Table 10.2.1).

Table 10.2.1: Reported flow rates from dolomitic springs (Source: Bredenkamp 2000).

Source Flow Rate (l/s)
Turffontein 247 - 492
Gerhardminnebron 666 - 920
Schoonspruit 824 - 1998
Olievendraai 7
Buffelshoek 19 - 146
Malmane 19 - 309


The Coetzersdam-Louwna Granite-Gneiss region - large yields of ground water also occur in this area. There are currently 60 centre pivots extracting ground water and water reserves are deemed to be being depleted at a rate in excess of the natural recharge rate. Large yields of ground water occur in the quartzite layers of the Vryburg Basin.

The Kalahari Basin: Penrith-Radnor - large yields of ground water occur in this area, but they are situated at deep levels. The farmers in the area are currently negotiating for the use of this ground water for irrigation purposes. The natural recharge of the ground water may not be able to balance the rate of extraction if further development occurs.

Groundwater in the other regions of the Province - the ground water in other regions of the North West Province occurs in secondary aquifers comprising the permeable transition zone between weathered soil and hard rock and fracture zones in hard rock and contact zones between intrusions and country rock. These zones occur at a relatively shallow depth of less than 50m.

Intergranular aquifers contained in loose and unconsolidated formations (e.g., sand, gravel). These are limited to Kalahari sands in the western section of the Province (e.g. Kalahari Basin: Penrith-Radnor) and alluvial covers of streams. Yields are variable, between 0.1 l/s and 5.0 l/s, depending on the size of the aquifer. Quite often these resources cannot sustain accelerated withdrawal for a long time due to physical size limitations.

Fractured aquifers store and transmit water in fractures only. Pure fractured aquifers are not widespread in the North West but are known to occur in the quartzite layer of the Magaliesberg Formation. Typical yields are low (0.1-0.5 l/s).

Intergranular and fractured aquifers are the dominant type found in the Province. Water is often stored in intergranular interstices and transmitted through fractures of various sizes. Quite often these aquifer systems occur as a combination of fractured (non-weathered bedrock) and intergranular (weathered or decomposed rock) - with water strikes and good yields at the interface. The yields of these aquifers are substantially lower than what can be found in karstic aquifers, typically between 0.5 and 1.5 l/s. Based on these properties typical groundwater yields per magisterial district can be summarised as follows in Table 10.2.2.

Table 10.2.2: Typical borehole yields per district (Source: Botha & Bredenkamp 1992).

Range Yield [l/s] DISTRICT
Very low <0.1 Odi 2
Low 0.1-0.5 Ganyesa, Christiana, Bloemhof, Schweizer-Reneke, Molopo, Ditsobotla, Rustenburg 1
Medium 0.5-1.5 Vryburg 1, Taung, Klerksdorp, Wolmaransstad, Delareyville, Madikwe, Mankwe, Swartruggens, Koster, Bafokeng, Rustenburg 2, Brits, Odi 1, Moretele
High 1.5-5.0 Vryburg 2, Potchefstroom, Marico, Lehurutse
Very high >5.0 Kudumane, Ventersdorp, Lichtenburg, Coligny


Apart from drinking purposes, groundwater is used extensively for irrigation. Substantial groundwater abstraction is known to occur in Louwna-Ganyesa area (20-27 million m3 per annum; Botha & Bredenkamp 1992); Pomfriet-Tosca; Sannieshof; Geysdorp-Delareyville; Lichtenburg, Ventersdorp, Rustenburg and other areas. The abstracted amounts vary between 0.1-1.0 million m3 per annum (e.g. Reivillo, Stella, Tosca, Morokweng, Heuningsvlei) up to more than 10 million m3 per annum (e.g. Ventersdorp, Rustenburg).

The recharge rate through rainfall of the Province's groundwater varies significantly from west to east, largely in response to prevailing climatic and geological conditions (Map 14). Recharge of groundwater through karst features, may make these vulnerable to large-scale pollution events. The large storage capacity of the dolomitic compartments can, to a certain extent, offset these pollution stresses by dilution. Due to partial dissolution of the rock material, dolomite aquifers experience geotechnical problems such as sinkhole formation and subsidence. Large withdrawals of groundwater from dolomite aquifers (more than 5-10 m of drawdown) are not advisable. Borehole yields are very variable as they depend on the level of fracturing and karstification. They can vary through several orders of magnitude.

The depth at which groundwater is stored also varies significantly throughout the Province (Map 50) . This affects the accessibility of the resource for domestic and agricultural use.

Groundwater quality

Groundwater quality is relatively good in most parts of the Province. Average major ion concentrations are within drinking water quality limits for more than 60% of groundwater samples. Map 51 and Map 52 show the dominant cation and anion types respectively which are found in groundwater in the Province.

From DWAF's National Groundwater Quality Monitoring Programme (NGWQMP), it was reported that in the North West Province in 1996 approximately 70% of boreholes of known water quality are suitable for human consumption, 18% are suitable for human consumption on short term basis (to be used in emergency water supply cases), and 12% are not suitable for human consumption but are suitable for agricultural and/or industrial use. Table 10.2.3 shows the known water quality by district council in the Province. Groundwater quality is classified according to different classes, ranging from 0-3.

Table 10.2.3: Groundwater quality for the North West Province in 1996. (Source: DWAF 1996).

WATER CLASS NORTH WEST PROVINCE DISTRICT COUNCILS
Bophirima Southern Rustenburg Eastern Central
Class 0&1 70% 68% 75% 80% 44% 78%
Class 2 18% 19% 13% 15% 32% 15%
Class 3 12% 13% 12% 5% 24% 7%

Class 0: water is of ideal quality.
Class 1: water is of good quality suitable for lifetime use with little health effects.
Class 2: water is suitable for short term only due to its associated health risk effect.
Class 3: water is unsuitable for use, especially by children and elderly because of health risk effects.

From Table 10.2.3 it is evident that groundwater in the north-east section of the Province shows signs of general deterioration from both natural and human factors. This is the most heavily populated and industrialised region of the North West Province.

High sodium, chloride, sulphate, or nitrate concentrations in groundwater usually (but not always) indicate presence of on-going pollution. High levels of nitrates, fluorides, chlorides, sodium and sulphates have been recorded from some areas in the Province. Elevated levels of these are mostly due to human-induced activities, while some are attributable to natural factors (e.g. high fluorides in the Pilanesberg area). See below for more details.

Total dissolved solids - the salinity levels of groundwater are a reflection of the total dissolved inorganic compounds, also known as total dissolved solids (TDS). High TDS levels in groundwater may be due to natural causes (from leaching from the parent rock) or more frequently from human induced pollution (such as irrigation return-flows, industrial and mining effluents. The groundwater TDS levels for the North West Province are indicated in Map 53. For large parts of the Province, recorded groundwater TDS concentrations exceed the upper limits of the Target Water Quality Ranges of 200 mg/l for domestic use as stipulated in South African Water Quality Guidelines (see appendix 1).

The highest TDS levels in groundwater are reported from the Potchefstroom, Klerksdorp regions as well as some parts of the eastern region. The western region of the Province also shows a general elevation in TDS concentrations, largely due to leaching from the rock types through which the aquifers flow. As this region receives less rainfall and has higher evapo-transpiration rates than the rest of the Province, groundwater resources in this region are prone to salinisation. Again, with the lower recharge rate characteristic of this arid and semi-arid region, the salinisation process is exacerbated.

Nitrates - although high nitrate concentrations in groundwater are usually caused by human activities, there are cases where it has been found to occur naturally as inorganic nitrate. This form is found in geological formations such as the basalt rocks in the Moretele II District. Map 54 portrays nitrate levels in the groundwater of the Province, which have been found to vary from low to very high. The concentration of nitrates in the Province varies from an upper limit of 6 mg/l typical of class 0 water (Zeerust, Swartruggens to Koster districts and Potchefstroom districts in the east) to above 20 mg/l for a class 3 water (Mafikeng, Sannieshof to Stella districts in the central region. Higher than ambient concentrations of nitrate are clustered in this central section of the Province, which has major agricultural production (maize, wheat farming). High nitrate concentrations exceeding 20 mg/L have also been reported from the Tosca-Morokweng districts in the west.

The minimum requirements of SABS recommend an upper limit of 10 mg/l of nitrate and concentrations which exceed this are deemed unacceptable to human health in the long-term. However, for large parts of the Province, recorded groundwater nitrate concentrations exceed the upper limits of the Target Water Quality Ranges of 6 mg/l for domestic use as stipulated in South African Water Quality Guidelines (see appendix 1).

It should be noted that nitrate concentrations are known to vary significantly within a short space and time, so even areas showing problem-free nitrate concentrations can actually contain boreholes with excessive nitrate or vice versa. This is demonstrated by samples from the NGWQMP showing point nitrate concentrations (in 2000) that are not always consistent with regional averages.

Fluorides - high fluoride concentrations in groundwater are limited to relatively small areas underlain by fluorite-rich rocks, sometimes associated with Bushveld Complex (Map 55). High fluoride concentrations are known to occur in the groundwater of the Pilanesberg and in the arid parts of the Province where its origin is associated with evaporation effects on groundwater chemistry. Other areas that have high fluoride concentrations in groundwater (concentration > 3.5 mg/l ) include: Moretele I & II, Odi I & II, Brits (former Eastern District Council); Mankwe (former Rustenburg District Council); and Ganyesa and Vryburg I (Bophirima District Council). The Southern District Council for instance has one borehole in Klerksdorp that has fluorides above the recommended standard limit of 3.5 mg/l out of seven Magisterial Districts with more than hundred boreholes of known water quality. The Central District Council has only three boreholes out of more than 1000 boreholes with known water quality. Large parts of the Province have recorded groundwater fluoride concentrations which exceed the upper limits of the Target Water Quality Ranges of 1 mg/l for domestic use as stipulated in South African Water Quality Guidelines (see appendix 1).

Sulphates - excessive sulphate concentrations are frequently linked to acid mine drainage (AMD) problems. Some of the dolomite springs in the Potchefstroom area (e.g. Gerhardminnebron Eye) show signs of AMD pollution emanating from east-lying goldmines of Far West Rand.

10.2.5 Impact

The main impact of pressures on groundwater quantity and quality is summarised in Table 10.2.4. Also refer to section 10.1.5 for more information on generic impacts of both surface and groundwater.

Table 10.2.4: The main impacts on groundwater quantity and quality in the North West Province

Impact Negative Positive
Reduced recharge Depletion of river flow decreased recharge, drought
Reduced storage Overexploitation of groundwater (e.g. irrigation), springs lowering yields Realisation that groundwater resources are not endless and need proper accounting and management
Acid mine drainage Local and regional transfer of contamination from mining operations
Nitrate Different processes responsible for high nitrate levels
Salinisation Reduced recharge/storage often accompanied by increased salinisation
General pollution Increased urbanisation and population development versus need to protect groundwater quality and quantity
Public awareness Misinterpretations sometimes promoted or misused Pressure on stakeholders to manage groundwater responsibly
Adoption of techniques and approaches allowing for more sustainable development Resistance to switch from extensive to responsible use of resources Sustainable and equitable use of groundwater resources

Due to population pressures and greater demand for ground water, almost all effects are expected to intensify at least in short-term.

Water quantity impacts

Water quantity affects groundwater resources, largely due to abstraction from boreholes for drinking water and central pivots for crop irrigation. This has major implications on the sustainability of groundwater resources if abstraction rates exceed recharge rates, particularly in times of prolonged drought. This also impacts on surface waters emanating from springs or dolomitic eyes.

Dewatering of dolomitic compartments for mining activities in the south-east of the Province is another impact. While the quantity of the groundwater diminishes during the dewatering process, surface water flow increases. This has occurred in the Mooi River catchment downstream from some gold mines.

Water quality impacts

Groundwater quality is impacted by pollution from return flows and surface waters which infiltrate and percolate into the groundwater. Table 10.2.4 outlines the source and nature of pollutants that may affect groundwater resources.

Poor sanitation provision in rural areas affects groundwater quality resources in rural areas. Pit latrines and the bucket system are still being used extensively in many rural communities. The siting and highly localised concentration of these in rural villages affects the groundwater quality (particularly increased nitrates) through seepage into aquifers. Incorrect siting of pit latrines and onsite disposal of sewage causes bacterial contamination and/or high organic nitrates or phoshates concentrations in the groundwater. This problem is further compounded when boreholes are located near pit latrines and bucket disposal points.

The siting of cemeteries in rural areas may have a serious impact on groundwater quality. Contamination depends on the proximity of the cemetery to aquifers and the depth and the direction of flow. Contamination of groundwater in rural areas as a result of the incorrect siting of pit latrines and cemeteries renders the water resource unusable and remedial actions are difficult to implement (S. Mpambani, NWDACE, pers. comm. 2001).

Long-term direct domestic consumption of groundwater with high nitrate concentrations can have serious health impacts for communities, particularly babies and young children (Table 10.2.5). Nitrate concentrations of above 20 mg/l in drinking water is known to cause a blood disorder known as methaemoglobinaemia or blue baby syndrome in infants which may result in death.

Table 10.2.5: The effect of Nitrate/Nitrite on Human Health (Source: DWAF, 1998).

Water Class Nitrate/Nitrite Range [ mg/l N] Effects
Class 0 0 - 6 No adverse health effects.
Class 1 6 - 10 Rare instances of methaemoglobinaemia in infants, but no effects in adults. Concentrations in this range generally well tolerated.
Class 2 10 - 20 Methaemoglobinaemia may occur in infants. No effects in adults.
Class 3 > 20 Methaemoglobinaemia occurs in infants. Occurrence of mucous membrane irritation in adults.


Exposure to high fluoride concentrations (greater than 4.0 mg/l) in groundwater used for long-term direct domestic consumption can have serious health impacts for communities (Table 10.2.6). Health impacts range from dental discolouration and tooth damage to crippling skeletal fluorosis, depending on the fluoride concentration and exposure.

Table 10.2.6: Effects of fluoride on aesthetics and human health (Source: DWAF, 1998).

Fluoride Range (mg/l) Effects
0 - 1.0 This level in water necessary to meet requirements for healthy tooth structure is a function of daily water intake and hence varies with annual maximum daily air temperature. A level of 0.75 mg/l corresponds to a maximum daily temperature of 26 oC - 28oC. No adverse health effects or tooth damage occurrence.
1.0 - 1.5 Slight mottling of dental enamel may occur in sensitive individuals. No other health effects are expected.
1.5 - 3.5 Mottling and tooth damage will probably be noticeable in most continuous users of the water. No other health effects occur
3.5 - 4.0 Severe tooth damage especially to infant's temporary and permanent teeth; softening of the enamel and dentine will occur on continuous use of water.
4.0 - 6.0 Severe tooth damage as above. Skeletal fluorosis occurs on long term exposure.
6.0 - 8.0 Severe tooth damage as above. Pronounced skeletal fluorosis occurs on long-term exposure.
> 8.0 Severe tooth damage as above. Crippling skeletal fluorosis is likely to occur on long term exposure.
> 100 Threshold for onset of acute fluoride poisoning, marked by vomiting and diarrhoea
> 2000 The lethal concentration of fluoride is approximately 2000 mg/l


Municipal and industrial leacheate from waste sites and pipeline leaks are some of the main causes of increased salinisation of groundwater. Irrigation return flows from agricultural lands which seep back into the groundwater also play a role in increasing salinisation levels. The impacts of increased salinisation of ground water include salinisation of irrigation soils, reduction in crop yields, increased scale formation in and corrosion of pipelines and geysers; and negative impacts on aquatic and soil ecosystems (Walmsley et. al 1999).

Human induced acidification of groundwater occurs mainly due to infiltration of industrial effluents and acid mine drainage. Although much of the groundwater of the Province is well buffered due to relatively high carbonate levels, acidification is likely to occur in mining areas such as Rustenburg and Brits region. This can lead to the mobilization of cadmium, cobalt, copper, lead, zinc and other heavy metals as well as radioactive elements such as uranium, especially in the gold mining areas around Klerksdorp, Orkney and Fochville. This could impact on the suitability of the water for domestic and agricultural use as well as the biota inhabiting soils (Walmsley et. al 1999). The sources and nature of pollutants affecting groundwater resources are summarised in table 10.2.7.

Table 10.2.7: Sources and nature of pollutants affecting groundwater resources (Source: Braune, 1994).

ACTIVITY SOURCE TYPE RISK CONTROL
AGRICULTURE
Irrigation (return flows) Diffuse Low Difficult
Fertilizer application Diffuse Low Difficult
Pesticide usage Diffuse High Easy
Manure application Diffuse Low Difficult
Extensive stock farming Diffuse Moderate Difficult
Intensive animal feeding units Diffuse High Difficult
MINING
Discard dumps Point High Difficult
Return water dams Point Moderate Easy
Ash dumps Point Moderate Easy
Slimes dams Point High Easy
Stockpiling Point Moderate Easy
Underground or opencast mining area Diffuse High Difficult
URBAN SECTOR
Sewage effluent Point High Easy
Leaking sewers Diffuse Moderate Easy
Sludge drying beds Point Moderate Easy
Landfills and dumps Point Moderate Depends on age
Storm water Diffuse Moderate Easy
Storage tanks and pipes Diffuse Moderate Easy
Informal housing Diffuse Moderate Difficult
INDUSTRIAL SECTOR
Industrial effluent Point High Easy
Bulk storage of chemicals Point High Easy
Solid Waste Point High Difficult
Abandoned sites Point Moderate Depends on age
Evaporation dams Point High Depends on age
Waste irrigation Point Moderate Difficult
Air pollution Diffuse High Easy
Transportation accidents Diffuse High Easy
OTHER ACTIVITIES
Borehole construction and abandonment Point Moderate Easy


10.2.6 Responses



Legislative responses

The legal environment affects the use of groundwater directly and indirectly, with the promulgation of legislative instruments designed to protect the integrity of the resource while promoting sustainable and equitable use of groundwater.

National Water Act (Act No. 36 of 1998) - the National Water Act (Act No. 36 of 1998) was promulgated to promote sustainable use of South Africa's water resources. In addition to the provisions stated in the surface water section (section 10.1.6), persons and authorities are required to apply for a licence to abstract significant quantities of water.

The NWA also advocates the establishment of a National Water Information System, which includes a groundwater information system.

The Dept. of Water Affairs and Forestry (DWAF) have developed a Policy and Strategy for Groundwater Quality Management in South Africa.

Other relevant legislation - other relevant acts and policies include Acts or White Papers that aim to protect environment (e.g. the National Environmental Management Act, Act No. 107 of 1998), or streamline development activities in a sustainable manner (Reconstruction and Development Programme, 1994). The Water Services Act (Act 108 of 1997) is chiefly concerned with the provision of water supply and sanitation to the people of South Africa (see chapter 13.4 on water supply and sanitation).

Waste management is proposed to be regulated by the White Paper on a Draft Integrated Pollution and Waste Management Policy (1998) with the aim to minimise waste and pollution generation and ensure the efficient and safe treatment of waste and pollution.

Other instruments such as EIA regulations (contained in the Environmental Conservation Act of 1989) and the recently proposed concept of groundwater reserve can contribute greatly to proper management of groundwater resources. See section 10.1 for more information on legislative responses.

Institutional responses

Formation of Water User Associations - in terms of the National Water Act which forms the basis of Catchment Management Agencies. While CMAs focus predominantly on surface water resources, they are envisaged to play a major role in the management of shared groundwater resources within their constituent WMAs.

Licensing of water uses - including the abstraction of significant quantities of groundwater in terms of the National Water Act.

Communities and their Groundwater Supply (North West) August 1998 - is a guide that was developed and compiled by Water Services Planning Directorate in DWAF to inform communities about groundwater quantity and quality. Rural sanitation provision - the provision of non-polluting sanitation measures in rural communities will facilitate the prevention of further groundwater contamination in rural villages.

Groundwater monitoring - the abovementioned responses advocate responsible use of resources, which is only possible with better quantification of the resource. Groundwater monitoring and numerical modelling of groundwater resources will be required to support this information system. Provincially, there appears to be a need to fund research to establish core reasons for nitrate occurrence and the way(s) to manage it.

South African Water Quality Guidelines - published by the DWAF in 1996 which provides Target Water Quality Ranges (TWQR) for constituents for different water uses viz. aquatic ecosystems, domestic, recreation, industry and agriculture. The TWQR are essentially ranges of concentrations or levels of constituents (e.g. nitrates, fluorides, TDS, pH) which would have no adverse or anticipated effects with long-term use. However, if the water quality exceeds the TWQR for a particular constituent, it does not mean that the water is unfit for use, but rather that further investigation is required. The TWQR's for some constituents are presented in Appendix 1.

Research - is important for the acquisition of essential information for decision makers and resource managers. The Water Research Commission (WRC) is the official funding body for water research in South Africa, and over half of the research funded is directed to water resource management.

A research project on the institutional arrangements for groundwater management in dolomitic terrains is currently underway in the North West Province. The project is investigating the necessary institutional arrangements for the management of dolomitic groundwater located across three Water Management Areas in the dolomitic south-eastern region of the Province. This work is focusing on the identification of key environmental assets, geological features, groundwater impact, user profiles and proposed institutional arrangements. The project is jointly funded and managed by IUCN-South Africa and International Water Management Institute (IWMI).

Education and awareness - further education and awareness campaigns are also necessary to reach more people in the Province about issues concerning groundwater utilization and conservation.

See section 10.1.6 for more information on institutional responses.

10.2.7 Outcomes



Major outcomes of the abovementioned responses to the current situation of groundwater resources are summarised in Table 10.2.8.

Table 10.2.8: Outcomes of responses on the groundwater resources of the North West Province.

Response Positive outcome Negative outcome
Development/entitlement -geared legislation Assured sustainability if resources managed properly Increased pressure on resources
Groundwater reserve implementation High confidence in the resource assessment Costs of assessment
Gearing with catchment management agencies and their strategies Level of participation and community's responsibility for its own affairs increases Substantial effort for consensual management required
EIA processes Water conservation and management ensured while development continues Relatively slow and fragmented
International treaties (e.g. Molopo) Preservation of groundwater resources at sustainable level Possibly less water for the Province


10.2.8 Linkages

Water is intricately linked to virtually every aspect of human economic, social and other activity. Not only does the impact of man's activities affect the use of water, but the volume and quality of available water impacts on man's activities. Thus, water is linked to all other chapters (see section 10.1 for linkages to specific chapters). Some linkages are provided in Table 10.2.9.

Table 10.2.9: Water resource linkages using the DPSIR model.



Driving Forces Pressures State Impacts Responses
Social Population growth Aquifers

Water Quality		 Positive impact Institutional legislation and policy
Climate Groundwater depletion Negative impact Human impact
Urbanisation Industrial demands


10.2.9 Data issues and indicators

Data issues - Data relevant to groundwater occurrence and quality are stored in various public and private sources. DWAF is the custodian of the most comprehensive datasets that can be relatively easy to access. National Groundwater Database stores information about boreholes, water levels and abstractions, while WMS database stores water quality data.

DWAF information has been synthesized into a set of 1:500 000 hydrogeological maps (Vryburg, Johannesburg and Kimberley sheets). Flow information from dolomite springs is usually well documented and stored in DWAF: Hydrology database.

Ambient monitoring of groundwater quality was started fairly recently under initiative of DWAF: Geohydrology Directorate. Presently 104 sites were registered as the NGWQMP stations. However, the NGWQMP programme only monitors two boreholes per magisterial district and hence is unable to effectively monitor groundwater quality on a provincial scale. This monitoring initiative may need to be complemented by other monitoring objectives, especially with the view to investigating patterns and processes of nitrate pollution. Very little is known about organic pollutants (e.g. from motor fuels, solvents etc.), although several investigations have shown potential for their existence in groundwater resources.

Other sources include investigation and monitoring reports from various mines in the area. The focus of these initiatives is mainly an impact on groundwater quality. Groundwater abstraction information is the least known quantity in terms of knowledge on groundwater regimes in the Province. Information from private boreholes is usually not accessible or available in electronic or hardcopy format.

Environmental Indicators - The most important environmental indicators related to groundwater include: See section 10.3 for more details.

10.2.10 Conclusions and recommendations



The North-West Province has substantial groundwater resources comprising dolomitic compartments and fractured aquifers. There are some high yield areas (e.g. Kudumane, Ventersdorp, Lichtenburg and Coligny) that yield up to 10 million cubic meters per annum. However, it is perceived that groundwater in the Province is not being sustainably utilised at present, due to current levels of abstraction by agriculture and mining and pollution of the resource.

The quality of groundwater in the Province is generally good. Almost 60% of sources were found to be within drinking water quality limits.

Most of the Province's groundwater systems have a long residence times and slow recharge rates making them highly sensitive to pollution and over-abstraction. This is important for the management of dolomitic areas. The high levels of nitrates in groundwater particularly in the central and parts of the western region of the Province is of concern, particularly to those communities who rely on the groundwater as a sole source for domestic use. The nitrate levels which exceed accepted levels have serious health implications for babies and children (such as blue baby syndrome).

High concentrations of fluoride in groundwater in the Pilanesberg and Rustenburg districts and some areas in the western region may have serious health implications for resident communities directly dependent on these water resources for domestic purposes. Potential health impacts range from crippling skeletal fluorosis and the loss of teeth.

Favourable legislative development, which includes the concept of groundwater reserve applicable to several regions in the Province must be accompanied by scientifically sound assessment, quantification and monitoring of groundwater resources and funding for most-pressing groundwater problems. New legislative measures aimed at general development an upliftment should always be carefully measured against their capacity to sustain groundwater resources.

Regularly updated spatial information on groundwater quality and quantity is required for the effective management of the resource on a provincial scale.

The following further recommendations are proposed:

10.3 Indicators for Water Resource Management

The South African national Department of Environmental Affairs and Tourism is currently in the process of selecting national environmental indicators for use in South Africa. A list of potential indicators for water resource management is presented in Table 10.3.1 as proposed in the National Core Set of Environmental Indicators, DEAT 2001. In addition to the indicators proposed, it is recommended that the North West Province identify appropriate indicators from this national set which they can then use at a provincial level for reporting on water resource management.

Table 10.3.1: The proposed list of Inland Water Resource Indicators for South Africa (Source: DEAT, 2001).


Issue Indicator Type Level Frequency Scale Linkages
Freshwater Resources Surface Water Resources per Capita S 1 5 yearly National CSD Environment
Surface Water Demand versus Available Resources P 2 Annual Primary catchment CSD Environment
Environmental Flow Requirements S 2 5 yearly Primary / secondary catchments
Water Use (sectoral requirements) P 1 5 yearly National
Groundwater utilised per sector P 2 5 yearly National
People supported by Groundwater S 2 5 yearly Provincial
Groundwater withdrawals as % of annual recharge P 2 5 yearly Geo-hydrological unit
Freshwater Quality Surface Water Salinity S 1 Annual Water management areas
Surface Water Nutrients S 1 Annual Water management areas
Surface Water Microbiology S 2 Annual Water management areas
Surface Water Toxicity I 2 Annual Water management areas
Groundwater Salinity S 1 Annual Geo-hydrological unit
Groundwater Nitrate S 1 Annual Geo-hydrological unit
Groundwater Microbiology S 2 Annual Geo-hydrological unit
Freshwater Ecosystem Integrity Aquatic Habitat Integrity S 2 Annual Water management areas
Wetland alteration I 2/3 5 yearly Quaternary catchment Ramsar
Aquatic biodiversity S 1 Monthly & Annual Water management areas CBD
Alien invasive organisms P / S 3 5 yearly Water management areas
Riparian vegetation S 2 5 yearly Water management areas
Freshwater Ecosystem Integrity Groundwater contribution to GDP D 2 Annual Sectoral
Surface water affordability R 1 Annual National
Number of people affected by waterborne diseases R 2 Annual National
Volume of water imported from neighbouring countries R 1 Annual National
Number of people with access to sanitation S 1 Monthly National CSD Social, DPLG
Number of people with access to water S 1 Monthly National CSD Social, DPLG
CBD: Convention on Biological Diversity
CSD: Commission for Sustainable Development
Ramsar: Convention on Wetlands of International Importance especially as Waterfowl Habitat
DPLG: Department of Provincial and Local Government Key Performance Indicators (KPIs)

Type refers to the D-P-S-I-R model categories (Driving Forces, Pressures, States, Impacts, Responses respectively).

Level indicates the current availability of information pertaining to each indicator: Frequency refers to the proposed frequency of reporting on each indicator for meaningful results and trends to be obtained. However, data collection will necessarily be more frequent than the reporting frequency.

Scale refers to the geographical scale at which the indicator is applicable: national, provincial, local or catchment level.

Linkages refers to possible commonalities between the particular indicator and other indicators used for reporting obligations as required by international conventions ratified by South Africa.

Please refer to the section on environmental and sustainable development indicators for more information on these proposed indicators for future monitoring and reporting.

References

Botha, L.J. & D.B. Bredenkamp. 1992. Quantitative estimation of recharge and aquifer storativity of the Louwna-Coetzersdam aquifer system. Technical report GH3786. Directorate Geohydrology. DWAF, Pretoria.
Braune, E. 1994. Approaches for Groundwater Quality Protection in South Africa. Workshop presentation: Practical Application of Water Quality Management. Port Elizabeth Technikon, 12-13 April 1994.
Bredenkamp, D.B. 2000. Groundwater monitoring: a critical evaluation of groundwater monitoring in water resources evaluation and management. Report to Water Research Commission. WRC Report No. 838/1/00. WRC, Pretoria.
Council for Scientific and Industrial Research (CSIR). 1999. Guide on how to set up a Groundwater Management System in Rural Communities. CSIR, Pretoria.
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Appendix 1: Extract from the South African Water Quality Guidelines Field Guide for aquatic ecosystems, domestic, recreation, industry and agriculture (Source: DWAF, 1996).

Alkalinity (mg CaCO3 /L)





Arsenic (mg/l)



Chloride (mg/l)



Chromium (VI) (mg/l)



Coliforms (counts/100 ml)


NA - Not available
NR - Not relevant
(a) E.coli
(b) Faecal coliforms
(c) Total coliforms


Cyanide (mg HCN/l)


NA - Not available

Fluoride (mg/l)


NA - Not available
(a) All other livestock
(b) Ruminants


Nitrate/Nitrite (mg/l)


NA - Not available
(a) NO3
(b) NO2
(c) N (inorganic)


pH (pH units)


NA - Not available


Radionuclides (Bq/l)


NA - Not available
(a) Gross ?beta ?activity
(b) Gross âlpha activity
(c) Uranium 238
(d) Thorium 232
(e) Radium 226
(f) Radon 222
(g) Radium 228


Sulphate (mg/l)


NA - Not available


Total Dissolved Solids (mg/l)


NA - Not available
(a) Dairy, pigs & poultry
(b) Cattle & horses
(c) Sheep




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