REPORT NO. P3-1

LEAD PROGRAMME IN TECHNOLOGIES FOR ENHANCED ENVIRONMENTAL MANAGEMENT

OUTPUT TRACKING SHEET

Project Phase: Phase 3

Title: Strategic Assessment of the Baseline Environmental Context in : water resources

Author: Colleen Todd & Marius Claasen, CSIR Environmentek

Version: 2

Reviewer: Shamilla Pillay, CSIR, Environmentek

Date of finalisation: 31 March 2000

Referenced as: Todd, C. and Claasen, M. (2000). Strategic Assessment of the Baseline Environmental Context in Cato Manor: water resources. LEAD Programme in Technologies for Enhanced Environmental Management. , March, 2000.

Sign-off:………………………………… Project manager

THE LEAD PROGRAMME IS FUNDED BY THE DEPARTMENT OF ARTS, CULTURE, SCIENCE AND TECHNOLOGY

STRATEGIC ASSESSMENT OF THE BASELINE ENVIRONMENTAL CONTEXT IN CATO MANOR:

WATER RESOURCES

Colleen Todd & Marius Claassen Environmentek, CSIR March 2000 EXECUTIVE SUMMARY

Cato Manor is situated 8km to the west of the Durban city centre within the Mbilo River catchment and the Umkumbaan River subcatchment. The entire area of Cato Manor is drained by the Umkumbaan tributary network.

Within the National Water Act No. 36 of 1998, water resources should not be seen as a commodity but as an entire ecosystem, of which water is one component. There are thus many other services and benefits, apart from water itself, which are provided by the aquatic ecosystem. Examples of these are listed.

The water resources of Cato Manor were assessed both in the natural and infrastructural sense.

Current uses of the natural water resources in Cato Manor are that of recreational and domestic use. These uses were assessed in context of the current water quality of the rivers in Cato Manor. It is concluded that the current water quality in Cato Manor is poor, with a high faecal coliform content. There is a risk of possible health effects if water is used for drinking and contact recreation.

Umgeni Water is the regional water authority responsible for bulk supply of water to the entire Durban metropolitan area, within which Cato Manor is situated. Wiggins Waterworks, the local waterworks in Cato Manor, receives water from Inanda Dam, which is situated in the neighbouring Mgeni Catchment.

Water quality of the entire Mgeni catchment’s rivers and dams is monitored using water quality indices developed by Mgeni Water. Data received for February 2000 shows that water quality in the Inanda Dam is unsatisfactory due to high total algal and Anabaena (blue- green algae) counts.

Sewage from Cato Manor is treated at Southern Sewage works and treated effluent is then disposed of via submarine pipelines.

A meta-database of relevant data needed for the strategic assessment of the water resources in Cato Manor is presented.

i ACKNOWLEDGEMENTS

The contributions of the following organizations and individuals are gratefully acknowledged:

Shamilla Pillay for her valuable input and knowledge of the area, and also for her data sourcing.

Tim Meara and Mike Webster for their GIS inputs.

Marelize van Zyl for assembling the report.

Durban Metropolitan Council for water quality and quantity data.

Mgeni Water for information on their water quality indices and water quality map.

Cato Manor Development Association for their input and population data.

ii TABLE OF CONTENTS

Page No. Executive Summary i

Acknowledgements ii

Table of Contents iii

List of Figures and Tables iv

1. Context 1

2. Significance of the Water Resources 1

2.1 Health 2 2.2 Economy 2 2.3 Waste 2 2.4 Institutional 2 2.5 Social 2

3. Uses of the Water Resource 2

4. The Water Resource in its Natural Sense 3

4.1 Location 3 4.2 Water Quality 4 4.2.1 Surface Water Resources 4 4.2.2 Groundwater 4

5. The Water Resource in its Infrastructural Sense 8

5.1 Water Quality 9 5.2 Water Quantity 9

6. A Meta-Database for Relevant Information 9

7. References 11

iii LIST OF FIGURES AND TABLES

Page

Figure 1 Diagrammatic Representation of the Natural and Infrastructural Water Resources of Cato Manor 3

Figure2 Water Quality Variables of Concern 5

Figure 3 Indicators of Microbial Pathogens 6

Map 1 Water Quality of Rivers and Dams for February 2000 (Umgeni Water) 7

Table 1 A Meta-Database of Water Resource Information 9

iv 1. CONTEXT

Cato Manor is situated approximately 8km to the west of the Durban city centre. The topography of the area is mainly hilly with many steep-sided valleys. Cato Manor lies within the Mbilo River catchment and the Umkumbaan River subcatchment. The Umkumbaan tributary network drains the entire area of Cato Manor.

Existing usage of the natural water resources in Cato Manor is mainly for recreational and domestic purposes. Domestic use is minimal because most housing is provided with freshwater reticulation. However, domestic use cannot be excluded, as natural water resources may well be used for domestic purposes. All formal housing is serviced by water- borne sewerage systems.

Greater Cato Manor encompasses an area of 2000 hectares of which 900 hectares are suitable for development. Population figures obtained from the Cato Manor Development Authority (CMDA), estimate an existing population total of 85 378 for the entire area of Cato Manor.

It is within this context that a strategic baseline assessment of the water resources within Cato Manor was done.

2. SIGNIFICANCE OF THE WATER RESOURCES

Water has generally been thought of as a commodity, something that can be contained, transported and traded. In fact, water should be seen not just as the commodity, water, but rather as the whole ecosystem, of which water is one component. The way in which the value of water resources is perceived should reflect both societal values and ethics and the specific characteristics of this complex resource. The ecological integrity, which gives a water resource its resilience, is an essential component of the value of the resource. In this context, a broader definition of a water resource has been proposed (MacKay, 1999), according to which a water resource is an ecosystem which includes the physical or structural aquatic habitats (both instream and riparian), the water, the aquatic biota, and the physical, chemical and ecological processes which link habitats, water and biota. It is this larger ecosystem that provides us, not only with the water, which we see as a commodity, but also with many other services and benefits. Some of the services provided by water resources are (adapted from Mander, 2000; The World Resource Institute, 1998):

• maintenance of ecosystem habitats • conservation of genetic resources (biodiversity) • drinking and basic human needs • recreation • transport (people and goods) • subsistence or commercial supplies of biotic and physical components • industrial use • irrigation & stock watering • assimilation of waste products • retention and storage of water • control of flood waters • soil formation • nutrient cycling • climate regulation • atmospheric gas balance

These services rely on hydrological, biological and ecological processes, and require at least some degree of maintenance of the natural structure and character of aquatic ecosystems.

1 Southerland (1998) lists four processes that describe ecosystem structure, viz. disturbance regimes, complexity, biotic interactions and population dynamics.

2.1 Health

Human health is affected directly by the proximity, availability and quality of water resources. Water is an important medium for many pathogens (typhoid, cholera, diarrhea, respiratory infection, etc) and vectors of diseases (malaria-mosquitoes, bilharzia-snails, etc.). Improved sanitation has a dramatic impact on health by reducing the spread of disease and infection.

2.2 Economy

The potential for economic growth and social development is largely dependant on the availability of adequate clean water.

2.3 Waste

Water Resources has a limited, but significant capacity to assimilate waste. Purification of waste products is mainly through biological or chemical breakdown, immobilization through adsorption or other mechanisms, and transportation of waste. The efficiency of assimilation is affected by factors such as the integrity of the system, retention time, dilution volumes, availability of wetland areas, presence of microbes and the chemical composition of the receiving water.

2.4 Institutional

The provision of formal services to the area will improve the water quality through limiting waste disposal in the river and reducing the direct dependency on the river for domestic use. Adequate institutional capacity is thus required to ensure delivery of appropriate water services to households.

2.5 Social

It is necessary to maintain the integrity of the water resources if it is to sustain the services offered to the local community. The primary services currently provided include aesthetics, recreation, water storage, flood control, potable use, waste disposal and conservation. The resource also provides services that indirectly affect the community, such as climate control and groundwater recharge. Other services can potentially be provided to the community, as long as the integrity of the system is sufficiently protected.

3. USES OF THE WATER RESOURCE

Within the National Water Act No. 36 of 1998, a water resource is defined as an ecosystem, which includes the physical or structural habitats, the water, the aquatic biota, and the physical, chemical and ecological processes which link habitats, water and biota (MacKay, 1999). Thus the aquatic ecosystem is the total water resource of which a certain level or resource base needs to be maintained to ensure protection and sustainable utilization of the resource.

Existing use of the natural water resources within Cato Manor are recreational and domestic (see Figure 1). Recreational use of the natural water resource includes children playing in the rivers, which is potentially harmful because of the high levels of microbial pathogens found in the rivers (see Figure 3). It is envisaged that with improved sanitation and water supply infrastructure to Cato Manor, these risks will be lowered and the rivers will once again be safe for recreational use.

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Domestic use of the natural water resource cannot be excluded because certain areas of Cato Manor do not have reticulated water supply to the households, for example the informal settlements of Jamaica and Cato Crest. However, all new housing developments have reticulated water supply as well as water-borne sewage. Domestic use of the rivers includes washing of household items in the rivers, for example carpets and clothing (Mxolisi Mwandla, CMDA, pers comm.). This is often to the detriment of the river water quality because detergents and bleaches used for washing end up in the river and are responsible for a drastic decrease in the water quality and biological health of the river.

A proposed future land-use that will have an impact on the water resources is that of industrial use. However, at present, there is no industrial activity in Cato Manor and thus no industrial use of water resources.

The National Water Act requires activities that affect either water quantity or quality to be considered in sustainable management of the resource. Licensing procedures may be required for certain uses, as specified in the Act. These may include effluent discharge, water abstraction and stream flow reduction activities.

4. THE WATER RESOURCE IN ITS NATURAL SENSE

4.1 Location

3 The Umkumbaan River is the largest tributary of the Mbilo, comprising almost 30% of the main river basin (Archibald, 1997). The Mayville Stream is a first order tributary of the Bellair Stream and both drain the northern sector of the Cato Manor area. The first order Chesterville Stream drains the western area and meets the main Umkumbaan before the latter is joined by the second order reach of the Bellair Stream (Archibald, 1997). These four reaches thus make up the Umkumbaan River subcatchment, which feeds into the Mbilo River from the north (Figure 2 & 3).

The Mbilo has a catchment area of 67km2, with a mean annual runoff of 65x106m3a-1.

4.2 Water Quality

4.2.1 Surface Water Resources

Water quality monitoring information was obtained from Durban Metropolitan Council. Monitoring information from 1995 to date was used for the assessment. Water Quality Guidelines were used to assess the data and to determine which variables were exceeding the guideline value. This data was then converted to a percentage of time that the variable exceeded the target water quality guideline range or value (Figure 2 & 3). Guidelines used were for the Recreational -, Domestic-, and Aquatic Ecosystem user groups. [Note: co- ordinates for sampling site locality are presented in decimal degrees, (Figure 2 & 3)].

For Recreational Use, pH and Escherichia coli were used. E. coli is a specific indicator of faecal coliforms, which is the most commonly used bacterial indicator of faecal pollution by warm-blooded animals (DWAF, 1996).

Indicators that were assessed for Domestic Use were pH, turbidity, total coliforms and faecal coliforms. Faecal coliforms are used to evaluate the quality of wastewater effluents, river water and raw water for drinking water supply, amongst others. Total coliforms comprise a heterogeneous group of bacteria which are used to assess the general hygienic quality of water and to evaluate the efficiency of drinking water treatment, as well as the integrity of the distribution system (DWAF, 1996).

For Aquatic Ecosystems, chlorine is the only variable reported, as this was the only variable available in the Durban Metro data that exceeded any of the corresponding guideline variables.

From the water quality data assessed, it can be said that the water quality of the Umkumbaan River subcatchment, is of an extremely poor quality, with a risk of possible health effects if water is used for drinking and contact recreation.

Further evidence that substantiate these findings was discussed by Hounsome (1997): “The quality of the water in Cato Manor is severely impacted by activities in the catchment. The current quality of the water at most of the points along the river course is of a poor quality with respect to bacterial contamination”.

Due to the high faecal coliform counts in the Umkumbaan tributary network, it is evident that raw sewage is entering the river system. This raw sewage puts downstream users at risk. However, with an increase in water-borne sewage systems in Cato Manor, these counts are expected to decrease significantly.

4.2.2 Groundwater

It is accepted that groundwater follows the natural drainage area of the surface water resources. An assessment of the groundwater resources was carried out for the strategic assessment of the draft structure plan for Cato Manor and it was concluded that it was unlikely that the groundwater would be a viable and useable resource (Hounsome, 1997).

4 5 6 Map 1 : Water Quality of Rivers and Dams for February 2000.

Hazelmere Dam 102.1% Msunduze River (sites 66.3 and 67): Unsatisfactory status due to high E.coli counts and nutrient Albert Falls dam (site 41.1) : concentrations arising from rainfall related sewer discharges Unsatisfactory water quality in Pietermaritzburg, overflow from the Darvill WWW due to high Anabaena counts. storm dam and the WWW discharge. Midmar Dam 101.3% Baynespruit (site 64.1 and 64.2) : Msunduze River (site 71): Unsatisfactory status Unsatisfactory quality due to high E. coli counts due to elevated concentrations of free ammonia . Nagle dam (sites 43.1 and 43.2) : and overall poor water quality resulting from broken Albert Falls Dam Unsatisfactory water quality and blocked sewers and illegal industrial discharges. 101.1% due to high Anabaena counts. Kwanyuswa inflow to Inanda (site 46): Dorpspruit (site 64): Greytown Unsatisfactory quality due to high E. coli Unsatisfactory quality due to i R. < Moo counts probably due to contamination by cattle. Nagle Dam high E. coli counts. 100.5% Camps Drift (sites 62.2 and 62.3) : Unsatisfactory water quality due to high E. coli counts and generally unsatisfatory water quality Henley Dam arising from the Slangspruit and Edendale areas. Mooi River < 67.0%

Mvoti R. Inanda dam (sites 51.1, 53.1 and 55.1) : Stanger Camps Drift Unsatisfactory water quality due to < high total algal counts and high Anabaena counts. Cutswayo (site 82): Inanda Dam Howick Unsatisfactory status due to high nitrate and phosphorus concentrations, 102.2% < Mgeni R. arising from the KwaNdengezi area.

Shongweni (site 97) : . Mdloti R Shongweni Dam Unsatisfactory water quality due to high Anabaena counts. 100.6% < PMBurg Mgeni (site 28.1): Msunduze above and below Edendale (sites 59.2 and 62) : e R. Unsatisfactory status due to high nduz Nungwane Dam Unsatisfactory conditions due to high E. coli counts Msu E. coli counts 100.6% arising from rainfall related runoff and sewer problems. M ge ni Mlazi R. R. Richmond Durban EJ Smith Dam < Sithundu (site 83 ): Slangspruit (site 61); < Unsatisfactory status due to high E.coli counts, 100.2% Unsatisfactory status due to high E. coli counts nitrate and phosphorus concentrations arising from and nutrient concentrations arising from rainfall M the Dassenhoek area and WWW. ko related runoff and sewer problems. ma zi R. Nungwane R. Mzinto Dam Blackboroughspruit (site 65.1): Mlazi (site 80): 100.2% Unsatisfactory quality due to Unsatisfactory status due to high E. coli counts. generally poor water quality .

Mopela (site 89): Legend Unsatisfactory status due to high E.coli counts. Mlazi (site 88.4) and Fongozi (site 88.6) : Excellent M Unsatisfactory status due to high E.coli counts and zim Mz ay generally poor water quality arising from sewer Good into i R R. . Satisfactory Sterkspruit upstream of Hammarsdale dam (site 94.1): problems in . Poor Unsatisfactory status due to generally poor water quality. M Unsatisfactory tw al um e No Data R . Mlazi (site 85): N Durban Metro Unsatisfactory status due to poor water Pietermaritzburg TLC Sterkspruit downstream of Hammarsdale Dam quality arising from the KwaNdengezi (sites 92, 93 and 94): Unsatisfactory status due to generally Dassenhoek area. < Towns poor water quality downstream of the Hammarsdale industrial area and WWW effluent discharge. Dams 0 10 20 Kilometers Catchment Boundary The Water Quality Index is calculated using the following variables : Algal count (Filter Clogging and Taste & Odour), Chlorophyll "a", E. coli, Turbidity, Conductivity, Nitrate, Free Ammonia, TP, SRP, Suspended Solids and TOC. Map compiled by Umgeni Water 7 From separate studies of the groundwater resources in the province of Kwazulu-Natal initiated by the DWAF in 1994, it was revealed that there is growing evidence of potential contamination of the groundwater from several sources, for example agricultural practices, human and animal sanitary contamination and waste disposal sites, amongst others (Archibald, 1996).

5. THE WATER RESOURCE IN ITS INFRASTRUCTURAL SENSE

Umgeni Water is a regional authority in Kwazulu-Natal, with responsibilities for bulk and rural water supply, wastewater treatment, pollution prevention and management of water quality (Simpson et al., 1995). Responsibility for bulk water supply for the Durban Metropolitan area lies with Umgeni Water.

Umgeni Water supplies water to Wiggins Waterworks – the local waterworks situated in Cato Manor. Wiggins is designed to treat water from the Mgeni River intake, and also water supplied from Inanda Dam (Umgeni Water, 2000 http://www.umgeni.co.za/home.htm). Once water has been treated at Wiggins, it is stored in either of three reservoirs, namely Chesterville-, Cato Manor-, or Sherwood Reservoir. From here, water is supplied to Cato Manor and other areas, via standard reticulation systems.

Durban receives high quality potable water from the Mgeni River. The Mgeni River system is a donor system to the Umbilo catchment. Wiggins Waterworks as well as the entire Durban metropolitan area receive water from various impoundments on the Mgeni River. Return flows can increase the flow in the recipient rivers and their associated estuaries, and thus alter the normal flow regime of the river.

Because of the increasing demand for potable water in the Durban area, five dams have been constructed in the main channels of rivers in and around Durban (Archibald, 1999). Four of these dams are situated on the Mgeni River, namely Nagle Dam, Midmar Dam, Albert Falls Dam and Inanda Dam.

Umgeni Water makes use of water quality indices which are used to determine the water quality of rivers and impoundments within their area of control. The indices integrate several water quality constituents to obtain an overall water quality index of the sample. For impoundment samples, an index was devised by Umgeni Water with an emphasis on variables that give rise to treatment problems at water works (Simpson et al., 1995).

Data received from Umgeni Water for February 2000 (Map 1) shows that the water quality in the Inanda Dam is unsatisfactory due to high total algal counts and high Anabaena counts (blue-green algae). It can be seen that displaying the data in such a manner is extremely useful to aid with management decisions.

Because of the increase in population in Cato Manor, there is a resultant increase in the volume of sewage requiring treatment and disposal. Sewage from Cato Manor is sent to Southern Sewage Works, at an estimated maximum of one megalitre per day (Peter Davis, Southern Sewage Works, pers comm.). The treated effluent is then disposed to the sea through submarine pipelines, resulting in a loss of freshwater, but a gain in nutrients for a nutrient deficient marine environment (Archibald, 1999).

The lower Mbilo River is partially canalized for 3-5km, which distinctly alters the habitat and thus results in a loss of riverine biodiversity and ecological functioning of the river. Furthermore, silt entering the Mbilo system is rapidly transferred through the system due to the canalization in its lower reaches and thus results in siltation of rivers and ultimately Durban harbour. The Mbilo River also receives sewage discharge from a sewage works situated in the upper catchment. Dams and weirs on the Mgeni River alter its natural flow regime drastically.

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5.1 Water Quality

The water quality of the Mgeni River has remained very good for many years (Archibald, 1996). This is due to the self-purification properties (assimilative capacity) of the upper Mgeni River, as well as the benefits of the succession of dams on the Mgeni which provide “in-situ metabolism”, providing water of a high quality. However, water quality problems are anticipated at Inanda Dam, which is the receptacle for runoff and point source discharges from the upstream urban/industrial complexes of Pietermaritzburg and (Archibald, 1996).

5.2 Water Quantity

Data received from Durban Metropolitan Council shows that the current total daily consumption of water for Cato Manor amounts to 23,9 Kl.

Wiggins Waterworks is able to treat up to 350 Ml of raw water per day and thus has a maximum annual capacity of 127 750Ml. (Umgeni Water Website).

6. A META-DATABASE FOR RELEVANT INFORMATION

The following table is a collection of all the data that is needed for the strategic assessment of the water resources. A description of the data is given, as well as whether or not the information was available and used for this study.

Table 1: A Meta-Database of Water Resource Information

Available Data Description Where Available at Used or Not for Available Time of Study Study GIS data Topography GIS Lab, CSIR Yes Some Water resources Durban Demographics Cadastral data Infrastructure Land cover Water Quality PH, Conductivity, pv4, Durban Metro Yes Yes Data Turbidity DO, NH4, NO2, NO3, TKN, SO4, PO4 Total coliforms, Escherichia coli, Faecal coliforms. Water Quality Indices Umgeni Water Yes Yes Water Quality Guidelines DWAF Yes Yes Water Quantity Flow data DWAF No No Data Impoundment data Umgeni Water Yes Yes Sewage Data Southern Yes Yes Sewage Works Waterworks data Wiggins Yes Yes Waterworks Consumption figures Durban Metro Yes Yes Biophysical Air-, terrestrial-, waste CSIR, Durban Yes Yes Sectoral Data data Other Sectoral Health-, economics-, CSIR Durban Health – No Data social-, institutional Economics – Yes data Yes Social – Yes Yes Institutional –

9 Yes River Management classes, DWAF No No classification Ecoregional data classification Water Resource Directed DWAF Yes Yes Resources Measures Policy

10 7. REFERENCES

Archibald, C. 1996. Freshwater, Chapter 4 of the State of the Environment Report, Durban, .

Archibald, C. 1997. Biophysical Assessment of the Greater Cato Manor, Draft Structure Plan. Sector Report: Surface Water Resources. Report prepared for Cato Manor Development Association, Durban, Kwazulu-Natal.

Archibald, C. 1999. Durban’s Freshwater Home Page. Extract from the Ceroi Report. Durban, Kwazulu-Natal.

DWAF. 1996. South African Water Quality Guidelines. Volume 1: Domestic Use. Department of Water affairs and Forestry, Pretoria, South Africa.

DWAF. 1996. South African Water Quality Guidelines. Volume 2: Recreational Use. Department of Water affairs and Forestry, Pretoria, South Africa.

DWAF. 1996. South African Water Quality Guidelines. Volume 7: Aquatic Ecosystems. Department of Water affairs and Forestry, Pretoria, South Africa.

Hounsome, R. 1997. Strategic Biophysical Environment Assessment of the Greater Cato Manor Draft Structure Plan. CSIR Report, Durban, South Africa.

MacKay, H. 1999. Water Resources Protection and Policy Implementation. In: DWAF (1999). Resource Directed Measures for Protection of Water Resources. Volume 2: Integrated Manual, Version 1.0. Pretoria, South Africa.

Mander M (2000) Methods for valuing aquatic goods and services. personal communication.

Simpson, D.E., Howard, J.R., Ramjatan, A.. and N.A. Hudson. 1995. The Development of Water Quality Indices in the Umgeni Water Operational Area and their Use as a Management Tool. Poster paper presented at the River Basin Management for Sustainable Development Conference, Kruger National Park, RSA.

Umgeni Water. 2000. Managing Water for Life. http://www.umgeni.co.za/home.htm

Archibald, C. 2000 CEROI Report: Durban Metro State of the Environment and Development: 1999. http://www.ceroi.net/reports/durban/index.htm

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