Water Quality Status in the Komati River Basin ANNUAL REPORT: April 2014-March 2015

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Prudence Thobekile Ngwenya Environmental Officer

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1 Background

The water resources of the Komati River Basin are used primarily for irrigation, hydropower generation, recreation, domestic and industrial water supply. Any changes to the quality of the water supplied by KOBWA could adversely affect its users. The water supplied by the project has to meet the water quality requirements for that use (fitness of use). It is essential for KOBWA to inform the Parties of the quality of the water and any changes thereof.

1.1 Why Monitor Water Quality?

KOBWA is required by various legislation to undertake water quality monitoring in the Komati River Basin. The relevant legislation includes:

1.1.1 The Comprehensive Mitigation Plans

National legislation in both South Africa and Swaziland require an Environmental Impact Assessment (EIA) and Comprehensive Mitigation Plan (CMP) to be compiled before a project of the magnitude of the Komati River Basin Development project is undertaken. The CMP binds the project proponent to its implementation. The CMP prescribes a water quality-monitoring program and is very specific on the variables to be measured and the frequency of measurement. The program covers both compliance (during construction) and status monitoring (post construction). Flow transformations caused by release patterns on the dams are mitigated through special design of Dam intakes and outlet works, as well as the implementation of Instream Flow Requirement (IFR) releases.

1.1.2 National Water Acts

National legislation in both countries specifies water quality objectives and standards for various uses. The Water Act (2003) and the Draft Water Pollution Control Regulations in Swaziland are key legislations setting water pollution standards. Similar legislation in South Africa defines the fitness of use, where water quality standards for irrigation, domestic, aquatic ecosystem health etc. are defined. It is important that KOBWA ensure compliance with these legal instruments when delivering water from the dams.

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1.1.3 The Treaty on the Development and Utilization of the Water Resources of the Komati River Basin which states the following:

 The Parties shall take all reasonable measures to ensure the protection of the quality of the existing environment [article 14(1) (b)].  The Parties shall prevent water pollution and minimize erosion [(article 14(6) (b)].  The JWC treaty further tasks the Parties with the prevention and control over the pollution of water resources and soil erosion affecting the resources and utilization. It also tasks the Parties to take the necessary steps to minimize waste and non-beneficial use of water from the Komati River Basin within their respective territories.

As the implementing agency for the JWC and the parties in this project, and as part of its own operation and maintenance program, KOBWA has developed a water quality-monitoring program for the Komati River Basin. This document shows the monitoring results from the monitoring program.

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2 Introduction

The Environmental officer is tasked with a responsibility to monitor and report on the water quality status of rivers and reservoir in the KOBWA area of operation. The key objective of these water quality status monitoring and reporting, is to assess the fitness for use in terms of its main uses, namely irrigation water supply, domestic water supply and maintenance of the aquatic ecosystem health and to identify any potential problems that would require management intervention.

In order to achieve the above objective, the following water resources quality monitoring programs are undertaken to gather the required data and information for KOBWA to meet the objectives stated above:

 River Health Monitoring;

 status monitoring;

 real time water quality monitoring;

 Biological Monitoring; and

 Microbiological Monitoring.

Please refer to Figure 2-1 for the location of the monitoring points

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Figure 2-1: KOBWA Water Quality Monitoring Points

The data acquisition component of the KOBWA water quality monitoring programme includes all the monitoring activities that are undertaken by KOBWA and includes obtaining data collected by other organisations undertaking water quality monitoring in the KOBWA area of operation; the main parties being Department of Water and Sanitation-RSA and Department of Water Affairs-SD.

This document reports on the water resources quality status based on the data collected from April 2014 to March 2015.

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3 RESULTS AND DISCUSSION

3.1 River Health Monitoring

This is a monitoring program initiated by KOBWA to assess the present water quality status in the rivers and streams located in the KOBWA area of operation. The fundamental information requirement is the need to describe the present water quality status and how it changes over time and space. Samples are taken on a monthly basis and analyses of the samples are conducted in KOBWA water mini lab. Most of the physical parameters are analysed in-situ to avoid possible changes in the physico-chemical, biological and aesthetic properties of the water. This section summarises the in-situ data.

3.1.1 Irrigation Use

Figure 3-1 to Figure 3-4 show the results for the fitness of use of water for irrigation purposes for the reporting period of October-December 2014. It can be observed from the results that the water quality In terms of the fitness for irrigation, the quality of the water in the Komati River Basin, over the specified reporting period, was seen to be ideal to good.

Figure 3-1: EC graph for fitness of irrigation Water Supply Purpose in Lomati River Catchment

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Figure 3-2: EC graph for fitness of irrigation Water Supply Purpose in Komati River Catchment

Figure 3-3: pH graph for fitness of irrigation Water Supply Purpose in Lomati River Catchment

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Figure 3-4: pH graph for fitness of irrigation Water Supply Purpose in komati River Catchment

From the above results it can be seen that majority of the catchment has access to ideal water quality. The Lower Komati area and Nsonyama area in Lumati were however varying from ideal to good for the fitness of irrigation when using electrical conductivity as an indicator of water quality. When the pH of water is used as an indicator of water quality, it shows that the water of the catchment is ideal for irrigation purpose.

3.1.2 Domestic Use

Figure 3-5 to Figure 3-12 show the results for the fitness of water use for domestic purposes. When Electrical conductivity, pH, Fluoride, Nitrate and E. coli parameters are used as indicators of water quality, it was observed from these results that the water quality in the Lomati River Catchment and Komati River Catchment was ideal fit for domestic use for the whole recording period.

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Figure 3-5: EC graph for fitness of Domestic Water Supply Purpose in Lomati River Catchment

Figure 3-6: EC graph for fitness of Domestic Water Supply Purpose in Komati River Catchment

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Figure 3-7: pH graph for fitness of Domestic Water Supply Purpose in Lomati River Catchment

Figure 3-8: pH graph for fitness of Domestic Water Supply Purpose in komati River Catchment

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Figure 3-9: Nitrate graph for fitness of Domestic Water Supply Purpose in Lomati River Catchment

Figure 3-10: Nitrate graph for fitness of Domestic Water Supply Purpose in Komati River Catchment

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Figure 3-11: E.Coli graph for fitness of Domestic Water Supply Purpose in Lomati River Catchment

Figure 3-12: E.Coli graph for fitness of Domestic Water Supply Purpose in komati River Catchment

3.1.3 Ecosystem

Figure 3-13 to Figure 3-16 show the results for the fitness for maintaining the aquatic ecosystem health. It can be observed that the water quality in terms of the fitness for ecosystem use, it is ideal for majority of the catchment except for Ingugwane and Nsonyama in the Lomati and the Lower Komati which ranged from good to fair when using electrical conductivity (EC) as an indicator.

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Figure 3-13: DO graph for fitness for maintaining Aquatic Ecosystem Health in Lomati River Catchment

Figure 3-14: DO graph for fitness for maintaining Aquatic Ecosystem Health in komati River Catchment

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Figure 3-15: EC graph for fitness for maintaining Aquatic Ecosystem Health in Lomati River Catchment

Figure 3-16: EC graph for fitness for maintaining Aquatic Ecosystem Health in Komati River Catchment

When dissolve oxygen (DO) is used as an indicator of water quality, the results shows that the water quality from was within fair to ideal category to maintain the health of aquatic ecosystem in the Komati and Lomati River catchment throughout the recording period, with the exception of June and July where it fell under the poor category. In the month November and December, the DO limit at Ingugwane was less than 5 mg/l which falls under poor category.

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3.2 Reservoir Monitoring

Temperature, Dissolved oxygen, Electrical conductivity, and pH profile data was recorded in Driekoppies Dam and Maguga Dam during monitoring visits at these dams in order to understand the key reservoir water quality changes and processes. The data was recorded at 1m intervals from the water surface to the bottom of the water column (or maximum length of the cable). The date, monitoring point and reservoir level on the day the profiles were taken was recorded in the spreadsheet. The reservoir level was recorded to relate the water depth to a height above sea level.

Chemical samples were also collected for the parameters requiring laboratory analysis. KOBWA has a mini laboratory where the samples are analyzed after each sampling exercise. Fluoride, Phosphate, Nitrates, Faecal Coliform and E. coli are analysed for in the KOBWA lab.

The data was stored in the spreadsheet to be analysed for the preparation of reports. In order to assess and express the fitness of the water for a specific water use sector, the data was compared to the four-tiered classification system by the Department of Water Affairs (DWAF, 2002a). The four-tiered classification system, describes a water resource as ranging from ideal to poor.

Please refer to Figure 3-17 to Figure 3-19and the paragraphs below for the results and discussion of the results.

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Figure 3-17: Electrical Conductivity Graph for Maguga Dam for the April 2014 - March 2015

Figure 3-18: pH Graph for Maguga Dam for the April 2014 - March 2015

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Figure 3-19: DO Graph for Maguga Dam for the April 2014 - March 2015

The electrical conductivity at all the selected points of the reservoir from the period of April 2014-March 2015 fit into the ideal category of the South African Water quality guidelines for all the water use sectors. The pH of water was also within the Ideal category for irrigation and domestic water use. Dissolve Oxygen was ranging from 3.4 to 10.4 mg/l for the entire recording period. From the month of March to June, the dissolve oxygen levels fell within the ideal to fair category of the South African Water quality guidelines for maintaining the aquatic ecosystem health. The levels of dissolve oxygen declined slightly in August at all the points to a poor category with the exception of point four which remains in the ideal category. Also in the month of December, the levels of Dissolve Oxygen recorded were very low at point 2, 3 and four of the reservoir and fell within the poor category. The levels of dissolve oxygen started picking up again on January to March and were within an Ideal to fair category of the South African Water quality guidelines for maintaining the aquatic ecosystem health.

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Figure 3-20 to Figure 3-22 below shows the results of Driekoppies Reservoir and describes the results as ranging from ideal to poor.

Figure 3-20: Electrical Conductivity Graph for Driekoppies Dam for the April 2014 - March 2015

Figure 3-21: pH Graph for Driekoppies Dam for the April 2014 - March 2015

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Figure 3-22: DO Graph for Driekoppies Dam for the April 2014 - March 2015

Electrical conductivity at Driekoppies reservoir for the recording period (April 2014-March 2015) ranged from 67.1 µS/cm – 150.4 µS/cm a range that falls within the “ideal” category of the South African Water quality guidelines for the fitness for irrigation water use, domestic water use and for maintaining the health of aquatic ecosystem. The pH values also fell within the “ideal” category for the irrigation and domestic water use purposes.

Dissolve Oxygen was ranging from 1.7 to 9.9 mg/l for the entire recording period. From the month of March to June, the dissolve oxygen levels fell within the ideal to fair category of the South African Water quality guidelines for maintaining the aquatic ecosystem health. The levels of dissolve oxygen declined in August at all the points to a poor category of the South African Water quality guidelines for maintaining the aquatic ecosystem health.

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The levels of Dissolve Oxygen recorded in the month of November, December and January were very low and fell within the poor category, with the exception of point 1and point 4 in December which fell within the good and ideal category respective. The levels of dissolve oxygen started picking up again on January to March and were within an Ideal to fair category of the South African Water quality guidelines for maintaining the aquatic ecosystem health.

3.3 Real time water quality monitoring

This monitoring programme is designed to record in real time the water quality discharged from the two reservoirs and at key points in the system using electrical conductivity and water temperature as an indicator of the macro-chemical composition of the water and potential impacts on biota.

Temperature and electrical conductivity probes are fitted at all the flow measuring stations, to utilize the real-time flow monitoring system to collect real-time water quality data and to utilize the data to track short-term water quality changes, in order to act as an early warning system of short term changes in water quality and to assess the magnitude and spatial extent of impacts on temperature as a result of the two reservoirs.

Please see below for the assessment of the Driekoppies, Lebombo, Sandbult, Tonga, Maguga, and Enjakeni real time conductivities data for the period of March 2014 – April 2015. The stations monitored data plots are presented on the figures below.

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3.3.1 Irrigation Use

Figure 3-23: Real time data plotted as pie diagram for the Fitness of irrigation water use

From the above results it can be seen that majority of the catchment has access to ideal water quality for the fitness of irrigation water use. The Lomati River Catchment was within the ideal category 100% of the time except at Sandbult where it was Ideal 80% of the time and good 20% of the time. The Komati River also has an access of ideal water quality except the Lower Komati which is ranging from good to fair at Tonga and Lebombo. There has been deterioration varying from Good 86% of the time to fair 14% of the time at Tonga. The Lebombo area was within a good category 100% of the time.

The Lower Komati is the most water stressed region in the catchment due to the high demands placed on it by the agriculture sector. There are numerous abstraction weirs

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3.3.2 Domestic Use

Figure 3-24: Real-time data plotted as pie diagram for Fitness for domestic use

The above results show that both Komati River and Lomati River has an access of ideal water quality for domestic use except the Lower Komati which is ranging from ideal to good at Tonga and Lebombo.

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3.3.3 Ecosystem

Figure 3-25: Real-time data plotted as pie diagram for Fitness for aquatic ecosystem health

From the recorded data, it can be seen that the quality of the water in the Lomati River catchment is in ideal class 100% of the time for fitness for aquatic ecosystem use, with the exception of Sandbult which was ranging from ideal class 57% of the time to good class for 43 % of the time.

The Komati River also has an access of ideal water quality except the Lower Komati which is ranging from good to fair at Tonga and at Lebombo.

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3.4 Biological monitoring

The state of the ecological health of rivers is a key issue in water management. Measurement of physicochemical parameters and chemical measures alone does not allow an assessment of the biological condition of surface waters. KOBWA assessed the water quality of fresh water through the collection of not only chemical and physical data, but also biological data.

The Biomonitoring programme is an internal KOBWA programme, however its data collection is outsourced to external service providers since there are no specialists within KOBWA to analyse the data. KOBWA uses the service of professionals for data collection and analysis.

KOBWA has conducted both wet and dry season bi- monitoring for the 2014/2015 water year. The results of wet biomonitoring are summarised in this section below.

Table 3-1 gives description of each biomonitoring sites selected. Please also refer to Figure 3-26 to Figure 3-27 for the maps showing the study area.

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Table 3-1: General information and description of localities selected for the KOBWA biomonitoring programme

Rationale River Site name Latitude Longitud Sub- EcoRegion Geomorphologic e quaternar V2 al unit y Reach

Loma DK-US - 31.42920 X14E- 3.7 D: Upper foothills Upstream of ti 25.764408 9° 01151 (Lowveld) Driekoppies ° Dam to reflect status of inflowing Lomati River

Loma DK-DS - 31.53443 X14G- 3.7 E: Lower foothills Downstream ti 25.710954 8° 01128 (Lowveld) (below) of ° Driekoppies Dam. Reflects worst case scenario based on flow modification by Driekoppies Dam and weir.

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Loma EWR_L1_Kleindorin - 31.62319 X14H- 3.7 E: Lower foothills Downstream ti gkop 25.649444 4° 01066 (Lowveld) of Driekoppies ° Dam to reflect Lomati River status below dam.

Kom MD-DS - 31.27640 X13B- 4.5 D: Upper foothills Downstream ati 26.080258 3° 01317 (below) of ° (North Maguga eastern Dam. Reflects Highlands) worst case

scenario

based on flow modification by Maguga Dam and weir.

Middl EWR_M1-Silingani - 31.39821 X13D- 3.7 E: Lower foothills EWR site e 26.099500 7° 01323 (Lowveld) approximatel Kom ° y 20km ati downstream of Maguga Dam close to

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the host/resettlem ent area.

Lowe EWR_K3A_Tonga - 31.79055 X13J- 3.7 E: Lower foothills EWR site in r 25.677639 6° 01130 (Lowveld) Lower Komati Kom ° River ati downstream . of Maguga Dam and upstream of Lomati River confluence

Kom EWR_K5_Lebombo - 31.95596 X13L- 12.1 E: Lower foothills EWR site at ati 25.447875 4° 00995 (Lebombo weir in lower ° uplands) reaches of Komati River after inflow of the Lomati River and before confluence with

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Crocodile River.

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Figure 3-26: General Local Map of KOBWA study area indicating biomonitoring sites

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Figure 3-27: Ecoregions and Secondary Catchments in the study area

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Please refer to Table 3-2 below for classification used for the results to classify the present state of the fish assemblage into a specific descriptive category (A to F).

Table 3-2: Descriptive categories used to describe the present ecological status (PES) of biotic components (adapted from Kleynhans, 1999).

CATEGORY BIOTIC INTEGRITY DESCRIPTION OF GENERALLY EXPECTED CONDITIONS Unmodified, or approximates natural conditions closely. The biotic assemblages compares to that expected under A Excellent natural, unperturbed conditions. Largely natural with few modifications. A change in community characteristics may have taken place but species richness and presence of intolerant species indicate little modifications. Most aspects of the biotic assemblage as expected under natural unperturbed B Good conditions. Moderately modified. A lower than expected species richness and presence of most intolerant species. Most of the characteristics of the biotic assemblages have been moderately modified from its naturally expected condition. Some impairment of health may be evident at the lower C Fair end of this class. Largely modified. A clearly lower than expected species richness and absence or much lowered presence of intolerant and moderately intolerant species. Most characteristics of the biotic assemblages have been largely modified from its naturally expected condition. Impairment of health may become evident at the lower end of this D Poor class.

Seriously modified. A strikingly lower than expected species richness and general absence of intolerant and moderately tolerant species. Most of the characteristics of the biotic assemblages have been seriously modified from its naturally expected condition. Impairment of health may E Very Poor become very evident.

Critically modified. Extremely lowered species richness and an absence of intolerant and moderately tolerant species. Only intolerant species may be present with complete loss of species at the lower end of the class. Most of the characteristics of the biotic assemblages have been critically modified from its naturally expected F Critical conditions. Impairment of health generally very evident.

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Table 3-3: Adjusted class limit boundaries for the diatom Specific Pollution Index (SPI) used to determine Present Ecological State

Index Ecological Desription Score Category (SPI) A 18 - 20 High Quality A/B 17 - 18 B 15 - 17 Good Quality B/C 14 - 15 C 12 - 14 Moderate Quality C/D 10 - 12 D 8 - 10 Poor Quality D/E 6 - 8 E 5 - 6 E/F Bad Quality 4 - 5 F < 4

3.4.1 Benthic Algae & Floating Macrophytes

3.4.1.1 Benthic Algae

Benthic algal abundance in the Lomati River in February 2015 was low, and ranged between 20 and 30 % (Figure 3-28).

Elevated algal abundance that exceeded the nominal target value of <40% was recorded in the Komati River at Site K3a (60%), and Site K5 (80%) (Figure 3-28). The algal composition was dominated by Stigeoclonium and Cladophora, both of which are typically associated with polluted rivers.

3.4.1.2 Floating Macrophytes

Floating aquatic macrophytes were absent at most sites in February 2015, but three species were recorded in low abundance (<1% cover) as follows:

 Duckweed (Spirodela sp), present in low abundance in the lower reaches of the Lomati River near Phiva.

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 Red Water Fern (Azolla filicoides), present in low abundance in the lower reaches of the Lomati River near Phiva.

 Kariba Weed (Salvinia molesta), present in low abundance in the lower reaches of the Komati River, at K5.

Figure 3-28: Benthic Algal Abundance in February 2015

3.4.2 Riparian Vegetation

A detailed assessment of riparian vegetation was not undertaken for this report, but a visual comparison of photographs taken at M1 in 2003/2007 and at the same location in 2015 show significant encroachment of riparian onto channel features, as shown in the photographs below (Figure 3-29).

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A: Aerial view of Komati River B) Aerial view of Komati River near near Site M1: 2007-07-02 Site M1 eight years later (2015-02- 05), showing extensive on islands and bars

C: Komati River showing the location of D: Komati River at M1 twelve years later a hydraulic cross-section at M1, (2015-02-28), showing extensive growth crossing a lateral gravel bar on 2003-11- of vegetation on what had previously 11. been a unvegetated gravel bar. Figure 3-29: Photographs at Silingani (M1), showing encroachment of riparian vegetation onto channel features

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3.4.3 Diatoms

The Present Ecological State of benthic diatoms in the Study Area in February 2015 is summarised in Figure 3-30. Compliance to ecological targets for diatoms is shown Table 3-4.

Figure 3-30: Present Ecological State classification of benthic diatoms in the Lomati and Komati Rivers in February 2015

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Table 3-4: Diatom based ecological classification for samples collected in February 2015 (from Van Dam et al. 1994).

Site pH Salinity Organic nitrogen Oxygen levels Pollution Trophic status levels Lomati River

US Neutral Fresh Elevated Fairly high Slightly Mesotrophic brackish concentrations (>75% polluted of organically saturation) bound nitrogen DK-DS Neutral Fresh Elevated Continuously Slightly Mesotrophic brackish concentrations high (~100% polluted of organically saturation) bound nitrogen L1 Neutral Fresh Elevated Moderate Slightly Eutrophic brackish concentrations (>50% polluted of organically saturation) bound nitrogen Komati River

No data MD- US

MD-DS Neutral Fresh Very small Continuously Slightly Mesotrophic brackish concentrations high (~100% polluted of organically saturation) bound nitrogen

M1 Alkaline Fresh Elevated Moderate Slightly Eutrophic brackish concentrations (>50% polluted of organically saturation) bound nitrogen

K3a Neutral Fresh Periodically Moderate Slightly Eutrophic brackish elevated (>50% polluted concentrations saturation)

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of organically bound nitrogen

K5 Neutral Fresh Very small Continuously Slightly Mesotrophic brackish concentrations high (~100% polluted of organically saturation) bound nitrogen

Table 3-5: Diatom Compliance to diatom targets

Lomati River Komati River Diatoms DK-US DK-DS L1 MD-US MD - DS M1 K3a K5 Ecological Targets Feb 2015 Target Feb 2015 Target Feb 2015 Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Specific Pollution Index (SPI) 17.6 >14 18 >14 14.2 - >14 16.3 >14 17.4 >10 13.5 >10 11.8 Pollution Tolerant Valves (%) 0 <20 0.3 <20 4.3 - <20 2.8 <20 0.8 <20 6.8 <30 22.5 Valve Deformities (%) 0 <2 0 <2 0.25 - <2 0 <2 0 <2 0 <2 0 Presence of Achnanthidium spp. (%) Present >15 Present >3 Present - >10 Present >5 Present >2 Present >2 Present Presence of sensitive spp. (%) Present >20 Present >10 Present - >20 Present >10 Present >2 Present >2 Present Absence of N. veneta Absent 0 Absent <2 Absent - 0 Absent <2 Absent <2 Absent <2 Absent Absence of Eolimna spp. Absent 0 Absent <2 Absent - 0 Absent <2 Absent <2 Present <2 Absent Nitzschia spp. abundance (%) Absent <5 Absent <10 Present - <5 Absent <10 Absent <10 Absent <10 Absent G. parvulum and G. minutum abundance (%)Absent <5 Absent <15 Present - <5 Absent <15 Absent <10 Present <15 Present Cocconeis placentula abundance (%) Absent <5 Absent <15 Present - <5 Absent <15 Present <20 Present <25 Present Compliance (%) - - 100% - 100% - - 100% - 100% - 90% - 80% Compliance (Category) - - Excellent - Excellent - - Excellent - Excellent - Good - Good/Mod Blue = Control; Green = Within Target ; Red = Target Failed

3.4.3.1 DK-US – Jeppes Reef

The Present Ecological State of diatoms in the Lomati River upstream of Driekoppies Dam in February 2015 was rated as Category A/B (SPI = 17.6). Nutrient, salinity and organic pollution levels were low to normal, with Pollution Tolerant Valves (PTVs) being generally absent. The diatom community was characterised by species with a preference for good, clean water with high oxygenation rates and included species from the genera Achnanthidium and Encyonopsis. The dominance of Fragilaria species indicated that flows were elevated at the time of sampling. The diatom community composition reflected species which were sensitive to deteriorated water quality and there was no evidence of major anthropogenically related impacts. No valve deformities were noted suggesting that metal toxicity was generally absent or below detection limits at the time of sampling.

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3.4.3.2 DK-DS – Driekoppies Dam

The Present Ecological State of diatoms in the Lomati River immediately downstream of Driekoppies Dam was rated as Category A (SPI = 18.1). The diatom data indicated that there was an improvement in biological water quality due to a general in increase in species with a preference for high oxygenation rates and good water quality conditions and included species from the genera Achnanthidium, Nupella and Encyonopsis. Nutrient and salinity levels remained relatively stable compared to DK-US, while there was a very slight increase in PTVs at 0.3%. Adlafia bryophila was also dominant and is an aerophilous species (Taylor et al., 2007b) which suggested that water levels fluctuated at the site. This could potentially impact the life cycles of aquatic biota. The increased abundance of Nitzschia amphibia also indicated that nutrient and salinity levels were increasing which could lead to the overall deterioration in water quality. No valve deformities were noted suggesting that metal toxicity was generally absent or below detection limits at the time of sampling. Compliance of ecological targets for diatoms at this site was rated as Excellent (100%).

3.4.3.3 DK-US L1 – Kleindoringkop

The Present Ecological State of diatoms in the Lomati River at Kleindoringkop (L1) was rated as Category B/C (SPI = 14.2). The diatom data indicated the accumulative impacts of anthropogenic activities in the middle reaches of the Lomati River. While salinity levels remained relatively stable, there was a slight increase in nutrient levels while there was a more notable increase in organic pollution with PTVs making up 4.3% of the total count. There was a general decrease in species with a preference for good water quality and high oxygenation rates and species from the genera Achnanthidium and Encyonopsis were sub-dominant rather than dominant. Species with a preference for moderate water quality with higher nutrient and organic pollution levels generally increased in abundance. C. placentula was dominant and prefers alkaline eutrophic conditions (Fore and Grafe, 2002); is tolerant of moderate organic pollution and also extends into brackish waters (Kelly et al., 2001). The dominance of this species, along with Gomphonema minutum, was an indication of rising organic pollution and nutrient levels which could be associated with irrigation return flows. Although valve deformities were noted at an abundance of 0.25%, these levels did not exceed general threshold limits and were not deemed problematic. Compliance of ecological targets for diatoms at this site was rated as Excellent (100%).

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3.4.3.4 MD-US – Hooggenoeg

Sampling of diatoms at MD-US in February 2015 was not possible because of high flows.

3.4.3.5 MD-DS – Maguga Dam

The Present Ecological State of diatoms in the Komati River immediately downstream of Maguga Dam was rated as Category B (SPI = 16.3). Nutrient, salinity and organic pollution levels were low to normal with PTVs making up 2.8% of the total count. The diatom community was characterised by species with a preference for good, clean water with high oxygenation rates, and included species from the genera Achnanthidium and Encyonopsis. The dominance of Achnanthidium minutissima along with Fragilaria capucina and F. nanana indicated the presence of elevated flows.

3.4.4 Aquatic Macroinvertebrates

The Present Ecological State of aquatic macroinvertebrates in the Study Area in February 2015 is summarised in Figure 3-31. Compliance to ecological targets for macroinvertebrates is shown Table 3-6.

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Figure 3-31: Present Ecological State classification of aquatic macroinvertebrates (SASS5) in the Lomati and Komati Rivers in February 2015

Table 3-6: Compliance to macroinvertebrate targets

Lomati River Komati River Macroinvertebrates DK-US DK-DS L1 MD-US MD - DS M1 K3a K5 Ecological Targets Feb 2015 Target Feb 2015 Target Feb 2015 Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Total SASS5 Score 142 >130 103 >130 137 - >160 63 >160 113 >100 163 >142 113 Average Score per Taxon (ASPT) 5.9 >6.0 5 >6.0 7.2 - >6.2 4.2 >6.2 6.3 >5.0 7.1 >5.1 5.4 Proportion of Sensitive Taxa (%) 29 >25 13 >25 53 - >25 7 >25 33 >25 43 >25 24 Proportion of Air-Breathing Taxa 25 <40 39 <40 35 - <40 47 <40 33 <40 26 <40 29 Abundant taxa ("D") Absent Absent Absent Absent Absent - Absent Absent Absent Absent Absent Present Absent Present Presence of Atyidae ------Present Present Present Present Presence of Perlidae Absent Present Absent Present Present - Present Absent Present Absent - - - - Presence of Baetidae (>2 spp) > 2 spp >2 spp 2 spp >2 spp >2 spp - >2 spp 1 sp >2 spp >2 spp >2 spp Present >2 spp Present Presence of Heptageniidae Present Present Absent Present Present - Present Absent Present Present Present Present Present Absent Presence of Leptoceridae Absent Present Present Present Absent - Present Absent Present Present Present Present Present Absent Presence of Tricorythidae (except winter) ------Present Absent Present Present Present Absent Present Absent Presence of Elmidae Present Present Present Present Present - - - - - Present Present - - Presence of Hydropsychidae Present Present Present Present Absent - >2 spp 2 spp >2 spp 1 sp >1 spp Absent - - Presence of Philopotamidae Present - - - - - Present Absent Present Absent - Present - - Alien Macroinvertebrates Absent Absent Present Absent Absent - Absent Absent Absent Absent Absent Present Absent Present Compliance (%) - - 50% - 80% - - 15% - 77% - 71% - 36% Compliance (Category) - - Mod - Good/Mod - - Critical - Mod - Mod - Poor Blue = Control; Green = Within Target ; Red = Target Failed

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3.4.4.1 DK-US – Jeppes Reef

The Present Ecological State of aquatic macroinvertebrates in the Lomati River upstream of Driekoppies Dam in February 2015 was rated as Category B (Total SASS5 Score = 142; ASPT = 5.9). The fauna was characterised by moderate numbers of Brushlegged Mayflies (Oligoneuridae), which are highly sensitive to water quality deterioration (QV=15). There was a high number of sensitive taxa (7), although the proportion of sensitive taxa was moderate (29%). The proportion of air-breathing taxa was low (25%), indicating that oxygen levels were not limiting. The results are similar to the previous survey conducted by Clean Stream in August 2014 (Total SASS5 Score = 161; ASPT = 6.7).

3.4.4.2 DK-DS – Driekoppies Dam

The Present Ecological State of aquatic macroinvertebrates in the Lomati River immediately downstream of Driekoppies Dam in February 2015 was rated as Category D (Total SASS5 Score = 103; ASPT = 4.5). This score is significantly lower than the target of value 130, and significantly lower than the value of 142 recorded upstream. The low SASS5 score cannot be attributed to limited habitats, as there were large stands of the waterweed Potamogeton schweinfurthii, and clean gravel beds with moderate current speeds, both of which provided ideal habitat for aquatic macroinvertebrates. The fauna was characterised by a low diversity of baetid mayflies (2 species only), a moderate diversity and abundance of snails, including the alien snail Physa acuta. There was also a notable absence of Flat-headed mayflies (Heptageniidae). The number of sensitive taxa was low (3), indicating disturbed conditions, whereas the proportion of air-breathing taxa was moderate (39%), indicating that oxygen levels were not limiting. Two species of filter- feeding blackflies were present, namely Simulium adersi and S. hargreavesi, both of which are typically found downstream of impoundment. The large caddisfly Macrostemum capense was present in moderate numbers. This species feeds on zooplankton, and is also typical of impoundment outlets. Overall, the results indicate significant deterioration in ecological conditions compared to upstream. Six of the 12 Key Performance Indicators for macroinvertebrates were met, which equates to a compliance rating of Moderate (50%). There are no biomonitoring data available for this site before the construction of Driekoppies Dam, but data collected on six occasions after construction show that ecological conditions at this site, have been consistently degraded.

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3.4.4.3 L1 – Kleindoringkop

The Present Ecological State of aquatic macroinvertebrates in the Lomati River at L1 was rated as Category B (Total SASS5 Score = 137; ASPT = 7.6). This score is within the target value of 130, and comparable to the value that was recorded upstream (142). The comparatively high score was despite limited suitability of instream habitats (Category C), as there was a noticeable absence of instream vegetation and stones-out-of-current habitats. The invertebrate fauna was characterised by moderate numbers of Stoneflies (Perlidae), Flat-headed mayflies (Heptageniidae), Riffle beetles (Elmidae), and a notable absence of Caddisflies (Trichoptera). The invasive alien crayfish Cherax quadricarinatus was not recorded, although it was found further downstream in the Lomati River at Phiva, near the confluence with the Komati River. Sensitive taxa included the mayfly Dicercomyzon (Dicercomyzidae), and Brushlegged mayfly Elassoneuria (Oligoneuridae). Overall, the results indicate almost complete recovery in ecological conditions compared to upstream. Ten of the 12 key Performance Indicators for macroinvertebrates were met, which equates to a compliance rating of Good to Moderate (80%). The non- compliance indicators were the absence of leptocerid caddisflies (Leptoceridae), and absence of Hydropsychid caddisflies (Hydropsychidae). There are no biomonitoring data available for this site before the construction of Driekoppies Dam, but data collected at this site on nine occasions after construction show the same trend.

3.4.4.4 MD-US – Hooggenoeg

Sampling of macroinvertebrates at MD-US in February 2015 was not possible because of high flows.

3.4.4.5 MD-DS – Maguga Dam

The Present Ecological State of aquatic macroinvertebrates in the Komati River immediately downstream of Maguga Dam in February 2015 was rated as Category E/F (Total SASS5 Score = 63; ASPT = 4.2). This score is significantly lower than the target of value 170. The low SASS5 score cannot be attributed to limited habitats, as the diversity and abundance of instream habits sampled was rated as highly suitable for invertebrates (Category A). The fauna was characterised by moderate numbers of flatworms (Turbellaria), Ripple Bugs (Veliidae) and Micro-caddisflies (Hydroptilidae). Overall, the results indicate significant deterioration in ecological conditions compared to upstream. Only two of the 13 Key Performance Indicators for macroinvertebrates was met, which

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3.4.4.6 M1 – Silingani

The Present Ecological State of aquatic macroinvertebrates in the Komati River at M1, located 20 km downstream of Maguga Dam, showed partial recovery to Category C (Total SASS5 Score = 113; ASPT = 6.3), but this score is well below the target of value 170. The low SASS5 score cannot be attributed to limited habitats, as the diversity and abundance of instream habits sampled was rated as highly suitable for invertebrates (Category A). The invertebrate fauna was characterised by moderate numbers of Baetid mayflies (Baetidae), Caenid mayflies (Caenidae), and Leptocerid Caddisflies (Leptoceridae). Sensitive taxa included Flat-headed mayflies (Heptagenidae) and Stout crawlers (Tricorythidae). Ten of the 13 Key Performance Indicators for macroinvertebrates were met, which equates to a compliance rating of 77%, which is classified as Moderate. The results are almost identical to the previous survey conducted by Clean Stream in September 2014 (Total SASS5 Score = 108; ASPT = 6.0).

Comparison of historical data from this site show a significant deterioration since the completion of the hydro-power plant in 2011. Prior to this, between 2002 and 2005, the operation of Maguga Dam did not have a measurable impact on the overall composition of macroinvertebrates (Figure 3-32).

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Figure 3-32: Time series of Present Ecological State classification of aquatic macroinvertebrates (SASS5) at Silingani (M1), in the middle Komati River

3.4.4.7 K3a – Tonga

The Present Ecological State of aquatic macroinvertebrates in the Komati River at Tonga (K3a), was rated as Category A (Total SASS5 Score = 163; ASPT = 7.1). This score is well within the target value of 100 for a Category D. The scores are within the same range recorded in 1997 and 1998, before the construction of Maguga Dam, when total SASS5 scores ranged between 142 and 240. Sensitive taxa recorded in February 2015 included Brushlegged mayflies (Oligoneuridae), Flat-headed mayflies (Heptageniidae), and Philopotamid caddisflies (Philopotamidae). The results indicate that overall water quality was within acceptable levels the protection of aquatic macroinvertebrates. Ten of the 14 Key Performance Indicators were met, which equates to a compliance rating of 71%, which is classified as Moderate. Non-compliance included the presence of the alien invasive crayfish Cherax quadricarinatus, and very high numbers of the alien invasive thiarid snail, Tarebia granifera.

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Figure 3-33: Time series of Present Ecological State classification of aquatic macroinvertebrates (SASS5) at Tonga (K3), in the middle Komati River

3.4.4.8 K5 – Lebombo

The Present Ecological State of aquatic macroinvertebrates in the Komati River at Lebombo (K5), was rated as Category D (Total SASS5 Score = 113; ASPT = 5.4). This score is well below the target value of 142. Although the Total Score was identical to the score recorded at M1, the average sensitivity was significantly lower, indicating water quality deterioration. Sensitive taxa recorded in February 2015 included Freshwater shrimps (Atyidae), Stoneflies (Perlidae), and Prongills (Leptophlebiidae). Three of the 11 Key Performance Indicators for macroinvertebrates were met, which equates to a compliance rating of 36%, which is classified as Poor. Non-compliance included very high numbers of the alien invasive thiarid snail, Tarebia granifera, and the presence of the alien invasive crayfish Cherax quadricarinatus. Furthermore, closer examination of one specimen showed that it supported large numbers of the alien parasite Diceratocephala boschmai.

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3.4.5 Fish

The Present Ecological State of fish in the Study Area in February 2015 is summarised in Figure 3-34, and the relative abundance of fish is summarised in Figure 3-35. Compliance to ecological targets for fish is shown Table 3-7.

Figure 3-34: Present Ecological State classification of fish (FAII) in the Lomati and Komati Rivers in February 2015

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Figure 3-35: bundance of fish in the Lomati and Komati Rivers in February 2015

Table 3-7: Compliance to fish targets

Lomati River Komati River Fish DK-US DK-DS L1 MD-US MD - DS M1 K3a K5 Ecological Targets Feb 2015 Target Feb 2015 Target Feb 2015 Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Target Feb 2015 Number of fish species 10 >15 8 >15 13 8 >15 2 >15 8 >15 7 >15 8 Abundance of fish (number / hour) 98 >50 99 >50 234 240 >50 21 >50 99 >50 68 >50 152 Presence of Barbus eutaenia Present Present Absent Present Present Present Present Absent Present Present Present Absent - - Presence of Labeo sp. Absent Present Absent Present Present Present Present Absent Present Absent Present Present Present Present Presence of Labeobarbus sp. Present Present Absent Present Present Present Present Absent Present Present Present Absent Present Absent Presence of Opsaridium perengueyi Present Present Absent Present Present Absent Present Absent Present Present Present Absent - - Presence of Chiloglanis sp. Present Present Present Present Present Absent Present Absent Present Present Present Present Present Absent Presence of Mormyridae Present Present Present Present Present Absent Present Absent Present Present Present Absent Present Absent Alien Fish Species Absent Absent Present Absent Present Present Absent Present Absent Absent Absent Present Absent Present Compliance (%) - - 33% - 78% - - 0% - 78% - 44% - 29% Compliance (Category) - - Poor - Mod - - Critical - Mod - Marginal - Poor Blue = Control; Green = Within Target ; Red = Target Failed

3.4.5.1 DK-US – Jeppes Reef

The Present Ecological State of fish in the Lomati River upstream of Driekoppies Dam in February 2015 was rated as Category C (Figure 3-34). A total of ten species of indigenous

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3.4.5.2 DK-DS – Driekoppies Dam

The Present Ecological State of fish in the Lomati River immediately downstream of Driekoppies Dam in February 2015 was rated as Category D (Figure 3-34). A total of seven species of indigenous fish recorded, out of 14 expected. This is the lower than the 12 indigenous species recorded during the previous two surveys, conducted in 2014 (Clean Stream 2014a&b), and significantly lower than the 17 species recorded in November 2005 (Engelbrecht and Roux 2006). Hydraulic diversity of habitats sampled was low, and comprised mainly shallow-fast and shallow-slow habitats, with no fast-deep or slow-deep habitat sampled. Cover availability of marginal and submerged aquatic vegetation was good, but there was no cover provided by boulders or large cobbles. The abundance of fish was moderate, with a Catch per Unit Effort of 99 fish per hour (Figure 3-35). The fauna was dominated by tolerant species comprising Tilapia rendalli (39.5% of the catch), and Pseudocrenilabrus philander (18.4%). The alien Largemouth Black Bass Micropterus salmoides was present in low abundance (5.3%). Two of the eight Key Performance Indicators for fish were met, which equates to a compliance rating of 25%, which is classified as Poor.

3.4.5.3 L1 – Kleindoringkop

The Present Ecological State of fish in the Lomati River at L1 was rated as Category B/C (Figure 3-34). A total of 12 species of indigenous fish recorded, out of 15 expected. The results indicate an improvement in conditions compared to upstream (DK-DS), where 7 species were recorded, and compared the previous two surveys conducted in 2014, when the total number of species recorded was 6 and 9 (Clean Stream 2014a&b).

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However, 20 species of indigenous fish were recorded at this site in November 2003 (AfriDev 2006). Hydraulic diversity was low, and comprised mainly shallow-fast habitats, and fast-deep habitat was absent. The abundance of fish was high, with a Catch per Unit Effort of 234 fish per hour (Figure 3-35). The fauna was dominated by moderately sensitive Labeo molybdinus (27.4% of the catch), and Labeo cylindrucs (17.1%). Sensitive species were present, but in low numbers. These comprised Chiloglanis anoterus (7.7%), and Opsaridium perengueyi (0.9%). Seven of the eight Key Performance Indicators for fish were met, which equates to a compliance rating of 88%, which is classified as Good. The one non-compliance indicator was the presence of alien Largemouth Black Bass Micropterus salmoides, which was recorded in low abundance (0.9%), for the first time at this site since monitoring started in June 1994.

3.4.5.4 MD-US – Hooggenoeg

The Present Ecological State of fish in the Komati River immediately upstream of Maguga Dam in February 2015 was rated, with low confidence, as Category C (Figure 3-34). The low confidence is because the river was in spate, so sampling was limited to the margins of the river. A total of eight species of indigenous fish recorded, out of 11 expected. By comparison, six species were recorded during the previous survey, conducted in November 2005 (Engelbrecht and Roux 2006). The abundance of fish was high, with a Catch per Unit Effort of 240 fish per hour (Figure 3-35). The fauna was dominated by the moderately sensitive Labeobarbus marequensis (60.0% of the catch), followed by Labeo cylindricus (12.5%). Species that were notably absent included Amphilius uranoscopus and Chiloglanis spp. The alien Largemouth Black Bass Micropterus salmoides was recorded in low abundance (1.3%), for the first time at this site since monitoring started in May 1997.

3.4.5.5 MD-DS – Maguga Dam

The Present Ecological State of fish in the Komati River immediately downstream of Maguga Dam in February 2015 was rated, with low confidence, as Category F. The low confidence is associated with depth and low conditions that restricted sampling to the edge of the river. The fauna comprised two species only: the indigenous catfish Clarias gariepinus and the alien Largemouth Black Bass Micropterus salmoides. The abundance of fish was very low, with a Catch per Unit Effort of 21 fish per hour (Figure 3-35). Previous surveys also reported very low abundance. However, the species composition in previous

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3.4.5.6 M1 – Silingani

The Present Ecological State of fish in the Komati River at M1, located 20 km downstream of Maguga Dam, showed partial recovery to Category C (Figure 3-34). A total of eight species of indigenous fish was recorded, out of 13 expected. This is significantly lower than the previous survey in September 2014, when 15 species were recorded (Clean Stream 2014b). The diversity was also significantly lower than the 17 species recorded in November 2003 (AfriDev 2006). The abundance of fish was moderate, with a Catch per Unit Effort of 99 fish per hour (Figure 3-35). The fauna was dominated by the highly sensitive Barbus eutaenia (30.3% of the catch), followed by the moderately sensitive Labeobarbus marequensis (21.2%) and the highly sensitive Opsaridium perengueyi (12.1%). Examination of available data shows significant reduction in the abundance of flow-dependent species since 2011, when the Maguga hydro-power plan started operation. The extent of the decline is illustrated in Figure 3-36, which shows changes in the relative abundance of the Shortspine suckermouth Chiloglanis pretoriae at M1 since 1997. Alien Bass were not recorded at this site in February 2015, but were recorded in low abundance during the previous survey, in September 2014 (Clean Stream 2014b). Six of the eight Key Performance Indicators for fish were met, which equates to a compliance rating of 75%, which is classified as Moderate. The non-compliance indicators were the low number of fish species and the absence of Labeos.

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Figure 3-36: Series of the relative abundance of the Short-spine Suckermouth Chiloglanis pretoriae at Silingani (M1), in the middle Komati River

3.4.5.7 K3a – Tonga

The Present Ecological State of fish in the Komati River at Tonga (K3a), in February 2015 was rated as Category D/E (Figure 3-34). A total of six species of indigenous fish recorded, out of 13 expected. This is lower than the 11 species recorded during the previous survey, conducted in September 2014 (Clean Stream 2014b), and significantly lower than the 21 species recorded in 1998 (AfriDev 2006). Habitat and cover availability were good, although there was no deep-fast habitat present. The abundance of fish was moderate, with a Catch per Unit Effort of 68 fish per hour (Figure 3-35). The fauna was dominated by the highly sensitive Chiloglanis pretoriae (29.4% of the catch), followed by the moderately sensitive Labeo cylindricus (23.5%). The average sensitivity was lower (2.6) than expected (3.1), which suggests water quality deterioration. The alien Largemouth Black Bass Micropterus salmoides was recorded in moderate abundance (11.8%), for the first time at this site since monitoring started in May 1994. Examination of available data shows that the River Sardine Mesobola brevianalis was common at this since prior to the construction of Maguga Dam, but has not been recorded since 1998. Three of the eight Key

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Performance Indicators for fish were met, which equates to a compliance rating of 37%, which is classified as Poor.

3.4.1.3 3.4.5.8 K5 – Lebombo

The Present Ecological State of fish in the Komati River at Lebombo (K5), was rated as Category C/D (Figure 3-34). A total of seven species of indigenous fish was recorded, out of 13 expected. This is lower than the 10 species recorded during the previous survey, conducted in September 2014 (Clean Stream 2014b). The abundance of fish was high, with a Catch per Unit Effort of 152 fish per hour (Figure 3-35). The fauna was dominated by two species of goby, namely Gossogobius giurus (57.7% of the catch), and G. callidus (19.2%). The latter species is not listed in the available records before 2013. The two species look similar, and it is likely that G. callidus was present before 2013, but simply overlooked and mistaken for G. giurus. The alien Largemouth Black Bass Micropterus salmoides was recorded in low abundance (2.0%), for the first time at this site since monitoring started in June 1994. Two of the six Key Performance Indicators for fish were met, which equates to a compliance rating of 33%, which is classified as poor.

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3.5 Microbiological monitoring

Microbiological monitoring was adopted as part of KOBWA’s water quality monitoring programme, to provide information on the status and trends of the extent of faecal pollution. It also provides information to help assess the potential health risk to humans associated with the possible use of faecally polluted water resources.

This progamme is an initiative of Department of Water and Sanitation in South Africa as part of the National Microbiological Monitoring Programme (NMMP). The programme is operated on a regional basis. There are currently 15 sites in Inkomati Region, of which 6 sites are within KOBWA area of operation where microbiological samples are collected and analyzed.

Water samples are collected every two weeks at key points in the catchments (See Table 3-8 and Figure 3-37). The samples are then analysed in a laboratory in Nelspruit and the data is sent to the regional coordinator to further forward to the national administrator. Through the microbiological monitoring, KOBWA is able to provide users and the parties’ guidance on the fitness of use of the water in the system based on the South African Water Quality Guidelines.

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Table 3-8: List of the Microbiological Monitoring Points in Nkomati Water Management Area

WMS site ID Sample site description River Latitude Longitude

Site located within KOBWA area of operation

187736 Ntulane River (near to Driekoppies Dam) 25º40’16”S 31º31’23.5”S

187737 Komati River below TSB Mill Komati River 25º36’39”S 31º51’41.4”S

182580 Naas WTW Komati River 25º38’27”S 31º50’25.4”S

187807 Block B Komati River 25º40’06”S 31º50’14.7”S

187734 Croc River below Komatipoort Crocodile River 25º26’16”S 30º58’24”S Golf Course (before @Komatipoort confluence)

187935 Komatipoort Bridge N4 (before Komati 26º27’3.5”S 31º57’6.48”S confluence with Crocodile River@komatipoort River)

Other Site within Nkomati WMA

184099 Mhlevo Dam (Acornhoek) 25º37’17.04000”S 31º04’09.84000”S

184097 Sabie River at Samora Dam Sabie River 25º58’49”S 30º28’58”S (Near Kruger gate)

184101 Nwarhele Nwarhele Stream 24º49’27.4800”S 31º03’24.48000”S

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WMS site ID Sample site description River Latitude Longitude

191498 Mwaritsi Mariti River D/S Mariti River 24º59’0.98”S 31º06’35.7”S Mapuleng Hospital

1000010076 Hoxani Bridge Sabie River 25º01’09.5”S 31º13’02.2”S

187731 Kanyamazane Bridge D/S Crocodile River 25º29’57”S 30º10’41”S

1000003124 Karino Bridge Crocodile River 25º28’12”S 30º06’02”S

1000003177 Emthonjeni (Machadodorp) Leeuspruit 25º41’33”S 30º15’20”S Leeuspruit

187847 Doornhoek at N4 Waterval Elands River 25º38’43”S 30º21’31”S Boven

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Within KOBWA area of operation

Figure 3-37: Microbiological Monitoring Points in Nkomati Water Management Area

Currently the sampling and analysis of samples in the Inkomati Water Management Areas, is been halted until further notice due to problems encountered with the labs.

KOBWA also conduct Microbiological analyses from the samples taken for the reservoir and river health monitoring program. The results are graphical represented in section 3.1 above and some are presented below:

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Figure 3-38: Faecal coliforms (count/100ml) of Lomati River Catchment

Figure 3-39: Faecal coliforms (count/100ml) of Komati River Catchment

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Figure 3-40: Faecal coliforms (count/100ml) of Maguga Dam

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Figure 3-41: Faecal coliforms (count/100ml) of Driekoppies Dam

Error! Reference source not found. to Figure 3-41show that the water quality in the catchment is of low risk when use to irrigate crops that are eaten raw. The four plots above also indicates that the water in the catchment was of high risk when drinking untreated and for full or partial contact except few monitoring points that recorded less than 400 counts/100ml at the Komati River Stretch and both Dam.

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4 Conclusion

From the results presented in this report, it was seen that the majority of the Komati catchment has very ideal water quality for the various water use sectors and as well as the environment. Apart from the lower Komati, the fitness of the water use for irrigation, domestic and ecological has been found to be ideal. In the lower Komati (especially at the base of the catchment) there is a slight decline of water from “ideal” to “good” for irrigation and domestic and from “ideal” to “fair” for ecosystem health due to this sections being a completely modified system.

The majority of these water quality problems in the lower Komati exist due to poor water resource management. Inadequate sanitation services, particularly in the Nkomazi region, and inadequate Waste Water Treatment Works, and Intensive agricultural and irrigation activities in the Lower Komati have serious negative impacts on water quality. The lower Komati is the most stressed region in the catchment where there is a perpetual struggle for the water resources by the agricultural sector. The existence of a number of abstraction weirs and dams control the resource. The lower reaches of the catchment have high salt concentrations and warmer temperatures (from irrigation return flows and high water abstraction), which pose a threat to the aquatic biodiversity and water for irrigation supply. It was seen that there is a trend of increasing pollution in the lower Komati due to the land use practices as well as population growth. This pollution will affect the users directly by affecting the water resources on which they are so dependent. The water resources in the lower Komati need to be managed such that there is minimal impact on the ecosystem on which the users are dependent. This needs to be implemented in order to sustain the system for the future, rather than abusing the system now and suffering the consequences later.

It can also be observed from the results above that the water from the two dams has very ideal water quality for all the three water use sectors, but the variables of concern are Total coliform counts and Dissolve oxygen. The Total Coliform counts must be zero for a water source in order for the water to be used for drinking purposes without any treatment. The dissolve oxygen limits recorded is very low for the survival of aquatic ecosystem. The cause of oxygen depletion is suspected to algae and rises in temperature.

Water temperature affects the capacity of water to retain dissolved oxygen. Cold water can hold more oxygen than warm water. Temperature inversely controls the solubility of

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Algae consume oxygen at all hours of the day and night. A stream experiencing an algal bloom exhibits large daily fluctuations in DO as extreme oxygen production during the day contrasts with the bacterial decomposition of algal detritus at night. Thus, the lowest concentrations of DO in the summer are typically observed just before dawn.

Compliance to ecological targets is summarised in Table below. The compliance of benthic diatom targets in the Lomati River and middle reaches of the Komati River was Excellent, but deteriorated downstream of Tonga (K3a). The deterioration is attributed mainly to elevated concentrations of nutrients.

The compliance of macroinvertebrate targets immediately downstream of Driekoppies Dam was Moderate, but conditions recovered well further downstream, at L1. In the Komati River, the compliance immediately downstream of Maguga Dam was Critical, with only partial recovery further downstream, at M1. The deterioration is attributed to short-term fluctuations in water level. Further downstream, near Komatipoort (K5), the compliance to macroinvertebrate targets was Poor. The poor compliance is attributed to elevated concentrations of nutrients.

The compliance of fish targets immediately downstream of Driekoppies Dam was Poor, but further downstream, at L1, conditions recovered partially. In the Komati River, the compliance for fish mirrored the general pattern shown for macroinvertebrates.

Lomati River Komati River DK-DS L1 MD - DS M1 K3a K5 Diatoms Excellent Excellent Excellent Excellent Good Good/Mod Macroinvertebrates Moderate Good/Mod Critical Moderate Moderate Poor Fish Poor Mod Critical Moderate Marginal Poor

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5 Recommendations

5.1 Nutrient Inputs

It is suggested that point-sources and non-point sources of nutrient inputs into the lower Komati and Lomati Rivers should be investigated in detail, and appropriate action taken to reduce inputs of nutrients into the two rivers.

5.2 Low Flows

The operation of both dams should be reviewed with the aim of eliminating periods of very low flow downstream of the dams, as far downstream as the confluence with the Crocodile River. All weirs should be managed to ensure constant overflow (spillage). Particular attention should be given to ensure that minimum monthly low flows, as recommended in the revised EWR, are maintained at Sandbult (KOB001), Tonga (KOB002), and Lebombo (KOB004). Daily average discharge at these weirs should continue to be monitored and the data analysed to understand the magnitude and duration of low flow events, and how these may affect the ecological state of the river downstream.

5.3 High Flows

It is suggested that the operation of both dams should be reviewed with the aim of ensuring periodic high flow events, as recommended by the EWR. Daily average inflows and releases from the dams should continue to be monitored and the data made available in order to understand the magnitude and duration of high flow events, and how these could affect the ecological state of the river downstream. A detailed review of the recommended high flow events and the observed high flow events upstream and downstream of both dams is recommended in order to inform potential changes in operation of the two dams.

5.4 Short-term Flow Variation

The operation of the Maguga Dam Hydro-Power plant should be reviewed with the aim of minimising short-term variations in discharge. A detailed review of the historical flow

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5.5 Ecological Water Requirement Targets

Appropriate warning thresholds for low flows should be clearly defined for key gauges downstream of the two dams, and appropriate management action taken when the warning thresholds are exceeded, or targets not met. The rules for implementing the EWR should be clearly defined for key gauges. A simple method for defining, in real-time, the periods of drought and maintenance flows, should be defined. Furthermore, the revised monthly EWR low-flow and high-flow targets should be extrapolated to other flow gauges in the catchment, where appropriate.

5.6 Alien Invasive Control

Bass fishing should be promoted. Bass specimens caught in the rivers during recreational fishing should be removed from the rivers.

5.7 Biomonitoring

Ongoing biomonitoring is recommended, using the same methods as presented in this report. Monitoring should include visual assessment of benthic algal abundance and floating macrophytes, as both provide simple methods of monitoring nutrient levels. The next survey is recommended to take place in Aug/Sep 2015

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6 References

1. AfriDev 2005. Ecological Water Requirement Quantity Report. Komati Catchment Ecological Water Requirements Study. Department of Water Affairs and Forestry, Pretoria. Report No. RDM X100-01-CON-COMPR2-0604. 2. AfriDev 2006. Aquatic monitoring in the lower Lomati and Komati Rivers. Internal report prepared by AfriDev Consultants (Pty) Ltd for the Komati Basin Water Authority. 3. AfriDev 2006a. Main Report. Komati Catchment Ecological Water Requirements Study. Department of Water Affairs and Forestry, Pretoria. Report No. RDM X100- 00-CON-COMPR2-1205. 4. AfriDev, Knight Piésold Joint Venture and JTK Associates 1999. Environmental Impact Assessment and Instream Flow Requirement CMP Supporting Report E: Instream Flow Requirements. Report prepared for the Komati Basin Water Authority Contract MDC-6. October 1999. 5. AfriDev. 2004b. Aquatic monitoring in the lower Lomati and Komati Rivers. Internal report prepared by AfriDev for the Komati Basin Water Authority. 6. Clean Stream 20013. Aquatic biomonitoring programme for Komati Basin Water Authority (KOBWA): Komati and Lomati Rivers. 2013 wet season biomonitoring survey. Report Reference KOBWA/B/2013. March 2014. 7. Clean Stream 20014a. Aquatic biomonitoring programme for Komati Basin Water Authority (KOBWA): Komati and Lomati Rivers. 2014 wet season biomonitoring survey. Report Reference KOBWA/C/2014. May 2014. 8. Clean Stream 20014b. Aquatic biomonitoring programme for Komati Basin Water Authority (KOBWA): Komati and Lomati Rivers. 2014 dry season biomonitoring survey. Report Reference KOBWA/D/2014. September 2014. 9. Engelbrecht J. S. and Roux, F. 2006. The present health of the fish and invertebrates in the Komati River. Draft Report submitted to the Komati Basin Water Authority (KOBWA), Driekoppies Dam, Malelane. May 2006. 10. Kleynhans, C. J. 1999. The development of a fish index to assess the biological integrity of South African rivers. Water SA 25(3): 265-278. 11. Nepid 2004. Aquatic monitoring of the lower Lomati and Komati Rivers. Internal report submitted to the Komati Basin Water Authority (KOBWA), Driekoppies Dam, Malelane. 12. Nepid 2006. Aquatic monitoring of the lower Lomati and Komati Rivers. Internal report submitted to the Komati Basin Water Authority (KOBWA), Driekoppies Dam, Malelane.

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13. Nepid 2009. Specialist Report: Baseline Assessment – Aquatic Ecosystems. Environmental study for the proposed Kangwane Anthacite Mine. Specialist Report. 23 March 2009. 14. Van Dam, H., Mertens A., and Sinkeldam, J. 1994. A coded checklist and ecological indicator values of freshwater diatoms from The Netherlands. Aquatic Ecology 28(1): 117-133.