8. THE BERG WMA 8.1 GENERAL DESCRIPTION Topography, Rainfall and Landuse Geological setting

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1 Western Cape IWRM Action Plan: Status Quo Report Final Draft 8. THE BERG WMA 8.1 GENERAL DESCRIPTION Topography, Rainfall and Landuse The topography of the Berg WMA varies considerably, with consequential impact on the climate of the region. Rainfall is highest in the southern mountain ranges where the mean annual precipitation is as high as 3000 mm per annum, whilst the north-west part of the WMA immediately inland of the coast, receives as little as 300 mm per annum. There is intensive irrigation in the Upper Berg River and Lower Berg River sub-areas and in parts of the Greater Cape Town sub-area (Eerste River and Lourens River catchments). The climate is a Mediterranean and rainfall is received in winter, when the water requirements are at their lowest. Figure shows the Berg WMA. Figure The Berg WMA Geological setting The bedrock of the entire Berg WMA (19) comprises the rock types of the Klipheuwel and Malmesbury Groups (see Figure 8.1.2). These Groups comprise argillaceous rock types, typically greywackes and shales. The Malmesbury Group is often referred to as Malmesbury Shale. These Groups occur extensively across the Swartland and are exposed from the Northern Suburbs, north to the Malmesbury region and north to Piketberg and Porterville. These basement rocks were intruded by the Cape Granite Suite and occur mainly as plutons, forming the rounded hills, for example Paarl, Perdeberg and Darling. The granite is typically very coarse grained. Following the intrusion of the granite a long period passed of upliftment and erosion, resulting in the deposition of sandstones which Status Quo Report DEADP 210

2 Western Cape IWRM Action Plan: Status Quo Report Final Draft form the Table Mountain Group (also known as the Table Mountain Sandstone ). In the WMA the TMG comprises two Sub-Groups and several formations with quite different lithological characteristics. The Peninsula Formation, which is part of the lower Sub-Group, is a very clear, extremely hard quartzite which forms the dramatic scenery of this area (e.g. Table Mountain, the southern Peninsula, Hottentot Holland Mountains and Piketberg). With an extensive time period the above mentioned rock types eroded, the softer rocks (Malmesbury Group) eroding more rapidly than the very hard Table Mountain Group (especially the more arenaceous formations) and unconsolidated deposits built up in the eroded valley areas. This resulted in extensive sand deposits forming, particularly in the western, more coastal portion of the WMA. These deposits comprise the Bredasdorp Group and Quaternary age deposits. They form areas such as the Cape Flats, the area around Atlantis and further northwards towards Langebaan and Velddrif Structural geology The Klipheuwel and Malmesbury Groups are typically more ductile and not prone to extensive faulting and fracturing. However, there are major faults that do occur within these Groups and, for some of the faults, the displacements are very large. The predominant fault direction is northwest/southeast. The Table Mountain Group comprises rock types that are very hard and brittle, resulting in numerous faults and fractures from the very local scale to regional scale. Status Quo Report DEADP 211

3 Western Cape IWRM Action Plan: Status Quo Report Final Draft Figure Geological setting of the Berg WMA. 8.2 WATER QUALITY Water quality in the Berg WMA varies not only between the individual river basins but also within individual river systems. The natural geology, agricultural practises, point, and non-point source pollution all play a role in determining the quality of water in this WMA. Most of the rivers in the water management area rise from the Table Mountain Group mountain catchments which provide very good quality of water with total dissolved solids concentrations of less than 60 mg/l. The Berg River arises in the mountains near Franschhoek and the runoff is characterised by ideal water quality. However, the quality deteriorates in a downstream direction as a result of human activities, such as agricultural activities (river modifications, water abstractions, and runoff from irrigated soils), urban storm water, discharge from wastewater treatment works, and runoff from informal settlements which tend to have no sanitation services. Many of the lower Berg River tributaries are underlain by Malmesbury shales of marine origin and therefore have naturally high Status Quo Report DEADP 212

4 Western Cape IWRM Action Plan: Status Quo Report Final Draft salinity concentrations. The shales coupled with agricultural return flows introduce elevated salinities in the middle and lower reaches of the Berg River and in the Diep River. This has an adverse impact on industrial water use and on crop selection. Furthermore, the potential economic impacts are of great concern where water quality standards in the rivers do not comply with those required by international export markets. Many of the urban rivers of Cape Town serve as conduits for discharging treated effluent to sea and whilst these rivers cannot be rehabilitated; their condition should at least be maintained at levels that will not introduce adverse health and social impacts. Storm water runoff from informal settlements and back-yard dwellings further adds to the water quality impacts in downstream reaches and this has had a notable effect in the Middle and Lower Berg, and the Eerste River downstream of the Stellenbosch area. Chapter 8 on Water Quality provides a more detailed overview on management related aspects that influence water quality challenges in the Province. An assessment of ecosystem health is included in Annexure D Water Quality Monitoring The water quality monitoring points within the Berg WMA and the various institutions responsible for undertaking that monitoring are shown in Figure The River Health monitoring programme was described and those monitoring points that are located in this WMA are shown on Figure Status Quo Report DEADP 213

5 Western Cape IWRM Action Plan: Status Quo Report Final Draft Figure Water quality monitoring points in the Berg WMA. Status Quo Report DEADP 214

6 Western Cape IWRM Action Plan: Status Quo Report Final Draft Figure River Health Programme monitoring points in the Berg WMA. Status Quo Report DEADP 215

7 Western Cape IWRM Action Plan: Status Quo Report Final Draft Surface Water Quality Status in the Berg This section provides a graphical interpretation of the water quality status of surface water in the Berg WMA. This is presented in Figure where the hexagon summary at the selected monitoring point represents the compliance of the water quality variable at that point along the river, with a generic set of Resource Water Quality Objectives (RWQO) that are applicable to all the rivers across the entire country. The figure shows that the general trend is one of decreasing water quality in a downstream direction, with fairly good water quality in the headwaters of most of the rivers. The reasons for this observation are briefly explained below. Annexure F provides the detailed records of the observed water quality profile on which the hexagon fit for use summaries at each monitoring point are based Water Quality Concerns in the Berg WMA From the numerous studies, investigations and monitoring information that is available on the subject, the following water quality issues are summarised for the Berg WMA: Salinity in the middle and lower Berg River A significant water quality problem in the Berg River catchment is salinization in the middle and lower reaches. This is caused by leaching from the natural geology, which extends from the north of Paarl to the Berg River mouth, consists of Malmesbury shale, as well as agricultural practices and the wash-off of salts from irrigated and dryland agricultural lands. The problem is exacerbated during the first winter rains, when accumulated salts are washed into the river resulting in elevated salinity in Misverstand Dam. Nutrient enrichment in the Berg River A further concern in the Berg River is nutrient enrichment as a result of the discharge of treated sewage effluent from WWTWs, irrigation with winery effluent, and the discharge of winery effluent that may not have been adequately pre-treated. Diffuse pollution which includes runoff from informal settlements, for example in the Klein Berg catchment (Tulbagh) impacts on the quality of water diverted into Voëlvlei Dam. This has led to increasing problems with nuisance algae in the middle and lower Berg River reaches and in Voëlvlei Dam. This has led to higher domestic water treatment costs. Microbiological water quality Concerns have been expressed about the microbial quality of rivers affected by treated wastewater effluent discharges and runoff from informal settlements. Rivers such as the Plankenberg and Eerste River near Stellenbosch, Stiebeul River near Franschhoek, and the Kuils River in Bellville are affected by poor quality effluents and runoff from informal settlements and high density settlements with poor sanitation services. Aging sewerage infrastructure and pump station breakdowns contribute to these problems. Some improvements in microbial water quality have in recent times been achieved in areas such as Stellenbosch and Paarl/Wellington due to interventions by the local municipalities. Concerns have also been expressed about the management and impacts of many small package plants that fall outside local authorities such as on golf estates and wineries. Water quality concerns in urban rivers Many of the urban river systems in the Berg WMA serve as conduits for treated effluent discharged to the sea. The Bellville, Scottsdene, Kraaifontein, Zandvliet, Stellenbosch, and Macassar WWTWs discharge treated effluent into the Kuils/Eerste River system. Borcherds Quarry and Athlone WWTWs discharge into the Black/Salt River and the Potsdam WWTW discharges into the Diep River, which feeds into the ecologically sensitive Rietvlei wetland system. The Cape Flats WWTW discharges into the canal downstream of the Zeekoevlei outlet control weir. These rivers no longer display seasonal flow patterns, and some, notably the Black/Salt and Kuils Rivers have become severely modified. High residual nutrients can lead to eutrophication related problems such as nuisance algal growth and excessive growth of aquatic weeds. Other problems associated with urban rivers include leaking Status Quo Report DEADP 216

8 Western Cape IWRM Action Plan: Status Quo Report Final Draft sewers, contaminated storm water runoff, litter, oil, and toxic spills. The constant and high base flows in these rivers also impact on the estuaries and many have lost their tidal variation. The locations of the WWTWs in the Berg WMA are shown in Figure Agro-chemicals and EDCs There are concerns about the accumulation of pesticide and herbicide residues in the surface waters, biota and sediments downstream of intensive irrigation areas. Concerns have also been expressed about the presence of EDCs in surface waters near intensive irrigation systems. POPs and EDCs are not monitored routinely in the Berg River WMA. Dissolved oxygen, piggeries, and organic effluents Concerns have been expressed about the impacts of many piggeries in the WMA on the organic loads to rivers. Organic compounds consume oxygen when they decompose in rivers thereby reducing the dissolved oxygen concentrations and negatively impacting aquatic organisms. Discharges not complying with COD standards and irrigated effluents high in organic content that are washed into rivers have similar impacts on aquatic ecosystems (DWA, 2010). Status Quo Report DEADP 217

9 Western Cape IWRM Action Plan: Status Quo Report Final Draft Figure Location of WWTWs in the Berg WMA. Status Quo Report DEADP 218

10 Western Cape IWRM Action Plan: Status Quo Report Final Draft Figure Water quality status "Fit for use" for the Berg WMA. (Source: DWA, 2010) Status Quo Report DEADP 219

11 8.3 GROUNDWATER Groundwater resources are available from primary aquifers along the coastal plain as well as from deeper rock-fractured and confined aquifers, of which the TMG holds the most potential for development, and is currently being investigated by the CCT. Groundwater is currently utilised from the primary aquifers near Atlantis and on the Cape Flats as well as from deeper aquifers in the Swartland. Monitoring networks to facilitate monitoring of aquifer systems and in particular the interaction between the surface and groundwater resource, are inadequate and local disputes between groundwater abstractors and resulting impacts on surface water users are common. As at 2005, the developed groundwater use in the Berg WMA was relatively small (about 57 million m 3 /a) in comparison to the yield available from developed surface water resources (about 230 million m 3 /a from major dams and 179 million m 3 /a from minor dams and run of river). A stronger reliance is likely to be placed on groundwater into the future by virtue of the fact that the surface water yield potential is reaching its exploitable limit, and options such as desalination remain relatively more expensive Aquifer types The WMA does host extensive aquifers. Figure shows the aquifer types, classified according to aquifer yield and springs. The Klipheuwel and Malmesbury Groups are typically not known for their high groundwater potential. However in places particularly where fracture/fault systems are well developed the groundwater potential is very high. In favourable geological settings borehole yields from these groups can be about 5 l/s and higher whilst the average borehole yield is lower. The Cape Granites are typically low yielding (~ 1 l/s) and these yields are only obtainable in highly weathered and faulted zones. Otherwise the granite is very solid and a non-aquifer. The Table Mountain Group also hosts fractured aquifers although conditions in the Group are highly variable and aquifer conditions are thus also highly variable. The wide range of lithological types also means that artesian conditions can occur as well when drilling into this Group. The sedimentary deposits, especially of Quaternary age, vary greatly in composition and grain size from peaty deposits (with a high clay and mud component), through to course, well rounded sand and gravel deposits. Where these coarse-grained deposits occur, and especially where they have been deposited in eroded valleys and large, saturated thicknesses, they have resulted in the occurrence of very high yielding aquifers. These high yielding aquifers include the Cape Flats Aquifer (CFA), the Atlantis/Silverstroom aquifer, and the Elandsfontein and Langebaan Road aquifers. Borehole high yields from certain portions of these aquifers can be extremely high in excess of 20 l/s. In summary, the Berg WMA hosts extensively-occurring groundwater in a variety of geological settings. The aquifer types within the Berg WMA are summarised in Table Table Extent of aquifer types within the Berg WMA Aquifer Type Percentage coverage of the Berg WMA Fractured 61 % Intergranular 22 % Intergranular and fractured 17 % Karst 0 % Status Quo Report DEADP 220

12 Table provides a summary of the aquifer types per average borehole yield. The most extensively occurring aquifer type is Fractured l/s. Status Quo Report DEADP 221

13 Status Quo Report DEADP 222

14 Figure Aquifer types for the Berg WMA. Table Aquifer types, sub-classes and coverage for the Berg WMA WMA Aquifer type and yield Area (km 2 ) % Area in Berg WMA BERG Fractured l/s BERG Fractured l/s BERG Fractured l/s BERG Fractured l/s BERG Fractured > 5.0 l/s BERG Intergranular l/s BERG Intergranular l/s BERG Intergranular l/s BERG Intergranular l/s BERG Intergranular > 5.0 l/s 74 1 BERG Intergranular and fractured l/s BERG Intergranular and fractured l/s BERG Intergranular and fractured l/s BERG Intergranular and fractured l/s BERG Intergranular l/s, Fractured l/s Groundwater Recharge For the Berg WMA the groundwater recharge varies from 5 Mm 3 /a up to 36 Mm 3 /a, with the high recharge areas being the mountainous regions in the Wemmershoek/Franschhoek area. Due to the relatively high rainfall in the Berg WMA the recharge across the WMA is considered good, as shown on Figure Status Quo Report DEADP 223

15 Figure Groundwater Recharge for the Berg WMA Groundwater Quality Due to the high rainfall received in the area and the favourable geological setting (Table Mountain Group sandstone), the southern and eastern portions of the WMA have very good groundwater quality. In addition the groundwater quantity associated with the Cape Granite Suite is also of excellent quality. The Status Quo Report DEADP 224

16 poorer water quality north of Saldanha is attributable to the close proximity to the coast, as the rainfall and associated groundwater recharge will be more saline than usual. The area between Malmesbury/Piketberg and Porterville has poorer groundwater quality due to the host rock ( Malmesbury Shale ). However one must be careful about the generalization as certain areas within the Malmesbury Group are high yielding aquifers of good quality groundwater. As mentioned before, this general overview of the Berg WMA indicates good quality groundwater, however site specific conditions need to be taken into account as water quality can vary significantly over short distances. The spatial variability in electrical conductivity (salinity) is shown in Figure Status Quo Report DEADP 225

17 Figure Groundwater quality (EC) of the Berg WMA Groundwater Abstraction The groundwater abstraction is based on available groundwater data from WARMS, based on work that was completed six years ago (DWAF, 2005) so the abstraction values should have changed since Status Quo Report DEADP 226

18 Whilst there was both over-registration and under-registration of water use in the period 1998/1999, abstraction values are now becoming more accurate and in the context of the Status Quo Report, the values from the DWAF (2005) work are considered usable. Figure shows the groundwater abstraction per Quaternary Catchment. The Quaternary catchments with the highest groundwater abstraction include the Cape Flats area (Phillipi - vegetable farming), the Atlantis area (Atlantis and Mamre - water supply) and Tulbagh region - mainly agricultural use). Figure Groundwater abstraction for the Berg WMA. Status Quo Report DEADP 227

19 8.3.5 Groundwater Stress Index The groundwater stress index for the Berg WMA is highest in the Atlantis area (Quaternary catchment G21B) and additional groundwater should not be abstracted in this area. The western portion of the Cape Flats Aquifer should not be developed further. However, the eastern portion has great potential for further groundwater abstraction. The Tulbagh area (as well as to the west of Tulbagh and south of Porterville) groundwater use should not be expanded. The groundwater stress index for the Berg WMA is shown in Figure Status Quo Report DEADP 228

20 Figure Groundwater Stress Index for the Berg WMA Groundwater contribution to river base flow Groundwater plays a significant role in supplying base flow to the Berg River in its upper reaches. The Table Mountain Group Aquifer contributes significantly to base flow, whereas in the more western region Status Quo Report DEADP 229

21 of the WMA, the role of groundwater towards baseflow contribution not significant. Figure shows the groundwater contribution to river base flow per Quaternary catchment. Figure Groundwater contribution to river base flow for the Berg WMA. Status Quo Report DEADP 230

22 8.3.7 Groundwater general comments The Berg WMA area is relatively highly urbanised and groundwater is used extensively. The bedrock (fractured) aquifers are used throughout to meet agricultural, municipal and domestic requirements. The intergranular aquifer at Atlantis has been properly designed and developed and forms a key source of water for the Atlantis residential and industrial areas. The monitoring of the Atlantis aquifer is recommencing after a lapse in this activity. The western portion of the Cape Flats Aquifer (CFA), which is also an intergranular aquifer, is used intensively by the farmers at Philippi. Groundwater holds great potential within this WMA and its careful use needs to be encouraged. Use of groundwater will relieve the demands on surface water resources. The Table Mountain Group Aquifer is being explored carefully and correctly as a potential source of groundwater to assist with the City of Cape Town municipal supply. There is extensive literature on the topic ( Another significant aquifer is the Cape Flats Aquifer, particularly the eastern portion. Extensive work has also been completed on this aquifer and it is recommended that a Task Team be selected to address all the aspects of the aquifer (quantity and quality) and it possible usage. The team needs to include numerous role players and the initiative would be best driven by the City of Cape Town. Table lists the quaternary catchments where the groundwater abstraction exceeds the groundwater recharge and the volume of groundwater required to meet the groundwater Reserve allocation. Intervention measures are required to ensure that sustainable use of groundwater occurs in these two Quaternary Catchments. Table Quaternary catchments where groundwater abstraction exceeds recharge and the Reserve within the Berg WMA WMA Quaternary Catchment Allocable Volume (Mm 3 /a) % Area of Quat included BERG G10E BERG G21B Groundwater development needs to be carried out in conjunction with correct monitoring and management. In addition monitoring of potential contamination sources also needs to take place, for example at waste disposal sites, transfer stations, waste water treatment works, areas where treated sewerage effluent is disposed, etc. Good communication needs to be maintained between all those involved in groundwater monitoring activities. 8.4 WATER RESOURCE INFRASTRUCTURE Based on the climatic characteristics (winter rainfall region) this WMA is one in which bulk water storage facilities (such as dams and aquifers) are critical in order to provide sufficient carry-over storage, such that water becoming available in winter, can provide for summer water requirements at acceptable levels of risk. Historically this has resulted in a focus on the development of surface water sources and in particular on large dams to provide for the needs of the WMA. Status Quo Report DEADP 231

23 8.5 STRATEGIC PERSPECTIVES FROM THE BERG WMA ISP The Berg WMA ISP (completed in 2004) which serves to guide the strategic management of water resources in this WMA until such time a s a CMA is in place and has developed its CMS. The following key strategic objectives and concerns are extracted from it: Strategic Objectives: Concerns: The Western Cape System Model of the water supply components must be updated regularly. The Berg River Reserve must be modelled to determine its impact on the availability of water (Note that this is currently being undertaken as part of the Voëlvlei Phase 1 feasibility study for abstracting Berg River winter water for storage in Voëvlei Dam). Develop water quality management strategies for the middle and lower Berg River. Licences for new irrigation expansion in the Berg WMA must be continuously considered with preference given to water trading. Reuse of treated wastewater must remain an important future source for investigation for supply to the Cape Metropolitan Area (Note that the CCT is currently intending to undertake a Feasibility Study on Water Reuse). Water quality in the lower reaches of the Berg River, and The effect of water resources development on the ecological functioning of the Berg River estuary (Note that this is currently being undertaken as part of the Voëlvlei Phase 1 feasibility study for abstracting Berg River winter water for storage in Voëvlei Dam) THE INTEGRATED WESTERN CAPE WATER SUPPLY SYSTEM In addition to supplying the City of Cape Town (CCT), the system also augments the local supply schemes of the towns of Paarl, Wellington, Stellenbosch, Saron and the West Coast District Municipality. The system also supplies water to irrigators along the Berg and Eerste Rivers. Bulk water supply infrastructure is mostly owned and operated by the CCT (for example Steenbras and Wemmershoek Dams). DWA however also own and operate some of the infrastructure (such as Voëlvlei Dam) within the WCWSS, whilst some local authorities own and operate local supply schemes themselves (for example the West Coast District Municipality and Drakenstein). Figure shows a schematic layout of the WCWSS. The existing storage dams (including the Berg Water Project form part of this integrated system), operated in such a manner that spills from the storage dams are minimised. The Berg Water Project is the latest scheme augmenting the system and consists of the Berg River Dam and Supplement Scheme, both of which came on line in The WCWSS is cooperatively managed by the CCT and the DWA Regional Office. The majority of towns in the Berg WMA are either wholly or partially supplied with water from this integrated scheme. A committee comprising DWA and all major stakeholders reviews the system storage and projected demands annually on 1 November and decides whether or not restrictions need to be recommended for the following year. Other operational challenges include the need for close cooperation with authorities such as Eskom, varying water quality, and the operation of the Riviersonderend Berg River Tunnel system which provides the means of transferring water from the Breede WMA into the Berg WMA. Status Quo Report DEADP 232

24 The main schemes currently supplying water into the WCWSS include the Palmiet River Government Water Scheme (Breede WMA), the Upper and Lower Steenbras Dams, Wemmershoek Dam and the offchannel Voëlvlei Dam. The latter is filled by diverting water out of the Klein Berg River, the Leeu River and the Twenty-Four Rivers. Theewaterskloof Dam in the Breede WMA is the largest dam within the WCWSS and water from it is transferred into the Berg WMA via the Riviersonderend-Berg River Tunnel System. This dam will also store water pumped from the Berg River Dam during winter, for transfer back into the WCWSS during summer. Figure The Western Cape water supply system. 8.7 BERG WMA WATER AVAILABILITY AND UTILIZATION The updated National Water Act is currently being developed and will contain revised estimates of water availability and utilization at WMA level. In 2005 (as published in Berg WMA ISP), the situation for the Berg WMA is as shown in Figure Status Quo Report DEADP 233

25 Figure Berg WMA water availability and utilisation (2005). It is relevant to note that in 2005: 27% of the water supply was via catchment transfer from the Breede WMA; The Berg River Dam and Supplement Scheme have since been implemented, adding an additional 80 million m 3 /a of yield to the WCWSS which has placed the WMA in a surplus, but only for the next 7-8 years (ie to 2018/19), and only if the CCTs WCDM strategy achieves its full objectives. The Western Cape Reconciliation Strategy shows that by 2018/19 further augmentation will again be required to meet the growing needs, primarily of the CCT and the West Coast. Between 2005 and 2008, DWA undertook a Berg Water Availability Assessment Study (WAAS) in which the hydrology of the Berg River catchments and Upper Riviersonderend (Theewaterskloof Dam) was updated. This was necessary in view of the fact that the last time the overall system hydrology in the Berg WMA was updated was during the 1990 Western Cape System Analysis Study. The updated hydrology is currently being used to evaluate the feasibility of a potential scheme to abstract limited surplus Berg River water into Voëlvlei Dam during winter (discussed further below). It is relevant to note that when comparing the updated yield (Berg WAAS, 2008) of the overall Western Cape Water Supply System (based on the latest information) with that from the 1990 Western Cape System Analysis, they remain similar (less than 0,2% difference). 8.8 THE WESTERN CAPE RECONCILIATION STRATEGY Over the years, the progressive development of surface water sources has taken place and the larger components have been linked by tunnels, pipelines and diversions in order to provide an integrated Western Cape Water Supply System. This allows for the operation and management of the system in such a way that optimum use is made available of the combined storage in the system, so as to reduce the risks of spilling of water from the dams and to best manage the numerous water transfers that take place into the system and within it. The Western Cape Reconciliation Strategy Study (WCRSS) continues to review the future water requirement scenarios and the reconciliation (scheme) options for meeting these water requirements within a planning horizon to The strategy identifies potential suites of reconciliation options for meeting water requirement scenarios from the WCWSS. It includes a host of possible implementation options which would offer flexibility in planning, so that possible changes in the projected water Status Quo Report DEADP 234

26 requirement scenarios could be accommodated. These options consist of a range of possibilities including groundwater development, desalination, surface water options, water reuse options and water demand management. One of the recent DWA appointments towards investigating interventions to address the gap in future water availability was to commission pre-feasibility and feasibility studies focussed on the remaining potential for surface water development options to supplement the WCWSS. These are known to be few and far between. That study is ongoing and is currently investigating two possible options to feasibility study, namely: First Phase Augmentation of Voëlvlei Dam by means of winter water pumped into the dam from the Berg River, after ensuring the ecological flows for the river and estuary have been met. Augmentation of Voëlvlei Dam by means of winter water diverted under gravity from the Upper Breede River at Michell s Pass, after ensuring that the ecological flows for the river and estuary, as well as existing water requirements for downstream users, have been met. DWA are also considering a feasibility study into the raising of the Lower Steenbras Dam, the study of which is likely to commence within the next few years and will offer increased flexibility in the operation of the system, as well as possible much needed additional storage, which must be considered for use within the options to be investigated in the CCTs proposed water reuse feasibility study. The CCT has indicated its intention to undertake a desalination feasibility study and a water reuse feasibility study, both scheduled to commence in Figure shows the both the unrestricted water requirement scenario and that including the anticipated WCDM savings. Superimposed onto that is a possible suite of development options that could be being considered towards meeting those requirements into the future. Figure The Western Cape Reconciliation Strategy. It is relevant to note that: Status Quo Report DEADP 235

27 The current available yield from the system is 556 million m 3 /a, and includes the recent augmentation of 81 million m 3 /a from the Berg Water Project, which came on line in If the CCT s water conservation and demand management objectives are achieved, then the next augmentation scheme will be required by 2018/19 (as shown on lower water requirement curve). Assuming the City s WC/WDM targets are only 50% achieved, then the next scheme would be required two years earlier, i.e. by On the basis of a completely unrestricted demand growth, the next scheme would be required by 2012, an impossibility from a planning perspective (as shown on upper water requirement curve), further highlighting the absolute necessity for WCDM to be elevated to the highest level of importance in the region. The potential Michell s Pass option mentioned previously is not shown on Figure It has been recognised by the BOCMA that until an updated water availability assessment study, including updated hydrology and land-use information has been undertaken in the Breede WMA, a cautionary approach should be adopted towards any further allocation of water from that system. Water reuse features as a favourable option. At present almost 160 million m 3 /a of treated effluent is discharged to sea. A large proportion of this could potentially be available as a source of water within the WCWSS. Whilst there may be social and religious objections, a mind-shift is required in order to further tap into this potential source. The CCT will be undertaking a feasibility study in due course to investigate this potential, and the possible options for its phased implementation, of which provision of adequate water storage will be an important technical consideration. 8.9 TOP PRIORITY AREAS AS PER BITT REPORT The BITT report has prioritized the bulk infrastructure needs in the Berg WMA as well as the need for skilled resources to operate and maintain the various WWTWs. This assessment excluded the CCTs and the prioritization was undertaken at District Municipal level, and not at WMA level. As such, the towns in the Cape Winelands DM and West Coast DM which lie within the Berg WMA are included in the subsequent chapters (Breede and Olifants-Doorn WMAs), together with the towns located in those WMAs. The West Coast DM priority list includes towns in the Berg and Olifants-Doorn WMAs, and this is provided below. Table Most Urgent Technical Interventions Required in the West Coast DM Ranking (1 = Highest Priority) Description 1 Citrusdal-WWTW upgrade & Relocation 2 Saldanha- 8.5Ml desalination plant 3 SaldanhaBay- Paternoster WWTW 2Ml 4 Vredendal- Raw Water Storage Dam 5 Swartland- Riebeeck West WWTW 6 Doringbaai WWTW 7 Saldanha- 4Ml Reservoir 8 Clanwilliam WWTW Status Quo Report DEADP 236

28 9 Bergrivier-Velddrift WWTW 10 Withoogte Vergelee reservoirs Table Most Urgent Skills Requirements for WWTWs in the West Coast DM Ranking (1 = Highest Priority) 1 Klawer 2 Lutsville West 3 Koekenaap 4 Strandfontein 5 Ebenhaezer 6 Doringbaai 7 Lutsville 8 Van Rhynsdorp Town/Suburb 9 Vredendal North 10 Vredendal South Vredendal and Doringbaai feature in both tables indicating that urgent attention is required at these two towns PROBLEM SYNTHESIS The problems and gaps identified in this Chapter that are broadly summarised as follows: Water quality in the Lower Berg River is impacted (amongst other factors) by natural geology resulting in high salinity. High nutrient and microbial concentrations, from sub-standard effluent return flows and from runoff from dense urban settlements is a significant concern. There is a risk that irrigation water not complying with the required standards by international export markets will have a very significant economic impact. The issues relating to operation and management challenges at WWTWs (and the recommendations) have been addressed under the Water Quality theme Groundwater development holds great potential within this WMA but its careful use needs to be encouraged. A cautious approach needs to be adopted where groundwater abstraction is greater than the groundwater Reserve allowed for and the recharge. Over-abstraction is evident in the Atlantis and Tulbagh areas and a cautionary approach to further allocation should be adopted in these areas. The yield of the integrated water supply system of the Western Cape was supplemented by an amount of 81 million m 3 /a by the Berg Water Project (2007). However if WCDM is not at all successful, then this will only provide for the growth in demand up to On the other hand if the CCT s WCDM strategy achieves its objectives, then this extends to The bottom line is that WCDM is a necessity and must be elevated to the highest level of priority. Water restrictions in 2005 showed a marked drop in overall water consumption but an upward trend again became evident after the Berg Water Project came on line. Consideration should be Status Quo Report DEADP 237

29 given to routinely implementing light water restrictions (again capacity to monitor and enforce will be required), so as to develop a change in behaviour over time. The opportunity for conventional water supply schemes (surface water development) is becoming less and less, and in the Western Cape there are now very limited, suitably located new dam sites for development. Alternative sources (after WCDM) must therefore be investigated, despite their much higher financial costs. The driver will ultimately be water availability and no longer cost. The CCT and DWA are currently embarking on such studies (water reuse and desalination) in this WMA, as is the West Coast DM (desalination). Status Quo Report DEADP 238