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7.4 Mgeni System

7.4.1 ‘251 Raw Water Pipeline: Midmar Dam to Midmar WTP

Planning No. 105.0

Project No. UI0302

Project Status Detailed design

Project Description

The Midmar Water Treatment Plant (WTP) draws raw water from Midmar Dam. Water from the dam is supplied under pumping via the ‘251 Pipeline. The ‘251 Raw Water Pipeline is a single, 1 626 mm OD (1 544 mm ID), cement-lined, steel pipe consisting of two sections. The first section, from the dam outlet works to the raw water pump station is approximately 550 m long. The second section, from the raw water pump station to the water works is approximately 2 450m long. The Midmar WTP currently has a design capacity of 250 Mℓ/day and is scheduled to be upgraded to 375 Mℓ/day in the near future (Section 7.4.2). Three pump sets are currently installed in the raw water pump station (2 duty + 1 standby). A fourth pump set is to be installed along with the Midmar WTP upgrade. With the WTP upgrade to 375 Mℓ/day, flow velocity in the single raw water pipeline will increase to 2.3 m/s. Being the only raw water supply into Midmar WTP, this pipeline is a strategic asset and its overall risk rating is thus high. DWA has modified the Midmar Dam outlet works and pipework to provide a second outlet pipeline and cross-connections at the dam wall. This intervention has minimised the risk of failure of the dam outlet works. Umgeni Water must now ensure that the overall risk of the raw water transfer between the dam and the Midmar WTP is mitigated by providing a second raw water transfer pipeline between the outlet and the WTP (Figure 7.11). Pumping efficiencies will also be achieved by installing this new pipeline.

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Figure 7.11 General Layout of the ‘251 Raw Water Pipeline: Midmar Dam to Midmar WTP.

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Key information on this project is summarised in Table 7.4.

Table 7.4 Project information: ‘251 Raw Water Pipeline from Midmar Dam to Midmar WTP.

Project Components: Raw water pipeline from dam outlet to Midmar WTP and fourth raw water pump.

Capacity: 375 Mℓ/day

Institutional Arrangements

The new infrastructure will be owned, operated and maintained by Umgeni Water.

Beneficiaries

The scheme will serve the ’61 System which supplies potable water to uMngeni, The Msunduzi, Umgungundlovu and eThekwini Municipalities.

Implementation

The project will be constructed over two years and is estimated to cost R90 million.

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7.4.2 Midmar Water Treatment Plant Upgrade

Planning No. 105.0

Project No. UI150

Project Status Design

Project Description

The Midmar Water Treatment Plant (WTP), which was commissioned in 1996, draws raw water from Midmar Dam. Water from the dam is supplied under pumping via the ‘251 Pipeline. The Midmar WTP has a design capacity of 250 Mℓ/day and is currently operating at an AADD of around 226 Mℓ/day. With the imminent implementation of the load transfer of the Western Aqueduct demand onto the Upper Mgeni System, it is necessary to upgrade the capacity of Midmar WTP. The WTP should be upgraded to 375 Mℓ/day so that the combined capacity of the Midmar WTP and D.V. Harris WTP will utilise the maximum yield (at a 99% assurance level) available from Midmar Dam once the MMTS-2 has been commissioned. The design of Midmar WTP fortunately lends itself to an upgrade to 375 Mℓ/day without major civil construction, as the clarifiers were already upgraded to this capacity during 2003. Such an upgrade is expected to include the design, installation and commissioning of a new filter plant, sludge plant centrifuge and outlet works (Figure 7.12) Key information on this project is summarised in Table 7.5.

Table 7.5 Project information: Midmar WTP Upgrade.

Project Components: WTP capacity upgrade from 250Mℓ/day to 375Mℓ/day(design, installation and commissioning of a new filter plant, sludge plant centrifuge and outlet works).

Capacity: 375Mℓ/day.

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Figure 7.12 General Layout of Midmar WTP upgrade.

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Institutional Arrangements

The Midmar WTP is situated in uMngeni Local Municipality. Umgeni Water will own, operate and maintain the upgraded Midmar WTP and will sell potable water from this system to the Msunduzi Local Municipality, eThekwini Municipality and Umgungundlovu District Municipality as per existing bulk water supply agreements.

Beneficiaries

The scheme will serve the ’61 System which supplies potable water to Msunduzi, Umgungundlovu and eThekwini Municipalities.

Implementation

The project will be constructed over two years and is estimated to cost R 225 million.

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7.4.3 Howick-North Reservoir Upgrade

Planning No. 105.31

Project No. UI0301

Project Status Construction

Project Description

Howick’s northern suburbs are currently served by three storage reservoirs situated at the old Howick WTP Complex (Eridene Road). Water treated at Midmar WTP is pumped from Mill Falls Pump Station and is discharged into Howick-North Reservoir 3. Water then runs under gravity to the remaining two reservoirs, namely Reservoir 1 and Reservoir 2 (Table 5.7). Howick is currently undergoing a sustained period of housing development growth, which has led to an increased demand for water (Section 3.3.3). Furthermore, new developments are currently being implemented, or are planned, for sites located above the command elevation of Howick-North’s reservoirs. Interim measures are currently being put in place by developers to boost pressure to supply such developments. However, Umgungundlovu District Municipality will need to construct a new reservoir at a higher level to serve these new developments in the long-term. With the required high level reservoir, the Howick-North Reservoir Complex (Figure 7.13) will serve as a distribution reservoir. The determination of the storage requirement at Howick-North Reservoir is indicated in Table 7.6.

Table 7.6 Storage Requirement at Howick-North Reservoir Complex.

Reservoir Function Demand

(Mℓ/day) Time

(hours) Required Storage

(Mℓ)

Reticulation 7.4 36 11.1

Distribution 3.0 15 1.9

TOTAL STORAGE REQUIREMENT 13.0

If projections increase at the rates expected, then the current storage of 6.6 Mℓ might need to be increased with a new 6.5Mℓ reservoir in 2014/2015.

352

Figure 7.13 General layout of the proposed Howick-North Reservoir.

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Key information on this project is summarised in Table 7.7.

Table 7.7 Project information: Howick-North Reservoir Upgrade.

Project Components: New Reservoir

Capacity: 6.5 Mℓ

Institutional Arrangements

The new Howick-North Reservoir will be owned, operated and maintained by Umgeni Water.

Beneficiaries

The upgrade to Howick-North Reservoir will benefit consumers in the Howick North area of uMngeni Local Municipality.

Implementation

The construction duration of this project is anticipated to be one year. The total cost of this project is estimated to be R 17 million. This additional storage may be required by 2014/2015.

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7.4.4 Howick-West Reservoir Upgrade

Planning No. 105.03

Project No. UI0613A

Project Status Design

Project Description

Potable water is supplied to the Howick-West Reservoir Complex from Midmar WTP via the Mills Falls Pump Station along a 700 mm NB diameter steel pipeline. The current total storage capacity at the Howick-West Reservoir Complex is 16.5 Mℓ and serves as the distribution node for the supply area. (Figure 7.14) Water is then pumped from the Howick-West Reservoir Complex to Mpophomeni and Groenekloof Reservoirs via the Howick-West Pump Station along a 250 mm and a 600 mm diameter steel pipeline respectively. The Groenekloof Reservoir Complex, with a current total storage capacity of 17.27 Mℓ, serves as a further distribution node from where the water is pumped to the Greater Vulindlela area and gravity-fed to the Sweetwaters and Blackridge terminal reservoirs. The uMngeni Local Municipality is in the process of implementing a low-cost housing development in the Mpophomeni supply area and middle to high-income residential development in the Garlington area. These proposed developments, combined with the natural growth of the Howick-West Supply System, will place undue stress on the Howick-West Reservoir Complex to sustain the projected demand. To sustain the current and future demand off the Howick-West Reservoir Complex, it is necessary to augment the existing storage capacity at the Howick West Reservoir Complex.

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Figure 7.14 General layout of the proposed Howick-West Reservoir.

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The storage requirement is based on the following reservoir sizing parameters:

Storage for reticulation supply : 36 hours

Storage for Mpophomeni Reservoir Supply : 15 hours

Storage for Groenekloof Reservoir Supply : 8 hours Groenekloof Reservoir is in itself a balancing reservoir therefore, to avoid “double accounting” of storage required for the Groenekloof demand, this balancing demand will be shared between the reservoirs.

Table 7.8 Storage Requirement at Howick-West Reservoir.

Supply Demand in 2025

(Mℓ/day) Time (hours)

Required Storage (Mℓ)

Reticulation 4.2 36 6.3

Mpopomeni 7.3 15 4.6

Groenkloof 38.8 8 12.9

TOTAL STORAGE REQUIREMENT 23.8

The determination of the storage requirement at Howick-West Reservoir is indicated in Table 7.8. Based on storage requirements and the demand projection, the upgrade of storage at Howick West Reservoir could be required in 2015. Reservoirs are sized for a 10 year future demand, hence the upgraded storage requirement is therefore determined on the 2025 demand. If projections materialise as expected, then the current storage of 16.5 Mℓ should be increased by adding a new 8 Mℓ reservoir in 2015/2016. This will bring the total storage up to 24.5 Mℓ. Key information on this project is summarised in Table 7.9.

Table 7.9 Project information: Howick-West Reservoir Upgrade.

Project Components: New reservoir

Capacity: 8.0 Mℓ

Institutional Arrangements

The new Howick-West Reservoir will be owned, operated and maintained by Umgeni Water.

Beneficiaries

The upgrade to Howick-West Reservoir serves as a balancing reservoir that will indirectly serve Vulindlela, Blackridge and Sweetwaters in The Msunduzi Municipality and Mpopomeni and Hilton in the uMngeni Municipality.

Implementation

The construction duration of this project is anticipated to be one year. The total cost is estimated to be R 17 million. This upgrade might be required by 2015/2016.

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7.4.5 Groenekloof Reservoir Upgrade

Planning No. 105.0

Project No. UI65

Project Status Planning

Project Description

The Groenekloof Reservoir serves as a balancing reservoir for Vulindlela, Sweetwaters and Blackridge (Figure 7.15). The current demand out of Groenekloof Reservoir is 21 Mℓ/day. This demand is expected to increase to 34 Mℓ/day by 2030 when 24 Mℓ of storage will be required. The current capacity of the reservoir is 17 Mℓ. The reservoir capacity will be over allocated by 2020. An additional 6 Mℓ storage will then be required. Key information on this project is summarised in Table 7.10.

Table 7.10 Project information: Groenekloof Reservoir Upgrade.

Project Components: New 6 Mℓ reservoir.

Capacity: 6 Mℓ.

Institutional Arrangements

The new reservoir will be owned, operated and maintained by Umgeni Water.

Beneficiaries

The upgrade to Groenekloof Reservoir will benefit consumers in the uMngeni and the Msunduzi local municipalities.

Implementation

The construction duration of this project is anticipated to be one year. The total cost is estimated to be R12 million. This upgrade may be required in 2020 if demands increase at projected rates.

358

Figure 7.15 General layout of the Groenekloof Reservoir Upgrade.

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7.4.6 61 Pipeline: Richmond Off-Take to Umlaas Road

Planning No. 105.21

Project No. UI25B

Project Status Construction

Project Description

Water demand in the Greater Pietermaritzburg/Edendale area and in eThekwini Municipality’s Outer West area has continued to increase significantly over recent years. This trend has increased the operational loading of the ‘61 Pipeline to the extent that the ’61 Pipeline between the D.V. Harris off-take and World’s View Reservoir and World’s View Reservoir to the Richmond off-take have been duplicated. These measures increased the available throughput of the system. The current implementation by eThekwini Municipality of their Western Aqueduct (Section 5.2.1) and the planned load transfer from the Durban Heights WTP onto the Umlaas Road Reservoir will result in the ’61 Pipeline System from ED2 to Umlaas Road not having sufficient capacity to meet these new demands. Hence, further augmentation of this section of the ’61 System is required. The existing 800 mm diameter pipeline between Richmond off-take and Umlaas Road has several constrictions (down to 600 mm and 400 mm diameter) along its length that restrict its throughput considerably. Notwithstanding these restrictions, the 800 mm diameter pipeline only has a design capacity of 87 Mℓ/day (at 2 m/s). In order to accommodate a portion of the planned Western Aqueduct load shift until such time as the proposed Mkomazi Water Project (Sections 4.4.4 and 7.2.1) comes on line, it will be necessary to both remove all the constrictions in the existing pipeline and install a 13 km section of new pipeline between the Richmond off-take and the Umlaas Road Reservoir Complex (Section 5.2.1). It has been proposed that a 1 100 mm nominal diameter steel pipeline be constructed. The proposed augmentation from Richmond off-take to Umlaas Road is shown in Figure 7.16.

360

Figure 7.16 General layout of the Richmond Off-Take Pipeline to Umlaas Road.

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Key information on this project is summarised in Table 7.11.

Table 7.11 Project information: Richmond off-take to Umlaas Road Pipeline.

Project Components: 13 km of 1 100 mm diameter pipeline.

Capacity: 164 Mℓ/day.

Institutional Arrangements

Umgeni Water will own, operate and maintain the ’61 Pipeline System infrastructure and will sell potable water from this system to the Msunduzi Municipality, eThekwini Municipality and Umgungundlovu District Municipality as per existing bulk water supply agreements.

Beneficiaries

The augmentation will primarily benefit the eThekwini Municipality and will allow for a partial load shift to the Western Aqueduct. Consumers within the Msunduzi and the Mkhambathini Municipal area of Umgungundlovu District Municipality will also derive benefit through increased flow reliability to their offtakes.

Implementation

The construction duration of this pipeline will be approximately two years with an estimated cost of R182 million. The project is currently being constructed and is scheduled for completion in 2014.

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7.4.7 Richmond Pipeline

Planning No. 105.15

Project No. UI105

Project Status Design

Project Description

In 2005 the Richmond Municipality requested that Umgeni Water consider supplying potable water to the town of Richmond as the existing water supply systems were proving problematic and unsustainable. Umgeni Water has thus proposed the construction of a pipeline from the ’61 Pipeline system to serve the town. The project will serve the potable water demands of the greater Richmond area (initially 8.3 Mℓ/day and ultimately 14 Mℓ/day) and will also tie into Umgeni Water’s existing Thornville sub-system (Section 5.2.1), which is currently served from the Thornville Pump Station situated on the ‘61 Pipeline between ED2 and Umlaas Road. The project will be fed off the ’61 Pipeline downstream of the ED4 take-off. A new pump station is required to lift the water to a new reservoir (Liliefontein Reservoir) sited near Thornville. The proposed Richmond Pipeline will run along the R56 main road to Richmond (Figure 7.17). The existing Thornville Pump Station will be decommissioned and the rising main will revert to a back feed gravity main once the Richmond Pipeline is in operation. The pipeline will terminate at the municipal reservoir that serves Richmond. Key information on this project is summarised in Table 7.12.

Table 7.12 Project information: Richmond Pipeline.

Project Components: 31 200 m long section of 450 mm diameter pipeline and a new booster pump station.

Capacity: 27 Mℓ/day.

363

Figure 7.17 General layout of the Richmond Pipeline.

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Institutional Arrangements

Umgeni Water will own, operate and maintain the Richmond Pipeline infrastructure and will sell potable water from this system to The Msunduzi Municipality and Umgungundlovu District Municipality as per existing bulk water supply agreements.

Beneficiaries

The consumers in The Msunduzi Municipal area and in the Richmond Municipality will benefit from this project.

Implementation

The construction duration of this project is anticipated to be two years. The total cost is anticipated to be R 224 million. The project is currently being constructed and is scheduled for completion in 2014.

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7.4.8 Greater Eston Bulk Water Supply Scheme

Planning No. 105.29

Project No. UI0341A

Project Status Design & Construction

Project Description

The Greater Eston area falls within Wards 4, 5, 6 and 7 of the Mkhambathini Local Municipality and Wards 5 and 7 of the Richmond Local Municipality. These municipalities fall within the jurisdiction of the uMgungundlovu District Municipality. The bulk water supply to the Greater Eston area, as depicted in Figure 7.18, requires three off-takes on the Eston-Umbumbulu Pipeline. The first off-take will supply the uMacalagwala area. The second off-take will supply the following areas:

Esigodini/Gulube

Ismont

Mpangisa

Embuthweni

Inhlazuka

Ukhalo The third off-take will supply the Ogagwini area. Key information on this project is summarised in Table 7.13.

366

Figure 7.18 Greater Eston Bulk Water Supply.

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Table 7.13 Project information: Greater Eston BWSS.

Project Components: 19km of 350mm diameter pipe 16km of 200mm diameter pipe 19km of 160mm diameter pipe 14km of 110mm diameter pipe 1 Break Pressure Tank 3.5 Mℓ Reservoir 2 Pump Stations

Capacity: Scheme to accommodate ultimate demand of 4.4 Mℓ/day

Institutional Arrangements

The scheme is jointly funded by DWA, Umgeni Water and Umgungundlovu District Municipality through its MIG allocation. The proposed scheme will be operated and maintained by Umgeni Water. Water will be sold to Umgungundlovu District Municipality under the existing Bulk Supply Agreement.

Beneficiaries

The beneficiaries of this scheme are shown in Table 7.14.

Table 7.14 Beneficiaries for the Proposed Greater Eston BWSS.

Area Current Population

Ward 4 - Mkhambathini 1,544

Ward 5 - Mkhambathini 5,912

Ward 6 - Mkhambathini 7,400

Ward 7 - Mkhambathini 9,448

Ward 5 & 7 - Richmond 16,936

TOTAL 41,240

Using an allocation of 60 l/c/day, with a population growth of 0.5% to 2.5% over the 30-year planning horizon, the long term demand is estimated to be 4.4Mℓ/day.

Implementation

Implementation will be undertaken as follows:

Phase 1: Bulk Supply, 400KL Reservoir and Reticulation to uMacalagwala (currently under construction). Construction to be completed in 2014.

Phase 2: Bulk Supply, 4 Storage Reservoirs and Reticulation to Ogagwini. This phase has been commissioned.

Phase 3: Bulk Supply to Ukhalo, 3,5Mℓ Bulk Reservoir, Pump Station and Trunk Main for supply to Phases 4 & 5. Currently under construction with completion targeted for 2014.

Phase 4: Bulk Supply and Reticulation to Ismont and Dwengu. Construction expected to start in August 2013 with completion targeted for end of 2014.

Phase 5: Bulk Supply to Embuthweni and Inhlazuka. Construction expected to start in August 2013 with completion targeted for end of 2014.

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7.4.9 Lion Park Pipeline Augmentation

Planning No. 105.25

Project No. UI0620A

Project Status Design

Project Description

The Lion Park Pipeline supplies domestic and commercial consumers as well as farmers along the P566 Provincial Road. The new Manyavu pipeline which extends from the Lion Park Pipeline to Manyavu has resulted in additional demand being placed on the existing Lion Park Pipeline. This has resulted in a need to augment the Lion Park Pipeline to accommodate this additional demand. The proposal is to augment the Lion Park Pipeline by constructing a 350mm diameter pipeline within the existing Lion Park Pipeline servitude (Figure 7.19). Key information on this project is summarised in Table 7.15.

Table 7.15 Project Information Lion Park Pipeline.

Project Components: 350 &300 mm diameter pipeline from Umlaas Road Reservoir extending to the termination point of the existing the Lion Park Pipeline. Length = 7.2km

Capacity: 16 Mℓ/day.

Institutional Arrangements

The new pipeline will be owned, operated and maintained by Umgeni Water.

Beneficiaries

The beneficiaries of this project will be the community of Manyavu (current population of approximately 15 000) and users along the P566 Provincial Road. The pipeline will also serve the growth in demand that is expected in Ashburton.

Implementation

The construction duration of this project is anticipated to be one year. The total cost is estimated to be R 29 million. This pipeline will be needed by 2014 if demands increase as expected.

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Figure 7.19 General layout of the Lion Park Pipeline Augmentation.

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7.4.10 Greater uMshwathi Regional Bulk Water Supply Scheme

Planning No. 105.22

Project No. UI99

Project Status Design

Project Description

The existing Wartburg Pipeline (also known as the ’69 Pipeline), is constructed of steel and is bitumen coated and cement mortar lined. This pipeline is approximately 26 km long and varies from 300 mm to 250 mm in diameter. Water flows under gravity from Claridge Reservoir for approximately 19 km to a break pressure tank (BPT) just before the town of Wartburg. A booster pump station pumps water from this point to the Wartburg Reservoir. There are two interlinked reservoirs at Wartburg that function as one, having a combined capacity of 2 Mℓ. The ’69 Pipeline is currently operating at its capacity of 9 Mℓ/day. Umgeni Water proposes to augment this system to meet the increasing demands in that supply area. In addition, the proposal is to extend this pipeline to the rural areas of Efaye, Ozwathini and Ndwedwe. In order to meet the projected demands for both existing consumers as well as the areas of greater Efaye, Ozwatini and Central Ndwedwe, new infrastructure will have to be constructed (Figure 7.20). The infrastructure required to augment supply to existing consumers, and to enable supply to Efaye, Ozwatini, and central Ndwedwe is summarised in Table 7.16.

Table 7.16 Project information: Greater Umshwathi Regional Bulk Water Supply Scheme.

Project Components: 26km, 750mm NB pipeline from Claridge to Wartburg including a

1.25MW booster pump station and 5Mℓ Reservoir at Wartburg.

15.5 km 600mm NB pipeline from Wartburg to Dalton including a 1.35

MW booster pump station and 10 Mℓ Reservoir at Dalton.

10.7km 550mm NB pipeline from Dalton to Fawn Leas.

21,7km long 500mm NB pipeline from Fawn Leas to an existing

reservoir at Ozwatini including a 0,5MW booster pump station.

14,5 km long, 250mm NB pipeline from Fawn Leas to an existing

Reservoir at Nadi Mvoti (in Efaye) including a 0.15Mw booster pump

station

Capacity: 50 Mℓ/day

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Figure 7.20 General layout of the Greater uMshwathi Regional BWSS.

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Institutional Arrangements

The new infrastructure will be owned, operated and maintained by Umgeni Water and will be part of the Bulk Supply agreement with Umgungundlovu District Municipality.

Beneficiaries

This project will initially benefit the residents of uMshwati Local Municipality and Ndwedwe Local Municipality. This scheme is estimated to serve about 324 433 people in 47 405 low income households.

Implementation

The phases of the project are anticipated to be completed as follows:

Phase 1: 2014/2015 – 2015/2016

Phase 2: 2016/2017 – 2017/2018

Phase 3: 2017/2018 – 2018/2019 This implementation programme is subject to funding being sourced. The total cost is estimated to be R 773 million.