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Background to the Project

The Mgeni System is the main water source that supplies about five million people and industries in the uMgungundlovu District Municipality and eThekwini and Msunduzi Local Municipality areas of jurisdiction, all of which comprise the economic powerhouse of KwaZulu-Natal. The current yield of the Mgeni system is not sufficient to meet the long-term water demands that are and will be placed on it.

The current Mgeni System comprises the Midmar, Albert Falls, Nagle and Inanda Dams in KwaZulu-Natal, a water transfer scheme from the Mooi River and the new Spring Grove Dam.

The current system has a stochastic yield of 334 million m³/annum (measured at Inanda Dam) at a 99% assurance of supply. The short-term augmentation measure, Phase 2 of the Mooi Mgeni Transfer Scheme (the construction of Spring Grove Dam), will increase water supply from the Mgeni system by 60 million m³/year. However, this will not be enough to meet long-term water requirements in the Durban and Pietermaritzburg areas. Pre-feasibility investigations, undertaken by the DWA a few years ago, indicated that the uMWP, which entails the transfer of water from the undeveloped uMkhomazi River to the existing Mgeni system, is the scheme most likely to fulfil this requirement.

Augmentation to meet long-term system requirements

The uMkhomazi River is the third-largest river in KwaZulu-Natal in terms of mean annual runoff (MAR).

Eight alternative schemes were initially identified, but only the Impendle and Smithfield scheme configurations emerged as suitable for further investigation. The pre-feasibility investigation, concluded in 1998, recommended that the Smithfield Scheme be taken to a detailed feasibility-level investigation as its transfer conveyances would be independent of the existing Mgeni System, thus reducing the risk of limited or non-supply to eThekwini and some areas of Pietermaritzburg, and providing a back-up to the Mgeni System.

The need for Smithfield Dam

The Mkomazi-Mgeni Transfer Pre-feasibility Study concluded that the first phase of the uMWP would comprise:

  • A new dam at Smithfield on the uMkhomazi River near Richmond

  • Water conveyance infrastructure (possibly including pipeline and/or tunnels) to a balancing dam at Baynesfield Dam or a similar in-stream dam

  • A water treatment works in the uMlaza River valley

  • A gravity pipeline to the Umgeni Water bulk distribution reservoir system, below the reservoir at Umlaas Road.

From the reservoir at Umlaas Road, water will be distributed under gravity to eThekwini and, possibly, the low-lying areas of Pietermaritzburg.

Phase two of the uMWP may be implemented when needed, and will comprise the construction of a large dam at Impendle further upstream on the uMkhomazi River to release water to the downstream Smithfield Dam.

Together, these developments have been identified as having a 99% assured stochastic yield of about 388 million m³/year.

Module 1: Technical Feasibility Study: Raw Water (Managed by the DWS)

This module considers water resources aspects, engineering investigations and project planning and scheduling and implementation tasks, as well as an environmental screening and assessment of socio-economic impacts of the proposed project.

The Mkomazi-Mgeni Transfer Scheme Pre-feasibility Study recommended the following objectives for Module 1:

  • Investigate Smithfield Dam (Phase 1) to a detailed feasibility level;

  • Investigate the availability of water from Impendle Dam (Phase 2) as a future resource to release to Smithfield Dam, and refine the phasing of the selected schemes;

  • Optimise the conveyance system between Smithfield Dam and the proposed Baynesfield Water Treatment Plant;

  • Undertake a water resources assessment of the uMkhomazi River Catchment, including water availability to the lower uMkhomazi;

  • Evaluate the use of Baynesfield Dam as a balancing dam; and

  • Investigate the social and economic impact of the uMWP.

In December 2011, the DWS appointed AECOM, in association with three sub-consultants (Africa Geo-Environmental Services, MMA and Urban-Econ to undertake uMWP1: Module 1 (Technical Feasibility Study: Raw Water).

Module 2: Environmental Impact Assessment (Managed by the DWS)

The proposed uMkhomazi Water Project, Phase 1 (uMWP1) requires authorisation in terms of the National Environmental Management Act (NEMA) (Act No. 107 of 1998), and the EIA will be undertaken in accordance the EIA Regulations that consist of the following:

  • EIA procedures - Government Notice (GN) No. R. 543;

  • Listing Notice 1 - GN No. R. 544;

  • Listing Notice 2 - GN No. R. 545; and

  • Listing Notice 3 - GN No. R. 546.

The project triggers activities under Listing Notices 1, 2 and 3, and thus needs to be subjected to a Scoping and EIA process. These processes will comprise the notification of landowners, following a public participation process, conducting specialist studies, drafting of a Scoping Report and an EIA Report, and finally notifying I&APs of DEA’s decision and the appeal process

In November 2013 Nemai Consulting was appointed by the Department of Water and Sanitation (DWS) to act as the Environmental Assessment Practitioner (EAP) to conduct the Environmental Impact Assessment (EIA) for the proposed uMkhomazi Water Project (uMWP) Phase 1 Raw Water component.

Module 3: Technical Feasibility Study: Potable Water (Managed by Umgeni Water)

The Potable Water component will link in with Module 1 in the Baynesfield area. Raw water will be received from either a dam or raw water tunnel in the Baynesfield area. The raw water will be treated at a proposed water treatment works and conveyed to the Umlaas Road area via a system of potable water pipelines. The responsibilities of Module 3 are:

  • Water demand projections for the proposed uMkhomazi Scheme;

  • Investigation into the required sizing and possible locations for a water treatment works and potable water reservoir;

  • Determining the diameter and pipeline routes for both raw and potable water pipelines between Baynesfield and the Umlaas Road precinct;

  • Phasing of infrastructure to match the projected growth in demands in the greater Durban region;

  • Geotechnical investigations at the proposed water treatment works site as well as along the proposed pipeline route; and

  • Engineering survey at the proposed water treatment works site as well as along the proposed pipeline route. This activity includes determining the extent of public and privately owned land that may be affected by the Potable Water module.

Module 3 will develop conceptual level designs and drawings as well as cost estimates for all required infrastructure. This costing will be input into the economic model developed by AECOM for Module 1 of the study.

In August 2012, Umgeni Water appointed Knight Piésold Consulting to undertake Module 3.