Sustainable Water Supply for Nelson Mandela Bay Metro

water dropThe Department of Water Affairs together with the Nelson Mandela Bay Metro (NMBM) is intensifying efforts to improve water security in the Nelson Mandela Bay Metro area amid concerns over the significant increase in water use since the drought of 2009-2011 was broken. Water use is currently between 296 and 300 megalitres per day. This has resulted in dam levels dropping by 1.5% per week.

This was among the concerns raised at the biannual meeting of the Algoa Reconciliation Strategy Steering Committee held Port Elizabeth. The meeting emphasised that the most important measures to ensure water security over the short to medium term for the Metro area are to intensify water conservation and water demand management measures as well as the completion of the Nooitgedagt Low-level Scheme.

In addition investigations relating to possible groundwater sources for Nelson Mandela Bay Metro are complete and drilling sites have been identified. Even with fully successful water conservation and water demand management it is anticipated that the water requirement will increase in this economically active area with its growing population.

The Metro is constructing the Nooitgedagt Low-level Scheme as an extension to the existing High-Level Scheme that treats Orange River water, delivered through the Orange-Fish-Sunday’s transfer system, to drinking water standard for supply into the Metro’s water supply system. Construction of Phase 1 of the project was completed last month.

In order to complete the scheme about R300 million additional funding is required. The Metro has approached National Treasury in this regard on several occasions but without success. It must be noted that when operating rules for the Algoa Water Supply System for the 2012/13 water year were evaluated, it was assumed that additional Orange River water would be available to supply the Metro from July 2013 via the Nooitgedagt Low-Level Scheme.

As the new scheme is not complete, the Metro has used more water from the Kouga system than anticipated and their allocation allows. Already 84% of the allocation from the Kouga Dam for the year July 2012 to June 2013 has been used by March 2013. This means that only 16% of the allocation (instead of 25%) is left to be used in the remaining 3 months of the year. From July 2012 to March 2013 the Metro also used its full allocation from the Kromme Supply System (Impofu and Churchill dams). As the average daily use is currently high, this would mean that water restrictions should be implemented in the near future to bring the abstraction of the Metro in line with their allocation from the Kouga system.

The purpose of the Reconciliation Strategy is to annually determine the current water balance and to develop possible future water balance scenarios for a 25-year planning horizon. This will ensure that interventions to augment the water supply will be implemented in time to prevent the possible risk of water restrictions. The Strategy Steering Committee monitors the implementation of the agreed strategies/actions, updates the Strategy as it becomes necessary, and informs all stakeholders and the public of progress with the implementation of the Strategy and the situation in the system.

The estimate of the uptake of industrial water requirements in the Coega Industrial Development Zone (IDZ) is still very uncertain as new heavy industries have previously committed and then withdrawn. The updated estimate of potable long-term water requirements has not changed much, but it must be noted that surplus potable water will become available from the Nooitgedagt Low-level Scheme once completed.

This potable water will be cost-effectively used as an interim industrial water supply to the Coega IDZ until the re-use project from the Fishwater Flats wastewater treatment works come on line in 2017. For this scheme too there are still major funding constraints.

Water conservation and water demand management is a corner-stone strategy for this area. The Reconciliation Strategy set the Metro a target to reduce water losses by 37 megalitres per day over a 5-year period. The reduction in losses over the past two years already amounted to 22.6 megalitres per day, representing 61% of the target. The on-going implementation and investment in water conservation interventions will ensure that the 5-year target is met. The active contribution and support by the Nelson Mandela Bay Business Chamber in this respect is noteworthy.

There is further significant potential for water savings if water leaks at schools in the Metro are repaired. The estimated savings that could be realised by such repairs is in the order of 10-15 megalitres per day. The Metro received R2.5 million from the Department of Education to start with repairs to schools in the area and 17 of the schools identified with the worst leakages were repaired with the funding received.

The Department of Water Affairs recently matched this amount to repair further leaks. The Metro also received $60 000 from the USA city of Jacksonville and the leaks at two schools were repaired with this funding. Additional funding is still urgently needed to repair leaks at schools in order further reduce water losses.

Other interventions:

Other interventions that would ensure water security over the longer term are:

Groundwater development: groundwater can provide an affordable, dependable supply with minimal management. The final borehole sitings along the Coega Kop and the Uitenhage areas are complete.

Water re-use: a study was done by the Metro to determine the feasibility of the large-scale use of treated water from the Fishwater Flats Waste Water Treatment Plant to supply industries in Port Elizabeth and the Coega Industrial Development Zone with industrial standard water. The environmental impact assessment for the Scheme has been approved by the Department of Economic Development, Environment Affairs and Tourism. Funds have been made available during the 2012/13 financial year for the detailed design and documentation of Phase 1 of the project and the design is nearing completion. Additional funding has been made available for the 2013/14 financial year and construction on the first 15 megalitre reservoir and gravity main into the Industrial Development Zone is planned to start in June 2013, with a construction period of 10 months. The balance of the scheme will be constructed as additional funds become available.

Desalination of seawater: The Metro has appointed consultants to investigate a new location for a desalination plant preferably to the western side of the Metro. Potential sites have already been identified. The planned completion of the feasibility investigation and concept design is June 2015.

Coega Sands Investigation: Natural dune sands south and north of Ngqura Harbour were assessed to see if they would be suitable for filtering surplus wastewater emanating from the Fishwater Flats Wastewater Treatment Works. It was found that the dune sands south of the harbour are too thin and unsuitable. Three areas north of the harbour are being further investigated to establish their thicknesses. If suitable, wastewater could be fed into the sands at the top of the slope of the sand layer, and withdrawn several hundred metres down-slope after a process of natural filtration.

Evaluation of the Raising of the Kouga Dam: An opportunity exists to raise the Kouga Dam in the Kouga River, in light of dam safety work to be undertaken. Capital costs of constructing the raised dam wall and unit water costs have been refined since earlier evaluations. Potential significant environmental concerns were identified and briefly evaluated. Once the extent of dam safety work that will be undertaken is clear, this option will be further evaluated.

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