Umgeni Water has the following markets for bulk water services (water and wastewater):
- Umgeni Water’s operational area: for water services and other related activities,
- Rest of KwaZulu-Natal: water services and other related activities,
- South Africa: water services and other related activities on demand, and
- Rest of Africa for knowledge management, networking and responding to bi-lateral agreements between South Africa and other countries.
The organisation’s bulk supply customers in its operational area are the eThekwini Metropolitan Municipality, iLembe District Municipality, Ugu District Municipality, Harry Gwala District Municipality, uMgungundlovu District Municipality and Msunduzi Local Municipality.
Bulk Provision and Infrastructure Assets
Umgeni Water purposefully undertakes its core bulk water and wastewater business to effectively serve its customer and stakeholder base. As part of its water supply function, raw water is consciously abstracted, from dams, river and borehole sources, is conveyed, using both gravity and the most effective pumping options to bulk water treatment works, treated to meet SANS 241:2011 quality standards and distributed to customers.
Equally, as part of its wastewater supply function, Umgeni Water receives influent from municipal sewer systems, treats this at bulk wastewater treatment works and constantly strives to improve the quality of effluent discharged back into receiving systems.
Umgeni Water’s infrastructure assets in support of its primary business comprise: approximately 746 kilometres of pipelines and sixty-six (66) kilometres of tunnels, fourteen (14) dams, fourteen (14) water treatment works and an additional fourteen (14) small water treatment works and ten (10) borehole schemes managed on behalf of the iLembe District Municipality.
Infrastructure assets in support of bulk wastewater, either owned or operated, comprise the Darvill Wastewater Treatment Works, Howick Wastewater Treatment Works, Ixopo Wastewater Treatment Works, the recently acquired Lynnfield Park Wastewater Treatment Works and two smaller works Albert Falls North and South Works.
A total of 440 million cubic metres of potable water per annum (1205 Ml/d) are currently supplied to customers (Figure 8.6) who serve a population of 6 million or 1.64 million households through reticulation networks. Treatment works’ capacities and utilisation are shown in Figure 8.7 (a) and (b) respectively. In the year there were no unplanned supply interruptions that exceeded 24 hours as per service level agreement.
The organisation currently treats bulk wastewater totalling 28 million cubic metres per annum (75 Ml/d). Wastewater treatment works’ capacities and utilisation are shown in Figure 8.7 (c) and (d) respectively.
Bulk Supply Agreements
Bulk Supply Agreements are concluded to cover obligations of both Umgeni Water and its customers in relation to water volumes, water quality, supply pressure, service interruption intervals, metering, tariff consultation, assurance of supply and capital infrastructure plans.
Signed agreements have been concluded with all customers. Of note, the long-outstanding long-term supply agreement was concluded and signed with Msunduzi Municipality in the 2012/2013 reporting year.Water demand projections are updated based on trends in historical water sales volumes and customer demand trends. In parallel, analysis of Umgeni Water’s bulk infrastructure and water works capacity in relation to demands highlight any infrastructure supply constraints or limitations on future growth that need to be responded to.
Figure 8.7: Water Treatment Works (a) Capacity, (b) Utilisation and Wastewater Treatment Works (c) Capacity and (d) Utilisation.
(a) WTW Capacity (MI per day)
(b) WTW Plant Utilisation %
|(c) WWTW Design Capaticy||(d) WWTW Utilisation|
Supply Capacity and Constraints
Several works, as shown in Figure 8.6 are currently operated above their design capacity to meet demands and this also impacts on water quality. Umgeni Water has put in place specific interventions to address these including:
- Midmar WTW: Once the upgrade has been completed, the load between the DV Harris WTW and Midmar WTW will be optimally managed.
- Hazelmere WTW: Capacity constraint will be addressed through a works upgrade from 45Ml/d to 75Ml/d. In the short-term, a 5Ml/d package plant is augmenting the supply to meet demands.
- Mvoti WTW: The Lower Thukela BWSS will replace this works by 2015. As a short-term solution refurbishment of the filters was completed and a 2Ml/d package plant installed.
- Maphephethwa WTW: The works upgrade was undertaken in 2012/2013 and was commissioned (1.5Ml/d to 4Ml/d) in December 2014.
- Ixopo, Mzinto and Mtwalume WTWs: Operational and process enhancements will alleviate constraints for these works in the short term: the Mzinto system load is to be shed through the Scottburgh-Ellingham Link pipeline. The load on the Mtwalume system will be shed to the South Coast Pipeline when the Pennington Link is completed by Ugu DM. The long-term solution to address the Mtwalume and Ixopo WTWs’ capacity constraints is the planned extension of the South Coast Pipeline and related system upgrades.
Operational Performance and Service Planning
Umgeni Water meets formally with all customers for operational performance and service planning and customer liaison has been significantly enhanced to ensure critical feedback is received regarding service level improvements and upgrades. In addition an independent multi-stakeholder survey was concluded, results analysed and action plans developed to address all pertinent issues raised by customer and stakeholders. Umgeni Water has met all customer requirements in relation to water volumes, supply pressure and metering. Some customer service interruptions occurred but were minimal and successfully addressed.
0.25% supply disruptions > 24 hours
Reasons for variance
A total of ten (10) days supply disruption > 24 hours were experienced in 2012/2013, comprising three (3) days in the first quarter for the Midmar system, three (3) days in the second quarter for the Mzinto and Mtwalume systems, due to severe flooding, and four (4) days in the third quarter for the Wartburg system due to power failure. No further disruptions were experienced in the last quarter of 2012/2013.
Actions taken: A pipeline rehabilitation programme for Midmar, and finalisation of the disaster management plan with customer for south coast systems will mitigate future disruptions for these areas. A back-up generator has been installed for the Wartburg system and in the long-term the planned capacity upgrade will mitigate supply outages for this area.
Structured consultation is also undertaken with customers, for communication of future demands, infrastructure plans and tariff assumptions, and responses are used to inform the future tariffs and infrastructure plans.
Conceptual plans for growth and expansion of water services have been developed, for existing and new customer areas, notably where there are high water services backlogs. The growth plan draft will be developed further in line with identified priorities and opportunities that unfold in the coming period. Customer engagement and consultation is core to Umgeni Water’s success and customers are intricately involved in developing future service plans.
Asset Condition, Maintenance and Management
Umgeni Water remains highly committed to meeting all obligations of its Bulk Supply Agreements and conducts regular maintenance and inspection of all its assets as an intrinsic part of continued operations management. This comprises planned maintenance, which is inclusive of preventative maintenance, repairs, redesign and modifications, which are complemented by ongoing unplanned, reactive and corrective maintenance in line with our asset management implementation plan for the year. The asset management strategy further drives the focus of condition assessments of the various components of key strategic and critical infrastructure to its various sub-components i.e. civil, mechanical, electrical, instrumentation and control.A key output of these assessments is establishment of the condition status of Umgeni Water assets. This status is vital in determining the useful life and future investments required to maintain level of service to all our customers.
The intention is to ensure there are no assets that pose significant risk to supply and there will be no major interruptions to its business over the next five years and beyond.
In the year the asset spend was R158m (Figure 8.7). Over the years Umgeni Water continues to maintain its assets and on average the maintenance investment is 4% of the value of the asset. Based on assessments conducted over the last year, there are no assets that pose significant risk to supply and the organisation envisages no major interruptions to its business over the next five years and beyond.
Water Loss Management and Metering
Umgeni Water has over the years successfully maintained non- revenue water below 5%. This has been a result of a metering strategy which focuses on metering all critical nodes and monitoring of meter accuracy. This initiative will continue through meters installed by Umgeni Water at various critical points in its systems.
For raw and potable water applications this includes meters at abstraction points, treatment works inflow, treatment works outflow, within the distribution system and at the point of sale. These provide value information for abstraction, storage monitoring and adequacy, water balancing purposes, computation of water loss between the various points and water loss management, distribution control sales and billing purposes.
In addition, measurement provides information for ongoing operations and efficiency improvements including unit processes management, ensuring correct filter backwashing rates, pump efficiencies, pipeline operation and other information to inform asset management.
Equally for wastewater applications meters at influent and effluent points provide valuable information for assessing plant loading, process control management, storage and treatment, including storm dam, billing and discharge information. On- going operational efficiency improvements will be made including unit processes, pump efficiencies and asset management.