Long-term water conservation and demand management for Umgeni Water in Kwa-Zulu Natal

Abstract

South Africa is considered a water-scarce country and is anticipated to encounter extensive water deficits in almost all its water management areas by 2025. Due to water scarcity, adequate resource management and planning are required to sustain its water resources. From 2015-2019 the country faced severe water shortages, which forced many provinces to implement water restrictions as a water conservation and demand management strategy. South Africa faces several obstacles regarding water management, such as long periods of inadequate rainfall, population growth, and excessive water losses, to name a few. South Africa has developed most of its water resources with limited scope for further development. The study focuses mainly on the Mgeni system, which consists of Upper and Lower Mgeni systems managed by Umgeni Water, the main supplier of potable water to most of the Kwa-Zulu Natal province. The Mgeni System is recognised as the main source of water supply in the Durban and Pietermaritzburg region situated in South Africa. The Durban-Pietermaritzburg region is the primary economic hub of Kwa-Zulu Natal, and this will bring about a high level of demographical pressure and water supply problems. The study's objective was to (i) analyse the study area to assess whether there will be sufficient supply to meet future demand with climate and demographic impacts, (ii) identify the quantity and causes of current water losses within the study area and to assess the Key Performance Indicators, and (iii) to evaluate efficient strategies, tools, and measures for water conservation and demand management which will reduce water losses in future years. The study adopts both quantitative and qualitative analysis. The quantitative analysis investigates the water supply and demand situation in the Mgeni System catchment and evaluates the future supply and demand accounting based on Water Evaluation and Planning (WEAP) software. The WEAP model is used to analyse the study area from 2009 to 2050 to develop outcomes scenarios that visualise future water supply shortfalls with current data inputs. The assessment model is computed based on four scenarios such as varying population growth rates and impacts of extended dry climates. The qualitative analysis utilises questionnaires to investigate the current WC/DM strategies. The qualitative method involves data collection from structured questionnaires targeting Umgeni Water department with thorough water conservation and demand management knowledge. The study found that the Mgeni catchment is relatively sensitive to changes in population growth, which will significantly alter water availability. Furthermore, an extended dry climate will cause a water supply deficit, thus exposing the study area to water scarcity problems. The study results also indicate that Umgeni Water currently has water conservation and demand management strategies and interventions in place, but it requires more investment from stakeholders to produce the required benefits. In response to the future water demands, the only way one can overcome the unmet demand is by introducing water conservation and demand management strategies such as pressure management, active leak detection testing to reduce the water losses encountered, as well as education and awareness which forms an integral part of the initiative. By implementing these strategies, water losses can be reduced, preventing early water scarcity, and giving decisionmakers time to provide further solutions to the water problems in the study area.