OVERVIEW OF PERFORMANCE WITHIN THE ORGANISATION
3.1.15 WATER PROVISION
Water is the most fundamental and indispensable of available natural resources – fundamental to life, the environment, food production, hygiene and for power generation.
Poverty reduction and improved water management are closely linked. Section 4B of the Constitution lists water and sanitation services, limited to potable water supply systems and domestic waste water and sewerage disposal systems, as a local government function.
Basic water is defined as 25 litres of potable water per day supplied within 200 meters of a household.
Due to on-going drought and very low rainfall recorded in recent years, the municipalities in the Western Cape had to enforce water restrictions. Stellenbosch Municipality supplies water to the consumers in their area of jurisdiction through the following six water supply systems:
Stellenbosch (Idas Valley - Own sources, DWS allocation and Paradyskloof WTW – Theewaterskloof;
Dam supply WCWSS [Western Cape Water Supply Scheme] via tunnel);
Franschhoek (Du Toits River-Own resources, Wemmershoek Dam WTW - CoCT);
Dwarsrivier (Wemmershoek Dam WTW- CoCT);
Blackheath (Blackheath WTW - CoCT);
Faure (Faure WTW – Steenbras Dam supply - CoCT); and
Boreholes BH1: Die Braak, BH2: Meerlust and BH3: Van der Stel.
The total population supplied with water in the Stellenbosch Municipal area amount to approximately 186 274 people. Water is also supplied to a fairly extensive industrial area.
Stellenbosch Local Municipality manages three water treatment works, namely Idas Valley, Paradyskloof and Franschhoek, which is a micro water treatment plant. The potable water supply from these works amounted to 18.01 Ml/d and a further 5.71 Ml/d was obtained from the City of Cape Town (CoCT) during the FY2018/19, ensuring a supply of approximately 23.72 Ml/d to the Municipality’s area of responsibility.
Areas supplied from the Wemmershoek Dam and water treatment works include half of Franschhoek town, La Motte, Wemmershoek, Pniel, Boschendal, Johannesdal, Kylemore, Lanquedoc, Klapmuts, Koelenhof, Elsenburg, Devon Valley and Muldersvlei. Areas supplied from Blackheath water treatment works include Polkadraai, Spier and Vlottenburg.
Areas supplied from Faure water treatment works (supplied from Steenbras Dam – CoCT) are Faure, Jamestown, De Zalze, Raithby and Lyndoc. Although these water treatment works fall within the sphere of responsibility of the City of Cape Town, their impact with regard to water quality and quantity needs to be monitored and considered by Stellenbosch Municipality.
Stellenbosch Municipality supplies potable water to the entire municipal area through a network and infrastructure consisting of 56 reservoirs / holding tanks and water towers, 36 water pump stations, 41 pressure reducing valve installations, 667 kilometres of pipeline and 79 water supply zones. The system is fully controlled and operated by a telemetry system.
The total bulk water input into the water network for the FY2018/19 was 8,1 Ml, with an annual average daily demand of 23,72 kl/day. 40% of the water supplied are purified from the Municipality’s own water sources at the Idas Valley and Franschhoek water treatment plants. The balance is supplied by the CoCT, where raw water supplied by the Department of Water and Sanitation is purified. Potable water supplied from the CoCT is analysed on a monthly basis.
Idas Valley and Paradyskloof water treatment works are equipped with some analytical capabilities and routine plant analyses are performed in-house. A full water quality monitoring programme is further performed for the Municipality by an accredited external laboratory/contractor. Maintenance of equipment for all three plants is outsourced to an external contractor.
Based on the Municipality’s IWA Water Balance sheet for the FY2018, the Municipality recorded 20.8%
for “non-revenue” water which is a decrease of 0.9 % from the previous financial year and 6.9% for Real Network Losses. Refer to the Municipality’s IWA Water Balance Sheet.
The no-revenue water for the financial year 2018/19 is 20.8% that is below the target set of 25%. The real physical network losses is at 6.9% that is well below the best practice value of 15%.
The table above is the International Water Association table to compute the water balance and is also accepted in the DWS reporting structure. This forms the basis of the information needed and what is currently used to calculate water losses. This is combined with a monitoring system installed on all bulk water supply points to determine and ensure accurate data of water provided. The consumptions data for all water users is drawn from the SAMRAS system with a regular data download to determine the total water sold. The table above is used as far as possible to reflect the water balance and water losses in the water systems. The water readings of all areas are also filled in on a spreadsheet that is sent to Figure 3:1: International Water Association
the DWS on a three monthly basis to monitor and control water usage and allocations of water. The following diagrams were used to calculate the water balance.
The Municipality has developed a comprehensive Water Conservation and Water Demand Management (WC&WDM) strategy, which includes a 10‐year financial plan. The strategy has two goals:
the Municipality will prioritise the implementation of WC&WDM, and will ensure ongoing planning, management, monitoring and an enabling environment. The WC&WDM initiatives includes water pipe replacement programme, indigent domestic leak repair and meter replacement programme, Stellenbosch water meter audit and Stellenbosch in-house water services operation and maintenance.
Stellenbosch Municipality implemented level 1 water restrictions from the 1st of November 2015 to achieve a 10% water consumption decrease. This was due to low supply dam levels and low rainfall figures during the rainy season. This was followed with the implementation of Level 2 restrictions from March 2016 due to extreme heat conditions and even lower supply dam levels in Stellenbosch and City of Cape Town. The Level 2 restrictions included the increased tariffs for water consumption to achieve a 22% savings on the water consumption.
City of Cape Town is currently on Level 1 water restrictions. Forturnately, the municipality was in a position to lower the water restrictions but will have to encourage low water usage for the time being.
Stellenbosch Municipality is on Level 2 water restrictions due to the fact that own water sources contribute a large percentage of the water input volume into the WC024 area.
3.1.15.1 Dam Levels
The following table reflect the current status of the dam levels supplying the WCWSS with water and status of Stellenbosch own dam levels.
Table 3:6: Western Cape Dams
Major dams 2019 Previous week 2018
(%) (%) (%)
Berg River 101,7 100,5 88,1
Steenbras Lower 98,9 88,7 58,7
Steenbras Upper 101 101,9 99,1
Theewaterskloof 70,8 67 43,4
Voëlvlei 83,2 78,6 62,6
Wemmershoek 85,1 78,9 83,1
Total Stored (Ml) 723 706 689 767 525 544
% Storage 80,6 76,8 58,5
Stellenbosch own Dams
Idas Valley 1 100 100 77
Idas Valley 2 100 100 103
The photos below represent the Idas Valley Dams 1 and 2 at 100% full.
W024 Bulk Water Input and Sales dramatically came down from values that reached a highest value in 2015 to June 2019.
Groundwater is now seen as a potential water source and will be investigated and evaluated after the new water resources study is completed.
Figure 3:2: Idas Valley Dams
Figure 3:3: Stellenbosch Municipality: Input vs Sales