REPORT ON THE STATUS OF THE INTEGRATED VAAL RIVER SYSTEM Presented by: Celiwe Ntuli Presented at: Water Conservation/Water Demand Management Best Practices Date: 15 May 2019

Provincial Dam Levels

Source: www.dws.gov.za

National State of Storage

Mine Water Discharge, Return Flows and Diffuse Salt Loads Dilution Rule Mine Water Discharge, Return Flows and Diffuse Salt Loads RUSTENBURG Vaal Barrage Vaal Bloemhof Dam Katse Mohale

Operating Rule Recommendations No restrictions for IVRS (2018/2019) Blending/Dilution Apply dilution rule in Vaal Barrage (600 mg/l) according to water quality status which needs to be monitored Thukela transfer 2018/2019 until Sterkfontein Dam is full Thereafter standard rule till Bloemhof Dam is full Releases from Bloemhof: No releases required during 2018/2019

IVRS State of Storage Dam Nett Cap 106m3 13 May 2019 06 May IVRS: Total Vaal Sterkfontein Katse Mohale Bloemhof Grootdraai 10 554 2 603 2 617 1 519 843 1 243 350 74,5% 72,8% 93,4% 35,6% 33,1% 100,5% 77,6% 75,5% 73,4% 93,5% 36,1% 32,5% 106,6% 79,2%

Probability distribution (boxplot) 0 % 5.0 % 25 % 50 % 75 % 95 % 100 % Percentage of sequence results exceeding given value Results for generated sequences

Box plot Description: Vaal Dam 1 May 2018: 104.6% 1 May 2019: 73.5%

Thukela Transfers to Sterkfontein No transfers currently taking place on the Thukela-Vaal Scheme due to safety issues at the pump station

Senqu Sub-system (LHWP) Vaal 2015/16 AOA SOF

1 May 2018: 100%

Katse, Mohale, Sterkfontein, Vaal 1 May 2018: 86% Vaal 2015/16 AOA SOF

Total Integrated Vaal System Last year 89% This year

Water use monitoring

Conclusion The state of storage in Vaal Dam was still below the median by 1 May 2019 decision date The state of storage within Senqu system is still low and of concern The LHWP, for the first time in history, will not be able to transfer the full annual allocation from Lesotho – because of the low levels in the Lesotho dams. Total system storage is tracking below the median projected storage and tracking the 95th percentile No Restrictions anticipated this year and restrictions in subsequent years dependant on runoff and the integrity of the infrastructure. Efforts to comply with water conservation and demand management measures are encouraged and must be continued

THANK YOU!

Draft Preliminary Water Balance (February 2018) High with target WC/WDM Desalination for urban use (from January 2022) Unlawful removed Re-use (Tshwane ) High water requirement Unlawful removed WC/WDM savings Tshwane re-use High water requirement Unlawful removed Earliest Date for Yield Replacement (2030) Short term availability due to favourable reservoir volumes System yield accounts for: Reduction due to excessive dilution prior to desalination of AMD. Unused storage (yield) in Komati River System. System Yield TWP Polihali Dam Net Yield Polihali Dam Yield Yield increases due to desalination of mine water Elevated risk of restrictions. Violation of risk criteria. Elevated risks without WC/WDM savings First transfer from LHWP Phase II – Dec 2025 19

By 2025 Level 1 Restriction occurs at about 5% risk: Risk of Restrictions (Scenario A) By 2025 Level 1 Restriction occurs at about 5% risk: 50% Irrigation Restriction 30% Urban Restriction Violation of Risk Criteria 0.5 % min % 1 % Min % 0.5 % 1.0 % 5.0 % 25 % 50 % 75 % 95 % 99 % 99.5 % Max % 5 %