Cape Town Water Outlook Updated 21 February 2018 Department of Water and Sanitation City of Cape Town

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1 Cape Town Water Outlook 2018 Updated 21 February 2018 Department of Water and Sanitation City of Cape Town

2 Cape Town s water is part of an integrated system Cape Town gets its water from a system of dams that supply agriculture and other urban areas. The current system is heavily dependent on rainfall. This complex system is managed by the national Department of Water and Sanitation. About a third of the water in this system is used by agriculture and 7% by other urban areas (smaller towns).

3 Why is there a shortage of water in Cape Town? Cape Town is experiencing an unprecedented multi-year drought event. The National Department of Water and Sanitation is responsible for planning and implementing water resources schemes to meet water demand for cities, industries, mining and agriculture. The Department plans at a 1 in 50 year level of assurance. This means that during droughts with a severity of 1:50 years or more, restrictions need to be imposed to reduce demand. The current drought is much more severe that a 1 in 50 drought event. The best estimate of the return interval of the meteorological drought in the region of WCWSS dams is 311 years, with 90% confidence that it actually falls between 105 and 1280 years 1. The next augmentation scheme for Cape Town was planned for 2022/3 and is being accelerated by the national Department. This scheme (augmentation of Voelvlei Dam) is unlikely to be ready before 2021.

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5 Will it rain again? Yes. Historical (grey) and predicted (pink) annual rainfall for Cape Town, according to 16 global climate models. Yellow dots indicate rainfall incidents equal to or lower than 2017 rainfall. Rainfall in the Cape Town area is variable. Wetter and drier years are common. 16 global climate models predict an overall decline in rainfall for Cape Town in the future with more dry years and fewer wetter years. A scenario in which it does not rain the future or in which it only rains at 2017 levels is unrealistic. Sources: 1 Facts are few, opinions plenty on drought severity again (January 2018) Is Cape Town s drought the new normal? (1 November 2017) Why Cape Town s drought was so hard to predict (19 October 2017)

6 Daily consumption MLD Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Evaporation - Maximum Urban (DWS average of last 5 years) Agriculture unrestricted RESTRICT TO Daily consumption MLD Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Evaporation - Maximum 45% restricted Urban Agriculture 60% restricted

7 Cape Town will get through the drought IF restrictions on dam withdrawals are enforced Overall level of the Dams The level of water in the dams supplying Cape Town will not drop below 10% this year if restrictions are adhered to and assuming another low rainfall year. Monitoring dam levels (inflow, evaporation and withdrawals) and managing dam withdrawals is a key to maintaining the integrity of the system and getting through the drought.

8 Both the City and agriculture MUST adhere to the restrictions imposed on the system. Cape Town is not yet meeting its target. Over abstraction by agriculture is a key risk to the system.

9 For Cape Town, this means that demand must now be managed down to below 450 Ml/day. While Cape Town has significantly reduced its demand (measured here as production from the treatment works), from a peak of 1200 Ml/day in 2015 down to below 600 Ml/day, a further reduction in demand is needed to below 450 Ml/day immediately due to not meeting the 500 Ml/day target. Demand reduction is saving 400 Ml/day Feb 2017 = 900 Ml/day Feb 2018 = 500 Ml/day Further measures are being put in place to reduce demand, including: punitive drought tariffs demand management devices & flow restrictors more aggressive pressure management

10 Current % Savings: 39% NDWS Target 45% Preliminary Scenario (as at Mid-Feb 2018): Anticipated Savings: >45% ASSUMPTIONS: - Incremental Savings assigned as follows: - Tariff Increases: estimated at 50Ml/day by end of June WMD installations: estimated at 10Ml/day by end of June Pressure Management; Target High Consumers; Leak Repair: 32Ml/day (mid February to Oct 2018) - Build Programme - 80% success on build programme delivering an additional 120Ml/day by end Oct 2018

11 Where augmentation came from: Water resilience emergency programme (May-Oct 2017) Premises: Assume no rain Build 500 Ml/day new augmentation as fast as possible No resource constraint Project list as at 24 Oct 2017

12 Advice from International Review (November 2017) 1. Assuming it will not rain again is not realistic 2. Prioritise ground water 3. Do not pursue temporary desalination and reuse 4. Re-use is cheaper than desalination and may be quicker to execute 5. Plan and execute permanent desalination at a optimum scale 6. A turnkey approach for reuse and desalination with a water purchase agreement will yield the lowest cost per unit of water 7. Do not delay decisions on permanent reuse and desalination.

13 Yield-cost curve informs priorities Augmentation of 400 MLD more than 7 times cost of WDM +400 MLD R 6 000m Approximate/Target Yield Unit versus costs cost (Rm per MLD) 30 4 th priority 25 3 rd priority 1 st priority MLD < R 800m nd priority 5 0 Ground (Sandy) +80 MLD Ground (TMG) 80 MLD R560m Savings through demand reduction (MLD) Additional supply (MLD) Reuse 75 MLD R1 500m Desalination 150 Ml/day R3 750 million

14 What about new water supplies? Planned augmentation treated surface water- historical groundwater extraction - sandy aquifer Equivalent annual inflow (millions of m 3 ) 300MLD 500MLD 2017 runoff Average runoff permanent re-use permanent desalination groundwater extraction - TMG temporary water re-use temporary desalination Wet winter runoff Estimated cost ranges for treated water by source (R/kl) R 0 R 10 R 20 R 30 R 40 R 50 AUGMENTATION Augmentation schemes are a far more expensive source of water than runoff from rainfall. The volume of runoff cannot be easily augmented in short time periods and is dependent on rainfall patterns. Under poor rainfall conditions like 2017 we would require augmentation of ~720MLD to match the volume of runoff. Despite all augmentation efforts, the supply scheme is vulnerable to poor rainfall. As can be seen below the cost per kl of water from other sources vary considerably. The cost of bulk water, waste water and reticulation is common so the costs below can be compared to the cost of runoff which is R5.20/kl vs temporary desalination at >R40/kl.

15 New water supplies are important for water security going forward but these will have little impact this summer. 70.0% 60.0% 50.0% 40.0% Impact of Rainfall Impact of Rainfall Urban restriction very important 30.0% 20.0% 10.0% 0.0% New supplies have a small impact this summer. But are very important for 2019 if winter rainfall is low JAN-18 FEB-18 MAR-18 APR-18 MAY-18 JUN-18 JUL-18 AUG-18 SEP-18 OCT-18 NOV-18 DEC-18 JAN-19 FEB-19 MAR-19 APR-19 MAY-19 JUN-19 JUL-19 AUG-19 SEP-19 OCT-19 NOV-19 Restricted, 100% MLD, 100% 2017 Restricted, No Augmentation Restricted, 75% rain Restricted, 150% rain

16 The New Water Program short term AUGMENTED VOLUME (MLD) Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Springs Ground Water Abstraction - sandy Ground Water Abstraction - TMG Temporary desalination Water transfer Zandvliet reclaimed water Actual Source: rev 01 dashboard Contracted projects (Dec 18 targets) Source Capacity (MLD) Ground (Sandy) 120 Agriculture 67 (4 months only) Ground (TMG) Between Desalination 16 (temp) Reuse (temp) 10 Springs 7 Total (excl. agric) Between Notes: Ground water prioritised Temporary desalination minimised

17 Financial implications of the drought The drought affects the city s finances in two primary ways: 1. Reduced sales means that city income is reduced because tariffs are volume based. 2. Additional expenditure is required to increase availability of water. New sources of water are more costly than the water obtained from the existing dams. This increases both capital and operating costs. Existing Restriction Tariffs (Water) Level 1 Level 2 Level 3 Level 4 Level 5 Level 6 Step 1 [0-6kl] Step 2 [6-10.5kl] Step 3 [ kl] Step 4 [20-35kl] Step 5 [35-50kl] Step 6 [+50kl] Commercial Primary goals in responding to challenges: 1. Recover full costs including cost of water resilience program and adequate depreciation. It is a legal requirement to balance budget 2. Retain affordability for poor people and improve payment levels 3. Increase resilience of tariff to shocks (greater revenue stability in face of drought conditions which the city is currently facing and is likely to face again in the future) 4. Tariff reflects value of water and supports sustainability (including adequate cash-backed depreciation to replace assets)

18 20 year Dam levels

19 Summary NEXT STEPS Decisions under consideration by the City on optimal augmentation types, volumes, methods; It is imperative that some re-use and desalination is brought on line at a suitable scale quickly; Financial impacts in future are still somewhat uncertain, but will be substantial as a result of reduced & indeterminate future sales combined with increased costs; Improved coordination and strong leadership within and between spheres of government is needed, particularly to fasttrack regulatory and procurement processes. 1. Day zero CAN be avoided by reducing demand (in line with NDWS restriction) 2. For City of Cape Town, level 6B restrictions and punitive drought tariffs (level 6) 3. Influence agricultural restrictions to stay within allocation 4. Improve communications and have consistent messaging across government 5. Engage stakeholders into active citizenry

20 Thank You