Cape Town relies on the Big Six dams with a combined storage capacity of 898,221 megalitres. Total average system storage was at 95.3% in October 2023, but the final 10% of dam water is generally difficult to treat because of silt, and evaporation can remove more than 2,000 megalitres a year. Theewaterskloof holds 53.5% of Western Cape Water Supply System storage, linking dam capacity directly to the city’s drought constraints and Day Zero-era limits.
Key Takeaways
- The total capacity of the Big Six dams is 898,221 megalitres
- The Theewaterskloof Dam accounts for 53.5% of the total storage capacity of the Western Cape Water Supply System
- The Voëlvlei Dam has a maximum storage capacity of 164,095 megalitres
- Agriculture in the Western Cape uses approximately 30% of the total water supply in the WCWSS
- The wine industry contributes R15 billion annually to the Western Cape economy
- 30,000 agricultural jobs were lost in the Western Cape due to the 2017/2018 drought
- Cape Town has over 11,000 km of water pipes in its network
- There are 12 water treatment plants serving the Cape Town metropolitan area
- Faure Water Treatment Plant has a capacity of 500 million liters per day
- Average daily water production in 2023 was approximately 850 million liters
- Residential consumers account for roughly 70% of total municipal water usage
- Houses (domestic) use approximately 64% of total residential water
- "Day Zero" was originally projected for April 12, 2018
- Crisis-level water restrictions (Level 6B) limited residents to 50 liters per person per day
- The drought was classified as a 1-in-300-year event by climatologists
Cape Town’s Big Six dams recovered after the 2018 drought, and water use still depends on strict conservation.
Related reading
01 · Category
Dam Levels & Storage30 stats
01
The total capacity of the Big Six dams is 898,221 megalitres
02
The Theewaterskloof Dam accounts for 53.5% of the total storage capacity of the Western Cape Water Supply System
03
The Voëlvlei Dam has a maximum storage capacity of 164,095 megalitres
04
Berg River Dam has a capacity of 130,010 megalitres and is the newest large dam in the system
05
Steenbras Lower Dam capacity is 33,517 megalitres
06
Steenbras Upper Dam capacity is 31,767 megalitres
07
Wemmershoek Dam capacity is 58,644 megalitres
08
Minor dams in the Table Mountain system account for less than 1% of total storage
09
During May 2018 peak drought, total dam levels dropped to 20.9%
10
The "Last 10%" of dam water is generally considered difficult to treat due to silt
11
Total dam levels reached 100% capacity in 2020 following the drought recovery
12
Evaporation loss from dams can exceed 2,000 megalitres per year depending on temperature
13
Cape Town's annual rainfall averages 515mm but varies wildly by topography
14
The City aims to maintain a 95% assurance of supply from surface water
15
Winter rainfall provides 90% of the dam recharge annually
16
Total average system storage was 95.3% in October 2023
17
Groundwater levels in the Table Mountain Group Aquifer are monitored at over 50 boreholes
18
The Kleinplaas Dam acts as a balancing dam for the Riviersonderend-Berg River Tunnel
19
Storage levels traditionally drop by 1% to 2% per week during summer
20
The Western Cape Water Supply System serves approximately 4.6 million people
21
Historical records show dam levels were at 100% in 2014 before the 3-year drought
22
The lowest recorded level for Theewaterskloof was 11.3% in April 2018
23
Cape Town manages 11 smaller dams in addition to the Big Six
24
Annual dam release for ecological reserve is mandated by the National Water Act
25
Surface water provides over 95% of Cape Town’s current potable water
26
Flash flooding in 2023 caused some dams to exceed 110% capacity due to spillway overflow
27
In 2017, the City used "cloud-seeding" research which was ultimately rejected as non-viable
28
Total storage available to the City is roughly 1.5 years of consumption without rain
29
Land Use in catchment areas affects runoff by up to 20%
30
Siltation reduces dam capacity by an estimated 0.1% per year
Interpretation
Dam Levels & Storage Interpretation
With over half the city's water eggs in one basket, Cape Town's supply is a thrilling rollercoaster ride from drought-induced panic to spilling-over-the-top relief, proving that when it comes to water, size isn't everything—reliability is.
02 · Category
Economic & Agricultural Impact30 stats
01
Agriculture in the Western Cape uses approximately 30% of the total water supply in the WCWSS
02
The wine industry contributes R15 billion annually to the Western Cape economy
03
30,000 agricultural jobs were lost in the Western Cape due to the 2017/2018 drought
04
Cape Town's Water and Sanitation budget is approximately R14 billion for 2023/24
05
Agricultural exports from the Western Cape fell by 20% in 2018
06
Tourism supports over 150,000 jobs in the Cape Town metro
07
A 10% reduction in water availability can reduce Western Cape GDP by 0.5%
08
Water tariffs increased by up to 500% for high-usage households during the drought
09
The City lost R1.6 billion in revenue in 2018 due to decreased water sales
10
Fruit farming (grapes, apples, pears) is the largest agricultural water consumer in the region
11
Commercial properties pay higher water rates than residential properties to cross-subsidize indigent services
12
Total citrus production in the region dropped by 15% during 2017-2018
13
The industrial sector accounts for approximately 4% of total water consumption in Cape Town
14
Water-intensive industries like breweries spent over R50 million on internal recycling during the crisis
15
80% of Cape Town's fruit is exported, requiring strict water-quality compliance
16
Small-scale farmers in the Philippi Horticultural Area provide 50% of Cape Town's fresh vegetables
17
The City charges a "fixed daily charge" based on meter size since 2018 to stabilize revenue
18
Investment in private boreholes by businesses in 2018 was estimated at R2 billion
19
The insurance industry saw a 25% increase in claims for subsidence-related damage during the drought
20
Car wash businesses reported a 60% revenue loss due to water restrictions
21
Landscaping and nursery businesses saw a 40% decline in sales during the crisis
22
Desalinated water costs roughly R15-R20 per kilolitre compared to R5 for surface water
23
The Western Cape produces 20% of South Africa's total agricultural output
24
50% of the Western Cape's agricultural land is under irrigation
25
Grain exports were less affected as they are primarily rain-fed (non-irrigated)
26
Every 1% increase in water tariffs is estimated to reduce demand by 0.15%
27
Direct potable reuse from wastewater is 50% cheaper than desalination
28
The food and beverage sector is the largest industrial user of water in the metro
29
Real estate values for homes with high-yield boreholes increased by 5-10% during 2018
30
The City estimates that becoming a "Water Sensitive City" will provide a 3:1 return on investment
Interpretation
Economic & Agricultural Impact Interpretation
Cape Town's water crisis is a brutal economic equation where a single drop sustains both a R15 billion wine industry and a city's salad bowl, proving that our faucets are directly plumbed into our wallets and our workforce.
03 · Category
Infrastructure & Augmentation30 stats
01
Cape Town has over 11,000 km of water pipes in its network
02
There are 12 water treatment plants serving the Cape Town metropolitan area
03
Faure Water Treatment Plant has a capacity of 500 million liters per day
04
Blackheath Water Treatment Plant can treat 360 million liters per day
05
The New Water Plan aims to produce 300 million liters per day from new sources by 2030
06
The Strandfontein Desalination Plant produced 7 million liters per day during the drought
07
The Monwabisi Desalination Plant provided 7 million liters of water per day
08
The V&A Waterfront desalination plant is a private-public project with 2 MLD capacity
09
The Table Mountain Group (TMG) Aquifer project aims to provide 50 MLD
10
Cape Flats Aquifer Management Scheme (CFAMS) will provide an estimated 30 MLD
11
Atlantis Aquifer has been used for over 40 years for managed aquifer recharge
12
The Zandvliet Wastewater Treatment works is being upgraded for direct potable reuse
13
The City operates 24 wastewater treatment plants
14
Over 8% of Cape Town's total water is recycled for industrial and irrigation use
15
The City plans to invest R5 billion in water infrastructure over the next 10 years
16
Energy usage for water pumping accounts for 10% of the City's electricity bill
17
Most Cape Town water flows via gravity from dams to treatment plants
18
The City replaced 30km of old water piping in the 2022/23 financial year
19
Pressure management zones (PMZs) prevent roughly 70 million liters of leaks per day
20
4.5 billion liters of treated effluent is used annually for irrigation of parks and golf courses
21
The "Water Star Rating" for businesses assesses infrastructure efficiency
22
800 staff members are dedicated to the Water and Sanitation department's technical repairs
23
Bulk water storage reservoirs have a 48-hour reserve capacity for the city
24
Invasive alien plants in catchment areas consume 55 billion liters of water per year
25
Clearing alien vegetation is 10 times cheaper than desalination per kilolitre
26
The City uses "acoustic leak detection" technology on over 2,000km of pipe annually
27
Total aquifer yield is expected to reach 100 MLD by 2027
28
Desalination is expected to contribute 10-15% of Cape Town's water by 2040
29
The Faure Permanent Reuse Plant (Direct Potable Reuse) will have a 70 MLD capacity
30
Smart pressure valves reduce night-time pressure to 1.5 bar to minimize loss
Interpretation
Infrastructure & Augmentation Interpretation
Cape Town is conducting a masterclass in not dying of thirst, orchestrating a multi-billion-rand hustle that marshals an army of pipes, plants, aquifers, and pressure valves to squeeze every last drop from the sky, the sea, and even yesterday's bathwater.
More related reading
04 · Category
Residential & Consumption Patterns30 stats
01
Average daily water production in 2023 was approximately 850 million liters
02
Residential consumers account for roughly 70% of total municipal water usage
03
Houses (domestic) use approximately 64% of total residential water
04
Flats and complexes account for 9% of total municipal water usage
05
Average per person water use target during non-drought periods is 150 liters per day
06
Informal settlements use less than 5% of total municipal water despite making up 15% of the population
07
Water meters are installed at over 95% of formal households in Cape Town
08
Approximately 250,000 Water Management Devices (WMDs) have been installed to curb excessive use
09
Average household size in Cape Town is 3.17 people according to Census data
10
During summer, residential consumption increases by roughly 20% due to outdoor use
11
Non-revenue water (leaks and theft) is estimated at 15-20%, which is lower than the national average
12
Potable water used for toilet flushing accounts for 30% of average indoor household use
13
Showers and baths account for 35% of indoor household water use
14
Laundry accounts for 15% of indoor water consumption
15
Cooking and drinking account for only 5% of average indoor water consumption
16
The City provides 6,000 liters of water free to indigent households per month
17
High-income households reduced consumption by 50% during the drought
18
The Step Tariff system charges more per kilolitre as usage increases into higher brackets
19
80% of Cape Town households have access to piped water inside their dwelling
20
Use of greywater systems for gardening increased by 400% during the drought
21
There are an estimated 20,000 private boreholes registered in the City of Cape Town
22
Swimming pools lose approximately 1,000 liters a month to evaporation without covers
23
Peak daily demand in Cape Town record was 1,200 million liters in 2014
24
In 2021, the average daily consumption was 755 million liters per day
25
Outdoor water use accounts for 10% of total annual residential use
26
Residents with gardens use 30-50% more water than those in apartments
27
Smart water meters can reduce household leaks by 80% through early detection
28
13% of households in Cape Town rely on communal taps
29
The City estimates 30% of total demand comes from commercial and industrial sectors combined
30
Average kitchen tap flow rate is 6 to 12 liters per minute
Interpretation
Residential & Consumption Patterns Interpretation
Despite Cape Town's water crisis inspiring heroic conservation—with high-income households halving their use and greywater systems multiplying—the sobering reality is that a staggering 30% of our precious drinking water is still flushed down the toilet, while homes with gardens continue to use up to 50% more than apartment dwellers.
05 · Category
Water Crisis (Day Zero) History30 stats
01
"Day Zero" was originally projected for April 12, 2018
02
Crisis-level water restrictions (Level 6B) limited residents to 50 liters per person per day
03
The drought was classified as a 1-in-300-year event by climatologists
04
Total water demand was slashed from 1,100 MLD in 2015 to 500 MLD in 2018
05
Day Zero was officially called off for 2018 on March 7, 2018
06
Level 1 restrictions were only reintroduced in late 2020
07
Agricultural water releases were cut by 60% during the height of the drought
08
The City established 200 emergency water collection points as part of Day Zero planning
09
The "Water Map" was launched to show household consumption and encourage peer pressure
10
143,000 households were targeted for Water Management Device installation during the crisis
11
Political friction between local, provincial, and national government delayed crisis funding by 12 months
12
Retailers saw a 300% increase in bottled water sales during early 2018
13
Tourism bookings for Cape Town dropped by 10-15% during the Day Zero announcement phase
14
1.5 million people in Cape Town were expected to stand in line for water if Day Zero occurred
15
The "Point-Of-Distribution" (POD) plan involved the South African National Defence Force for security
16
Cape Town's water use per capita during the drought was among the lowest in the world for a major city
17
Rainfall in 2017 was the lowest recorded since 1933
18
The City spent over R400 million on emergency groundwater and desalination projects in 2018
19
Water pressure was reduced globally across the city to save 50 million liters per day
20
5-minute showers were replaced by "stop-start" 90-second showers as a cultural norm
21
The City prohibited the use of all municipal water for car washing and filling pools
22
Total regional agricultural losses due to the drought were estimated at R5.9 billion
23
Theewaterskloof Dam reached a record low of 10.2% shortly after the crisis peak
24
Businesses were required to reduce their consumption by 45% under Level 6 restrictions
25
Cape Town was the first major city in the world to potentially run out of water
26
Residents used hand sanitizers to save 2-3 liters per hand wash
27
Public toilets in malls were switched to groundwater or recycled water
28
The "Day Zero" date moved forward or backward weekly based on the previous week's consumption
29
Water consumption decreased by 54% between 2015 and 2018
30
Local schools launched "Water Explorer" programs to teach children conservation
Interpretation
Water Crisis (Day Zero) History Interpretation
Cape Town stared down a 1-in-300-year drought with the grim efficiency of a military operation, transforming a city on the brink of becoming the world's first major metropolis to run out of water into a global case study in radical collective conservation, proving that while nature can be merciless, a motivated populace armed with stop-start showers and a shame-inducing water map can be even more formidable.
Reference
Cite This Report
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APA
Nathan Caldwell. (2026, February 13). Cape Town Water Usage Statistics. Gitnux. https://gitnux.org/cape-town-water-usage-statistics
MLA
Nathan Caldwell. "Cape Town Water Usage Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/cape-town-water-usage-statistics.
Chicago
Nathan Caldwell. 2026. "Cape Town Water Usage Statistics." Gitnux. https://gitnux.org/cape-town-water-usage-statistics.
Sources & references
25 datasets cited across this report · attribution is report-level
capetown.gov.zadws.gov.za
tcta.co.za
unep.org
news24.com
csir.co.za
weathersa.co.zawesterncape.gov.za
nature.orgstatssa.gov.zawrc.org.za
journals.sagepub.com
waterwise.co.za
bbc.comcsag.uct.ac.za
dailymaverick.co.za
nielsen.com
wesgro.co.za
theguardian.com
waterexplorer.org
water-technology.net
wosa.co.za
ab-inbev.com
santamblog.co.za
pamgolding.co.za