Main Reef Reservoir
A reservoir. What Johannesburg Water (JW) reported about it, from March 2025.
Latest JW report
JW reported supplying adequately on 29 September 2026 at 21:00. The board read “Supplying adequately”. JW put it on its website 1 October 2026 at 13:40. JW's page for this board ↗ · JW's image of the board ↗
Live updates during the day: Johannesburg Water ↗ and OurPower ↗. This page keeps the history.
Suburbs it supplies
JW's pages and notices link no suburb to Main Reef Reservoir.
Up the supply chain
On 29 September 2026, JW reported Main Reef Reservoir supplying adequately
Where the water comes from, top to bottom, and what JW reported for each part on 29 September 2026. A suburb draws on every supply listed at once; JW does not say which street each one reaches.
Showing 29 September 2026, the last day in the record.
Bulk supply
Main Reef Reservoir: no public JW source names its system or the Rand Water station that feeds it
System
No public JW source names the system for these supplies.
Supply
JW reported supplying adequately.
As printed: “13:40 Supplying adequately.”; “21:00 Supplying adequately”
JW's reported status of the reservoir or tower, not measured water at taps. Boards from March 2025.
Source: Johannesburg Water's System Update boards and notices, read by us. How this record is made.
Cite this figure
watersearch (2026). “On 29 September 2026, JW reported Main Reef Reservoir supplying adequately”. Data release 2026-09-29-318d9dca. https://watersearch.co.za/reservoir/main-reef-reservoir#fig-chain
The data as a table
| Part | What it is | Feeds | How we know | On 29 September 2026 |
|---|---|---|---|---|
| Unknown | Chain stops | the system | Main Reef Reservoir: no public JW source names its system or the Rand Water station that feeds it | No JW status for it |
| Main Reef Reservoir | Reservoir | JW's page or notice | supplying adequately |
Main Reef Reservoir over time
In 2026 so far, JW reported Main Reef Reservoir short of water on 0 days
What JW reported each day, 3 March 2025 to 29 September 2026, one row a month; the number at the right is the month's days short of water. Based on 20 days with a JW report. A day counts as short of water when JW's worst report for it that day was “poor pressure to no water” or “critically low”. Gaps: Main Reef Reservoir: no report from 3 March 2025 to 30 August 2026.
- water as normal
- supplying fairly
- JW warned
- low, or weak in places
- short of water
- critically low
- shut for the night
- no JW report
- still filling in
JW's reported status of the reservoir or tower, not measured water at taps. Boards from March 2025.
Source: Johannesburg Water's System Update boards and notices, read by us. How this record is made.
Cite this figure
watersearch (2026). “In 2026 so far, JW reported Main Reef Reservoir short of water on 0 days”. Data release 2026-09-29-318d9dca. https://watersearch.co.za/reservoir/main-reef-reservoir#fig-year
The data as a table
| Month | Days reported | Days in record | Adequate or fair | Poor pressure in places, or low | Warning: no water may occur | Poor pressure to no water | Critically low | Overnight closure |
|---|---|---|---|---|---|---|---|---|
| March 2025 | 0 | 29 | 0 | 0 | 0 | 0 | 0 | 0 |
| April 2025 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| May 2025 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| June 2025 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| July 2025 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| August 2025 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| September 2025 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| October 2025 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| November 2025 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| December 2025 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| January 2026 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| February 2026 | 0 | 28 | 0 | 0 | 0 | 0 | 0 | 0 |
| March 2026 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| April 2026 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| May 2026 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| June 2026 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 0 |
| July 2026 | 0 | 31 | 0 | 0 | 0 | 0 | 0 | 0 |
| August 2026 | 1 | 31 | 1 | 0 | 0 | 0 | 0 | 0 |
| September 2026 | 19 | 29 | 19 | 0 | 0 | 0 | 0 | 0 |
From April to September 2026 (six months), JW reported Main Reef Reservoir short of water on 0 of 20 reported days
Days per month short of water, stacked: critically low at the base. The tick is the median supply in the city that month. The strip under each bar is the share of days with a JW report; a month with none says gap. 3 March 2025 to 29 September 2026.
In 2026 so far: 0 days short of water for Main Reef Reservoir, from 20 days with a report. The median supply in the city: 4 days.
JW's reported status of the reservoir or tower, not measured water at taps. Boards from March 2025.
Source: Johannesburg Water's System Update boards and notices, read by us. How this record is made.
Cite this figure
watersearch (2026). “From April to September 2026 (six months), JW reported Main Reef Reservoir short of water on 0 of 20 reported days”. Data release 2026-09-29-318d9dca. https://watersearch.co.za/reservoir/main-reef-reservoir#fig-days
The data as a table
| Month | Days short of water | Days reported | Days in record | City median |
|---|---|---|---|---|
| March 2025 | gap | 0 | 29 | 0 |
| April 2025 | gap | 0 | 30 | 0 |
| May 2025 | gap | 0 | 31 | 0 |
| June 2025 | gap | 0 | 30 | 0 |
| July 2025 | gap | 0 | 31 | 0 |
| August 2025 | gap | 0 | 31 | |
| September 2025 | gap | 0 | 30 | |
| October 2025 | gap | 0 | 31 | |
| November 2025 | gap | 0 | 30 | |
| December 2025 | gap | 0 | 31 | |
| January 2026 | gap | 0 | 31 | |
| February 2026 | gap | 0 | 28 | 0 |
| March 2026 | gap | 0 | 31 | 0 |
| April 2026 | gap | 0 | 30 | 0 |
| May 2026 | gap | 0 | 31 | 0 |
| June 2026 | gap | 0 | 30 | 0 |
| July 2026 | gap | 0 | 31 | 1 |
| August 2026 | 0 | 1 | 31 | 0 |
| September 2026 | 0 | 19 | 29 | 0 |
In words
2026 so far: JW reported it at “poor pressure to no water” or “critically low” on 0 days. JW published a report for it on 20 of the 272 days in the record; the other 252 days have no report, and we do not count them as normal. The median supply in the city had 4 such days.
JW's boards first named Main Reef Reservoir on 31 August 2026 and last on 29 September 2026: 33 statuses on 33 boards, over 20 days. 0 of those statuses announced a scheduled overnight closure, which we count apart, never as an outage.
Month by month
Days JW reported Main Reef Reservoir at “poor pressure to no water” or “critically low”, out of the days it reported it at all. A month with few reported days says little.
| Month | Days short of water | Days with a report | Same month a year earlier |
|---|---|---|---|
| March 2025 | No JW report this month | ||
| April 2025 | No JW report this month | ||
| May 2025 | No JW report this month | ||
| June 2025 | No JW report this month | ||
| July 2025 | No JW report this month | ||
| August 2025 | No JW report this month | ||
| September 2025 | No JW report this month | ||
| October 2025 | No JW report this month | ||
| November 2025 | No JW report this month | ||
| December 2025 | No JW report this month | ||
| January 2026 | No JW report this month | ||
| February 2026 | No JW report this month | ||
| March 2026 | No JW report this month | Too few reports to compare | |
| April 2026 | No JW report this month | Too few reports to compare | |
| May 2026 | No JW report this month | Too few reports to compare | |
| June 2026 | No JW report this month | Too few reports to compare | |
| July 2026 | No JW report this month | Too few reports to compare | |
| August 2026 | 0 | 1 | Too few reports to compare |
| September 2026 | 0 | 19 | Too few reports to compare |
Recent JW reports
The last 20 statuses JW printed for Main Reef Reservoir, newest first.
JW reported supplying adequately on 29 September 2026 at 21:00. The board read “Supplying adequately”. JW put it on its website 1 October 2026 at 13:40. JW's page for this board ↗ · JW's image of the board ↗
JW reported supplying adequately on 29 September 2026 at 13:40. The board read “Supplying adequately.” JW put it on its website 1 October 2026 at 13:41. JW's page for this board ↗ · JW's image of the board ↗
JW reported supplying adequately on 28 September 2026 at 14:10. The board read “Supplying adequately.” JW put it on its website 1 October 2026 at 13:42. JW's page for this board ↗ · JW's image of the board ↗
No JW report since 25 September 2026. JW reported supplying adequately on 25 September 2026 at 13:45. The board read “Supplying adequately.” JW put it on its website 28 September 2026 at 10:31. JW's page for this board ↗ · JW's image of the board ↗
No JW report since 23 September 2026. JW reported supplying adequately on 23 September 2026 at 18:20. The board read “Supplying adequately”. JW put it on its website 25 September 2026 at 10:41. JW's post ↗ · JW's image of the board ↗
No JW report since 23 September 2026. JW reported supplying adequately on 23 September 2026 at 11:22. The board read “Supplying adequately.” JW put it on its website 25 September 2026 at 10:40. JW's post ↗ · JW's image of the board ↗
No JW report since 22 September 2026. JW reported supplying adequately on 22 September 2026 at 11:10. The board read “Supplying adequately.” JW put it on its website 22 September 2026 at 15:41. JW's post ↗ · JW's image of the board ↗
No JW report since 21 September 2026. JW reported supplying adequately on 21 September 2026 at 18:55. The board read “Supplying adequately”. JW put it on its website 22 September 2026 at 14:09. JW's post ↗ · JW's image of the board ↗
No JW report since 21 September 2026. JW reported supplying adequately on 21 September 2026 at 13:45. The board read “Supplying adequately.” JW put it on its website 22 September 2026 at 14:08. JW's post ↗ · JW's image of the board ↗
No JW report since 18 September 2026. JW reported supplying adequately on 18 September 2026 at 16:15. The board read “Supplying adequately.” JW put it on its website 21 September 2026 at 09:06. JW's post ↗ · JW's image of the board ↗
No JW report since 18 September 2026. JW reported supplying adequately on 18 September 2026 at 10:05. The board read “Supplying adequately.” JW put it on its website 21 September 2026 at 09:04. JW's post ↗ · JW's image of the board ↗
No JW report since 17 September 2026. JW reported supplying adequately on 17 September 2026 at 15:15. The board read “Supplying adequately.” JW put it on its website 18 September 2026 at 10:41. JW's post ↗ · JW's image of the board ↗
No JW report since 17 September 2026. JW reported supplying adequately on 17 September 2026 at 09:10. The board read “Supplying adequately.” JW put it on its website 18 September 2026 at 10:40. JW's post ↗ · JW's image of the board ↗
No JW report since 16 September 2026. JW reported supplying adequately on 16 September 2026 at 14:55. The board read “Supplying adequately.” JW put it on its website 16 September 2026 at 15:56. JW's post ↗ · JW's image of the board ↗
No JW report since 16 September 2026. JW reported supplying adequately on 16 September 2026 at 09:45. The board read “Supplying adequately.” JW put it on its website 16 September 2026 at 15:52. JW's post ↗ · JW's image of the board ↗
No JW report since 15 September 2026. JW reported supplying adequately on 15 September 2026 at 16:35. The board read “Supplying adequately.” JW put it on its website 16 September 2026 at 10:17. JW's post ↗ · JW's image of the board ↗
No JW report since 15 September 2026. JW reported supplying adequately on 15 September 2026 at 10:10. The board read “Supplying adequately.” JW put it on its website 16 September 2026 at 10:11. JW's post ↗ · JW's image of the board ↗
No JW report since 14 September 2026. JW reported supplying adequately on 14 September 2026 at 09:59. The board read “Supplying adequately.” JW put it on its website 15 September 2026 at 11:25. JW's post ↗ · JW's image of the board ↗
No JW report since 11 September 2026. JW reported supplying adequately on 11 September 2026 at 10:58. The board read “Supplying adequately.” JW put it on its website 15 September 2026 at 10:59. JW's post ↗ · JW's image of the board ↗
No JW report since 10 September 2026. JW reported supplying adequately on 10 September 2026 at 20:02. The board read “Supplying adequately.” JW put it on its website 11 September 2026 at 08:46. JW's post ↗ · JW's image of the board ↗
Past outages
Each row is one outage: a stretch of time JW reported Main Reef Reservoir at “poor pressure to no water” or “critically low”, newest first. An outage has no reported end when JW's reports stopped before it ended, or when it was still going at JW's last report; its length is then a minimum.
JW reported no such outage for this supply.
What JW's boards cannot tell you
- Whether water reaches your street or your tap.
- Which streets lose water first: JW warns of higher-lying areas but does not name the streets.
- Why a supply ran low, unless a JW notice gives a reason.
- Pipe bursts, tankers and valve work, which are not on the boards.
Source: JW's System Update boards and notices, read by us. The full list, and how this record is made.