Down one

Latest news from the City of Cape Town water dashboard:

Here are a few takeaways from  this week’s numbers and the information provided therein.

We are still using too much water. And by “we”, I mean people who aren’t me or my family. But even so, even with those people who aren’t me and my family, Cape Town has cut its water use by almost 50% when compared with similar periods a few years back.
Can “we” do better? Well, “we” should be able to, but interestingly, “we” have been stuck at this sort of level for a while now. Could this be some sort of impasse, and if so, why is it happening and what can the City do to get past it? There are already plenty of measures in place, but are they actually having enough effect?

582 million litres x 7 days = 4,060 million litres, but actual volume stored in the dams dropped by 8,739 million litres. That discrepancy is mainly due to evaporation because of the hot weather and strong winds we’ve seen this week over the Winelands area. So, in the last 7 days, we’ve lost an additional 8 days at 582 million litres back up to the sky. And let’s face it – it’s going to be hot and windy a lot more over the summer.

The good news is that even with this continuing overuse and huge evaporation, the dam levels “only” dropped by 1%. Simple maths suggests that with 26% of usable water still available, and using/losing 1% a week, we can last another 26 weeks. I’ve been doing some (more) rudimentary calculations and I reckon that takes us to the middle of May. We might just make it. Or not. I actually have no idea.

Because historically, water usage goes up at this time of year into summer.
However, there is some good evidence that water restrictions will curb this increase:

Taking 2014/15 as an example of unrestricted use, and comparing it with last summer (when restrictions were in force), we can see that there has been a reduction of maybe 400 million litres a day. And yes, production (blue line) is still above where we need it to be (pink line), but that graph tells a good story, and with more draconian measures in place this year, will hopefully continue to do so. Addition of temporary small scale desalination plants and tapping into local aquifers will mitigate supply issues a little too.

It rained this morning, which ruined the kids’ sports day, but at least I got another 100 litres or so from my sausages. And I’m only concentrating on that latter fact, because we’re really not in any position to complain about any negative effects of precipitation in Cape Town right now.

Chin up. We might just survive this yet. Keep saving. Every little helps.

Suddenly: August

It’s nearly the end of July, and that means that it’ll soon be August. After that… [double checks] yes, September.

So what? This happens every year, right?

Well, yes it does, but September 1st is unofficially known as Spring Day in South Africa, bringing with it… well… Spring. Not really Spring, but unofficially Spring. Springy enough not to be Winter anymore. Unofficially, at least.

That also happens every year, but given that we’re basically 5 weeks away from it (and therefore 5 weeks away from what is unofficially the end of the rainy season), and our dams are still looking emptier than an ANC promise, we really should be well into full panic mode by now. Especially given that the medium term forecast for the next fortnight (making up, as it does, 40% of that 5 week period) shows no sign of significant rainfall for the Western Cape.

Look, tomorrow is not going to be dry, but with a forecast of just 5.2mm of precipitation over 24 hours, it’s not going to be particularly wet either.

With the Cape Town dams sitting at 27.4% of capacity (as per this morning’s city figures) – and with the last 10% of that infamously “unusable” – things are looking every bit as precarious as ever. Add to that the fact that Cape Town’s residents are using 643,000,000 litres a day (that’s 143,000,000 litres or almost 30% more than we should be) and you (actually “we”) have a recipe for disaster.

There’s enough publicity about this situation on the TV, the internet (not least this damned blog), the radio and everywhere else for everyone in Cape Town to understand the gravity of the situation. But given that we’re apparently still paying no attention and not saving nearly enough of the wet stuff, I’ve now come to the conclusion that a lot of the locals simply don’t care.

I wonder how they’ll feel in 6 months time?

Good news, bad news

GOOD NEWS!
As of 0600 this morning (it’s Friday today, for those wondering), the Theewaterskloof dam has 5,476,628,400,000 more litres of water in it than its low point on Tuesday at 1200.

BAD NEWS!
That only equates to its volume being 1.14% up on earlier in the week.
Current level = 14.05%*.

 

And therein lies the message that there’s a long, LONG way to go yet till we’re out of this mess, folks. Keep saving water!

* Obviously, there will still be inflows that haven’t reached the dam yet, so this figure will rise a bit.

Damn

Dam level figures released today for Cape Town’s ‘Big 6’ indicate that we’re 0.4% worse off than we were this time last week, teetering once again just above the magical 30% ‘CRITICAL‘ level, below which nothing actually changes.

Fullscreen capture 30-May-16 92448 PM.bmp

Oh then, to be in Sheffield (as I was a couple of weeks ago) where the dams are just about as full as they can be:

That total of 10,410,000,000 gallons is equal to 47,324,796,900 litres, in case you were wondering.

And what does a dam that’s 98% full look like? Like this.
And what does the other side of the wall look like when the dam is 100.1% full? Like this.

Going critical

Nothing good comes from things going critical. Nuclear power plants are probably highest up the list of things which are bad when they go critical, with toddler tantrums pretty close behind.
Critical isn’t good situation to be in. Critical is… well… critical.

Unless something rather remarkable occurs very shortly, when their capacities are measured again on Monday, Cape Town’s dams will have fallen below the “critical” level of 30%.

Fullscreen capture 2016-04-14 100229 AM.bmp

It’s obviously an arbitrary level that they’ve chosen to call “critical”, and quite what happens when we cross that threshold is unclear, although we have been told that we shouldn’t panic. But then, that begs the question, why bother having a “critical” level in the first place if nothing changes once you find yourself below it?

After all, very little happened when we crossed the legendary “careful now” 70% margin, nor the distinctly worrying “er… guys…?” 50% line.

I do hope that the city council have got this all in hand…

Barry Wood, the city’s manager of bulk water supply, told the council’s portfolio committee “We don’t have to be too concerned, provided that it starts to rain.”

Ah. That’s all ok then.
Colour me completely reassured.