If the cable car were a bus route, it'd be London's 407th busiest

Look at all those happy punters. Image: Scott Heavey/Getty.

Great news, everyone! London's favourite cable car has hit a major milestone!

 

Five million people! Isn't that brilliant?

Let's put that amazing number in context, shall we?

Over the last year, just under 1.6m people have used the cable car. That's so many it's approximately one tenth of the number that used* London's smallest tube line, the Waterloo & City line shuttle.

Approximately 50,000 passengers a week use the nearby Woolwich Ferry to cross the Thames; that means that the cable car is attracting nearly 60 per cent as much traffic as that.

And if it was a bus route, it'd be London's 407th busiest! Take that, H14 from Hatch End to Northwick Park Hospital. How’s it feel to be in 408th place? Loser.

To sum all this up, here's the passenger traffic on the cable car compared to selected other transport routes in London:

Here’s another version of the chart which includes the Central Line. That’s London's busiest route, and even that only receives a mere 168 times as much traffic as the Emirates Air Line.

And it only did that well by having 49 stations and cheating by actually going to places people want to go. Watch your back, Central Line!

But we shouldn’t just think of the route itself of course: we should think of the stations, too.

Those 1.56m people each, presumably, used both Emirates Greenwich Peninsula and Emirates Royal Docks stations once each. (If they didn't, that raises some worrying questions.) That gives each of them an annual consolidated "entries + exits" figure of, yes, 1.56m.

Compare that figure with those published for the London Underground network, and you'll find that, if the cable car's two terminals were tube stations, as the tube map seems to think they are, they'd be joint 248th most popular! That’s ahead of around 20 other contenders, including such big names as Mill Hill East, Chalfont & Latimer and Upminster Bridge. Amazing.

To finish up, let's check out the long term passenger usage trends on the cable car route. Here's a graph showing average weekly passenger numbers over the past three years:

And here’s another version, this time using a 10 week rolling average, so you can see the long term trend and the effect of the seasons more clearly. 

 

Two things jump out at you here. One is that the cable car's traffic is seasonal, hitting its peak in summer.


The other is that nearly a quarter of the people who have ever used the Emirates Air Line did so in its first three months of existence – a period which, coincidentally, included London's Olympic Games. Since then, passenger numbers have been gently, but gradually, falling.

But never mind all that on this joyous day. Congratulations, to Transport for London and the Emirates Air Line, for hitting this amazing milestone.

The Emirates Air Line cost an estimated £60m to construct and £500,000 a month to run.

 

*Incidentally, tube passenger figures are for 2011-12, the most recent year we could find. Given the network-wide trend towards growth, it's almost certainly an underestimate. 

 
 
 
 

What can other cities learn about water shortages from Cape Town’s narrow escape from ‘Day Zero’?

Cape town. Image: Pixabay/creative commons.

Cape Town was set to run dry on 12 April, leaving its 3.7m residents without tap water.

“Day Zero” was narrowly averted through drastic cuts in municipal water consumption and last-minute transfers from the agricultural sector. But the process was painful and inequitable, spurring much controversy.

The city managed to stave off “Day Zero,” but does that mean Cape Town’s water system is resilient?

We think not.

This may well foreshadow trouble beyond Cape Town. Cities across the Northern Hemisphere, including in Canada, are well into another summer season that has already brought record-setting heat, drought and flooding from increased run-off.

Water crises are not just about scarcity

Water scarcity crises are most often a result of mismanagement rather than of absolute declines in physical water supplies.

In Cape Town, lower than average rainfall tipped the scales towards a “crisis,” but the situation was worsened by slow and inadequate governance responses. Setting aside debates around whose responsibility it was to act and when, the bigger issue, in our view, was the persistence of outdated ways of thinking about “uncertainty” in the water system.

As the drought worsened in 2016, the City of Cape Town’s water managers remained confident in the system’s ability to withstand the drought. High-level engineers and managers viewed Cape Town’s water system as uniquely positioned to handle severe drought in part because of the vaunted success of their ongoing Water Demand Management strategies.

They weren’t entirely mistaken — demand management has cut overall daily consumption by 50 per cent since 2016. So what went wrong?


Limits to demand management

First, Cape Town’s approach to water management was not well-equipped to deal with growing uncertainty in rainfall patterns — a key challenge facing cities worldwide. Researchers at the University of Cape Town argued recently that the conventional models long used to forecast supply and demand underestimated the probability of failure in the water system.

Second, Cape Town’s water system neared disaster in part because demand management seemed to have reached its limits. Starting late last year, the city imposed a limit on water consumption of 87 litres per person per day. That ceiling thereafter shrunk to 50 litres per person per day.

Despite these efforts, Cape Town consistently failed to cut demand below the 500m-litre-per-day citywide target needed to ensure that the system would function into the next rainy season.

The mayor accused the city’s residents of wasting water, but her reprimanding rhetoric should not be seen as a sign that the citizens were non-compliant. The continuously shrinking water targets were an untenable long-term management strategy.

Buffers are key to water resilience

In the end, “Day Zero” was avoided primarily by relying on unexpected buffers, including temporary agricultural transfers and the private installation of small-scale, residential grey-water systems and boreholes in the city’s wealthier neighbourhoods. The former increased water supply and the latter lowered demand from the municipal system. These buffers are unlikely to be available next year, however, as the water allocations for the agricultural sector will not be renewed and there is uncertainty in the long-term sustainability of groundwater withdrawals.

For more than a decade, Cape Town has levelled demand, reduced leaks and implemented pressure management and water restrictions. This made Cape Town’s water system highly efficient and therefore less resilient because there were fewer reserves to draw from in times of unusual scarcity.

The UN Water 2015 report found that most cities are not very resilient to water risks. As water managers continue to wait for climate change models to become more certain or more specific, they defer action, paralysing decision-makers.

If we really want our cities to be water-resilient, we must collectively change long-held ideas about water supply and demand. This will require technological and institutional innovation, as well as behavioural change, to create new and more flexible buffers — for example, through water recycling, green infrastructure and other novel measures.

Although Cape Town avoided disaster this year, that does not make it water-resilient. Despite the arrival of the rainy season, Cape Town is still likely to face Day Zero at some point in the future.

The ConversationThere’s a good chance that the city is not alone.

Lucy Rodina, PhD Candidate, University of British Columbia and Kieran M. FindlaterUniversity of British Columbia.

This article was originally published on The Conversation. Read the original article.