Turning
the tide

The diver descends slowly, dressed like an astronaut and breathing heavily like Darth Vader. His equipment, including a sealed suit designed for underwater dives in the frigid North Sea, weighs 60kg.

Fetid air rises through the pumping plant from below and penetrates the nasal cavities like a rotten egg lodged in the throat. It is the rancid smell of sewage.

Plastic drinks bottles bob next to clusters of Styrofoam cups and the occasional bloated dead rat. The steel platform that lowers the diver is draped with strands of fuzzy sludge. He plunges into the pea-green liquid, releasing ripples in his wake.

Julio César Cu is a sewer diver, submerging into the dark nearly every day to dislodge obstructions from Mexico City’s vast waste water system. Much of the megalopolis’s water infrastructure is decades old. It was designed to handle waste from perhaps 5m inhabitants; more than 20m people now reside in the metropolitan area.

The drains are also taxed by abundant litter. At some reservoirs, Mr Cu encounters layers of rubbish thick enough to walk on. A few years ago, a dam’s outlets became blocked by an actual wall of garbage, 1m tall and 50cm thick. Engineers pondered the problem for several days before calling in a demolition crew to blast the garbage apart with dynamite.

In addition to the waste produced by the copious population, heavy rains overwhelm gutters during the city's months-long wet season. Preventative maintenance is vital to prevent the network collapsing.

In early September, Mr Cu was dispatched to the south side of Mexico City, where heavy rains had caused a river to overflow, sending swift currents of water rushing on to roads, inundating houses and submerging vehicles. In late June, torrential rains overwhelmed the smart neighbourhood of Polanco and created bottlenecks in the Reforma office district. Main thoroughfares became gushing waterways. The subway flooded. Pavements filled with weather refugees.

Some days, like today, Mr Cu retrieves large rocks that block grates. On his worst days, he is sent down to locate corpses.

There is zero visibility in the sludge. He must rely on his sense of touch to distinguish a branch from a pipe or a human limb. His only connections to the world above in those moments are the audio in his helmet (to communicate with colleagues on land) and what Mr Cu calls the “umbilical cord”, a tube that supplies him with oxygen. A cool head is vital when the oxygen tube becomes tangled or ensnared. Unravelling it requires him to retrace his steps with confidence.

Despite the stench and the uncertainty, Mr Cu finds going underwater a zen-like experience. He feels calm and secure — in touch with himself. But the fear is always there.

A scratchy voice calls out on the communications console. “I’m already at the bottom,” Mr Cu informs them from 4m underwater.

“Just be careful, very careful,” a colleague urges.

Mr Cu, 57, has been diving for the city since 1983. The job is rife with hazards. The biggest threat is a cut or puncture wound that could expose the diver to noxious bacteria. A mere 6mm of rubber suit protect him from potential contaminants.

Mr Cu is the only diver working for the water utility. Others have retired or switched professions, while one colleague was swept away when a dam plugged with rubbish suddenly became unplugged. That death persuaded Mr Cu to tighten his safety precautions, but he never considered quitting. Every dive is an adrenaline rush for a man whose childhood dream was to become an aircraft pilot.

There is no manual, per se, for sewage diving. Mr Cu’s training consisted of courses in conventional scuba and industrial diving to learn skills such as underwater welding, plus lots of practice. He is currently teaching two apprentices in the hope of swelling the diving ranks.

Mr Cu can think of other dangerous professions, such as working in a mine. But he can’t think of anyone with a dirtier job than him.

Mr Cu quickly frees the debris underwater and re-emerges, tiny air bubbles heralding his arrival back at the surface. A co-worker dumps a 19-litre bucket of soapy water on him to clear some of the bacteria before another co-worker helps him out of the suit.

The filth is dangerous. Ernesto Huerta, an operator at this plant, tells of a man who picked up a fatal infection while cleaning that same tank. The cleaner had donned protective gear — goggles, a mask, gloves — but did not clean off a drop of water that landed on his cheek. By the time he checked into a hospital a few days later, “the bacteria had eaten his intestines,” Huerta says.

Mr Cu sparks a Marlboro cigarette to decompress after the dive and reflects on the role his job plays in Mexico City. Residents have no idea that water management employees are working round the clock in an effort to prevent floods. “Potable water and drainage are the veins of the city,” he says. “If they fail, the city dies.”

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From the Weathernews headquarters high above Chiba city on a Friday afternoon, the view is blue skies and wispy clouds for 25km back to Tokyo. Daisuke Abe, the company’s chief meteorologist, contemplates this placid scene — and warns of a potentially deadly weekend ahead.

As our interview plays out, Typhoon 18 is being tracked, analysed and forecast on dozens of screens surrounding Mr Abe’s desk. At the same time, a delegation from the organising committee of the Tokyo 2020 Olympics is visiting to learn more about how accurately Mr Abe and his team will be able to forecast the exact timing and volume of precipitation during the games. But the alarming, constantly updating images of the typhoon dominate the room: it is approaching Kyushu, the southernmost of Japan’s four main islands. It may hit the main island — on which Tokyo and the industrial might of central Japan sit — a day later.

As Mr Abe points out, these are events that fully deserve to make meteorologists, along with the government and general population, extremely nervous: in July, when Typhoon 3 crashed on to rural Kyushu, the flooding flattened villages and left 39 dead. Three years earlier, when Typhoons 11 and 12 made back-to-back landfall in the urban sprawl of Hiroshima, the deluge killed 77. Japan has no shortage of violent weather and has always suffered the effects of flooding, but Mr Abe feels his role as the most senior meteorologist in what he claims is the nation’s most accurate forecasting service is becoming even more critical.

As well as the annual typhoon season, Japan is becoming the victim of a phenomenon that Mr Abe and others have learnt to fear as “guerrilla rain” — sudden bursts of heavy precipitation that can bring transport to a halt and cause flash floods which, at their worst, cripple the intricate component supply chains on which Japanese manufacturing depends.

“When I joined 22 years ago, I didn’t often see these sudden, powerful precipitation events,” says Mr Abe, whose official title is chief service officer. “Nowadays, I feel they come every month. The climate is dynamically changing.”

Mr Abe’s obsessive pursuit of ever more accurate rainfall forecasting for corporate customers and the public is woven into the culture of Weathernews: its mission is to provide higher quality information than Japan’s state-run Meteorological Agency. The company, which is private, was founded by Hiro Ishibashi in the mid-1980s as a direct response to a shipping disaster that he felt responsible for: a sudden storm, unpredictable using the tools of the day, sank a cargo vessel he had chartered, costing many lives.

His answer, developed over the intervening three decades, is the immense network of radar stations, satellites, robotic sensors and artificial intelligence-based analytical tools that now give Mr Abe the edge. But even with all that, Mr Abe has pushed for more.

At his insistence, Weathernews has developed a mobile phone app that draws on text descriptions of local weather and the photographs of clouds uploaded — at a rate of 180,000 per day, the company says — by ordinary Japanese people pointing their phones at the sky. By analysing the pictures, words and locations, combined with radar data, the company is on its way to perfecting a system that will provide early warning for guerrilla rain events.

“In the past, sudden severe rain has not been detected because weather radar cannot detect the type of raindrops. But we have done this deal with mobile users that allows us to understand where there is a possibility of such hard rain. We can provide a 50-minute warning in some cases,” Mr Abe says.

At one level, he says, corporate customers’ interest in the accuracy of rain-related forecasts relates to day-to-day commercial concerns — from the cancellation of big sporting events and train services to the number of bento lunch boxes produced and umbrellas stocked in branches of Japan’s convenience stores.

But at a deeper level, companies are worried about what appear to be the increasing costs of flooding. According to land ministry data, between 2007 and 2010 flooding caused Y860bn ($7.6bn) damage across Japan. That rose to Y1.5tn between 2013 and 2016.

Damage peaked with the devastating tsunami of 2011, which claimed more than 18,000 lives. The government puts the repair bill at Y25tn.

An accidental discovery made after the tsunami, however, has created a powerful tool for dealing with future disasters. A study of radar data from a Japanese coastguard vessel that was off the Fukushima coast before the tsunami showed that its collision detection systems “saw” the tsunami approaching the shore. If the same data had been analysed now, it might have provided a far longer evacuation warning.

“In the past, radar was not used to detect tsunamis but we understood that it could be used that way so we put 28 radars around Japan’s coast. Using that data, we can detect one coming at 15km from the coast — that gives 10-15 minutes’ space to evacuate, and that is very valuable for people and industry.”

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Halfway down the river Thames as it stretches out into east London, nine shiny metal domes rear up from the water. The domes are part of the Thames Barrier, a steel wall stretching 520m that can be raised across the river to protect the city from tidal flooding.

But the Thames Barrier, which became operational in 1982 and had been closed 179 times as of October 2017, is ageing. So are seven similar facilities dotted around the river’s estuary and more than 4,000 other flood defence measures such as walls and embankments.

One of the people working on repairing and updating the barrier is Alex Gentleman, a 26-year-old civil engineer and project manager with building contractor Balfour Beatty, who says that, “given changes to climate”, the barrier is being used more than its designers envisaged.

Mr Gentleman has worked on ports, roads and water mains, but for the past two years has been involved in TEAM2100, a £308m, 10-year plan to maintain and upgrade the Thames’ tidal flood defences along 175km of the river, with a view to protecting London until the next century.

According to the UK government, more than 40,000 business properties are at risk from tidal flooding on the Thames. They include sites that are critical to the UK’s infrastructure and economy. Towards the eastern end of the river lies Tilbury, London’s main port. It includes more than 7.5km of quays and more than 500,000 sq m of warehouse space, and serves millions of people across the south-east of England.

Further west, on the other side of the barrier, is Canary Wharf, one of Europe’s most significant financial centres, where pillars of the financial services sector such as banks HSBC and Morgan Stanley and consultants EY have offices.

A tidal flood could cause severe damage to some or all of these industries, along with central London’s tourism and thousands of other businesses that have made their homes along the river. New residential and business developments like Nine Elms, in west London, sit beside the Thames.

Some of the flood defences are old — there are wooden walls, for example, that date back to the 1930s. Decisions have to be made about whether to upgrade or replace them. “From an engineering perspective,” says Mr Gentleman, “although we are not building anything new, it is actually incredibly challenging — in some cases more challenging than having a fresh greenfield site.”

Then there is the question of access. Across the river from Mr Gentleman’s office by the barrier looms an enormous Tate & Lyle sugar refinery. If any work is needed on the flood defences in that area, Mr Gentleman and his team will have to work around the sugar refiners. “Sometimes there is a requirement for us to work from the river as opposed to from the land,” he says — an expensive adaptation.

The problem is particularly acute on the barrier itself. Balfour Beatty can take possession of it to perform work but if it has to be raised in a hurry, then the contractor has to be able to down tools quickly.

Solutions can be surprisingly traditional. Upriver from the barrier, an old timber wall had been showing signs of wear. The ebb and flow of the tides and the buffeting of the waves had exposed the piles at the bottom of the wall. The solution involved mesh bags filled with stone, shipping containers filled with rail ballast and “socks” filled with concrete.

Other techniques, such as using drones, are very 21st century. Historically, wall examinations would have been a time-consuming, labour-intensive task, with inspectors sent out to look over every inch of the flood defences. These days the drones have taken over, flying over the floodwalls and embankments, taking detailed 3D images.

“You can reduce health and safety risks because you don’t have people climbing around on walls,” says Mr Gentleman. “We get really good quality information as well. That information will be useful to the Environment Agency for years to come.”

Mr Gentleman says that the project gives him a lot of satisfaction. “What we do is not in people’s field of vision,” he says. “A lot of what I build is underground. Civil engineers do not get a lot of recognition — if a project like a flood defence works well, people might never know about it.”

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New York is undertaking one of the largest urban flooding protection projects in the world. Originally called the Big U, the 10-mile concept is meant to reshape Manhattan’s coastline to protect the island from dangerous storm surges like those that hit Texas and Florida this August and September.

Business is keenly attuned to the threat. Total economic losses from Hurricane Sandy in 2012 were estimated at $50bn, and New York City accounted for $15bn of that, with the cost to businesses alone reaching $4.5bn.

The first phase of the East Side Coastal Resiliency Project is to protect 2.5 miles of coastline. Also known as the Dryline, it is designed by Bjarke Ingels Group (BIG), a Copenhagen and New York-based architecture practice. Construction is due to begin in 2019, with completion in 2024, and will run from East 25th Street south to Montgomery Street on Manhattan’s east side.

“Our focus quickly became lower Manhattan, given it’s the most dense urban area in the country,” says Jeremy Siegel, who is managing the project for BIG.

The first phase is devoted principally to a residential area, but the second phase and future sections will envelope the Financial District, an engine of the global economy.

There are more than 100m sq ft of commercial office space in Lower Manhattan, an area containing Wall Street and employing 478,000 people in financial services.

“It’s a disruption to economic activity whenever you have a flood,” says Mr Siegel. “With increasing flood events, that becomes an economic disruption that [is] untenable.”

Significant infrastructure projects in New York historically have been top-down affairs, often with devastating consequences for racial minorities and the poor. Robert Moses, the unelected city official who simultaneously held 12 official titles in the mid-20th century, ruthlessly reshaped New York to create “a city of dehumanizing superblocks strangled in ribbons of expressways”, as one New York Times critic put it. His chief opponent was Jane Jacobs and her egalitarian, pro-community activism.

From the outset, BIG was “really focused on the community, protecting the community and dealing with their needs and desires”, Mr Siegel says, particularly the 110,000 residents of public housing that represent “the last bank of affordable housing in lower Manhattan”.

Lilah Mejia, who was until recently the disaster relief co-ordinator for Good Old Lower East Side, a community group that focuses on housing and preservation, says people on the Lower East Side — historically a working-class immigrant community — are often wary of outsiders bearing gifts. “At the beginning we were a little hesitant,” Ms Mejia says, “because our community is being quickly gentrified, so any time you propose beautifying our lands, we think, ‘Oh, you’re trying to displace us’… but they gave the community 95 per cent of what we asked for.”

Mr Siegel, the architect in charge of the project, says all major infrastructure investments should avoid “cutting communities apart and repeating the mistakes of the 20th century”.