Looking for 2017’s answer to the status symbol? Try the water bottle. Yes, a reusable water bottle that you can fill, drink from and use again is the alpha accessory of now. Think of it as the new tote bag: an instant way to signpost that you’re environmentally conscious, while also adding a Insta-friendly fashion statement to your everyday look. It says: “I know *sadface* that by 2050 the amount of plastic will equal the number of fish in the ocean but, hey, I still need to get my two litres of water a day to stay hydrated, k?”

The water bottle has been spotted far beyond the gym this summer – at Glastonbury, where it may well have contained something other than water, and round the pool in the Love Island villa, where contestants had water bottles with their names on. (These were available to buy on the TV show’s app, for £15, with your own name scrawled on the side.) There are currently more than 300,000 posts on Instagram with #waterbottle. Celebrities including Gisele Bündchen, Emily Ratajkowski and Reese Witherspoon tout water bottles by Bkr, Bobble and S’well, and Glamour magazine has declared that the answer to “Still or sparkling?” is now “Tap”.

The S’well gold water bottle. Photograph: S'well

Of course, not all reusable water bottles are equal. To make yours part of a trend, rather than something to leave in the car cup-holder, you’ll want to avoid the ones in the camping department for £1.50. If Chaos is the alpha choice of phone case – about £185, with your initials on it, endorsed by Alexa Chung – S’well is the brand that typifies the designer bottle trend. In 2016, the company – set up by American Sarah Kauss in 2010 – posted revenues of $100m (£77m), up from $10m in 2014. These bottles, which retail for about £20, come in very “now” finishes including palm-tree leaves, emoji-like faces with heart eyes and marble, and keep water cold for 24 hours. Kauss describes the brand as a way to get “a better drinking experience and the opportunity to do a little extra good for the world”.

At Frame, a fashionable gym with branches across London, S’well is the only water bottle for sale. Sophie Allan, the retail buyer, says the gold finish, called “sparkling champagne”, is the most popular. Frame is selling twice as many water bottles this summer as last. Allan says that while the price may sound high, it’s a one-time-only purchase – “there’s great cost-per-wear here”.

BKR water bottle.

The trend is partly down to brands realising the power of the green pound. For a woke consumer who is concerned with their own wellbeing as well as that of the wider world, the guilt at the environmental impact of the 1m plastic bottles bought every minute is real. Millennials are concerned with issues such as sustainability in their shopping choices – in a 2015 survey, 72% of 15-20-year-olds said that they were willing to pay more for environmentally sound products. “I think millennials are typically more environmentally conscious, but they are also massive consumers,” says Allan. “We’re like: ‘Ooh, what else can we buy?’ That’s where stuff like this fits in.”

Hydration has long been fashionable – with the right water bottle a status symbol. See the receptacles of ancient desert explorers filled with precious drinking water and – on a slightly less life-or-death death note – the mineral water boom of the 80s, when the green bottle of Perrier was the mark of an informed, urbane lifestyle, and the mineral water bar that became a destination at the Colette concept store in Paris in the 00s. Drinking loads of water is now a well-established keystone of alpha wellness – Beyoncé says she drinks four and a half litres a day, while Elle MacPherson swallows a mere three. God knows how much Gwyneth Paltrow drinks.

Sass & Belle Flamingo water bottle. Photograph: ASOS

As well as a stealth symbol of your environmental commitment, then, a water bottle signals a gym lifestyle, even if your actual lifestyle is more boxset than boxfit. This plugs into the athleisure trend for fitness-like clothes. “It’s like that guy going for coffee dressed to go to yoga but not going to yoga,” says Mr Porter buyer Daniel Todd. “The gym is now a place to hang out, it’s a lifestyle.” It has to be said that walking around with a S’well bottle – as I do for a weekend – does have a sort of sporty style that’s appealing; my bottle even gets compliments. The fact that the water remains satisfyingly chilled is also pleasing. And saving the environment one sip at a time? Sure, that, too.

Quench your thirst: water bottles for under £10

Flamingos ensure this water bottle is a conversation starter. Sass & Belle flamingo, Asos.com, £7

A dot is displayed here every time the bottle is filled, encouraging you to drink more. Joseph Joseph dot, Selfridges.com, £9

Joseph Joseph water bottle.

This bottle has storage at the bottom, to be filled with healthy snacks. Jerry Tritan, jerrybottle.com, £7.99

A water bottle that comes with added motivational slogan? One for the workouts. Water bottle, hm.com, £6.99

Take Love Island style into your own life with an initialled water bottle. Initial water bottle, newlook.com, £6.99