Water bottle

#OneLess - Because everything we do touches the ocean 

One Less

Visit the #OneLess website

Refilling from drinking fountain


A healthy ocean makes life on Earth possible, protecting us from the worst impacts of the climate crisis. It has provided half the oxygen we breathe, is home to most of the world’s biodiversity and is a crucial source of protein for billions worldwide. However, plastic pollution continues to accelerate at an alarming rate, threatening the future of the ocean we depend upon.

Single-use plastic bottles are a major contributor to the ocean plastic problem and are one of the most discernible items of litter found in the marine environment, around the world and in London. In the UK alone, almost eight billion single-use plastic bottles are bought every year, with Londoners purchasing 175 single-use plastic water bottles on average per person annually.

London is an estuarine city, directly connected to the ocean via the iconic tidal River Thames, and our actions in this city profoundly impact the ocean. Eradicating single-use plastic water bottles is one of the simplest and most effective things that we can do to support a healthy ocean, and the #OneLess campaign has been leading the charge on this movement in London since 2016.


#OneLess has a vision where unnecessary single-use plastic is a thing of the past, enabling a much cleaner, healthier and resilient future for our ocean. We have taken an experimental, values-based, systems approach to effecting necessary change in London. We have done this through taking a collaborative approach to connect, facilitate and mobilise action at different levels of the system, as well as devising our own interventions to enable long-term change for the state of our ocean. Across the system, we have worked to influence and change policy, drinking water infrastructure, behaviour, institutional practices, and peoples’ deeper held beliefs and values. 


At #OneLess, we create experimental interventions to inject momentum at different levels of the system, in order to enable London to eliminate single-use plastic water bottles. Here are some examples of what we have created:

#OneLess pioneer network 

We created a ‘Pioneer Network’ of businesses, councils, local authorities, academic institutions, emerging innovators, and landmark venues in London, who were all ahead of the curve in voluntarily reducing and eliminating plastic water bottles or encouraging new ways to drink water.

The Pioneer Network acts as a collective movement, supporting early adopters to eliminate bottled water, to learn what’s effective together, to keep momentum on their efforts, and to collaborate on reducing plastic in London. Together our pioneers have removed more than 5 million single-use plastic water bottles to date from their shops, events, venues, and supply chains! Find out how they did it and be inspired to act by reading our case studies.

join the pioneer network 


#OneLess pioneer network

London's drinking fountains 

A major barrier to avoiding the purchase of bottled water was limited access to refill points when out and about in London. In January 2018, #OneLess formed a partnership with the Mayor of London and fountain supplier MIW Water Cooler experts to install London's first modern-day network of drinking fountains across the city. Since then, we've installed 28 drinking fountains across 11 London boroughs. 

The project has been a huge success, with the fountains dispensing the equivalent of 413,790 single-use plastic water bottles to date. The positive uptake of this initial fountain network catalysed a £5 million fund by the Mayor of London and Thames Water to help deliver a further 100 drinking fountains across the city. 

download our guide to installing drinking fountains

Refilling from drinking fountain

Thames bottle monitoring programme

#OneLess is working with project partners and citizen scientists to deepen our understanding of the extent of plastic bottle pollution in the River Thames through our science-based Thames bottle monitoring programme. 

Since April 2016, we have collected and removed more than 100,000 single-use plastic bottles from along the River Thames, of which nearly 50% of the categorised bottles were water bottles. 


Find out more in our report 

Person collecting bottles during a beach clean

Hello London, Goodbye Ocean Plastic initiative 

'Hello London, Goodbye Ocean Plastic' is a campaign to raise awareness about the alternatives to plastic bottled water in London and showcase the visionaries who provide them. 

We've teamed up with some of London's leading visitor attractions, popular destinations and events to encourage Londoners and tourists to drink water the London way and stop using plastic water bottles. 


artwork on bus shelter


#OneLess is hosted by the Zoological Society of London, in partnership with Forum for the Future, The International Programme on the State of the Ocean, and the Thames Estuary Partnership and is working with major London attractions and businesses, to find and implement solutions to eradicate plastic bottled water and enable a refill culture across our city.

#OneLess partners

Humboldt penguins investigate recycled plastic bottles at ZSL London Zoo
ZSL London and Whipsnade Zoos have removed all single-use plastic water bottles from its shelves, as part of the #...


People involved at ZSL: 

Heather Koldewey, Fiona Llewellyn, Shauna Jordan, Surshti Patel and Alice Chamberlain.