Former ‘Bake Off’ front woman and QI host Sandi Toksvig is thought to have claimed a very unique ‘world first’ after headlining a stand-up comedy gig - while standing in the River Chess.

On Monday, May 17, comedian, broadcaster, author and keen environmentalist Sandi led an exclusive comedy gig to a live audience from within the chalk stream, which rises near Chesham and flows all the way to Rickmansworth, through Buckinghamshire and Hertfordshire.

Coined ‘Britain’s Great Barrier Reef’, the beautiful chalk streams, of which many are in the Chilterns, boast clear water from underground springs but are more endangered than both the Bengal tiger and black rhino.

These iconic natural gems are now at risk due to unsustainably high demand for water resulting in groundwater being taken.

SOS: Save Our Streams, a campaign launched by Affinity Water, encourages the public to waste less water by providing tailored water saving support.

Compered by comedian, author and sports pundit Mark Watson, the private, closed event, performed in front of 30 invited VIP guests, also featured support acts, Eshaan Akbar and Helen Arney.

Now Affinity Water is launching its landmark movement, calling on everyone to join these efforts and take action to save chalk streams from the brink by saving 21 million litres per day (less than 10 litres per person, per day).

Shockingly, this is the equivalent of 140 million cups of tea, 37 million pints of water, 262,500 baths of water and 8.4 Olympic swimming pools.

Sandi said: “In my 40-year career I can honestly say I never thought I would be telling jokes standing in a river, but what a fantastic way to draw attention to this extremely important issue – and what a stunning location.

“I am a firm believer that the protection of our environment is a shared responsibility. Having previously lived in a house boat, our waterways have a special place in my heart and I am proud to be helping to raise awareness and understanding of the simple steps we can all take to save these beautiful areas.

“What better way to do it than through entertainment and humour; let’s all ‘stand up for our streams’ and play a part in the protection of these national treasures.”

Jake Rigg, Corporate Affairs Director at Affinity Water said: “Stand-up for Our Streams has been a fantastic, innovative way for us to highlight this major environmental issue facing the UK.

“To help people tackle their water wasting habits we have created SaveOurStreams.co.uk, a new and helpful resource with easy, personalised tips to help us all waste less water, and free water-saving gadgets.”

“Affinity Water is committed to ending unsustainable abstraction from local streams, but it must be a community effort. Saving water at home will help us do this and support our efforts towards a zero-carbon future.”

Event compere Mark Watson added: “It has been a real privilege to be part of this one-of-a-kind event, which has certainly offered a completely new career experience for me.

“Behind the laughter is a very serious message – we need to start treasuring our water now for the precious resource that it is. If no changes are made, by 2025 we will have a shortfall of 43 million litres per day.

“More and more people are understanding the crucial need for environmental protection, but it’s easy to forget what a big impact water waste has on both our carbon footprint and our local environment. Taking action needs to become part of our daily lives so that we can all contribute to the changes we need to see.”