A schoolgirl beat competition from across the South East to come up with the best idea for a poster on how to save water.

Rebecka won the top prize of a £5,000 ‘water saving’ garden for her school, St Teresa’s Primary.

Her winning digital poster design is being displayed in the Elstree and Borehamwood areas to create public awareness of the country’s diminishing water resources.

The competition was introduced in school assembly and 100 pupils at St Teresa’s took part.

Affinity Water company asked them to create a poster showing how to save water and help protect local rivers and streams.

“I could see the boundless creativity of the young innovators,” competition judge Rebecca Froud said. “Their ideas show the future is filled with care for the environment by the next generation.”

The youngsters have become “water stewardship champions” to spread public awareness about risk of drought due to changing climate and growing population.

St Teresa’s Primary is having the garden installed in the school grounds in Brook Road while the five runner-up schools get £500 each for education materials. All 117 schools that took part are being given water butts to encourage conservation.

The competition aimed to spark early awareness for generations to come.

But even conscientious suppliers like Affinity and other water companies face leakage of millions of litres a day from mains feeding into homes, schools and businesses.

The company aims to reduce seepage by 20 per cent by 2025, having reduced its daily leakage by 28 million litres so far over the last three years.

The South East region is “in serious water stress”, the company points out. Household demand soaks up a high proportion of the effective rainfall available through groundwater sources, river abstractions, reservoirs and underground storage.

All regions are in “serious water stress”, according to the Environment Agency’s assessment.

Affinity Water supplies 950 million litres a day to a population of 3.8 million in the South East, in areas like Elstree and Borehamwood, as well as parts of north London boroughs such as Barnet, Harrow, Brent and Enfield.