But the water company says it has to keep grass short to comply with the law.
More than 1,000 people have signed a petition calling for the utility firm to observe ‘No Mow May’ and ‘Let it Bloom June’ on the Tile Kiln Lane reservoir site near Hornsey Lane.
They say doing so would allow wildflowers and grasses to flourish, with further benefits for insects and further up the food chain.
The campaign on Change.org was set up by Maisie Tomlinson, who lives in Hornsey Lane.
She has gathered support from Liberal Democrat councillor Scott Emery, the Highgate Neighbourhood Forum and local biodiversity organisation Growing Green.
They have asked Thames Water engineers to meet them on site to discuss the issues and any possible compromises but say they have had no response.
Maisie added: “During May, the reservoir becomes an absolute joy, full of wildflowers of all kinds, and brimming with birds and butterflies.
“It’s heartbreaking to see it all stripped away in an afternoon. The fact that so many signatures have been gained shows the strength of local feeling about these small patches of wild biodiversity.”
She said they all understand that the site needs maintenance but that mowing is always “irregular” with flowers sometimes chopped as soon as they appear but not mown at all until late June in other years.
She added: “The reservoir has not been mown this month, which shows it is possible. All we are asking is for an already irregular practice to become a formal policy.”
Britain has lost 97% of its wildflower meadows since the Second World War , which has contributed to a 37% loss in insect life and a 16% decline in birds since the 1970s .
Research by Butterfly Conservation has shown a 93% increase in visits by butterflies to wildflower areas in June, in turn creating a food resource for birds.
Claudia Kretzschmar from Growing Green said: “Letting the reservoir meadow bloom not only is a sight to behold, it also connects green spaces in the neighbourhood, creating a corridor for insects and other species”.
A Thames Water spokesperson said: “While we welcome the interest in the green spaces at our reservoir sites, we need to keep the grass short to comply with the Reservoir Safety Act and be able to comply with their associated inspection regimes.
“We understand neighbours see the grassed areas as a place to encourage biodiversity, but its principal function is as part of the water supply system.
“We need to comply with the law and maintaining safety and operability is the principal concern.”
To sign the petition visit: https://www.change.org/p/save-the-tile-kiln-lane-reservoir-meadow?source_location=search
