Richmond Park has been known for its rich wildlife and tranquil landscape for hundreds of years, but the controversial expansion of Heathrow airport will mean hundreds of aircraft flying at low altitude over the royal park, according to consultation documents issued by the airport.

Maps of the new flight paths released as part of the consultation process for a third runway reveal the extent of proposed air traffic over the park, with some aircraft flying as low as 300 metres (1,000ft). Current flight paths to Heathrow are not routed directly over the park.

The Heathrow Airspace and Future Operations consultation, which follows MPs’ approval of the third runway last year, indicates that 47 arrivals an hour and between 17 and 47 departures would fly directly over the park at below 900 metres. Heathrow’s flights are currently capped at 480,000 a year, but it wants to increase this by 25,000 in 2021 and further when the third runway is built.

Environmental campaigners say the noise and pollution will be disastrous for the sensitive wildlife and the tranquillity of an area visited by more than 5.5 million people a year. Thousands of nocturnal animals – including 11 of the UK’s 17 bat species, all of which are protected by law, and little and tawny owls – the park will be threatened, they say.

The park, which stretches over 1,000 hectares (2,500 acres), is a site of special scientific interest, a national nature reserve and a European conservation area. Sir David Attenborough said in a recent documentary that the largest royal park in the capital was home to thousands of wildlife species supported by the sensitive and legally protected acid grasslands.

The changes to flight paths will start in 2021, because Heathrow plans to increase flights by 25,000 a year ibefore the proposed third runway is built, and will be adopted in full on completion of the third runway in 2026.

Heathrow, which is owned by Heathrow Airports Holdings Ltd, has placed noise monitors across the park in preparation for the proposed flights.

Ron Compton, the chairman of Friends of Richmond Park, said: “It is disastrous. It is shocking to see the potential impact the proposed flight paths could have on Richmond Park and its wonderful wildlife and environment so treasured by millions.

“The park is the darkest and the quietest place in London and this will be shattered by these new flight paths. Increasingly, medical experts and even government bodies recognise the important value of green, quiet open spaces to the nation’s physical and mental health. We call on all the millions of visitors who treasure the park to protest against these proposals.”

The royal park was established by Kings Charles I as a hunting ground in the 17th century. Attenborough said in his documentary that steps had to be taken to protect the park from the impact of increased human activity.

The expansion of Heathrow airport from two to three runways will be challenged next month in a judicial review that will involve five separate legal challenges.

Five councils – Hillingdon, Hammersmith and Fulham, Richmond, Wandsworth and Windsor and Maidenhead – Greenpeace and the mayor of London, Sadiq Khan, are involved in the legal fight to stop the third runway being built.

A spokesperson for Khan said: “Sadiq has serious concerns about the impact of a third runway on air quality, noise pollution and public transport.

“That’s why the mayor has joined councils and Greenpeace in taking legal action against the additional runway at Heathrow. He is hoping the government sees sense and doesn’t proceed with the plans that will be damaging for our city and for the wellbeing of Londoners.”

Friends of the Earth revealed this week that almost 2,000 locations in England and Wales had illegal air pollution levels from transport emissions, most of them in London.

Paul McGuinness, the chair of the No 3rd Runway Coalition, said the expansion would mean poorer air quality and increased noise.

“Operations at Heathrow, which is already – statistically – the world’s most highly disruptive airport, have been keeping its residents up at night for years. And it’s now proposed that their treasured spots of tranquillity should be overflown, at low altitudes as well.

“The price that Heathrow is demanding of residents, so that it can increase its operations by over a whole half again, is simply disproportionate and unacceptable.”

A Heathrow spokesperson said: “Our consultation is an opportunity for local communities to share their views on our proposals and the potential impact. Feedback from this consultation, together with our design principles and technical requirements, will be used to develop our flight path options. These will be the proposed routes that aircraft will fly and we plan to hold a further consultation on our preferred options.”

The consultation closes for feedback at midnight on 4 March.