Britain’s only planned new island community has reached completion.

Work to develop St Mary’s Island in Chatham has finished after almost 30 years.

The site, previously part of Chatham Dockyard, has been transformed into 1,700 homes for about 5,000 people, along with a primary school, parks, community centre and doctor’s surgery.

The 150-acre estate has been built by developer Countryside Homes, part of the Vistry Group, in partnership with government housing agency Homes England.

After Chatham Dockyard closed in 1984, the site known as today’s St Mary’s Island was set aside for residential-led development, with planning permission granted in 1996.

Work got underway in 1998 and reached completion in March this year, and the final new homes were occupied over the summer.

Last month a celebration event took place at Copper Rivet Distillery, attended by key people who have been involved in the 26-year project.

Stephen Teagle, chief executive at Countryside Partnerships, said: “Our celebration event was a wonderful way to mark the end of this hugely significant regeneration project.

“Creating a new community on this scale is an immense task and it was a privilege to come together with organisations and individuals who have been involved with the project over those years and reflect on what we have achieved here.”

Alison Crofton, chief property officer at Homes England, commented: “The completion of the St Mary’s project signals the culmination of a 30-year project to completely transform Chatham Maritime, from disused, contaminated land to a thriving new neighbourhood.”

Cllr Simon Curry, Medway Council’s portfolio holder for regeneration, added: “It has been great seeing the development at St Mary’s Island progress over the years, and I am delighted for all those involved in its successful completion.

“It’s a remarkable transformation of a historically significant area, which has come during the 40th anniversary of the closure of Chatham Dockyard.”

Once marshy land, St Mary’s Island became part of Chatham Dockyard in the mid-19th century to cater for the Royal Navy’s growing operations.

This left a legacy of heavy contamination, leading to a major clean-up with almost 1.5 million tonnes of soil removed before housebuilding could begin in the 1990s.

Non-profit organisation Chatham Maritime Trust acts as the long-term ‘caretaker’ of the island, responsible for the estate’s management and maintenance.