Reopening leisure facilities at Grafham Water would risk bringing in large number of visitors who would park in local villages, its operator Anglian Water has said.
Huntingdon-based Anglian Water closed its water parks, including Grafham, with immediate effect last month in a bid to prevent the spread of coronavirus.
The decision comes as the Government has been pressing for parks to be reopened to provide space for people to get vital exercise.
But Anglian Water said there were major differences between parks in urban areas and those in open countryside like Grafham.
It said ministerial advice on keeping parks open was aimed more at parks in towns and cities where local people had limited access to gardens and the countryside, whereas its reservoirs were rural tourism destinations where residents had access to other open spaces such as public rights of way and the countryside generally.
A spokesman for Anglian Water said: “We realise that many of our customers are disappointed about our parks being closed. We do understand how much people love visiting our green spaces and it has been a difficult decision for us to make.
“Re-opening our parks would attract large numbers of people from out of the area and, following the scenes we’ve all witnessed recently where people have travelled outside of their locality, we need we do all we can to discourage this.”
The spokesman said: “We all need to stay at home where possible, exercise locally and observe social distancing measures. For these reasons, and for the safety of our staff, our parks will remained closed to public access until the national guidance changes.
“We’re sending all our best wishes to our customers and visitors, and look forward to welcoming them back to enjoy our parks again as soon as we can.”
Anglian Water said park areas at reservoirs like Grafham were of a considerable size and were difficult to police, especially in areas like social distancing.
Grafham provides a wide range of leisure facilities and is a top centre for fly fishing and sailing but the closure has led to the cancellation of summer events at Anglian Water’s sites.