A specialist command centre has been set up in Sheffield over fears of flooding in the city.
South Yorkshire Police said a Silver Command would be running into the night following a day of torrential rain.
Gary Slatter, control room supervisor, said there were no incidents at present and the situation was being monitored.
Police have advised people to avoid the Meadowhall area because of high water levels on the River Don and a number of flood warnings are in place.
A Silver Command is a hub co-ordinating emergency services and agencies involved in responding to any flooding.
John Roberts, from South Yorkshire Fire and Rescue Service, said the Meadowhall area was the most likely place to flood.
He said: "If Meadowhall remains unaffected then hopefully the rest of South Yorkshire will too."
Meanwhile, a major outdoor pursuits festival due to take place at the weekend has been cancelled due to the weather.
The Cliffhanger Festival in Sheffield was expected to attract about 20,000 visitors, organisers said.
The event, at Graves Park in Sheffield, was to have included rock climbing, mountain biking and running events.
Festival organisers said on the event's website they were "really sorry".
Richard Eyre, head of city centre management and major events at Sheffield City Council, said recent rainfall and more heavy rain forecast for the next few days was to blame.
"We are disappointed to have to make this decision as we know many people were looking forward to the event," said Mr Eyre.
"But staff and public safety must always be our main concern in these cases."
The British Bouldering Championships, due to take place at Graves Park on Saturday and Sunday, would still go ahead, organisers confirmed.
Two other events, the South Yorkshire Orienteers short and park courses, were also still due to take place at the same location at the weekend, they added.
- 6 July 2012