Residents in Louth in Lincolnshire have been warned about possible flooding as water levels rise on the River Lud.
Flood sirens have been sounded in Louth
The Environment Agency sounded flood sirens in Louth and Horncastle early on Monday to give people advance warning.
Officials said levels on the River Lud were rising and residents were being told to protect their homes.
There were also some reports of flooded properties around Middle Rasen. Louth was flooded twice in 2007 during heavy rain in the summer.
An Environment Agency spokesman said: "Just because the sirens stop does not mean the threat of flooding is over. We don't want people to panic but we do want to warn them."
Drivers are being warned of standing water on roads in the Louth area.
Bette, a Louth resident who was flooded twice last year and is facing a further flood threat, said she could not believe the bad weather had returned.
"It is extremely worrying but I imagine there were more than 100 people in the town who didn't get any sleep last night," she said.
A flood warning has also been issued for Stainfield Beck and there is a flood watch in place for the Fossdyke Canal from Torksey Lock to Lincoln.
Brian Kirkham, head of the county's emergency planning, said run-off from fields could also cause some flooding across the county.
He said emergency officials were keeping a watch for possible flooding risk in Horncastle.
Jenny Cooper from Alford Town Council said drains in the town were full and residents were being asked not to use washing machines if possible.
She said sand bags were being handed out to residents who needed them.