There have been fresh flood warnings issued for Sleaford and Ruskington Beck after more heavy rain fell yesterday (Thursday) and overnight leading to the Environment Agency admitting that the river system is "overwhelmed".
Flood warnings are also in place for the Witham and its tributaries between Lincoln and Boston.
The latest warnings were issued last night, meaning that flooding was expected and immediate action was required.
Streams such as the Holdingham Beck, which feeds into the River Slea have already overflowed and the Slea has risen to its highest recorded level.
A statement last night from the Environment Agency said: "Heavy rain has fallen in the Slea catchment and will continue throughout Friday.
"This is causing River Slea to rise to its highest recorded level and is forecast to continue to rise through the night. The rising levels have already caused flooding of low lying gardens and roads in Sleaford, and due to the deteriorating weather conditions we now expect properties in Sleaford to be affected from Thursday onwards.
"Low lying properties near the River Slea, Electric Road Station, West Banks and nearby locations are most at risk. There is also a risk of groundwater flooding from springs emerging from the ground.
"Remain safe and be aware of your local surroundings. Please avoid contact with flood water. Our staff have been out in Sleaford to operate sluices, gates and manage water levels in the area but the river system is now being overwhelmed. We will be closely monitoring the situation."
The Agency said the heavy rainfall over the last 24 hours has caused the Ruskington Beck to rise. Levels are now stable, but remain at levels of concern. Low lying land and roads in the Ruskington area will remain flooded. Low lying properties near the river Ruskington Beck are most at risk.