A woman was found dead in her car which had crashed into a water-filled ditch at Counter Drain Drove, Tongue End, near Spalding.
Emergency services were called after a passer-by spotted the submerged grey Peugeot at around 9am on Saturday.
The dead woman was 28 years old and from south Lincolnshire. Police were expected to release her identity later today.
There were no other vehicles involved in the accident and nobody else was in the car. Police are trying to find out how and when the car left the road.
The woman is the 65th person to die on Lincolnshire's roads this year.
Anyone with information should contact police on 01522 558855.
Click here to send us a tribute to the dead woman.
The full article contains 131 words and appears in Lincolnshire Free Press newspaper.