Flooding a grass field which has never been flooded before

WE have been managing this field for 35 years and there has never been an issue with standing water. Two weeks ago we took the tractor in to mow the grass for hay and got bogged down, we have been unable to mow 1 acre of this field. We know this has been a wet year, but this water is not drying up, and there is a film of oil over it, suggesting to us that it is run off from the road. Last year the road was resurfaced and a new property built opposite with a new driveway, we are concerned that the ditches either side of the road have been compromised in some way and the water that usually runs down them is now flowing in to our field.