Images posted on social media indicated that the paddock and TV compound had already been affected by accumulated water after a lengthy period of rain in the area caused the level of the river to rise.
Teams are in Imola preparing their garages, engineering trucks and hospitality units ahead of this weekend's Emilia Romagna GP.
The ongoing bad weather has led to speculation that the event could be under threat.
The Emilia Romagna region has been badly affected by storms in recent weeks, and on Monday the Department of Civil Protection issued a red alert warning, suggesting that there will be 100mm of rain through Tuesday and a total of 150mm by late on Wednesday.
Forecasts indicate that it could continue to rain up until Sunday's race day.
A meeting has been held between the National Crisis Unit and local politicians to discuss the situation in the region, with the department noting: "It was shared the possibility that, in the areas affected by the red alert, the mayors could foresee, for tomorrow, the closure of schools and roads most at risk, starting from those near the banks and landslide areas.
"The invitation to citizens is to avoid travel as much as possible and to resort, where possible, to smart working."
Although there are still a couple of days before track action gets underway, the latter suggestion appears to clash with the prospect of thousands of racing fans from Italy and other countries arriving in the area ahead of the race.
There is also a possibility that car parks and spectator areas could not be usable due to being waterlogged.
