Ashton does notice damage caused by the storm as well as erosion and standing puddles of water. He also notices that none of their passage just hours ago is evident anywhere as it has all been washed away. After providing the food to the others, the farmer begins working to fix the damage and erosion. Further he explains that this kind of damage is fairly typical after one of these big storms that passes through here periodically. He conjectures that the various farms would ceases to be evident if not constantly tended to and that the more fragile crops farmed elsewhere cannot be grown here as they would not survive these rain storms. In fact his herb garden, which he seems to be proud of, has to be grown under a shielding canopy or they would be destroyed. Of course sometimes some of his herbs do get damaged but he usually is able to restore most of them but loses do happen.
With what he can see, and what he is told it is evident to him that unless a raiding party were to have decimated a farm or most of it that much of the damage would have been overlooked. The obvious take away being, who reported the damage as thus far none of the farmers they have talked to indicated they noticed any damage out of the ordinary. Well at least until, they had brought it up.