Keep in mind that it is mud season in northern NE and it's probably worth sticking to paved roads unless you have 4wd and good ground clearance. The ruts are real.
Flexible brush (https://www.chewy.com/sungrow-food-bowl-water-dispenser/dp/379167) and a hose will blast the junk right off the sump pump. Wear a mask to keep the spray out of your mouth.
What a difference 24 hours makes. We ended up with 3+ feet of water in our yard and 6 feet of water in the basement after Irene. Since then the town of Stowe have upgraded a 3' culvert to a 5' box culvert and replaced a double culvert with a bridge. No flooding and I'm guessing the rainfall surpassed Irene here. There was a lull yesterday afternoon that helped drain some of the water out before it started downpouring again late in the afternoon.