 Strong swells from the hurricane produced a moderate storm surge which peaked at 8 @.@ 66 feet ( 2 @.@ 64 m ) in Reedy Point . Tides were only slightly above normal , though high surf on top of the storm surge resulted in beach erosion , particularly in Sussex County . Waves of 17 feet ( 5 @.@ 18 m ) in height were reported near the coastline . The high waters breached dunes south of Bethany Beach , and several locations along Delaware Route 1 were flooded . The large circulation of Isabel produced gusty winds across the state , including a maximum of 70 mph ( 113 km / h ) in Delaware Pilot Tower in the Delaware Bay . Onshore , gusts peaked at 62 mph ( 100 km / h ) in Lewes , where sustained winds of 53 mph ( 85 km / h ) were also reported . Precipitation was heavy but sporadic , amounting to a maximum of 1 @.@ 88 inches ( 48 mm ) in Greenwood . Heavy rainfall further inland resulted in moderate to severe river flooding . The Christina River at Cooch 's Bridge crested at 2 @.@ 38 feet ( 0 @.@ 725 m ) above flood stage , and the Red Clay Creek at <unk> crested at roughly 4 inches ( 100 mm ) above flood stage . Runoff from streams were slowed due to the approaching storm surge from the hurricane . 
