22.5' - Significant flooding is occurring. More than a hundred buildings in Petersburg are flooded.
20' - Several city blocks on the south side of Petersburg are flooded. Backwater may also flood portions of the eastern sections of the city.
18' - Water covers the entire runway at Grant County Airport and is in nearby structures. Hundreds of acres of lowlands are flooded. Water approaches homes on the north side of the river in Petersburg.
17' - Water reaches structures at the Grant County Airport. Flooding also begins south of the river on the south side of Petersburg.
15' - Two structures are flooded upstream of Petersburg. Water also approaches the runway at the Petersburg Airport.
14' - Water approaches structures upstream of Petersburg. Water also begins to cover Fish Hatchery Road near the river.
12' - Water overflows the natural banks into nearby lowlands. River Road alongside the river begins to flood in its lowest spots.