Potomac River near Washington DC (Little Falls), MD

The last 7 days and the forecast

NWS forecast issued Mon, Oct 12, 8:57 PM. Forecasts change as rain falls and as upstream water arrives.

Flood stages

What floods at each level

From the National Weather Service, highest first.

• 17 ftWater overflows the overlooks at Great Falls National Park and approaches the lower level of the visitors center. Most of the C&O Canal towpath downstream of Pennyfield is flooded. There is approximately a foot of water in the clubhouse on Sycamore Island.
• 16 ftWater reaches the clubhouse on Sycamore Island.
• 15 ftMost of the C&O Canal towpath from Pennyfield downstream is flooded.
• 14 ftSignificant portions of the C&O Canal towpath are flooded. The Blockhouse Point Park is flooded. Water reaches the retaining wall at Overlook 1 at Great Falls National Park but does not overtop it.
• 12 ftThe C&O Canal overflows at the Great Falls Tavern. Water covers the towpath in many areas.
• 11.5 ftWater covers the towpath in multiple spots between the Washington Aqueduct Dam and Pennyfield Lock, mileposts 15 to 19 on the C&O Canal.
• 11 ftWater covers the towpath between Swains Lock and Pennyfield Lock, mileposts 17 to 19 on the C&O Canal.
• 10 ftWater begins to overflow the banks into low lying areas on the Maryland side of the river near Little Falls. Water begins to enter the canoe shed at Sycamore Island.
• 9 ftSeveral trails on both sides of the river between Great Falls and the Chain Bridge are flooded and will be closed.
• 7 ftUpper portions of the River Trail at Great Falls National Park begin to flood and will be closed.
• 5.5 ftWater reaches the top of the ferry landing for Sycamore Island. Ferry service to the island will likely be suspended.
• 5 ftPortions of the Potomac Heritage Trail begin to flood. Water begins to affect portions of the Billy Goat Trail between Great Falls and Carderock. These trails will be closed.
• 4.5 ftThe river reaches danger level for boaters, as defined by the State of Maryland. Conditions for boating will be extremely hazardous.
• 3.5 ftThe river reaches caution level for boaters, as defined by the State of Maryland. Fast moving water and changing currents will be experienced.

Highest crests on record

1. 22.03 ft — June 24, 1972
2. 19.29 ft — January 21, 1996
3. 17.99 ft — November 7, 1985
4. 17.84 ft — September 8, 1996
5. 13.73 ft — February 16, 1984

Recent crests: 11.73 ft (May 16, 2025) · 10.16 ft (May 9, 2022) · 11.56 ft (December 17, 2018) · 11.01 ft (September 29, 2018) · 10.85 ft (September 11, 2018)

Up and down the river, and nearby

• UpstreamPotomac River at Edwards Ferry, MD
• DownstreamPotomac River at Georgetown / Wisconsin Ave, DC
• Dead Run near McLean, VA
• Rock Creek at Joyce Road in Washington, DC
• Difficult Run near Great Falls, VA
• Sligo Creek near Takoma Park, MD
• Four Mile Run at Alexandria, VA
• Turkey Branch near Aspen Hill, MD
• Anacostia River at Buzzard Point in Washington DC, DC