Monocacy River near Frederick at Interstate 70

1. 30.00 ftWater reaches the second floor of Gambrill Mill on the Monocacy National Battlefield.
2. 24.00 ftWater approaches Urbana Pike near Monocacy National Battlefield.
3. 21.00 ftMaryland Route 26 is flooded near the Monocacy River bridge.
4. 20.00 ftWater reaches Gambrill Mill on the Monocacy National Battlefield.
5. 17.00 ftSignificant lowland flooding is occurring along the river, with backwater flooding also occurring. Numerous roads are closed. Water is approaching the parking lot at Gambrill Mill on the Monocacy National Battlefield. Backwater flooding from Carroll Creek is likely approaching the underside of the bridge leading to the Frederick city wastewater treatment plant.
6. 16.00 ftMuch of Pinecliff Park and Rivermist Park in Frederick are flooded. Buckeystown Community Park is also flooded with water approaching the parking lot. Waters are also approaching the Frederick city wastewater treatment plant and the Ballenger Creek wastewater treatment plant. Significant backwater flooding is occurring. Several roads will be closed along the river and adjoining creeks.
7. 15.00 ftBoth banks of the river are flooded. Water begins to flood low-lying fields at Monocacy National Battlefield. Water reaches the access road of the Frederick city wastewater treatment plant. Backwater flooding is occurring on several area creeks, particularly Carroll Creek in Frederick.
8. 14.00 ftTwo low-water crossings, one on Michaels Mill Road /State Route 880/ in Buckeystown, and one on Retreat Road north of Frederick, begin to flood.
9. 13.00 ftWater covers portions of Pinecliff Park in southeast Frederick. Water also approaches Rivermist Park in northeast Frederick.
10. 10.00 ftThe east side of the Monocacy River, or left bank, begins to flood east of Frederick. Although no structures are affected, water approaches an access road at Pinecliff Park.
11. 5.00 ftAfter rain events, the river may become hazardous for recreational purposes when stages are over 5 feet.

Chance of flooding, September to November

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 28, 2026.

Most recent crests

• January 10, 2024: 17.75 ft
• September 24, 2021: 19.04 ft
• September 2, 2021: 22.10 ft
• May 1, 2020: 15.83 ft
• May 6, 2019: 16.62 ft
• March 22, 2019: 16.59 ft
• December 17, 2018: 16.38 ft
• November 25, 2018: 15.57 ft
• September 28, 2018: 16.32 ft
• September 10, 2018: 21.36 ft

• UpstreamMonocacy River at Monocacy Blvd. in Frederick
• Bennett Creek at Park Mills
• Soper Branch
• Catoctin Creek Near Middletown
• Monocacy River at Dickerson
• Ten Mile Creek at Clarksburg
• Potomac River at Point of Rocks
• Ten Mile Creek at Boyds

Forecasts by the Middle Atlantic River Forecast Center. Forecasts are issued routinely year-round. Stage may be affected by ice.

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.