On this date in 1972, the remnants of Hurricane Agnes produced a deluge in the DC area that resulted in one of the worst flood disasters in the region’s history. As the storm’s moisture surged northward along the Eastern Seaboard, it merged with a second, non-tropical tsorm, unleashing days of relentless rain across the Mid-Atlantic.
“Torrential rains, whipped by heavy winds, caused major flooding in the Washington area last night and sent streams and rivers in central and northern Virginia and central and western Maryland on a rampage as the remnants of Hurricane Agnes swept up the Eastern Seaboard,” The Washington Post wrote on its front page on June 22. “Hundreds of families in Northern Virginia were ordered to abandon their houses and apartments.”
Rainfall totals were extraordinary. A June record 6.11 inches fell in DC on June 21, followed by another 1.41 inches on the 22nd. To the west, totals exceeded a foot in parts of Virginia and Maryland, funneling enormous volumes of water into already swollen rivers and streams.
Here are some select storm totals:
- Chantilly: Around 16 inches
- Westminster, Maryland: 14.68 inches
- Woodstock, Maryland: 13.85 inches
- Dulles Airport: 13.65 inches
- National Airport: 8.16" inches
- Baltimore: 6.81 inches
"In a five-hour period nearly five inches of rain fell at National Airport," Capital Weather's Kevin Ambrose wrote in The Washington Post. "During the downpour, winds backed to northwest and strengthened to tropical storm force, reaching sustained speeds of 43 mph at National Airport, with gusts as high as 49 mph. Trees and branches fell throughout the area and wires snapped in the gale, cutting power and phones for tens of thousands of homes.
The Potomac River bore the brunt of the runoff, reaching a peak streamflow of 359,000 cubic feet per second — roughly 45 times its normal flow. Low-lying areas along the river flooded extensively, with water inundating roads, homes and businesses. Tributaries such as Rock Creek and the Anacostia River also surged, compounding the damage across the metropolitan area. Rock Creek Parkway was closed with cars abandoned all along it. Along the Potomac, Canal Road, the Whitehurst Freeway and parts of Maine and Inependence avenues were closed.
"In Virginia, portions of nearly every major artery were closed due to flooding, including Routes 29-211, Route 7, Route 1, Interstate 66 and Interstate 95. Countless secondary roads were likewise affected," Ambrose wrote. "A bridge on Route 1 in Woodbridge, Virginia was swept away. At least a dozen other bridges were reported damaged.."
The human toll was significant. Sixteen people lost their lives in the region, and widespread evacuations were ordered as floodwaters rose rapidly. President Richard Nixon declared both Virginia and Maryland disaster areas, triggering federal aid and recovery efforts.
Agnes stands as a defining flood event for the DC region, not because of hurricane-force winds, but because of the sheer volume and persistence of rainfall. It remains a benchmark for inland flooding, a reminder that even weakened tropical systems can produce catastrophic impacts far from the coast.
Here are some articles about this event:
- AGNES: 3-DAY FLOOD, 20-YEAR WAKE (from The Post in 1992)
- THE DELUGE THAT TRANSFORMED A TOWN (from The Post in 1992)
- The Wrath of Agnes (from The Post in 1999)
- Hurricane Agnes: A look back after 40 years (from The Post in 2012)
- Retrospective: The Damage Caused by Hurricane Agnes (from Washingtonian in 2012)
- 50th Anniversary of Hurricane Agnes (NOAA)
Here are other notables from this day:
- Average high: 87
- Average low: 69
- Record high: 99 (2012)
- Record low: 51 (1940)
- Record rainfall: 6.11 inches (1972)
