The Flood of March 17-19 1936

Some call it the “Record Flood of 1936.” Others refer to it as the “Great Potomac Flood.” Still others noted it as the “Saint Patrick’s Day Flood of 1936.”  No matter what you call it, one of the region’s worst natural disasters took shape 80 years ago.   According to figures from the U.S. Census Bureau, nearly 97 percent of us weren’t alive when this event occurred. Given that an event of this magnitude has not happened since – in the case of the Potomac River, nothing even close since 1942 – it is important to look back on what happened, why it happened, and the likelihood that it will happen again.

For something that happened so long ago, a surprisingly good archive of the event exists, between National Weather Service files and newspaper archives, a wide-ranging USGS/Weather Bureau joint report on the flood, and many intermediate retrospectives which have been compiled since.

How It Happened

Oftentimes, a flood event occurring in this time of year might be at least partially caused by snowmelt.  In fact, February 1936 was cold, with lows below zero several times in the mountains of West Virginia, and a fairly persistent (though not major) snowpack. Conditions changed toward the end of February, though, with a substantial warmup melting much of the snowpack in a gradual manner.  DC and Baltimore ended February with no snow on the ground; even further west in Dale Enterprise (Rockingham County) and Wardensville (Hardy County) there was just a trace.

March was quite a warm month, with highs in the 60s fairly common, and only short-lived light snow events. But the weather pattern was unsettled. By mid-month, Baltimore, Washington, and many other areas had already seen nearly the entire normal rainfall for the month of March.   Much of that fell on March 11^th, as a storm that had developed in the Gulf of Mexico swung northward along the coast, then moved from the Outer Banks right up the Chesapeake Bay, intensifying as it moved north.  Rain totals of 2 to 3 inches were common, generally not enough to cause flooding but certainly enough to elevate streams in advance of what was to come.

As the name implies, the storm took shape on Saint Patrick’s Day (March 17^th) 1936, with a deepening low pressure in the Carolinas and strong clash of warm and cold air right through the mid-Atlantic region.  Deep, strong southeasterly winds pumped Atlantic moisture into the region, with morning temperatures around 60 degrees. The heaviest rains (and some wraparound snow at the end) fell along and west of the Blue Ridge Mountains.  In fact, the metro areas generally saw less than an inch of rain. But totals further west were 5 inches or greater in many areas, including the following:

Post-analysis from the United States Geological Survey showed that almost all of this rain turned to runoff and immediately went into the streams, with very little soaking into the ground west of the Blue Ridge. This led to the substantial flooding which occurred.

Although most areas were snow-free prior to the storm, there was a limited snowpack of 3-6 inches on the ground in Shenandoah National Park and in the Allegheny Mountains. This, however, added only minimally to the flood.  In fact, due to wraparound snowfall at the end of the storm, some areas of the Potomac Highlands actually had more snow on the ground after the storm than before.

What Happened

Although much of the focus of this event was on the Potomac River, impacts were actually felt throughout a larger swath of the area. Impacts for individual locations follow:

Cumberland, Maryland

The town of Cumberland was severely damaged by this storm.  This image from the Washington Herald shows some of the flooding. On Wednesday, March 18^th, the front page of the Cumberland Evening Times read: “Cumberland’s Worst Flood Paralyses Downtown Shops.” An employee at the Academy Cigar Store was swept out of a window of the shop after the force of the water broke open the store’s windows. The man was rescued from the floodwaters by rope from persons on the second floor of a nearby drugstore, and amazingly suffered only cuts and bruises. Several others in Cumberland suffered worse injuries. Flood damage in Cumberland alone was estimated at $3 million (factoring in inflation, that would be over $50 million in today’s dollars).  Only two businesses in Cumberland were known to have flood insurance, according to the Evening Times. 

Governor Harry Nice declared a bank holiday in Allegany County due to the flood damage and called the Maryland National Guard to Cumberland to assist.  Flood waters were reported to be “up to the counters of every bank in the city, with only one exception.” Declaring the bank holiday required the Maryland general assembly to act, as prior to this, state law only allowed for statewide bank holidays to be declared. This was the first time it was declared for only one county.

“The tremendous destruction around the City Hall and on Centre and Mechanic streets southward is evidenced by slime and mud overspreading everything, store fronts missing, glass cracked, and stock or equipment cleaned out and washed away as if some giant hand had reached in and tore it asunder.”  -Quote from Cumberland Evening Times

Dozens of businesses and homes were damaged, along with substantial infrastructure, including sewer and water systems and streets.

Both immediate and long-term response were swift. Plans to prevent future flooding began to be formulated within a week of the flood, and Congress authorized the Cumberland-Ridgeley Flood Risk Management Project just three months later, as part of the Flood Control Act of June 22, 1936.  The resulting levee system has prevented an estimated $38 million in damages since its completion, more than twice what it cost to build.

Morgan & Hampshire Counties, West Virginia

Almost every bridge in Morgan County was washed out by the flood, even those on tributaries of the Potomac. Berkeley Springs was totally inundated by Warm Springs Run, with a scope of flooding that was not even approached again until 2012. The Cacapon River set a record which still stands today, cresting above 30 feet, more than 20 feet above flood stage, and six feet higher than the Great Flood of 1889.  The river was reported to stretch “from mountain to mountain.” The Potomac was twenty feet over its banks. Around a dozen buildings in Paw Paw were swept downriver. People went from house to house by boat searching for stranded persons.

Virtually every tributary stream was out of its banks, sweeping clubhouses and property with the high water. The 65-mile trek from Romney to Martinsburg by car reportedly took one motorist seven hours to complete due to washed out roads.

Hancock, Maryland

The town of Hancock suffered substantial damage. A record flood of 47.6 feet – more than 17 feet above flood stage – swept through the town, breaking buildings apart, damaging roadways, and causing buildings and homes to float downstream. An emergency center was set up in the Hancock Fire Hall for the 150 people left homeless by the flood. The entire town was without electricity. One resident told The Hancock News, “we could have reached out from the boat and touched the electric wires” because the water was so high. The depth of the water along Main Street in Hancock was reported to be as much as 15 feet in spots.

Hancock did get some warning of what was to come as word came from Cumberland of what was happening there.

 “…we are surrounded by oceans of water, in fact we are working to get out this issue with at least 12 feet of water under our plant.” – Quote from The Hancock News

The center span of the bridge connecting Hancock to West Virginia washed away, and the bridge was not rebuilt until 1939.  That bridge – on present-day US 522 – still stands today and is used by thousands of cars daily.  Nearby, the National Highway was severely damaged by flooding of Sideling Creek and Tonoloway Creek.

Williamsport, Maryland

The Potomac reached an incredible 48.6 feet in Williamsport, three feet higher than the 1889 flood.  Amazingly, the bridge crossing between Williamsport and West Virginia survived the 1936 flood unscathed – the only bridge between Cumberland and Washington DC to be so lucky.  In fact, thousands paid a 10-cent toll to be able to use that bridge to see the powerful floodwaters.

The town was not as fortunate. Even at a level 10 feet lower than the peak, buildings and river cabins were being swept downriver. Animals were reported to be in or on some of the structures as they floated down. The high water forced the Potomac-Edison power plant to shut down, after more than 3 million gallons of water inundated the condenser pit, leaving thousands in the dark. The lack of electricity, in turn, forced the Hagerstown water pumping plant to be unable to pump water, leaving thousands without water to drink. Officials said the drinking water supply would be affected for at least a month.

In addition to the Potomac floodwaters, the Conococheague Creek was also in flood for the second time in a week, adding to the issues.

Shepherdstown, West Virginia

The toll bridge connecting Shepherdstown to Maryland, which had been rebuilt after the 1889 flood, was destroyed by the floodwaters of 1936 as well. A ferry had to replace the river crossing for three years until the bridge could be rebuilt.  The Potomac peaked at 42.07 feet, about three feet higher than 1889. While far more substantial than the other two, this was the third flood at Shepherdstown in three weeks – first the ice/snow melt flood in late February, and then a minor flood a week earlier from the previous storm.

Harpers Ferry, West Virginia

Two bridges were lost forever in the floods of 1936. The longstanding Bollman Bridge was built in 1852, and severely damaged by the 1924 flood.  The 1936 flood did it in permanently.  The Shenandoah River bridge, which connected “The Point” in Harpers Ferry to the other side of the Shenandoah, was built in 1882, swept away in the 1889 flood and rebuilt, and destroyed for good in the 1936 flood. The piers of the Shenandoah Bridge can still be found in the river today. The so-called “Sandy Hook” bridge, connecting Maryland and Harpers Ferry, was not rebuilt until 1947.

Many businesses in Lower Town Harpers Ferry were devastated by the 1936 flood and the flood essentially put an end to manufacturing and commercial development in that area. But the flood led to events that changed the area forever – Congressman Jennings Randolph recommended the National Park Service survey the area the following year; and in 1944 President Franklin Roosevelt established Harpers Ferry National Monument, the precursor to today’s Harpers Ferry National Historical Park.

Brunswick, Maryland

The worst flood ever observed in Brunswick left the mill and roundhouse areas of Brunswick flooded. The bridge over the Potomac, built in 1893, was damaged and was not fully repaired for over four years. Ferry service kept people and commerce moving in the meantime. The B&O passenger rail station was flooded and the railyards there were covered by water. Eight families had to abandon their homes.

Point of Rocks, Maryland

The bridge connecting Maryland and Virginia at Point of Rocks, which had been built following the Civil War, was destroyed, with six of the eight spans of the bridge being carried away. The new bridge, built after the 1936 flood, still stands today. The Railroad Station there, which dates back to 1873, survived but was flooded. Boats became the preferred mode of transportation through town, with the flood the most severe on record. 26 homes and businesses, the post office, and the only two churches in town, suffered flood damage.

At the time, people spent time and even lived on the islands in the Potomac. Heaters Island, the large landmass visible from Point of Rocks in the Potomac River, flooded, with water reaching the second story of a house on the island. Several people had to be rescued.

Further downstream, rescues also occurred on Mason Island, just north of Whites Ferry; and Harrison Island, just south of Whites Ferry.   Coast Guard members from Baltimore assisted in the rescues, and the rescue from Harrison Island was hampered when the boat being used for the rescue crashed into a tree and had to be repaired.

Washington, DC

The deep southeasterly winds with the St. Patrick’s Day storm led to minor flooding in Washington DC near East Potomac Park, but minimal impacts, on St. Patrick’s Day itself. However, the freshwater from upstream began arriving less than 24 hours later, with water levels reaching moderate flood on the afternoon of the 18^th and major flood by the morning of the 19^th.  The tide gauge near Hains Point peaked at 10.55 feet, which was the highest level ever recorded at the time, and remains the 2^nd highest on record even today (behind the October storm of 1942).

Flood waters crested at Key Bridge at 18.5 feet. Much of Potomac Park was underwater and the Civilian Conservation Corps (CCC) had to construct a temporary levee on the north side of the Reflecting Pool to keep water from spreading further into the city. It worked, but there was still flooding south of the levee which affected the tidal basin, killing some of the signature cherry trees.  When the Flood Control Act of 1936 (referenced earlier) was passed by Congress, it authorized making the efforts of the temporary levee permanent.  An earthen berm was built to the north of the Reflecting Pool in 1939. 

The Washington-Hoover Airport, the predecessor to today’s Reagan National Airport, which sat on the current location of The Pentagon, flooded with up to 6 feet of water. Commercial air service had to be diverted to Logan Field in Baltimore.  Three airport employees tried to boat across the airport grounds to rescue employees stuck in the administration building. Their watercraft capsized when it encountered a swift drainage current – two of the three swam to safety; the third had to be rescued and hospitalized.

Hains Point was unrecognizable – only treetops and the tea house were visible.  For a time, only Key Bridge was open to connect Virginia to DC.  The Navy Yard, Army War College, Naval Air Station, and Bolling Field all flooded significantly. 6 feet of water covered the aptly-named Water Street in Georgetown, and water reached the second-floor ballroom at the Washington Canoe Club.  Hundreds of thousands of dollars in damage occurred, and the damage and cleanup threatened the annual Cherry Blossom Festival from being able to be held.

The Washington Post described onlookers viewing the flood from Key Bridge as follows:

“Looking over the parapet of the bridge, they beheld a wild scene – a boiling current, rushing toward the bay, and carrying with it small yachts and houseboats, cottages and shacks, beds and ice boxes, and a pitiful array of drowned animals and birds.”

The Evening Star reported the aftermath like this:

“Early today groups of riverside residents, who had lost all they owned, warmed their hands over bonfires on the ridge separating the Chesapeake & Ohio Canal from the river. The ridge was piled high with canoes, furniture, and clothes. At one point on the road which skirts the canal a cottage was thrown against a lamppost. It was estimated that 35 cottages were either swept away or smashed to bits.”

An event of this magnitude is so rare that it statistically has less than a 1% chance of occurring in a given year.

Below Washington, DC

In the tidal zone below Washington, DC, the river widened enough to experience virtually no impact. Even at Alexandria, where flooding did occur, the damage estimates were less than $10,000. At Indian Head, the flood peak was only 3.8 feet, barely noticeable. In these areas, water levels were actually higher during the St. Patrick’s Day tidal surge than from the freshwater flood.

Learning From Floods

Each flood offers an opportunity to learn something and make changes to lessen the risk of future flooding. The levees built as a result of the Flood Control Act of 1936 are still helping protect residents and critical assets today. But lessons had been learned even before 1936. Samuel Lubell wrote in The Washington Post:

“The surprising feature of Washington’s great flood of 1936, as the Potomac’s rampage on Thursday has come to be known, was, paradoxically, the total lack of surprises. The flood arrived on schedule, inundated the areas it was expected to flood, rose to a crest as high as 1899, as was predicted, and departed on schedule – presenting in all a striking contrast to 47 years ago, when a similar volume of water turned part of Pennsylvania Avenue into a canal and left damage estimated at $1,000,000 in its wake.”

A plan was put in place between District and Federal officials in 1930; the plan was utilized in 1936; and limited the damage to less than half what occurred in 1889.

References/Acknowledgments

Information contained within this retrospective was collated from:

• U.S. Weather Bureau archives and Daily Weather Maps
• multiple newspaper sources, including the Washington Herald, Cumberland Evening Times, Hancock News, Evening Star, Washington Post, and others.
• Harpers Ferry National Historical Park
• Library of Congress
• Geological Survey Paper #800, "The Floods of March 1936, Part 3"