An Unnecessary Tragedy: The Johnstown Flood

May 31, 2014 is the 125th anniversary of the single worst dam failure in the U.S.: the Johnstown Flood. Guest co-author Kenneth E. Smith, P.E. explores how that preventable tragedy illustrates three dangerous dam safety myths

[Countless times in many states over the past decade, whenever I would outline my 1913 research to a local archivist or reference librarian, the first question asked was “Oh, was that the Johnstown Flood?” That has long made me puzzle why the Johnstown Flood—a local disaster in western Pennsylvania—is still so famous around the country whereas the geographically widespread 1913 natural disaster has been so thoroughly forgotten. At the 2014 Operation Stay Afloat conference in Indianapolis in March, a riveting presentation regarding the Johnstown flood, by Indiana Department of Natural Resources engineer Kenneth E. Smith, illuminated why some destruction in Dayton and elsewhere in 1913 was so catastrophic: many levees collapsed with the effect of breaking dams. Worse, as guest co-author Smith points out, a frightening number of dams today are at grave risk of failure—because of three dangerous myths. –T.E.B.]

The Johnstown Flood disaster of May 31, 1889, was the most horrific dam failure in the history of the United States. In about an hour, a monumental wall

The juggernaut flood wave released by the burst South Fork Dam was far faster and more violent than "normal" river flooding, with churning debris, more akin to tornado damage. Artist's conception in Harper's Weekly. Credit: Johnstown Flood Museum.

of water released by the collapse of the South Fork Dam killed over 2,200 men, women, and children in the valley below. Many who were not instantly drowned were trapped in an enormous tangle of wooden debris and barbed wire, and then immolated by fire.

Like the Great Chicago Fire of 1871 or the San Francisco Earthquake of 1906, the Johnstown Flood became an iconic event in our nation's history. While judging past causes using current standards poses risks, the Johnstown Flood provides a classic case study for exploring three very common but false—potentially fatally false—myths about dam safety that are all too persistent today:

·         “The dam is old, so it must be good”

·         “The dam gets inspected by ______, so it must be safe”

·         “I am just the ________, dam safety is someone else’s role, so there is nothing I need to do”

A preventable tragedy

In a river valley on the Appalachian Plateau of western Pennsylvania, the South Fork Dam was built across the steep-sided South Fork of the Little Conemaugh River, by the Commonwealth of Pennsylvania. The dam held 

The earth and rock-fill South Fork Dam (1), as originally designed and built 1838-1854, had safety features expected today, including a principal spillway inlet tower (3), principal spillway outlet (4), plus an auxiliary emergency spillway (2). Credit: Photo by Robert M. Evans of exhibit at Johnstown Flood National Memorial 

back the Western Reservoir, which was later renamed Lake Conemaugh, as a water source for the 103 mile Western Division Section of the Pennsylvania Canal that ran between Johnstown and Pittsburgh. This canal was part of a larger State-funded 391-mile system known as The Main Line of Public Works, which was to connect Philadelphia and Pittsburg (as it was then spelled).

Because construction and filling the reservoir took 15 years (1838 to 1853), by 1854—only a year after its completion—the Pennsylvania and B&O railroads through that part of the state had rendered the canal system obsolete. After the financial failure of the state’s canal system, ownership of the dam changed to private hands several times until the South Fork Fishing & Hunting Club bought it in 1879.

Many nice summer homes were built around the artificial Lake Conemaugh. 

Half a dozen smaller towns were also destroyed by the Johnstown Flood, which was named after the largest city destroyed. Credit: Johnstown Area Heritage Association. 

Below the dam, South Fork Creek flowed north into the Little Conemaugh River, which in turn flowed west through several smaller towns before reaching Johnstown, a city of about 30,000 people. Over 14 river miles, the river steeply descended from above 1,500 feet in elevation above sea level down to nearly 1,100 feet.

At the end of May 1889, an extreme rainfall event dumped between 6 and 10 inches of rain in 24 hours. The water runoff from the 53-square-mile drainage area above the lake exceeded the dam’s spillway capacity. This caused the lake to rise, and water began to flow over the top of the dam. The overtopping

The entire lake drained through the breach in 40 minutes. Credit: Photo by Robert M. Evans of exhibit at Johnstown Flood National Memorial

erosive flow then caused the dam’s earthen embankment to collapse in a classic V-shaped dam failure breach. In only 40 minutes, the entire two-mile–long lake drained through the breach.

Then as now, when dams catastrophically breach, the flood wave that juggernauts downstream is far beyond normally experienced stream flooding. The failure flood wave moves much faster and is far more violent, with churning debris, creating devastation more like tornado damage than “normal” flood damage. The peak flow from the South Fork Dam breach was estimated at 325,000 cubic feet per second, equivalent to 2,430,000 gallons per second. For comparison, that voluminous flow is about four times the average flow over Niagara Falls, or a little over half the average flow of the mighty Mississippi River at its mouth in Baton Rouge, Louisiana.  

Just 57 minutes after the dam overtopped, the flood wave destroyed five small towns before hitting Johnstown 14 miles downstream. At that point, it was a veritable tidal wave: half a mile wide and nearly 40 feet high, it roared downhill 

Locomotives were swept nearly a mile by the force of the powerful flood wave. In the background are the wrecked offices of the Cambria Iron Co. Credit: Johnstown Area Heritage Association.

at 40 miles per hour. Its force swept several 85-ton locomotives nearly a mile away, and completely destroyed four square miles of downtown Johnstown. Entangled in the flood wave’s wreckage were miles of barbed wire from the Gautier Wire Works.

An arch bridge near the downstream side of Johnstown held when hit by the wall of water, logs, chimneys, carriages, and thousands of people. Entangled in barbed wire, the debris piled more than 40 feet high behind the stone bridge and covered 30 acres. Many who survived drowning were trapped in the tangle and did not survive the fires that soon engulfed the debris pile.

Many who were not drowned were trapped in the debris and immolated. Credit: Johnstown Area Heritage Association. Kurz & Allison, color.

Altogether some 1,600 homes were destroyed with $17 million in property damage was done (about $425 million in current value). Worse, death claimed 2,209 people (396 of them children), including 99 whole families. Bodies continued to be found as late as 1911 far downriver.

And it didn’t have to have happened.

Resembling Arlington Cemetery, the Unknown Plot in Johnstown's Grandview Cemetery is dedicated to the 777 Johnstown Flood victims who could not be identified. Credit:Photo by Robert M. Evans

The Johnstown Flood is a tragic case study of the three dam myths that, 125 years later, still stands as a gruesome lesson today.

Myth #1: An old dam is a good dam

By far, the most repeated dangerous dam safety myth is “The dam is old, so it must be good.” It is said all too often by dam owners, local officials, emergency managers, complacent downstream property owners, realtors, contractors, and—sadly—even by a few engineers with little experience in the dam safety profession. This myth, however, was busted by the Johnstown Flood. When the South Fork Dam failed, parts of it were between 35 and 51 years old.

Various records and discussions indicate that the South Fork Dam appears to have been thoughtfully designed. The earthen dam was about 72 feet tall and 930 feet long; it held back a 374 acre lake some 2 miles long up to 1 mile wide. A narrow dirt road allowed people and carriages to travel across the top of the dam. 

The violent Johnstown Flood wave utterly scoured the town of Woodvale out of existence. Credit: Johnstown Area Heritage Association.

The dam was designed with protective features we even today expect to see in dam design. To allow dry season flow for the canal system and to pass routine floods without harming the dam, there was a principal spillway inlet tower with control gates connected to five cast-iron pipes under the dam leading to the canal. An auxiliary spillway system also existed around the right abutment of the dam, set at a level above the normal pool, to carry the water flow from extreme rainfall events. The top of the dam was built higher than the normal pool level, that is, it provided freeboard: vertical margin from the top of the water to the top of the dam. Thus, in addition to allowing a flood to flow out of the spillway system, the freeboard would provide some room for the reservoir level to rise before lake levels overtopped the dam. Some of the design features, however, may have been changed during the construction process, and some planned design features may not have been constructed at all.

Downstream below the dam, the attitude of the townspeople and other stakeholders were summarized by Johnstown Flood survivor Victor Heiser, age 16 at the time of the tragedy:

“When the earthen dam had first been constructed, there had been some apprehension. There was a ninety foot head of water behind the embankment, and only a small spillway had been provided. But the dam had never burst and, with the passage of time, the townspeople, like those who live in the shadow of [the volcano] Vesuvius, grew calloused to the possibility of danger. ‘Some time,’ they thought, ‘That dam will give way, but it won’t ever happen to us.’”

Contrary to this locally believed myth, however, the South Fork dam had deteriorated with age. The dam had received only limited maintenance. Low points had formed in center of the earthen embankment. Trees and woody 

Poor maintenance of the South Fork Dam (in the middle distance behind the Unger house) contributed to its failure. Roots of trees and woody vegetation penetrated the dam and loosened its internal structure. Credit: Johnstown Area Heritage Association. 

vegetation were allowed to grow on the slopes, and their root systems had invaded the compacted earthen fill. Compounding the maintenance problems were poor human choices and modifications. The principal spillway had been abandoned after a fire in the control tower. The original five cast-iron pipes under the dam were removed (unclear why) so there was no longer a readily available feature to draw the lake down for maintenance or as a response to incidents at the structure. The normal water level had raised to the level of the emergency spillway, higher than originally designed. The top of the dam was lowered by a few feet so as to widen the road so two carriages could pass at 

A fish retention screen that easily clogged with debris blocked the auxiliary spillway. Credit: Johnstown Area Heritage Association.

the same time. A fish retention screen had been built across the auxiliary emergency spillway—the only remaining spillway—and it easily plugged with debris.

The combination of poor maintenance and poor human choices combined into a recipe for disaster.

Contrary to myth, Reality #1 is: “Dams deteriorate with age”.

Myth #2: An inspected dam is a safe dam

The second false dam safety myth “The dam gets inspected by ____, so it must be safe” was also busted by the failure of the South Fork Dam. 

Before its failure, the South Fork Dam was observed by various professionals. In 1880 geologist and engineer John Fulton and another engineer P.F. Brendlinger visited the structure and commented on deficiencies they saw, including a series of leaks near the base of the structure. The South Fork Dam Owners, however, did not act upon such warnings of deficiencies by 

Magnitude of devastation on Main Street in downtown Johnstown was akin to tornado damage. Credit: Johnstown Area Heritage Association.

professionals (inspections, to use current terminology). No qualified engineers are known to have monitored any construction repairs or modifications made to the dam. By 1889, an engineer named John Parke did work for the South Fork Club. On the very day the dam failed, in fact, Parke had even ridden his horse to a telegraph office in the town of South Fork to send warnings to Johnstown.

Contrary to myth, Reality #2 is “Inspections alone do not make a dam safe.” The reality was that the South Fork dam owners needed to wisely address the deficiencies found by inspections.

Today the stone arch bridge, where the debris pile formed, still stands and is an important Johnstown landmark. An eternal flame burns nearby in memory

The stone arch bridge downstream of Johnstown held, and the wood and barbed wire debris pile covered 30 acres. Here survivors were clearing the debris pile to search for bodies of friends and family. Credit: Johnstown Area Heritage Association.

of the flood’s victims. Both the bridge and the eternal flame serve as a reminder that inspections alone did not make the South Fork Dam safe.

Similarly, today, it is not uncommon for inspections of the more than 85,000 state-regulated dams in America to identify dam safety deficiencies. Today many stakeholders still hope that private, state, or federal inspections mean their dam is safe. While inspections are essential tools, inspections alone do not make dams safe. 

All too many dams today have deficiencies that owners must address in order to prevent tragedies. Credit: Kenneth E. Smith

Dam owners—the majority of them being private owners—need to be financially prepared for routine maintenance costs and less frequent rehabilitations. They need to act wisely and promptly when inspections note deficiencies in dam safety, and fix those deficiencies. And they need to be prepared to respond to incidents and emergencies at their dam.

Myth #3: Dam safety is someone else’s job

The third false dam safety myth “I am just the ________, dam safety is someone else’s role, so there is nothing I need to do” was also busted by the South Fork dam failure. Stakeholders often fill this blank in with: lake front property owner, realtor, dam owner, downstream resident, contractor, local planning or zoning official. Typically many stakeholders, even private dam owners, hope or assume that someone else is taking care of all aspects of the dam.

Contrary to myth, the Reality #3 is: “We are all stakeholders with a dam safety role to play”.

Years of coordination with state and county emergency management personnel reaffirm what has been heard from dam safety officials around the country: dam safety incidents and emergencies are substantially locally managed events. Especially during heavy regional rainfall potentially affecting many dams, individual incidents are typically coordinated between individual dam owners, their private engineers, county or local emergency management officials, local contractors, local first responders, and downstream property owners at risk. 

Moreover and very sobering: Many dams have been built just slightly smaller than jurisdictional size, in order to avoid being state-regulated. In Indiana, one of the key size criteria is height. Dams built 20 feet or more tall are regulated and need to go through the State’s permitting process. State-regulated dams also then get inspected, and repair of deficiencies are coordinated with the dam owners. Non-regulated dams—those just under 20 feet high (say 19.9 feet high, and also smaller than other size criteria) often do not require permits and thus receive no routine inspections. 

But some of those non-regulated dams may still sit above downstream life and  property, and they often have dam safety deficiencies such as deteriorated or undersized spillway systems that are too small for the job in

Living dangerously today. Credit: Kenneth E. Smith

the event of substantial flooding. Thus, when local officials learn of incidents at non-regulated dams, there is typically no written or documented history for the structure and generally no public or private engineering familiarity with the dam upon which to base an informed local response. For such non-regulated structures, the dam safety role of local stakeholders is more imperative—and more daunting. 

Dam failures and incidents are not just someone else’s problem elsewhere.

Hundreds of dams have failed around the nation. Failures have been documented in every state, the remaining dams continue to age, and the number of deficient dams continue to rise. ASDSO

The Association of State Dam Safety Officials (ASDSO) explains:

Hundreds of dam failures have occurred throughout U.S. history. These failures have caused immense property and environmental damages and have taken thousands of lives. As the nation’s dams age and population increases, the potential for deadly dam failures grows.

No one knows precisely how many dam failures have occurred in the U.S., but they have been documented in every state. From Jan. 1, 2005 through June 2013, state dam safety programs reported 173 dam failures and 587 "incidents" - episodes that, without intervention, would likely have resulted in dam failure.

Even scarier, ASDSO observes:

From 1998 to 2008, the recorded number of deficient dams (those with structural or hydraulic deficiencies leaving them susceptible to failure) rose by 137%—from 1,818 to 4,308. While federally owned dams are in good condition, and there have been modest gains in repair, the number of dams identified as unsafe is increasing at a faster rate than those being repaired.

A further example demonstrating why “We are all stakeholders with a dam safety role to play” is seen in the American Society of Civil Engineers’ (ASCE) report card on America’s infrastructure. Our nation’s dams continue to receive a grade of D. After first noting that the grade is based on eight key criteria

In 2013, the Infrastructure Report Card of the American Society of Civil Engineers gave the nation's dams an overall grade of D.

(capacity, condition, funding, future need, operation and maintenance, public safety, resilience, and innovation), the report card states:

The average age of the 84,000 dams in the country is 52 years old. The nation’s dams are aging and the number of high-hazard dams is on the rise. Many of these dams were built as low-hazard dams protecting undeveloped agricultural land. However, with an increasing population and greater development below dams, the overall number of high-hazard dams continues to increase, to nearly 14,000 in 2012. The number of deficient dams is estimated at more than 4,000, which includes 2,000 deficient high-hazard dams. The Association of State Dam Safety Officials estimates that it will require an investment of $21 billion to repair these aging, yet critical, high-hazard dams.

National Dam Safety Awareness Day

National Dam Safety Awareness Day occurs each year on May 31 to commemorate the tragic failure of the South Fork Dam in Johnstown, Pennsylvania on May 31, 1889. This year’s National Dam Safety Awareness Day marks the 125th anniversary of that tragedy. More than just a historic commemoration, however, National Dam Safety Awareness Day was created 15 years ago (in 1999) to encourage and promote individual and community responsibility, codify best practices for dam safety, and publicize steps stakeholders can take to either prevent or lessen the impact of dam failures.

On May 31 each year, National Dam Safety Awareness Day commemorates the failure of the South Fork Dam and the unnecessary tragedy of the Johnstown Flood. Credit: ASDSO

As the 125^th anniversary of the tragically unnecessary Johnstown Flood approaches at the end of this month, this article honors the 2,209 who perished by publicizing not only their tragic legacy but also their enduring message: that all dam safety stakeholders today—i.e., every one of us—must learn from yesterday to prevent needless recurrence tomorrow.

Kenneth E. Smith gratefully acknowledges two experts instrumental in clarifying his thoughts for his "Stay Afloat 2014" presentation that developed into this article: Robert "Bob" M. Evans, recently retired from Lawson-Fisher Associates, who provided photos, and whose recent trip to Johnstown after years of working on dam rehabilitation projects inspired Smith to start thinking about the legacy of the Johnstown dam failure; and Siavesh Beik, Christopher B. Burke Engineering,who provided valuable background on "beyond minimum standard" concepts being considered or adopted at local ordinance level [see sidebar below].

Per the request of co-author Kenneth E. Smith, the text of this particular installment is in the public domain (excepting for the quotations from other sources and the illustrations).

Kenneth E. Smith, P.E., a Registered Professional Engineer in the State of Indiana with 37 years of experience in water resource engineering, has a B.S. in civil engineering from Valparaiso University and an M.B.A. from Butler University. An Assistant Director of the Division of Water in the Indiana Department of Natural Resources, he is responsible for the Division's Compliance and Projects Branch, which includes the State's Dam and Levee Safety Section, the Project Development Section, the Surveying and Mapping Section, and the Compliance and Enforcement Section. A past president of the Association of State Dam Safety Officials (ASDSO), he also has served on the National Dam Safety Board of Review. He is also a member of the Indiana Silver Jackets, an inter-agency natural hazard mitigation team, working together to protect life, property, and resources, with the vision “Many Agencies, One Solution.” He may be reached through e-mailing me.

Next time: "Magnum Opus" 

SIDEBAR:

Steps communities can take to make dams safer

The recently published Association of State Dam Safety Officials’ (ASDSO) brochure “Living with Dams: Know Your Risks” has many insights for the larger group of dam safety stakeholders.

Some local communities are beginning to expand their stakeholder roles by adopting local ordinances and practices that go beyond existing minimum state standards. They are embracing the approach of No Adverse Impact (NAI) management advocated by the Association of State Flood Plain Managers (ASFPM) to ensure that actions of one individual or group does not adversely impact the property and rights of others.

In brief, some local ordinances have adopted or are considering wording such as the following:

• Proposed New Policy on Dams In ____County
• The following shall be required by ____ County for any proposed new or improvements to any existing dam
• These requirements are in addition to what is normally required by this Ordinance or by State or Federal agencies
• Designs shall at least meet the latest professional best practices
• Prior to local permitting a copy of a long term financial operations, management, and maintenance plan shall be submitted
• And a funded cumulative maintenance escrow account must be established by owner
• A owner’s engineer must develop and submit an Incident and Emergency Action Plan (IEAP), including a detailed dam breach inundation map
• Owners must developed updates of the IEAP every two years
• Owners must conducted periodic exercises of IEAPs at least once every four years
• Unless the Breach Inundation Area is entirely contained within the applicant’s property and/ or contained within the downstream 100-year floodplain
• A copy of recorded downstream flood/inundation easements or a recorded written consent for every property within the potential Breach Inundation Area shall be submitted
• In addition, all affected property owners within the Breach Inundation Area must be notified of a hearing relevant to the proposed added risk
• Following construction,
• routine inspections by the dam owner’s private engineering shall be submitted to ____,
• evidence that any identified maintenance deficiencies have been corrected shall be submitted to the local community

                                                                                                                   - K.E.S.

Selected references

For information about special events being organized for this year’s 125th anniversary of the Johnstown Flood, see the websites of the Johnstown Area Heritage Association, the Johnstown Flood Museum, the U.S. National Park Service Johnstown Flood National Memorial, the Association of State Dam Safety Officials (ASDSO), and the Federal Emergency Management Agency (FEMA). Co-author Kenneth E. Smith also expresses thanks to those organizations for their assistance to him in the preparation of this article and the presentation on which it is based.

The American Society of Civil Engineers (ASCE) 2013 Report Card of America’s Infrastructure that awards an overall grade of D to conditions and capacities of the nation’s dams is here.

The Association of State Dam Safety Officials (ASDSO) has two superb web pages: Dam Safety 101 and Dam Failures and Incidents; the latter includes a link to a list of dam failures since 1869. An eyeball totaling indicates that at least 4,100 people have lost their lives to collapsing dams, and another 1,000 were killed when levees collapsed during or after Hurricane Katrina in 2005.

The website of the Association of State Floodplain Managers (ASFPM)  has a wealth of information, including materials related to No Adverse Impact.

The Federal Emergency Management Agency (FEMA) has several blog posts related to National Dam Safety Awareness Day and the Johnstown Flood, such as “Dam Safety is a Shared Responsibility” for May 30, 2013. Watch for a new blog post in May related to the 125th anniversary of the Johnstown Flood.

The Johnstown Flood Museum has more details about the South Fork Dam Failure here.

A riveting modern book on the Johnstown Flood, still in print, is David McCullough, The Johnstown Flood: The Incredible Story Behind One of the Most Devastating Disasters America Has Ever Known (Simon & Schuster, 1968).

A chilling 2012 study by the National Academies Dam and Levee Safety and Community Resilience: A Vision for Future Practice can be downloaded here.

Another link between the Johnstown Flood and the 1913 Great Easter Flood: The Pittsburgh Gazette Times reported at some length how the city of Johnstown, Pennsylvania, rushed four train cars full of supplies plus about $3,000 in 1913 dollars (equivalent to some $65,000 today) off to flood-stricken Dayton, Ohio, before the end of the first week. For graphic photographs detailing the tragedy in Dayton, see Trudy E. Bell, The Great Dayton Flood of 1913, Arcadia Press 2008. For tornado-like damage testifying to the force of walls of water released by breaking levees, see especially images on pages 20-21, 24, and the entire third chapter "Devastation" pages 51-72.