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Dam Safety Awareness Commemorates an Epic Flood

The Johnstown Flood of 1889

It had been raining heavily for several days in late May of 1889. People living below in the narrow Conemaugh Valley were eager for the spring rains to end. Just a month earlier, deep snow had lined the steep ravines of the Allegheny Mountains range and the ground was sodden with the heavy spring runoff. Floodwaters at the South Fork Dam high above the City of Johnstown, Pennsylvania were causing the lake level to rise, threatening to overtop the large earth embankment dam.

As the spring rains continued, life was about to change for the working-class city of 30,000 and other communities beneath the South Fork Dam.

Originally constructed in 1852, the South Fork Dam provided a source of water for a division of the Pennsylvania Canal. After a minor breach in 1862, the dam was hastily rebuilt creating Lake Conemaugh. By 1881, the dam was owned and maintained by the South Fork Fishing and Hunting Club, who created a recreational area by the large lake, enjoyed by their elite clientele from nearby Pittsburgh.

For the pleasure of their private members, club owners soon began modifications to the dam. Fish screens were installed across the spillway to keep the expensive game fish from escaping. The dam was lowered by a few feet so that two carriages could navigate the carriage road to the clubhouse. Relief pipes and valves that controlled the water level and spill off from the original dam were sold off for scrap, and rustic cottages were built nearby.

Ignored Warnings

Notoriously leaky, repairs to the earthen dam had been neglected for years. As torrential rains came down, swollen waters from the lake put tremendous pressure on the poorly maintained dam. With fish screens trapping debris that kept the spillway from flowing and with no other way to control the lake level, the water kept rising.

Club officials struggled to reinforce the earthen dam, but it continued to disintegrate. When the lake’s water began to pour over the top, it was apparent that a catastrophic collapse was inevitable and imminent. Frantic riders were sent down the valley to alert the local communities and tell them to evacuate. Sadly, few residents heeded the alarm being so often used to the minor seasonal flooding from the Little Conemaugh river.

This time, however, the flood danger was much more serious and deadly.

On May 31, 1889 at 3:10pm, the South Fork Dam washed away, leaving a wake of destruction that killed 2,209 people and wiped the City of Johnstown off the map forever. It took only 10 minutes for the raging torrent of 20 million tons or about 4.8 billion gallons of water to rip through the communities of South Fork, Mineral Point, Woodvale, and East Conemaugh.

Along the way, the deluge accumulated everything in its path, including all sorts of debris—from city buildings, houses, and barns. Piles of boulders, trees, farm equipment, rolls of barbed wire, horse carriages, and railroad cars churned in the turmoil. Embroiled in the devastation were also animals and people—both dead and alive.

By the time the raging waters reached Johnstown at 4:07 pm, the mass of debris was a wave 45-feet-tall, nearly a half mile wide and traveling at 40 miles per hour.

Despite the shocking immensity of this tragedy, relief efforts to the ravaged communities began almost immediately. Emergency shelters for homeless residents popped up and the grim task of cleaning up began. Volunteers and donations poured in from across the country and world, sending tons of supplies and help. One of the first to arrive was Clara Barton, who had founded the American Red Cross just a few years earlier.

It would take months to sift through all the wreckage to find the bodies and years to fully recover from the aftermath.

Lessons Learned

It is widely thought the South Fork Fishing and Hunting Club was to blame for the catastrophic failure of the South Fork Dam. Members of the club neglected to properly maintain the dam and made numerous dangerous modifications. Lowering the dam crest to only about four feet above the spillway severely impaired the ability of the structure to withhold stormwater overflow. The missing discharge pipes and relief valves prevented the reservoir from being drained for repairs and the elaborate fish screens clogged the spillway with debris. The club had also been warned by engineers that the dam was unsafe.

A hydraulic analysis published in 2016 confirmed what had long been suspected, that the changes made to the dam by the South Fork Fishing and Hunting Club severely reduced the ability of the dam to withstand major storms.¹

The South Fork Dam was simply unable to withstand the large volume of stormwater that occurred on that fateful day on May 31, 1889.

Although the South Fork Fishing and Hunting Club failed to maintain the dam, club members were never legally held responsible for the Johnstown Flood after successfully arguing that the disaster was an “act of God.”

Due to what many perceived as an injustice and outrage towards the wealthy club members, American law was ultimately challenged and “a non-negligent defendant could be held liable for damage caused by the unnatural use of land”. This legal action eventually imposed laws for the acceptance of strict liability for damages and loss.

National Dam Safety Awareness Day

On May 31^st, we commemorate the catastrophic failure of the South Fork Dam by recognizing this day as National Dam Safety Awareness Day.

The Johnstown flood or the Great Flood of 1889, as it was later known as, was the single deadliest disaster in the U.S at the time. This tragedy, 129 years later, is still a harsh reminder of the critical importance of the proper maintenance and safe operation of dams.

Earth embankment dams may fail due to overtopping by flood water, erosion of the spillway discharge channel, seepage, settling, and cracking or movement of the embankment.

Routine dam evaluations and inspections, as required by law, can identify problems with dams before conditions become unsafe. Dams embankments, gatehouses and spillways, like other structures, can deteriorate due to weather, vandalism, and animal activity. Qualified engineering firms can perform soil borings, soil testing, stability analyses, hydrologic and hydraulic modeling for evaluating spillway sizing and downstream hazard potential, arrange for under water inspections by divers, permitting, and assistance in applying for funding for repairs. Also required, are Emergency Action Plans (EAP) that identifies potential emergency conditions and specifies preplanned actions to be followed in the case of a dam failure to minimize property damage or loss of life.

The required frequency of dam inspections will vary depending on the state, but generally are based on hazard classification, with high hazard dams requiring more frequent inspection. Generally dam inspections should be performed every two years for high hazard dams, unless the state requires more frequent inspections. The best time of year for inspections is in the fall, when reservoir levels are typically low, and when foliage and tree leaves are reduced, allowing improved visibility around the dam.

A wealth of information on dam safety awareness, can be found at the Association of State Dam Safety Officials website

¹Wikipedia.com

The High Cost of High-Hazard Dams

It is well known that our nation’s infrastructure is in desperate need of repair or replacement. In fact, the American Society of Civil Engineers (ACSE) 2017 Report Card has given our country’s infrastructure an overall grade of D+. Dams are a part of that critical infrastructure, and they have received an abysmal D grade from ASCE. We have over 90,000 dams in our country, and the average age of these dams is 56 years old. Considering that dams built 50 years ago were not designed for current standards and usually have inadequate spillway capacity, these numbers are concerning.

Even more alarming, America has nearly 15,500 high-hazard dams, with over 2,170 of these being deemed deficient. A dam is rated high-hazard when dam failure could result in the loss of human life, and deficient when it is at serious risk of failure. A deficient, high-hazard dam is a tragedy waiting to happen. Also, considering the estimated cost to repair these deficient, high-hazard dams is almost $45 billion, it is apparent that we have a dam crisis on our hands.

About Dams

Lake Mead, impounded by the Hoover Dam, is one of the most popular vacation spots in the country.

Dams provide significant economic and social benefits to society, including flood control, water storage, irrigation, debris control, and navigation. In addition, around 3% of our nation’s dams provide hydroelectric power — a clean, renewable energy source — accounting for 35% of our country’s renewable energy and 10% of our total power needs. And, of course, the most frequent function of dams is recreation. Dams impound eight of the top ten most popular vacation lakes in the United States, accounting for millions of tourist dollars and some of our country’s most beautiful and enjoyable areas.

mill-river-dam-flood — The Mill River Dam collapse was the first manmade dam disaster and one of the worst of the 19th century. On May 16, 1874, the Mill River Dam in Williamsburg, MA failed, killing 139 people and wiping out four towns in western Massachusetts within one hour.

Catastrophic dam failures have occurred in the United States for well over a century, resulting in the deaths of thousands of people and causing millions of dollars in damages. This year, we narrowly avoided a disaster when California’s Oroville Dam stabilized after threatening to fail. During the crisis, over 188,000 people were displaced due to mandatory evacuations of the area. Although the Oroville Dam crisis thankfully ended without loss of life, the cost to repair the spillway is estimated to be $275 million. In 2003, the Silver Lake Dam in Michigan failed, causing approximately $100 million in property damages and putting over a thousand miners out of work. In 2004, the Big Bay Lake Dam in Mississippi failed, destroying 48 homes and seriously damaging 53 others. In 2006, the Ka Loko Dam in Hawaii failed, killing seven people and releasing nearly 400 million gallons of water, causing significant property and environmental damage.

dam-map-ma — Click on the image for an interactive map of dams in Massachusetts.

High-hazard dams are cause for concern in every state in the nation. In Massachusetts, 1,453 dams are included in the National Inventory of Dams, 333 of which are high-hazard. Of those, about 50 are classified as “poor” or “unsatisfactory” and in urgent need of repair. If any of these dams were to fail, there is a high likelihood that there would be a loss of human life. Dam failure is most frequently caused by overtopping, accounting for 34% of all dam failures. Causes of overtopping include inadequate spillway design, blocked spillways, settlement of the dam crest, and floods exceeding dam capacity. Other causes of dam failure include foundation defects such as slope instability and settlement (30%); piping, resulting in internal erosion caused by seepage (20%); and other causes including structural failure of materials, settlement and resulting cracking, poor maintenance, and acts of sabotage (16%).

Safety Programs

oroville-dam-damage — Draw down and cut off of releases from the damaged spillway at Oroville Dam. Taken on Feburary 27, 2017. Dale Kolke/California Delpartment of Water Resources.

The National Dam Safety Program (NDSP) was signed into law in 1996. NDSP was established to improve safety and security around dams by providing assistance grants to state dam safety agencies to assist them in improving their regulatory programs; funding research to enhance technical expertise as dams are built and rehabilitated; establishing training programs for dam safety inspectors; and creating a National Inventory of Dams. Every state in the nation excepting Alabama has a dam safety program, and 41 states also have Emergency Action Plan (EAP) requirements. A detailed and up-to-date EAP is critical to a successful dam safety program for high-hazard and significant-hazard dams. States without EAP requirements are Alabama, Georgia, Illinois, Iowa, Kentucky, North Carolina, Vermont, Wyoming, and — believe it or not — California.

Unfortunately, about one-third of our nation’s high-hazard dams lack an EAP. In addition, state dam safety programs are sorely underfunded and understaffed, and many of our nation’s deficient dams are not being repaired or rehabilitated in a timely manner. Why? State dam safety programs provide the inspection, permitting, recommendations, and enforcement authority for 80% of our nation’s dams, yet the average ratio of dams to dam safety inspectors is 207:1. Also, about two-thirds of our nation’s dams are privately-owned. Without enforcement of repair recommendations, some dam owners simply choose not to sink any money into their deficient dam.

For example, the Ka Loko Dam in Hawaii was privately-owned, and owner James Pflueger was sentenced to seven months in prison in exchange for a plea of no contest to reckless endangering. By entering the plea, prosecutors agreed to drop the seven counts of manslaughter. But admittedly, the dam failure was the result of a series of negligent events. The State of Hawaii, like most states in the nation, had a shortage of dam inspectors, and the Ka Loko Dam had not been adequately inspected. Also, Pflueger performed unpermitted construction activities at the dam, including grading and filling in the spillway. The County of Kauai ordered Pflueger to cease and desist all illegal grading operations, yet Pflueger ignored the order with help from then-Mayor Maryann Kusaka, who served as mayor of Kauai from 1997-2004. He also knew that there was seepage at the dam prior to the failure.

Key Issues

The Wachusett Dam in Clinton, MA is a high-hazard dam, rated in satisfactory condition.

Clearly, the Ka Loko Dam failure was due to gross negligence and was completely avoidable. To avoid similar tragedies in the future, all of the key issues facing our nation’s dams should be addressed. First and foremost, our country needs to invest in infrastructure and to prioritize funding of dam safety programs. It is imperative that dam safety agencies have adequate personnel and resources to enforce inspection, repair, and rehabilitation recommendations. Also, since two-thirds of our nation’s dams are privately-owned, lack of funding for private dam upgrades is a huge problem. Adequate maintenance and rehabilitation of dams is costly, ranging from thousands to millions of dollars, and many private owners simply cannot afford these costs. Because of the high risk of high-hazard dams, our nation must prioritize funding assistance and loan programs to both public and private owners. It is also crucial that high-hazard dams have an up-to-date EAP, including action plans as well as notification and evacuation procedures, so that authorities are prepared and residents living downstream of the dam are protected. And speaking of residents, public outreach and awareness may be the most critical component of dam safety and awareness. The typical American citizen has no understanding of the role that dams play in our lives, or of the devastation that could come about from a dam failure. Even developers and officials are often in the dark about dams in their own communities. And, of course, everyone needs to understand that all high-hazard dams, no matter how seemingly structurally sound, are potentially dangerous and that there is inherent risk living in a dam break flood-prone area. Also, many of the private dam owners in our country are largely unaware of both their responsibility toward residents and businesses located downstream of their dam and of proper dam maintenance and repair procedures.

In Conclusion

We must change the way we manage our nation’s dams in order to prevent future catastrophes. The recent Oroville Dam crisis should serve as a warning to residents and legislators. As our dams age and climate change increases severe weather events, we must invest in the oversight, funding, and awareness of this critical infrastructure. Until we do, events such as the Oroville Dam crisis and the Ka Loko Dam failure may occur with increasing frequency, resulting in loss of life, environmental damage, and economic disaster.

The Four Most Haunted Dams in the United States

Halloween is just around the corner, and with it comes ghosts, goblins, and all things haunted – even dams. This year, we are taking a look at the four most haunted dams in the United States. Did we miss any? If so, let us know in the comments. Happy Halloween!

This memorial plaque commemorates those who died during the construction of the Hoover Dam — This memorial plaque, located on the Nevada side of the dam near the two winged figures, commemorates those who died during the construction of the Hoover Dam

Haunted Hoover

Arguably the most well-known dam on our list, the Hoover Dam has a long history of haunted happenings. Constructed on the Colorado River on the border between Nevada and Arizona during the Great Depression and one of the Seven Modern Engineering Wonders of the World, the Hoover Dam employed thousands of people at a time when it was needed most. It was not without its problems, however, as 112 workers lost their lives during its construction, although not from being entombed in the concrete during construction as promulgated by one popular urban legend. The deaths occurred in more typical ways such as falling, drowning, and being struck by equipment and debris. In addition to the 112 who perished from industrial accidents, 42 workers were said to have died from pneumonia; however, not a single non-worker in the area died from pneumonia during this time. Workers allege that the construction company made up the whole pneumonia story in order to avoid any lawsuits, as the workers had actually perished from carbon monoxide poisoning while operating vehicles inside the diversion tunnels. Considering that approximately four people per year commit suicide by jumping from the dam as well, it should come as little surprise that tales of spirits and hauntings at the dam are commonplace. There have been numerous reports of crying sounds and footsteps inside the facility, and apparitions of men wearing old-fashioned work clothes have been seen, although no photos have been captured.

The Hales Bar Dam old hydroelectric plant is now used as a dry dock

Horrifying Hales Bar

Constructed from 1905-1913 primarily to hold back the whirlpools along the Tennessee River, the Hales Bar Dam in Tennessee was the nation’s first hydroelectric dam. Unfortunately, it was also built on cursed land. According to legend, Native American War Chief Dragging Canoe cursed the land on March 17, 1775 after the controversial Treaty of Sycamore Shoals was signed. He said that the land would be “dark and bloody” to any who attempted to live there. In addition, the waters surrounding the dam were considered sacred by Native Americans. In fact, Native Americans believed that they could see the souls of their ancestors being sucked into one of the largest whirlpools, nicknamed The Suck, and that any who were unfortunate enough to get too close to The Suck would be pulled down into the whirlpool by their dead ancestors. Like the Hoover Dam, legend also says that many workers fell to their deaths during the construction of the dam and were entombed in the concrete, but there are no actual historical accounts to corroborate the legend.

The construction of the dam encountered numerous issues, including soft bedrock and shale on which the dam was constructed; accidents, illnesses, racial tension, and deaths of workers; and even numerous leaks springing up immediately after construction was completed. Also, the town that the creation of the dam flooded contained the old town graveyard, and none of the bodies were disentombed. The Hales Bar Dam never functioned properly, and after a failure in the 1960s, the dam was demolished, flooding the area behind it, which included a cemetery filled with hundreds of graves of mostly children who had died during the 1918-1919 Spanish Flu epidemic. With such a strange history, it is no wonder that the Hales Bar Dam is considered a haunted hotspot. Visitors and employees have seen apparitions and shadows, have heard and seen footsteps that actually kicked up dust, and have heard children’s voices chanting and crying. Some unlucky visitors have even felt hands reach out and touch them from the whirlpool, while others have reported seeing a strange figure in the cat walk, believed to be the restless spirit of War Chief Dragging Canoe himself.

Daunting Devil’s Gate

Devil’s Gate Dam was constructed on the Arroyo Seco in Pasadena, California in 1920 as Los Angeles’ first flood control dam. Where the dam was built was a natural rock formation bearing resemblance to a side profile of a devil, hence the name. The gate, a steel structure that is part of the dam, is believed by some to be a portal to the spiritual world, with some going so far as to say it is one of the Seven Gates of Hell. The reasons for the theory are numerous. Jack Parsons, a rocket scientist who co-founded Jet Propulsion Laboratory, was a practicing occultist who believed the Devil’s Gate Dam to be a portal to the otherworld. He frequently practiced occult rituals, along with Scientology founder L. Ron Hubbard, which some say triggered the opening of the portal. They even went so far as to try to summon a “moonchild,” but were not-so-surprisingly unsuccessful. Furthering the superstition surrounding the dam was the disappearance of four children within a one-year period in the 1950s. Two of the children were never found, while serial killer and road construction worker Mack Ray Edwards confessed to killing the other two and of burying their bodies beneath the asphalt of a newly paved freeway. In addition, Devil’s Gate Dam is part of what is considered Pasadena’s haunted triangle, which includes the dam, the Colorado Street “Suicide” Bridge, and the Enchanted Forest/Cob Estate. The triangle is called Demon’s Gate, and is believed to be the driver of all spiritual activity in the region.

teton-dam-failure — The Teton Dam failure

Terrifying Teton

Constructed on the Teton River in Idaho by the Bureau of Reclamation, the Teton Dam catastrophically failed on June 5, 1976 as it was filling for the very first time. Having only 40 minutes to warn residents prior to the dam’s collapse, 11 people and 13,000 cattle perished in the disaster. Also, thousands of homes and businesses were destroyed and damages were estimated to be about $2 billion. BJ’s Bayou Restaurant was once a hotel that was destroyed during the dam failure and never reopened. It was converted to a restaurant, bar, and residence in the 1980s, and is said to have been haunted ever since its opening. Visitors tell tales of seeing the ghosts of both a young girl and an older man in uniform, both of whom are believed to have been victims of the flood. In addition, the dam itself is said to be haunted by demons as a result of occult activities that took place there, with witnesses reporting having very strongly negative feelings when they are inside the spillway. There is good that came from the Teton Dam failure, however. The Bureau of Reclamation’s Dam Safety Program was instituted in 1978 as a direct result of the disaster. Less than a year later, the Federal Emergency Management Agency (FEMA) was created, and in 1986, dam safety was addressed in the Water Resources Act. FEMA’s National Dam Safety Program, passed in 1996, was the first national legislation to address dam safety, the purpose of which is to “reduce the risks to life and property from dam failure in the United States through the establishment and maintenance of an effective national dam safety program to bring together the expertise and resources of the Federal and non-Federal communities in achieving national dam safety hazard reduction.”

National Dam Safety Awareness Day

There are over 87,000 dams in the United States. With one-third of those dams posing a serious threat to people’s lives and property if they fail, dam safety is nothing to ignore. Dams are a critical part of our infrastructure providing flood protection, water supply, hydropower, irrigation, and recreation. Although dam safety may not seem to be a big concern, dam failure can affect people for miles and miles, with sometimes fatal results. National Dam Safety Awareness Day is a day to acknowledge the progress we have made in making our dams safe structures and the continuous progress we still have yet to make.

Damage caused by Lake Delhi Dam failure in Iowa, July 27, 2010

As our population keeps growing, our dams are getting older and some are even deteriorating. A dam can fail within hours of the first signs of breeching. Dam safety is a shared responsibility. Dam owners, engineers, community planners, along with federal and state leaders all have important roles in keeping dams running efficiently and safely.

The National Dam Safety Program (NDSP), led by FEMA, has been working for 30 years to keep Americans safe from dam failures. The NDSP assists states in establishing and maintaining dam safety programs along with providing technical training to state and federal dam safety staff. Their support for research and development has greatly helped raise awareness about improper dam safety along with lessening the impact on a community if a dam were to fail.

Why Dams Fail

One of the most frequent ways dams fail is overtopping. Overtopping is a strong indicator of an unsafe dam. This can happen due to a number of reasons but typically it is from inadequate spillway design, debris blockage, or settlement of the dam crest. Overtopping accounts for about 34% of all dam failures in the United States and can also lead to erosion of the downstream face of the dam. Without proper maintenance of the downstream face, the dam is at a heightened risk of failure. Wind and other harsh weather conditions can cause waves to erode the upstream face which can make the dam unsafe during heavy rainfall or flash floods.

Missouri River Flood: Breeching of the levee at mile 550 in Aitchison County, June 19, 2011

Other important factors that can cause dam failure are seepage and foundation defects. These defects account for about 30% of dam failures in the US, typically due to slide failure. If seepage or other factors weaken the soil supporting a dam, the overall strength of the dam greatly diminishes, creating the potential for a landslide-like affect.

Improper construction measures such as insufficient soil testing also contribute to dam failures. When permeable cavities or course gravel are present in dam foundations, seepage is a big concern because it erodes the soil at a fast rate. This often results in the dam settling or sinking which causes failure. A dam can fail by water passing under, over, through, or around it. Every dam should be properly connected to the ground and constructed using the best materials and methods to meet current design and construction standards.

How to Prevent Failures

When constructing and maintaining a dam, taking the proper engineering steps is vital. For example, completing sufficient soil tests prior to construction helps ensure that the dam will be adequately supported. The soil on the actual site should be examined before any detailed planning is put into place. It is also important to confirm the existence of impervious clay to seal the excavation and form the core of the bank. Failures can be prevented if the contractor is aware of any soil limitations at the site.

Dam failures have taken the lives of hundreds of people in recent decades so it is important to hire the right contractors to do the proper work. Nothing can take the place of a reliable and reputable contractor. Having experienced engineers and machine operators greatly reduces the risk of failure. It is important to review every employee’s credentials before starting a job and to always seek professional advice from an engineer when planning and designing a dam. Improper construction and inspection can lead to a weak structure, which can be dangerous and, sometimes, even fatal.

Maintenance and inspection must be routinely completed in order to keep dams safe. If a problem associated with a dam is not addressed in a timely manner, it can become more dangerous as time goes on. Dam inspectors should document every inspection in order to accurately assess needed repairs. While maintaining a dam, vegetation control, erosion repair, and clearing debris from spillways should be a routine practice. A healthy layer of grass can help prevent erosion, and any debris within 25 feet of the dam should be removed. A poorly maintained dam can cost the owner more to repair than a dam which is regularly inspected and checked for needed repairs.

Emergency Action Plans

Damage left behind after the Teton Dam failure, Rexburg, Idaho, 1976

173 dams across the country have failed since 2005 so it is important to know what your community’s Emergency Action Plan (EAP) is if a local dam were to fail. An up-to-date EAP is critical to reduce the risk of lost lives and property damage. A good EAP accomplishes three main goals: identify the area below the dam that would be flooded, establish a line of communication for the dam owner and emergency response, and provide warnings and evacuations to be conducted by local emergency teams. Below are the six essential elements of a successful EAP.

Notification Flowchart. This is to identify who should be notified by whom, and in what priority. This information is crucial for the notification of the persons in charge of taking emergency actions. The flowchart should have detailed information about each position in the chart such as title, office, and multiple ways of contacting that individual. EAPs should include the residents and businesses downstream of the dam that should be notified in case of an emergency. Proper communication and assigned roles can drastically reduce the impacts of a dam failure.
Emergency Detection, Evaluation, and Classification. This ensures that the appropriate course of action is taken based on the urgency of the situation. Having procedures in place to classify an emergency situation properly will better prepare a community to activate their EAP before a catastrophe occurs. Early detection of a potential problem can save hundreds of lives and millions of dollars in property damage.
Responsibilities. When an emergency occurs, everyone should know their role in reacting to the situation. Typically, the dam owner’s responsibilities include developing, maintaining, and implementing the EAP while state and emergency management officials are responsible for warning and evacuation. Without proper assignment of responsibilities, the EAP would be ineffective.
Preparedness. This section outlines actions to be taken before an emergency occurs. Preparedness actions are taken to moderate or minimize the effects of a dam failure and to identify specific responses to be taken in emergencies.
Inundation Maps. An inundation map identifies the areas affected if a dam were to fail. This map is important in identifying a strategy to notify and evacuate areas in danger. These maps graphically display flooded areas and show travel times for wave front and flood peaks at critical locations.
Appendices. This section contains information directly applicable to the actions of the dam owner and the emergency management parties. The appendices provide information that supports the material used to develop the EAP such as maintenance requirements and dam break investigations.

In Conclusion

Dams serve an important role in our nation’s infrastructure. Millions of people in every state rely on dams to bring them benefits such as flood control, water supply, irrigation, recreational areas, and renewable energy. Safe operation and maintenance is important to sustaining these advantages and avoiding disasters which are very often preventable. Dams fail for a number of reasons but the primary source of failure is poor inspection and maintenance, inadequate design, and improper operation. Know your risk when it comes to dam failure in your community. Getting familiar with your community’s EAP and level of risk from a dam failure can greatly help you in an emergency situation. National Dam Safety Awareness Day is an opportunity to raise awareness about our nations deteriorating dams and to take steps in making them safer structures for our community.

Happy National Dam Safety Awareness Day!

Tag: dam failure

Dam Safety Awareness Commemorates an Epic Flood

The Johnstown Flood of 1889

The High Cost of High-Hazard Dams

The Four Most Haunted Dams in the United States

National Dam Safety Awareness Day

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