The Importance of Dam Safety Awareness

The Importance of Dam Safety Awareness

On May 31, 1889, the South Fork Dam near Johnstown, Pennsylvania collapsed during a large storm. The failure of this dam claimed 2,209 lives as 20 million tons of water flooded the town. Prior to the dam failure, dam safety awareness was minimal and was not widely recognized. Now, 131 years later, strong dam safety programs, investment in America’s critical infrastructure, and dedication to public-private partnerships are just as crucial. The importance of Dam Safety Awareness must continue growing to assure America’s dams are safe, resilient, and operational.

Garrison Dam – ND

Dams in America

There are more than 90,000 dams in the United States that have been built to maximize the use of our most valuable resource – water. They serve several functions including water supply for agricultural, community, domestic, and industrial use; flood control; recreation; and renewable energy.

Water Storage – Dams create reservoirs that supply water for irrigation, domestic and commercial water supply, recreation, fire control, and more.

Flood Control – Damns aid in reduced flooding and erosion.

Irrigation – Ten percent of the water used by American cropland is stored behind dams.

Renewable Energy – Dams produce 8-12 percent of the nation’s power needs via hydropower. Without hydropower, the United States would have to burn an additional 121 million tons of coal, 27 billion barrels of oil, and 741 billion cubic feet of natural gas.

Recreation – Boating, fishing, swimming, and camping are just some of the recreational activities that take place as a result of hydropower created by dams.

Dam Safety Issues in America

Safe operation and maintenance of dams are critical when it comes to avoiding potential dam failure and disaster. With tens of thousands of dams across the country, many of which are approaching their life expectancy, it’s important to be on the lookout for dams with high-hazard potential. High-hazard potential dams climbed to more than 15,000 in 2018, and only continue to grow due to growing populations. This increase is known as ‘hazard creep’. Hazard creep describes the growth of development such as people, buildings, and businesses, that moves closer to dams.

Investing in Dams

Dams are a major piece of our country’s critical infrastructure, and investment is needed to rehabilitate those that are deficient.

Dam on the Green River, upstream from the Green River Covered Bridge, near Brattleboro, Vermont.

Why do dams need upgrading?

  • Deterioration
  • Changing technical standards over time
  • Improved techniques for building
  • Increases in population
  • Better understanding of precipitation patterns in areas
  • Changing land use

Upgrading a dam when it reaches an increased hazard potential is critical for the integrity of the dam structure as well as the safety of those living in the vicinity. The problem that dam owners have (especially on the private side) is the difficulty in funding the upgrades.

The Association of State Dam Safety Officials have tracked dam rehabilitation costs for non high-hazard and high-hazard dams since 2004.

Recreational Dam Safety Awareness

Outside of critical infrastructure, dams provide recreational opportunities for boaters, swimmers, kayakers and more. Unfortunately, there are dozens of deaths on American waterways each year that take place at structures called ‘low-head’ dams.

Low-head dams are low in height and typically have a 1-15 foot drop off, allowing water to flow off the dam. Below the drop off, water falling from the dam can create circulating currents that can trap people and objects underwater against the face of the dam. The force of the water is extremely strong, and these structures have earned the title of ‘drowning machines.’

Many people are unaware of the dangers associated with dams which is why it is so important to educate communities of dam safety.

Click here to learn more about public safety around dams.

Infrastructure Week 2019

Infrastructure Week 2019

From May 13-20, the seventh annual Infrastructure Week is taking place with the support of hundreds of affiliates across the country. Infrastructure Week was created to help raise awareness for our country’s growing infrastructure needs and stress the message that we must #BuildForTomorrow. Led by a coalition of businesses, labor organizations and policy organizations, this week will unite the public and private sector to send this important message to leaders in Washington and beyond.

No matter where you live, your age, your education, if you drive a car or a truck or take the bus or a bicycle, infrastructure has a profound impact on your daily life. We all have to get around. We all need lights to come on and water to come out of the tap.

Consequently, too much of our nation’s infrastructure is under-maintained, too old, and over capacity. When it comes to water infrastructure alone, we are dealing with a massive network of pipes that are well over 100 years old. In short, droughts in western states have caused wells and reservoirs to fall dangerously low; saltwater intrusion of Florida’s drinking water infrastructure, and dam and levee failures in California, South Carolina, and Louisiana have caused evacuations and put hundreds of thousands of people and homes at risk.

infrastructure week photo with stat stating that 'most Americans' wter systems have been in operation for 75-100 years - well past their lifespans.

The High Cost of Water Infrastructure

And this is just the tip of the iceberg. A study conducted by the American Water Works Association revealed that the cost to replace our nation’s water infrastructures would cost more than one trillion dollars over the next 25 years.

No state, city, or county alone can tackle the growing backlog of projects of regional and national importance, and Americans get it: more than 79 percent of voters think it is extremely important for Congress and the White House to work together to invest in infrastructure.

For years, near-unanimous, bipartisan support for infrastructure investment has been steadily increasing. Leaders and voters have been rolling up their sleeves to spark efforts in the rebuilding and modernizing of transportation, water, and energy systems. Certainly, large strides have been made as a country, but there is still a lot to be done.

Every four years, the American Society of Civil Engineers (ASCE) publishes The Report Card for America’s Infrastructure, which grades the current state of the nation’s infrastructure on a scale between A and F. The last survey from 2017 gave tremendous insight into the state of our infrastructure surrounding drinking water, dams, and wastewater.

Drinking Water Infrastructure

The drinking water that we get in our homes and businesses all comes from about one million miles of pipes across the country. While the majority of those pipes were laid in the early to mid-20th century, many are showing signs of deterioration. There are many reasons for a water main to break including localized influences such as aggressive soil and weather conditions, as well as poor design/construction. Approximately 240,000 occur each year, consequently resulting in the waste of two trillion gallons of treated drinking water. Drinking Water received a grade of D.

Dams

The average age of the 90,000+ dams in the United States is 56.  Nearly 16,000 (~17%) have been classified as high-hazard potential. Dam failures not only risk public safety, they also can cost our economy millions of dollars in damages as well as the impairment of many other infrastructure systems, such as roads, bridges, and water systems. As a result, emergency action plans (EAPs) for use in the event of a dam failure or other uncontrolled release of water are vital. As of 2015, 77% of dams have EAPs – up from 66% in the last 2013 Report Card. Dams received a grade of D.

Wastewater

There are approximately 15,000 wastewater treatment plants across the U.S that are critical for protecting public health and the environment. In the next 15 years, it is expected that there will be 56 million new users connected to the centralized treatment system. This need comes with an estimated $271 billion cost. Maintaining our nation’s wastewater infrastructure is imperative for the health and well being of the 76% of the country that rely on these plants for sanitary water. Wastewater received a grade of D+.

In the water sector alone, it’s clear how heavily we rely on solid infrastructure. If the issues in our nation’s water infrastructure are not addressed, millions of people as well as our environment will be at risk. Many communities around the country are working hard to deliver projects to solve these problems – but there is always more to be done. Reversing the trajectory after decades of under-investment requires transformative action from Congress, states, infrastructure owners, and the American people. Join us this week to help spotlight the continued advocacy and education of infrastructure needs. Afterall, this is the true foundation that connects our country’s communities, businesses, and people.

 

Dam Safety Awareness Commemorates an Epic Flood

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.

Before the dam breachAs 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.

Lake ConemaughFor 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.

Aftermath of floodClub 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.

aftermathIt 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.

flood damageA 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 31st, 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

ASCE-report-cardIt 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.

kaloko-dam
The Ka Loko Dam breach in Hawaii resulted in the deaths of seven people, including a pregnant woman and a toddler.

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.

Dams: To Remove or Not To Remove?

The Hoover Dam created America’s largest reservoir, Lake Mead.

Dams are an integral part of modern day infrastructure, providing many benefits to society. Yet dams have also come under scrutiny in the past few years as they can potentially have a negative effect on an area’s ecology. Some people, including environmental groups, are vehemently calling for the removal of many dams, while others continue to promote the positive impact that dams have on our culture. To remove or not to remove? That is the question.

The Benefits of Dams

Dams have been in existence for over 5,000 years. The first known dam to be built was the Jawa Dam, which was constructed around 3,000 BCE in Mesopotamia. Since that time, dam engineering has progressed significantly, and there are now about 50,000 large dams in use worldwide. The United States currently has 87,000 dams over six feet in height, 2,000,000 dams in total, and 50 major dams — the most in the world. And though they may have an ecological impact, dams admittedly provide myriad benefits, both economically and socially.

Recreation

The most prevalent function of America’s dams is to provide recreation. Families flock to our nation’s lakes that are created by dams for vacations and downtime to enjoy boating, camping, picnic areas, water skiing, fishing, and water sports. Some of the most beautiful and enjoyable vacation spots in the nation are lakes created by dams. In fact, of the top ten most popular vacation lakes in the United States, eight are impounded by dams, including number one on the list, Lake Tahoe. These recreational areas bring in millions of dollars of tourist funds and are important to the economic health of the nation.

Flood Control

Flood control dams impound floodwater to help prevent loss of life and protect property caused by flooding. They also protect farmers’ crops from being destroyed by flood inundation. Protecting people, property, and crops also provides high economic benefit.

Water Storage (Fire & Farm Ponds)

While major dams create massive lakes, thousands of other dams create smaller reservoirs throughout the nation that supply water for industrial, municipal, and agricultural uses. Water from these human-made lakes supply water for livestock and fire protection for cities and towns, as well as industrial uses.

Irrigation

grand-coulee-irrigation
The Grand Coulee Dam in Washington state is a gravity dam on the Columbia River built to produce hydroelectric power and provide irrigation water.

Over ten percent of American crops are irrigated using water impounded by dams. This irrigated farmland provides thousands of jobs to hardworking American people, providing huge economic benefit to our nation.

Mine Tailings

Mine tailings are sometimes overlooked as dams, but there are actually over 1,300 mine tailings impoundments in the United States. The tailings allow for the mining and processing of coal and other minerals while protecting the surrounding environment.

Electrical Generation

While only 2.9% of our nation’s dams provide hydroelectric power, they account for over 35% of our nation’s renewable energy, over 6% of our total electricity, and around 10% of our nation’s total power needs. In fact, the United States is the second largest producer of hydropower in the world, second only to Canada. Hydropower is considered a clean energy source because it does not contribute to air pollution, climate change, or ozone depletion.

Some other uses for dams include debris control and navigation.

Negative Effects of Dams

While our nation’s dams provide many benefits, they also cause many concerns. First, the cost of maintenance sometimes outweighs any positive impact the dam may provide. In addition, dams can also have a negative effect on the environment, and some pose serious hazard to people and property. By 2020, about 70% of our nation’s dams will be over 50 years old and will require significant rehabilitation and repair. In fact, the Association of State Dam Safety Officials has estimated that it could cost over $51 billion to rehabilitate our nation’s non-federally owned dams. Therefore, it is imperative that we consider all aspects of dams and their environmental, economic, and social impact before making any rehabilitation decisions.

Many dams continue to provide benefit to our nation and its communities, while others have simply outlived their useful function. In these cases, it makes sense to remove them rather than to pour increasingly dwindling funds into their repair. Since 1912, over 1,300 American dams have been removed, 62 of these being removed in 2015 alone.

Maintenance vs. Removal

oroville-dam-spillway
The Oroville Dam in California, the tallest dam in the country, suffered spillway damage during controlled water discharges and forced the evacuation of almost 200,000 Californians in February 2017. Photo courtesy of  California Department of Water Resources.

Like all infrastructure, dams require routine and ongoing maintenance to keep them safe and functioning. Frequently, dams are allowed to deteriorate until they pose a threat to public safety, particularly when they have fallen out of usage. In these cases, it is prudent for dam owners to work with state and federal dam experts to determine whether it makes sense to simply remove the dam rather than repair it.

Environmental Impact

One of the most significant impacts that dams have on the environment is interference with migratory fish such as salmon. Dams block the migration of these fish to upstream spawning areas, while also limiting the movement of both sediment and woody debris necessary to the maintenance of downstream spawning grounds. Many environmental activists call for the removal of dams that interfere with fish spawn, citing disruption of local ecology. The good news is that once a dam is removed, species quickly return to their upstream spawning areas, regardless of the length of time that the dam has been in place.

Tourism

Free flowing rivers provide many tourism and recreational opportunities.

While dams provide significant recreational benefits, in some cases they can also hinder them. When a river is returned to its free-flowing state by dam removal, new recreational opportunities arise, including whitewater rafting, kayaking, and fly fishing. These activities can greatly benefit local economies by increasing tourism to these typically remote communities. Also, removing dams can increase the number of recreational and commercial fish species such as trout and salmon. Both commercial fisheries and recreational fishermen benefit from increased catch rates though additional revenue and increased tourism, respectively.

Decreased Cost-Effectiveness

Many aging dams were originally built to supply hydro power to nearby industrial facilities such as mills and factories, and they generate little electricity. Because the nation has shifted away from local power supply to a more regional production, the power generated by these older dams is expensive and, since many of the older factories and mills have permanently shut down, are oftentimes no longer even needed.

Cultural Implications

Many Native American populations place significant spiritual and cultural value on free-flowing rivers and the natural ecology, as evidenced by the long standoff between the federal government and the Standing Rock Sioux tribe. Because dams change the natural ecology and prohibit the free flow of rivers and waters, Native American tribes often view them in a negative light.

Property Value

Dams have the tendency to drive down property values, particularly smaller dams which are no longer used for their original purpose. These dams can present flood risk as well as lower water quality, and removal of these dams improves property values.

In Conclusion

Tata & Howard provided design and construction services for the rehabilitation of the Means Brook Dam in Connecticut. See here for details.

The question remains: to remove or not to remove? The reality is that there is no easy or right answer. The decision on whether to repair or remove a dam is complex, and all contributing factors must be considered carefully before determining the best course of action. The decision must include weighing the current value of the dam, including its social and economic benefits, against the costs of upkeep and the detrimental effects of the dam on the environment. When the dam has little social or economic effect either way, the long-term costs of maintenance versus the cost of removal must be considered.

Thousands of American dams have aged to the point that they require significant repair, while scientific understanding of our world’s delicate ecology and has grown exponentially. Also, advances in economic methodology has highlighted the positive impact that dam removal can have on local and regional communities. Because of these modern-day shifts, it is often considered prudent to remove dams that no longer properly serve their original purpose. At the same time, dams that still function and provide important benefits such as irrigation and flood control are often repaired and maintained. The fact remains that the answer is not clear or definitive. All aspects of a dam, its location, original use, state of repair, social and cultural implications, and surrounding environment must be considered prior to determining the best course of action.

Dam Safety and the Criticality of Emergency Action Plans

Devastation from the Ka Loko Reservoir Dam breach in 2006

This month marks the ten year anniversary of Hawaii’s Ka Loko Dam failure on the island of Kauai. On March 14, 2006, after 40 days of heavy rainfall, the rising water finally overtopped the dam near the original spillway — which had been filled in by the owner. At the time, the State of Hawaii lacked resources and legal authority to properly ensure that the owner fully addressed safety concerns. The break sent almost 400 million gallons of water downstream four miles until it finally reached the ocean, and the water reached about 20 feet in height, destroying whatever was in its path, including trees, homes, and vehicles. The disaster, which was entirely preventable, killed seven people, including a pregnant woman and child, and caused millions of dollars of property damage as well as significant environmental damage. As a direct result of the disaster, Hawaii increased funding to its dam safety program, allowing for improved regulation of local dams.

Historic U.S. Dam Failures and Legislation

Unfortunately, the Ka Loko Dam failure in Hawaii was not an isolated incident. Dam failures in the United States have caused catastrophic damage and loss of life for well over a century:

Aftermath of the 1874 Mill River Flood in Williamsburg, MA
Aftermath of the 1874 Mill River Flood in Williamsburg, MA

May 16, 1874 – Williamsburg, Massachusetts
At 7:20 a.m., the 43-foot-high Mill River Dam above Williamsburg, Massachusetts failed, killing 138 people, including 43 children under the age of ten. At the time, this failure was the worst in U.S. history.

May 31, 1889 – Johnstown, Pennsylvania
Over 2,200 people — more than 20% of the residents of Johnstown — perished in the flood caused by the failure of South Fork Dam, nine miles upstream. To this day, the South Fork Dam disaster is the worst in U.S. history. National Dam Safety Day is celebrated each May 31 in remembrance of the catastrophe.

Around the turn of the century, many more dam failures occurred, resulting in the passing of some early state dam safety legislation.

March 12,1928 – San Francisquito Canyon, California
The failure of St. Francis Dam, which killed over 450 people and caused over $13 million in damage, the equivalent of about $180 million by today’s standards, was a landmark event in the history of state dam safety legislation, spurring legislation not only in California, but in neighboring states as well. It was also the worst civil engineering disaster of the 20th century, serving as the catalyst for the engineering licensure requirement in California.

Only one small section of the St. Francis Dam remained after its catastrophic failure in 1928
Only one small section of the St. Francis Dam remained after its catastrophic failure in 1928

In response to the St. Francis Dam disaster, the California legislature created an updated dam safety program and eliminated the municipal exemption. In addition, the State was given full authority to supervise the maintenance and operation of all non-federal dams. However, even in the wake of such a horrific disaster, most other states had severely limited dam safety laws — that is, until a series of dam failures and incidents occurred in the 1970s:

February 26, 1972 – Buffalo Creek Valley, West Virginia
The failure of a coal-waste impoundment at the valley’s head took 125 lives, and caused more than $400 million in damages, including destruction of over 500 homes.

June 9, 1972 – Rapid City, South Dakota
The Canyon Lake Dam failure took an undetermined number of lives (estimates range from 33 to 237). Damages, including destruction of 1,335 homes, totaled more than $60 million.

June 5, 1976 – Teton, Idaho
Eleven people perished when Teton Dam failed. The failure caused an unprecedented amount of property damage totaling over $1 billion.

July 19-20, 1977 – Laurel Run, Pennsylvania
Laurel Run Dam failed, killing over 40 people and causing $5.3 million in damages.

Damage from the Toccoa Falls, Georgia dam failure in 1977
Damage from the Kelly Barnes Dam in Toccoa, Georgia dam failure in 1977

November 6, 1977 – Toccoa Falls, Georgia
Kelly Barnes Dam failed, killing 39 students and college staff and causing about $2.5 million in damages.

In response to these tragedies, President Jimmy Carter implemented the “Phase I Inspection Program” that directed the US Army Corps of Engineers to inspect the nation’s non-federal high-hazard dams. The findings of the inspection program, which lasted from 1978-1981, were responsible for the establishment of dam safety programs in most states, and, ultimately, the creation of the National Dam Safety Program, which today supports dam safety programs in 49 states. Alabama is the only state in the nation that has yet to pass dam safety legislation, although Alabama State Representative Mary Sue McClurkin introduced a bill on March 18, 2014 which, if passed, would establish a state dam safety program.

Emergency Action Plans

One of the key components of a successful dam safety program for high hazard and significant hazard dams is a comprehensive, up-to-date Emergency Action Plan (EAP). Hazard level does not reflect the condition or age of the dam; rather, it indicates the potential for loss in the event of dam failure. According to FEMA, the classifications are as follows:

High hazard: Facilities where failure will probably cause loss of human life. Such facilities are generally located in populated areas or where dwellings are found in the flood plain and failure can reasonably be expected to cause loss of life; serious damage to homes, industrial and commercial buildings; and damage to important utilities, highways, or railroads.

Significant hazard: Facilities where failure would likely not result in loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. Such facilities are generally located in predominantly rural areas, but could be in populated areas with significant infrastructure and where failure could damage isolated homes, main highways, and minor railroads or disrupt the use of service of public utilities.

Low hazard: Facilities where failure would result in no probable loss of human life and low economic and/or environmental losses. Such facilities are usually located in rural or agricultural areas where losses are limited principally to the owner’s property or where failure would cause only slight damage to farm buildings, forest and agricultural land, and minor roads.

Map courtesy of James S. Halgren, Office of Hydrologic Development, National Weather Service, National Oceanic and Atmospheric Administration
Map courtesy of James S. Halgren, Office of Hydrologic Development, National Weather Service, National Oceanic and Atmospheric Administration

Unfortunately, about 22% of high hazard dams and 40% of significant hazard dams nationwide still do not have EAPs, meaning that thousands of dams across the United States lack EAPs required by law. And dams are still failing. According to the Association of State Dam Safety Officials, 173 dams across the United States have experienced failures since 2005.

The lack of an EAP could be problematic in the event of dam failure, said Mark Ogden, project manager for the Association of State Dam Safety Officials, who also noted that while such worst-case scenarios are rare, they have happened. “An exercised, well-prepared emergency action plan is a valuable tool to help save lives,” Ogden said.

Ogden also noted that even when dams have an EAP, downstream residents often do not know where to find it. “There have been a lot of efforts in recent years to try to make the public aware of dams and the potential dangers, and to know if they live in an area downstream of a dam, the failure inundation zone, who to talk to – whether it’s the dam owner or more likely the local emergency management officials – to find out if there is an EAP for that dam and what they would need to do,” Ogden said.

Legislation

The Saville Dam in Barkhamsted, Connecticut is rated high hazard
The Saville Dam in Barkhamsted, Connecticut is rated high hazard

The good news is that most states have responded to the need for dam safety regulations and require EAPs for high hazard and significant hazard dams. The most recent legislation came in February of this year, when the State of Connecticut Department of Energy and Environmental Protection (DEEP) adopted new regulations concerning the preparation and update of EAPs for Class C and Class B dams. In 2013, fewer than 60% of regulated high hazard dams in Connecticut had an EAP, a statistic the State is hoping to drastically improve. The new EAP regulations include criteria for inundation mapping, dam monitoring procedures, formal warning notification and communication procedures, emergency termination protocols, and EAP review and revisions.

Currently, the only states without EAP requirements are Georgia, Illinois, Iowa, Kentucky, North Carolina, Vermont, Wyoming, and — ironically enough — California. Since Alabama still has no formal dam safety program, they also do not require EAPs.

Lake Martin in Alabama was created by the construction of the Thomas Wesley Martin Dam, which stopped the flow of the Tallapoosa River just southwest of Dadeville. It is the largest man-made lake in Alabama.
Lake Martin in Alabama was created by the construction of the Thomas Wesley Martin Dam, which stopped the flow of the Tallapoosa River just southwest of Dadeville. It is the largest man-made lake in Alabama.

ASDSO continues to work alongside the American Society of Civil Engineers (ASCE), American Council of Engineering Companies (ACEC), and other stakeholders to promote dam safety and to encourage legislation to protect the public and the environment from disasters such as the Ka Loko Dam failure in Kauai, Hawaii.

“The tenth anniversary of the dam’s failure reminds us of the potential dangers posed by dams and the critical importance of both responsible dam ownership and strong dam safety programs,” said Lori Spragens, executive director of the Association of State Dam Safety Officials (ASDSO). “Most dam failures are preventable disasters. Dam owners must keep their dams in the state of repair required by prudence, due regard for life and property, and the application of sound engineering principles. The quality of dam maintenance, emergency planning, and enforcement programs directly affects the safety of communities, as sadly demonstrated on Kauai. With more than 87,000 dams of regulatory size in the U.S., we all have a stake in dam safety.”Subscribe-to-our-newsletter1

The 7 Most Interesting Dams in the United States

Grand Coulee Dam
Grand Coulee Dam

1. Grand Coulee Dam

The Grand Coulee Dam, a concrete gravity dam, is located on the Columbia River west of Spokane, Washington and is listed by the American Society of Civil Engineers as one of the seven civil engineering wonders of the United States. The dam’s reservoir, Franklin D. Roosevelt Lake, stretches 150 miles north and almost reaches the Canadian border. The dam was constructed to provide hydroelectric power and irrigation.

Even more enormous than the Great Pyramid of Giza, the Grand Coulee is an absolutely massive structure, and one of the largest ever constructed by mankind. The 550 foot tall dam contains over 12 million cubic yards of concrete, which is enough to build a highway all the way from Miami, Florida to Seattle, Washington, and stretches 5,223 feet — just 57 feet shy of a mile. The construction of the Grand Coulee dam took place between 1933 and 1942 and provided jobs to thousands of men during the Great Depression. The Grand Coulee provided the immense electrical power needed to manufacture aluminum for the production of World War II planes and ships, and, continuing in its war-like vein, it also powered the production of plutonium at a secret lab on nearby Hanford Site. Plutonium, of course, turned out to be the key ingredient of the atomic bomb – and the rest is history.

The dam is not without some controversy. 77 men lost their lives during the construction of the dam and its original two powerhouses, and another four perished during the construction of the third power plant constructed between 1967-1975, bringing the final death count to 81. Also, creation of the reservoir partially flooded the ancestral lands of Native Americans and forced the relocation of over 3,000 people, and environmentalists have condemned the dam for blocking the migration of salmon and steelhead to spawn.

Today, the Grand Coulee is used to irrigate about 670,000 acres of farmland used for growing grains, fruits, vegetables, and wine grapes, as well as livestock grazing.

Hoover Dam
Hoover Dam

2. Hoover Dam

The Hoover Dam, located in the Black Canyon of the Colorado River on the border of Arizona and Nevada, is a massive concrete arch-gravity dam whose 600-foot base is as wide as the full length of two football fields. The giant concrete wedge stands 726 feet tall, or the height of a 60-story building, and holds back the immense power of the Colorado River. The Hoover Dam was constructed in order to generate electricity as well as provide irrigation and control flooding, and today generates about four billion kilowatts of electricity per year – enough to provide the power needs for 1.3 million people.

At the time of its construction between 1931 and 1935, the Hoover Dam was the most expensive engineering project in United States history at a cost of $49 million, which, adjusting for inflation, would be $700 million by today’s standards. The Hoover Dam created the enormous reservoir known as Lake Mead, which even today is the largest manmade reservoir in the U.S. at 110 miles long and 560 feet deep. In addition, the Hoover Dam and beautiful Lake Mead have created a bustling tourism community by providing plenty of outdoor recreation including boating, swimming, and fishing. Lake Mead also supplies municipal water for Las Vegas, Phoenix, and Tucson, and provides storage during drought.

Building the Hoover Dam took enormous effort. Construction of the dam utilized 91.8 billion cubic feet of concrete to create a retaining wall that weighs about 6.6 million tons. In fact, the mass of concrete in the Hoover Dam would pave a road from San Francisco to New York City. In addition, the volume of water in Lake Mead, when filled to capacity, is enough to submerge the entire state of Connecticut in ten feet of water. Incredibly enough, although the dam was expected to take five years to construct, it was actually completed ahead of schedule. 96 people died during the construction of the Hoover Dam; however, contrary to the popular urban legend, none of the deceased are encased within the dam’s concrete.

Oroville Dam
Oroville Dam

3. Oroville Dam

Oroville Dam, located about 70 miles north of Sacramento at the three forks of the Feather River, is the tallest dam in the United States, standing over 770 feet tall. The dam is an earthfill dam that holds back Lake Oroville, a manmade reservoir containing 3.5 million acre-feet of water. Oroville Dam stretches three quarters of a mile at its base and almost 7,000 feet across at its top.

The most highly monitored dam in the world during construction, the Oroville Dam was built between 1961 and 1967, and was officially dedicated in 1968. Just seven short years later, in 1975, a significant earthquake struck a few miles southeast of Oroville, and the new dam was put to the test. To the credit of the engineers, the dam oscillated with the earthquake and did not suffer a solitary crack or leak.

The Oroville Dam, along with its reservoir, Lake Oroville, not only provides drinking water, water storage, and hydroelectric power, it also protects downstream residents from the flooding of the Feather River. Providing about 750,000 acre-feet of flood control storage, the Oroville Dam has minimized damage from floods that have occurred in every decade since the dam’s construction. It also provides a beautiful location for a plethora of recreational activities including boating, camping, and fishing.

Tragically, 34 men died during the construction of the Oroville Dam. Just two years after the dam’s completion, President Richard Nixon signed the Occupational Safety and Health Act (OSHA) into law, drastically reducing the number of workplace accidents and casualties.

Redridge Steel Dam
Redridge Steel Dam

4. Redridge Steel Dam

Located across the Salmon Trout River in Redridge, Michigan, the Redridge Steel Dam is is a flat slab buttress dam constructed of steel. Steel is rarely used for construction of dams, which are typically earthenworks or masonry, and the Redridge Steel Dam is one of only three steel dams ever constructed in the United States. The other two are the Ashfork-Bainbridge Steel Dam, constructed in Arizona in 1898 to supply water for railway operations and still fully operational, and the Hauser Lake Dam, which was constructed in 1901 in Montana but failed less than a year later.

Timber Crib Dam Falls
Timber Crib Dam Falls

Prior to the construction of the Redridge Steel Dam, the Atlantic Mining Company built a timber crib dam across the Salmon Trout River in order to create a reservoir to supply water for mining operations. The reservoir created by the timber crib dam was insufficient, and so the Redridge Steel Dam was built; however, the original timber crib dam remained submerged in place upstream of the new dam. After operating for several decades, the Redridge Steel Dam fell into disrepair after mining operations ceased, and in 1941, the dam broke and caused a flood. The dam owners opened the spillways and cut holes in the steel dam so that it would no longer retain any water, and in this way the original timber dam was revealed — and along with it, breathtaking waterfalls.

With the threat of being labeled a “significant hazard” dam by the Michigan Department of Environmental looming, the timber dam was lowered 13 feet in 2004 in order to relieve pressure and make it safer. While a more permanent solution is still needed, both dams have been estimated to be safe for the foreseeable future, allowing visitors the ability to appreciate the lovely falls created by the old timber dam.

Roosevelt Dam
Roosevelt Dam

5. Roosevelt Dam

Constructed between the walls of a box canyon near the Salt River and Tonto Creek, the Roosevelt Dam was the first water project built under the 1902 Reclamation Act, and was the largest masonry dam in the world at that time. Italian stonecutters carved the stones used in the construction of the dam from the nearby cliffs, and when completed, the dam stood 280 feet tall and 184 feet wide at its base. The dam supplied water and electricity while also controlling the dangerous floods that had plagued the nearby Phoenix area.

Construction of the dam occurred between 1905 and 1911 while Arizona was still just a territory, and the total cost was $10 million. Supplying electricity to rural households, the Roosevelt Dam was a modern marvel. It would be ten years before the National Rural Electrification Act brought power to the rest of rural America, and so Phoenix quickly became a bright, modern city, and Arizona officially became a state only one year after the dam’s completion. The Roosevelt Dam was listed as a National Historic Landmark in 1963 and, to this day, it adorns the state seal of Arizona.

Dworshak Dam
Dworshak Dam

6. Dworshak Dam

Located just outside the city of Orofino, Idaho on the North Fork of the Clearwater River, the Dworshak Dam is the tallest straight axis gravity dam in the Western Hemisphere and the third highest dam in the United States. Constructed between 1966 and 1973, the Dworshak Dam is primarily used for flood control and hydroelectric power. The dam has three power-generating unts and received authorization for three more in 1990; however, the authorizations were revoked amid political controversy and citizen opposition when it was found that a second dam would be needed to handle peak loads.

The reservoir created by the Dworshak Dam holds almost 3.5 million acre-feet of water and is 53 miles long. The dam stands 717 feet tall, generates 380,000 kilowatts of power, and contains more than twice the concrete than does Cheope’s Great Pyramid in El Giza, Egypt.

Perhaps more notable than its significant mass is the controversy that has surrounded the Dworshak Dam since its inception. In his travel guide Idaho for the Curious, Cort Conley writes, “There have always been more politicians than suitable damsites. Building the highest straight axis gravity dam in the Western Hemisphere, on a river with a mean flow of 5,000 cubic feet per second, at a cost of $312 million, in the name of flood-control, is the second-funniest joke in Idaho. The funniest joke is inside the visitor center: a government sign entreats, ‘…help protect this delicate environment for future generations.’ The North Fork of the Clearwater was an exceptional river with a preeminent run of steelhead trout, and the drainage contained thousands of elk and white-tail deer. The Army Corps of Engineers proceeded to destroy the river, habitat, and fish; then acquired 5,000 acres for elk management and spent $21 million to build the largest steelhead hatchery in the world, maintaining at a cost of $1 million dollars a year what nature had provided for nothing.”

New Cornelia Mine Tailings Dam
New Cornelia Mine Tailings Dam

7. New Cornelia Mine Tailings

OK, so the New Cornelia Mine Tailings is not really a dam per se, but it IS often cited as the largest dam structure in the country by its volume of 7.4 billion cubic feet. Located just south of Ajo, Arizona, the New Cornelia Mine was operational from 1912 until 1983, when it closed due to the low price of copper. Mine tailings are waste materials such as bits of rock, dirt, mud, and process effluent from the mining process. While the mine was operational, the tailings were heaped into an enormous pile in order to hold back future tailings, and therefore the tailings pile is actually considered a dam. Today, Phelps Dodge owns the mine. There has also been recent talk of mining the tailings, although nothing has yet been scheduled.

Do you agree with our list of the 7 most interesting dams in the United States or do you know of a dam that should be included? Let us know – we’d love to hear from you!

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Dam safety in the United States

What are dams?

Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California and is the tallest dam in the country.
Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California and is the tallest dam in the country.

In general terms, a dam is any structure that obstructs or converts the flow of water in rivers and streams, and they frequently serve more than one purpose. Dams store water to compensate for fluctuations in river flow, and they also provide irrigation, hydropower, drinking water, flood control, and support for recreational activities. There are four main types of dams, and dams are often a combination of these different types:

Embankment
Embankment dams are typically constructed from natural earth materials such as rock and compacted soil, and are therefore far less expensive than concrete dams. Therefore, not surprisingly, more than 80% of all large dams in the United States are embankment dams. Typically used to retain water across wide rivers, embankment dams have a triangular profile and an impervious core and are termed “earthfill” or “rockfill” depending on whether they are primarily comprised of earth or rock.

Gravity
Gravity dams are constructed of concrete or stone masonry and span narrow river valleys with firm bedrock. They are designed to hold back water by simply using the weight of the dam alone to resist the horizontal water load pushing against it. Each section of the gravity dam is stable on its own, independent of any other dam section.

hoover_dam_arch_gravity_dam
The Hoover Dam is a massive arch-gravity dam that was constructed during the Great Depression, and the project’s success helped usher several decades of major water projects funded by the U.S. government.

Arch
While arch dams are also constructed of concrete, they differ from gravity dams in that they are designed to transfer water loads to adjacent rock formations. Arch dams are constructed only in narrow canyons with strong rock walls that are able to resist the arch pressure at the foundation and sides of the dam. Arch dams are thin and require less material than any other type of dam.

Buttress
Buttress dams are hollow gravity dams with a solid upstream side that is supported by a series of buttresses on the downstream side. Constructed of reinforced concrete, buttress dam walls are straight or curved and are extremely heavy, pushing the dam into the ground.

Dams in the U.S.

In the United States, there are approximately 84,000 dams. The average age of these dams is 52 years old, and by 2020, over 70% of our nation’s dams will be over 50 years old, which is the widely-accepted longevity of most dams. In addition, the number of high-hazard dams, which are dams whose failure would likely cause the loss of life, is on the rise. Currently there are over 14,000 high-hazard dams nationwide, with another 13,000 being labeled significant-hazard, meaning their failure would cause significant economic loss. There are over 4,000 deficient dams, meaning they are at serious risk of failure, and 2,000 of these deficient dams are also high-hazard. The cost to repair these dangerous dams is estimated to be about $21 billion.

Many of our dams were originally constructed as low-hazard dams, which have more lenient design criteria due to their location in non-developed areas, typically agricultural. However, with the nation’s population growth and extensive development, these dams are now located in populated areas and considered high-hazard. This trend is expected to continue as population steadily increases.

The Johnstown Flood, known as the Great Flood of 1889, occurred on May 31, 1889 after the catastrophic failure of the South Fork Dam on the Little Conemaugh River 14 miles upstream of the town of Johnstown, PA. The dam broke after several days of extremely heavy rainfall, unleashing 20 million tons of water from the reservoir known as Lake Conemaugh. With a flow rate that temporarily equalled that of the Mississippi River, the flood killed 2,209 people. National Dam Safety Day is celebrated on May 31 every year in memory of this flood.
The Johnstown Flood occurred on May 31, 1889 after the catastrophic failure of the South Fork Dam on the Little Conemaugh River 14 miles upstream of the town of Johnstown, PA. The dam broke after several days of extremely heavy rainfall. With a flow rate that temporarily equalled that of the Mississippi River, the flood killed 2,209 people and decimated the town (Main Street shown in photo). National Dam Safety Day is celebrated on May 31 every year in memory of this flood.

The federal government owns only 3,225 — about 4% — of our nation’s dams. The remaining dams, over two-thirds of which are privately owned, fall under the jurisdiction of state dam inspection programs, with no federal oversight or regulation. State dam safety programs provide the permitting, inspection, and recommendations, along with enforcement authority, for 80% of our nation’s dams. Only one state, Alabama, completely lacks a dam safety regulatory program, but the rest are sorely underfunded and understaffed. For example, the average number of dams per dam safety inspector is 207. It is indeed daunting that dam safety programs are largely responsible for public safety, yet lack the resources to effectively provide that safety.

What causes dam failure?

  • Overtopping causes 34% of all dam failures. Inadequate spillway design, blocked spillways, settlement of the dam crest, and floods exceeding dam capacity are all causes of overtopping.
  • Foundation defects such as slope instability and settlement cause about 30% of all dam failures.
  • Piping, resulting in internal erosion caused by seepage, causes 20% of all U.S. dam failures.
  • The remaining 16% of dam failures are the result of other causes including structural failure of materials, inadequate maintenance, settlement and cracking, and deliberate acts of sabotage.

What can we do?

Of the 14,726 high-hazard dams in the country, only 8,854 have EAPs in place
Of the 14,726 high-hazard dams in the country, only 8,854 have EAPs in place

The 2010 Iowa Lake Delhi dam failure cost our economy about $170 million between damages and economic losses, and the 2006 Kaloko Reservoir Dam failure in Hawaii killed seven people. To make matters worse, the Kaloko dam was over 100 years old and had never once been inspected prior to its failure. Our dams have been given a “D” rating from the American Society of Civil Engineers (ASCE) 2013 Infrastructure Report Card, and the ASCE has recommended steps to take to improve that rating, one of which is the development of Emergency Action Plans (EAPs) for 100% of our nation’s high-hazard dams by 2017. Only 66% currently have EAPs.

Having effective EAPs at all high-hazard, and most significant-hazard, dams in the United States is the most important step in reducing the risk for loss of life and property damage from dam failures, and it is absolutely critical that deficient high-hazard dams have updated EAPs in place. To that end, Tata & Howard has been working with the Connecticut Department of Energy and Environmental Protection (CT DEEP) this spring to perform over 40 dam inspections and update over 30 EAPs.

T&H VP Sal Longo, P.E., assisted CT DEEP with the inspection of over 40 dams this spring.
T&H assisted CT DEEP with the inspection of over 40 dams this spring. Shown above is Vice President Sal Longo, P.E., during an inspection.

Besides maintaining EAPs for high-hazard dams, ASCE recommends the following steps to address our nation’s dam infrastructure:

  • Reauthorize and fully fund the National Dam Safety Program (NDSP), which is a partnership of the states, federal agencies, and other stakeholders that encourages individual and community responsibility for dam safety.
  • Establish a national dam rehabilitation and repair funding program to cost share repairs to publicly owned, nonfederal, high-hazard dams.
  • Implement a national public awareness campaign to educate individuals on the location and condition of dams in their area.
  • Encourage incentives to governors and state legislatures to provide sufficient resources and regulatory authorities to their dam safety programs.
  • Require federal agencies that own, operate, or regulate dams to meet the standards of Federal Guidelines for Dam Safety.

In addition to local and federal oversight and regulation, there are a number of steps that the public can take to minimize the risks associated with dam failure:

  • Know your risk. Find out if you live in a dam breach inundation zone by contacting your local emergency management agency or by contacting your state dam safety program (www.damsafety.org).
  • Know your role. Know the dams in your area where you live and work, and be aware of potential maintenance issues and report them to authorities immediately. Dam owners have the responsibility to maintain their dams and to have an EAP, especially for high-hazard dams, and should work with the federal or state regulator to comply with safety standards.
  • Take action. Inform your friends and neighbors about the benefits and risks associated with dams and have an evacuation route in place for your family and/or business should a dam fail. If you live below a dam, it is imperative that you maintain flood insurance.

In conclusion

Dams are an integral part of our infrastructure, providing many important benefits. A large percentage of our nation’s dams are in need of repair and updating, and our high-hazard dams are of particular concern. It is critical that all of us, including the federal government, states, communities, engineers, and private dam owners, work together to promote dam safety and education. Our future depends on it.

For more information on dam safety, please visit https://www.fema.gov/dam-safety#

www.scientificamerican.com
www.encyclopedia.org
www.harimurti.blogspot.com
www.infrastructurereportcard.org
www.damsafety.org
www.americanprogress.org

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Roald Haestad, Inc. staff join the Tata & Howard team

Roald Haestad, Inc. staff join the Tata & Howard team

Tata & Howard enhances its water, wastewater, and stormwater consulting engineering services and adds dam engineering services by acquiring the assets of Connecticut-based consulting firm Roald Haestad, Inc. 

Members of the team on the first day at our new offices
Members of the team on the first day at our new offices

WATERBURY, CT, August 27, 2014 – Tata & Howard, Inc., a leading innovator in waterwastewaterstormwater, and hazardous waste engineering solutions, announced today that it has acquired the assets of Roald Haestad, Inc., (RHI) a civil engineering consulting firm located in Waterbury, CT.  Founded in 1971, RHI is a full service civil engineering firm providing services in water supply, stormwater, water distribution systems, and wastewater collection systems, with targeted expertise in safe yields and dam engineering. Throughout its 43-year history, RHI has built a solid reputation for providing superior design and engineering services along with exceptional client relations. Additional services include roadways, permitting, funding assistance, GIS, and surveying, including GPS, floodplain mapping, and bathymetric surveys.
“Our acquisition of RHI complements our existing engineering consultant offerings by allowing us to provide additional civil engineering services, including dam engineering, surveying, and streamflow release analysis,” noted Donald J. Tata, P.E., co-founder and President of Tata & Howard, Inc. “We intend to provide the same high-level service to the clients of RHI, and are excited about the wide variety of options we can now offer to our existing and new clients,” explains Tata.
To provide the best possible transition for current RHI clients, Tata & Howard will continue operations from Haestad’s Waterbury location, along with existing RHI employees. “The acquisition significantly adds to our talent base and also expands our geographic presence in New England,” Tata commented. “RHI employees bring decades of solid engineering experience to the table, and we are enthusiastic to have them on the Tata & Howard team.”
Ronald G. Litke, P.E., President of RHI, will be retiring and remain available on a limited basis, He commented, “In looking to the future, our key concerns were our clients and our employees” he commented. “By joining Tata & Howard, we have ensured seamless transition and exceptional service for our clients, along with a stable and bright future for our employees. It’s a win-win situation.”