Residents living along the South Carolina coast breathed a sigh of relief when forecasters announced the area would be spared a direct hit from Hurricane Joaquin. Unfortunately, many residents in the Low Country and the Midlands did not realize they faced flooding from 1,000-year rains that stressed several neglected aged dams to the breaking point.
While it is no secret that infrastructure in the United States desperately needs repair, rehabilitation, or replacement, most people tend to associate the word “infrastructure” with roads and bridges. The historic rain event that occurred during the first week of October 2015 in South Carolina brought another form of infrastructure to the attention of the public – our nation’s system of dams. Due to the 1,000 year rains leading to historic high readings on 17 USGS stream gages, as well as 15 record breaking readings during the time the USGS has measured the water flow in South Carolina’s rivers and streams, 36 dams failed and caused additional flooding that devastated homes and businesses long after the rains subsided. Adding to the catastrophe, 19 people lost their lives during the floods.
While some people attributed the failure of the dams to the record-breaking rainfall event, the reality is that a 2013 study of South Carolina’s dams classified many as “high hazards” to both life and property and in need of repair or replacement. In fact, many of the dams that failed were more than a century old. Unfortunately, concerns of lakefront property owners about the potential effects of lowering reservoir levels on property values led to politicians to tie the hands of regulators in regard to issuing emergency orders to mitigate risk. In addition, the state legislature grossly underfunded South Carolina’s dam safety program, administered by the South Carolina Department of Health and Environmental Control (SCDHEC). In fact, according to the American Society of Civil Engineers (ASCE) 2013 Report Card for America’s Infrastructure, South Carolina’s dam safety budget of $65,000 ranked 49th when compared to other states. While South Carolina state officials said they could not provide information about the current budget and staffing levels for dam safety, the Association of State Dam Safety Officials reported the 2014 budget allocated $260,000 for dam inspections and safety. The Greenville Times reported the S. C. dam safety budget for 2015 was $453,000 and called for the legislature to make dam safety a priority.
Dam Safety: Out of Sight, Out of Mind
Unlike roads and bridges that the public sees and uses, most of our nation’s 84,000 dams are not readily visible to most people. In addition, 69 percent of dams in the United States are privately owned. Many dams were built more than half a century ago to prevent flooding of land used for agricultural purposes. With the development of farmland into residential neighborhoods, dam safety officials changed the designation of low-risk earthen dams to high hazard dams. In the case of South Carolina, during the 1950s and 1960s, developers of lakefront neighborhoods constructed dams and then passed the ownership, as well as the maintenance responsibilities, onto neighborhood homeowner’s associations. The owners of these dams are often unaware of the cost of maintaining them. In fact, when SC DHEC sent out emergency repair orders to 75 private dam owners, they faced a backlash from some of them about the cost of hiring an engineer and making repairs.
According to the New York Times, the problem of neglecting dams is not an issue limited to South Carolina. During the past five years, 73 dams, with an average age of 62 years, in the United States failed during “extreme weather events.” The ASCE reports that more than 4,000 dams in the US are structurally deficient and that dam safety officials consider 2,000 dams as high-hazard dams, meaning the failure of the dam would cause significant risk of harm to both people and property. While the ASCE estimates the cost of repairing structurally deficient dams to be $21 billion, the price of neglecting high hazard dams is unimaginable.Aerial View of 2015 South Carolina Floods
Video Link: https://www.youtube.com/watch?v=9QgbQ1DWVkQ
The Cost of Neglecting Our Nation’s Dams
The total economic losses directly attributed to the 2015 South Carolina floods are likely to total $2 billion, according to Insurance Information Institute. This estimate does not include the hundreds of thousands of dollars in uninsured losses incurred by state agencies for lost billing for services, as is the situation reported by the South Carolina of Mental Health, which estimated their losses at $800,000. In addition, the state’s emergency management agency and the South Carolina National Guard testified to the S.C. House Ways and Means Committee that their agencies “little dollar” flood-related expenses totaled $37 million. The US Department of Transportation provided the state with a $5 million in emergency funding to make emergency repairs to roads and bridges destroyed by the floodwaters. While these expenses are significant, especially in a relatively poor state like South Carolina, many property owners and businesses face flood-related losses with costs not yet determined, in addition to dam rehabilitation and replacement costs.
Post-Flood Inspections Reveal Many Privately Owned Dams Need Immediate Repairs
After the floodwaters had receded, SCDHEC inspected more than 650 dams throughout the state of South Carolina that posed a risk to human life and/or property in the event of their failure that fell under their jurisdiction. Due to SCDHEC’s deficit of qualified dam safety staff, the US Corp of Engineers assisted in the evaluations. These assessments resulted in SCDHEC issuing 75 emergency orders to the parties responsible for dams deemed to be at-risk for imminent failure. If the dam owner does not submit a plan to rehabilitate or replace the dam by a deadline set by SCDHEC, the individual, business, or HOA not only has to pay to restore the dam, but they also need to remit payment to cover fines that can be as much as $500 per day. The agency also issued 167 notices advising property owners their dams incurred damage during the historic weather event or the structures needed routine maintenance. In the event the property owner or HOA chooses not to repair the dam, or is unable to do so because of the expense involved, the other acceptable solution is to lower the lake or reservoir water level as so to decrease the pressure on the dam. While this may seem like a viable solution, the dam owner will find that draining a lakes and reservoir has other long-term hidden expenses.
Lake Front Homeowners May Incur a Loss in Property Values
After the flood waters had receded in late October, some people who lived downstream from failed dams discovered that portions of their property washed away by the floods. While these people struggled with the consequences water inundating their land, lakefront homeowners faced the issues stemming from the exact opposite problem – a lack of water. When an 115-year-old dam collapsed, the water in Lake Elizabeth, located in the Midlands region of South Carolina, quickly drained. According to The State newspaper, homeowners living along the shores of at least three other lakes experienced the same fate. With the cost of replacing dams costing approaching $ 1 million, many property owners are starting to come to terms with the prospect that their lake views are now a part of history. Adding insult to injury, the value of the former waterfront properties decreased from 30 to 40 percent essentially overnight. The only option currently available to these homeowners is to appeal the tax assessor’s valuation of their property.
Owners of Failed Dams and Others Face Civil Lawsuits Filed by Flood Victims
Another challenge posed to the owners of failed dams in South Carolina is an inundation of civil liability lawsuits filed by flood victims. These legal actions allege the owners of the dams were negligent in the maintenance of the dams, which led to their failure. A review of a 2006 report published by The Association of State Flood Plain Managers provides insight into the potential complexity of these suits. Since many of the individuals and HOAs that owned these dams did not have insurance to cover these losses, the expenses related to negotiating settlements or litigation, along with the actual cost of any compensation to flooding victims, will be fully the responsibility of the dam owners. Other parties named in the lawsuits include the following: county governments, which homeowners allege failed to maintain drainage systems; insurance carriers that denied claims unjustly according to the plaintiff; and South Carolina Electric and Gas, a power company that released water from dams and lakes that compounded flooding issues as per residents that live downstream.
Nuclear Power Plants Downstream from Dams at Risk of Failure
According to the Union for Concerned Scientists (UCSUSA), one reactor at the H.B. Robinson Nuclear Power Generating Station, located in Hartsville, S.C. and two reactors at the Oconee Nuclear Station, located in Seneca, S.C. are downstream from dams at risk of failure. In a 2011 report, the UCSUSA identified 32 other nuclear reactors that are also subject to similar hazards. As illustrated by the meltdown of four reactors at the Fukushima Daiichi nuclear plant when a tsunami inundated the facility in 2011, such an event poses at significant risk to those who live near these plants. In South Carolina alone, between 40,000 to 90,000 people would be in harm’s way if a flooding event occurred at either of the nuclear power plants.
The Need to Prevent Future Dam Disasters
Many state officials and media sources misinterpreted the National Weather Service’s description of the October 2015 South Carolina floods as the result an event that is likely to occur once every 1,000 years. The correct meaning of the phrase “1 in 1,000-year rainfall event” is that the chance of such heavy rain is 0.1 percent annually. In other words, a similar event many occur again next year in South Carolina, although the risk is not great. In fact, since 2010, six 1 in 1,000-year rainfall events have occurred in the United States according to USA Today. Unfortunately, as the climate continues to warm, the likelihood that these extreme events will occur is increasing.
According to the predictions published in the 2014 National Climate Assessment (NCA), not only is the frequency of these extreme weather events rising, but the amount of rainfall is also increasing. In fact, since 1991, the precipitation during these once rare events is 30 percent greater than in the preceding 90 years. The following map from the 2014 NCA shows the areas where flooding events are likely to occur as well as the areas where the magnitude of flooding events are decreasing.
The Lessons from the 2015 South Carolina Point to Solutions for the Future
As South Carolina recovers and rebuilds, the catastrophic dam failures have gained the attention of not only government officials, but also engineers, architects, and surveyors across the country. The post-flood inspections of high hazard dams provide engineers with information about the performance of different types of barriers, as well as the design flaws that contributed to the failure of some structures. When designing homes and commercial buildings downstream from dams, architects may need to convince their clients that inland structures in floodplains require elevation just like houses and businesses do along the coast. When mapping a site, surveyors need to take care to identify privately owned dams, as well as those that built a century ago and forgotten, so homeowners, HOAs, and business are aware of them. Most of all, state and federal officials need to make certain dam safety programs have adequate funding, staffing, and enforcement authority.