Investigators are examining the exact causes of the Edenville and Sanford dam failures in 2020, but there have already been calls for regulatory reform
Dam safety in the US state of Michigan was thrown into the spotlight after the failure of Edenville and Sanford Dams during May 2020. International Water Power and Dam Construction (IWP&DC) magazine takes a closer look.
On 19 May 2020, the Edenville and Sanford Dams near Midland in the US state of Michigan, failed.
Over a 48-hour period more than 15-20cm of heavy rain fell locally and subsequent rainfall placed additional stress on the many dams located on the Tobacco and Tittabawassee Rivers.
Edenville, along with Secord, Smallwood and Sanford, is part of a four-dam system on the Tittabawassee River. Due to the heavy rainfall and already saturated state of the water system, the river surpassed the flood stage in many areas.
At around 5.30pm on 19 May, a portion of Edenville Dam’s earthen embankment failed, causing an uncontrolled release of impounded water downstream towards the town of Edenville, Sanford Lake and Sanford Dam. The level of Sanford Lake rose quickly and by 7.45pm Sanford Dam had overtopped and failed.
The combined failures sent a torrent of water rushing down the already swollen Tittabawassee River through the village of Sanford, towards the cities of Midland and Saginaw.
More than 11,000 people were evacuated and 2,500 structures were damaged by the floods but no major injuries or fatalities were reported. Preliminary damage estimates were in the region of $250m.
Until 25 September 2018, all four dams on the Tittabawassee River were hydroelectric and regulated by the Federal Energy Regulatory Commission (FERC). However, FERC revoked the licence to generate power at Edenville Dam as, for more than 14 years, dam owner Boyce Hydro Power had reportedly refused to follow orders to increase dam spillway capacity to handle severe floods.
Regulatory authority was then transferred over to the Department of Environment, Great Lakes and Energy (EGLE) in Michigan.
Prior to 2018, EGLE says it had no regulatory authority over the operation and maintenance of the dam. It wasn’t until this authority was “abruptly” transferred over that the department was able to receive and review decades worth of records and inspection reports. These had previously been unavailable as they were protected under federal critical infrastructure laws.
EGLE says that until it was able to review the records, it had no factual basis to take legal action under state law to force Boyce Hydro Power to improve dam capacity to withstand severe flooding.
At the same time, EGLE was working with a local stakeholder group to purchase Edenville Dam from Boyce Hydro. The group, the Four Lakes Task Force, planned to upgrade the dam and reacquire its federal hydropower generating licence. Unfortunately, tragedy struck before the plans could be fully realised.
On 27 May 2020, Michigan Governor Gretchen Whitmer directed EGLE to lead an investigation into the causes of the disaster and examine the storm event, the integrity of the dam and dam owner compliance, along with the wider issue of dam safety in Michigan, to prevent such an event from happening again.
On 1 September 2020, EGLE submitted its initial status report to Whitmer to summarise department action taken during the three and a half months after the dam failures, and review state dam safety operations. The Preliminary Report on the Edenville Dam Failure, Response Efforts and Programme Reviews, was the first in a series of reports that EGLE would receive from investigating teams.
“EGLE staff have been on the ground since day one of this tragedy and we will continue to do all that we can to help the residents of mid-Michigan and the communities in which they live, work and play,” said EGLE director Liesl Clark.
“We will continue to support, in an open and transparent way, the search for answers as to how these dam failures happened and why. We will also thoroughly review any recommendations and findings in future reports with an eye toward improving our department programmes and overall dam safety in Michigan.”
EGLE said that the exact cause of the dam failures will not be known until a thorough independent investigation has been completed. As the failure of Edenville Dam was likely to have impacted Sanford Dam, EGLE and FERC agreed to establish one investigation team to comprehensively review all contributing factors.
In late May 2020, FERC and EGLE directed dam owner Boyce Hydro to assemble an investigation team and provide resumes to FERC and EGLE for review and acceptance. It is standard FERC protocol to require the dam owner to fund the dam failure investigations, but the dam owner is not permitted to be involved in the investigative process.
In the following weeks, Boyce submitted resumes for six “very qualified” team members, which were unanimously accepted by FERC and EGLE. However, after an initial meeting on 17 June 2020, Boyce failed to finalise contracts with team members to commence the investigation.
After several attempts to compel Boyce to do so, FERC, in consultation with EGLE, took over the investigation team contracts and pressed forward with the investigation.
On 13 August 2020, the independent investigation team was directed to define their own scope and not take direction from EGLE, FERC or Boyce. The team has extensive experience probing dam failures (several members participated in the investigation of the 2017 failure of the Oroville Dam in California) and anticipates that this investigation will take approximately 12-18 months.
“With the knowledge and experience these professionals bring to the independent investigation, I am confident that we will get a clear picture of what went wrong with the two dams and why,” Clark said. “Transparency is extremely important as this process moves forward and EGLE is ready to provide any information necessary to help get answers to this tragedy.”
The five team members are:
- John France – team lead and expert in geotechnical engineering and emergency action planning
- Irfan Alvi – expert in structural engineering and human factors
- Jennifer Williams – expert in geotechnical engineering
- Steve Higinbotham – expert in hydraulic structures
- Arthur Miller – expert in hydraulic engineering, hydrology, and reservoir operations.
Dam Safety Task Force
On 3 September 2020, EGLE announced the 19 members who would comprise the Michigan Dam Safety Task Force and provide recommendations on policy, budget, legislative and enforcement reforms to prevent future dam failures across the state.
“The Michigan Dam Safety Task Force members have broad expertise and knowledge in all areas related to dam safety,” said Clark. “The historic rain event which led to the dam failure and catastrophic 500-year flooding event in Mid-Michigan illuminated the consequences of inadequate investing in infrastructure.
“It also points to potential improvements that should be made in policies, procedures, funding and regulations. The task force will analyse those areas and others and we are eager to see their recommendations.”
The task force is expected to release its findings early in 2021 and they will complement the other in-depth internal and external reviews taking place.
Association of State Dam Safety Officials
EGLE also enlisted the service of the Association of State Dam Safety Officials (ASDSO) to perform a thorough review of Michigan’s dam safety programme. On 1 October 2020, this was presented at a meeting of the Michigan Dam Safety Task Force.
The task force will analyse the report as part of its review and help state regulators and lawmakers prioritise recommendations to determine which are the most necessary and impactful to undertake.
The ASDSO report concludes that, when compared to a model programme, Michigan’s is understaffed and constrained by limited time, resources and budget; Michigan’s investments in dam safety have been lacking for decades, which increases the risk to public safety and the environment; and owners of high-hazard dams should perform detailed engineering re-evaluations to uncover latent dam safety defects commonly found in ageing structures.
“The ASDSO report acknowledges the decades of underinvestment in infrastructure in Michigan, which includes many dams that, if they failed, would put downstream residents’ lives in jeopardy,” Clark commented.
“We, along with the task force members, will take a close look at the many thoughtful recommendations in the report and welcome working collaboratively with the legislature and other stakeholders to strengthen Michigan’s dam safety programme while also holding owners accountable for safely operating their dams.”
The peer review team evaluated EGLE’s programme relative to ASDSO’s governing regulations and how a programme matches up with ASDSO’s Model Dam Safety Programme. The success of any dam safety programme, the team said in its report, depends upon:
- Adequate funding
- Quality physical inspections
- Dedication and commitment of the regulatory agencies
- Due diligence of the dam owner or operator
While Michigan’s dam safety staff “are dedicated, well-educated, experienced engineers that are doing the best they can,” the ASDSO team concluded that the programme should ideally have 11 staff, including three senior dam safety engineers and three junior safety engineers to oversee approximately 1,060 state-regulated dams.
Michigan’s programme currently has two dam safety engineers and one supervisor with a third dam safety engineer to be hired soon. In the fiscal year 2021 state budget recently signed by Governor Whitmer, there is funding for hiring two more dam safety engineers, which would bring the total to five.
For years, Michigan has not had rigorous enforcement of dam safety violations, which the team called “commonly accepted practice in Michigan”. It also recommended adding into statute a requirement that owners of ageing high-hazard dams perform periodic detailed evaluations of their facilities.
The ASDSO report outlined recommended changes that would have to be made by the legislature. It said the dam safety programme lacks the authority to require owners to obtain a permit to operate and maintain dams in a safe condition, nor to annually report on maintenance, operation and engineering investigations.
Also, there are no requirements for owners to maintain key records, periodic exercising of emergency action plans or for owners of high-hazard dams to provide proof of financial responsibility or security for the continued safe operation and maintenance of their dam.
A collaborative effort between EGLE, ASDSO and FERC was also called for to simplify the transfer of key information when the state takes over regulation of a former hydroelectric dam. The state of Michigan had to file Freedom of Information Act requests with FERC to obtain key documents and reports about the dam after FERC had revoked the hydropower licence for Edenville Dam.
The report suggested Michigan should follow the examples set by other states, including Pennsylvania and New Jersey, in offering a revolving loan programme to provide grants and low-interest loans to public owners of high-hazard dams that need rehabilitation.
Without investment in dam safety over many decades, the need for maintenance has increased as dams have aged. “National experience has demonstrated that a state organised and funded programme for grants and low interest loans is critical to achieving real progress in rehabilitating publicly-owned dams,” the report said.
The American Society of Civil Engineers (ASCE) 2018 Report Card for Michigan’s Infrastructure and the 21st Century Infrastructure Commission Report were also mentioned; both of which cited underinvestment in dam maintenance.
The ASCE Report Card gave Michigan a grade of C- and said “Michigan must make more progress to address dams in need of repair or removal. Expanded funding is needed to provide additional staffing for the EGLE dam safety unit, and for resources for dam owners to address dam repair or dam removal projects.”
The Infrastructure Commission Report estimated that Michigan needed $227m in state funding over 20 years to support maintenance and removal of dams.
In response to the Michigan dam failures, Malcolm Woolf, president and CEO of the National Hydropower Association (NHA), said that as an industry, dam safety is “our top priority”.
“Non-compliance with safety standards is unacceptable,” he stated. “While undoubtedly additional facts will emerge as FERC and other responsible agencies conduct investigations, initial reports indicate that, after years of unsuccessfully directing the owner to modernise the facility to meet federal dam safety standards, FERC revoked the owner’s licence to operate in 2018.
“The hydropower industry supports the necessary actions by FERC to ensure that dams are safe, remain safe, and meet performance expectations particularly during extraordinary flood events such as this one.”
On 10 December 2020, Congresswoman Debbie Dingell and Congressman John Moolenaar from Michigan, introduced bipartisan legislation that was written in response to the aftermath of the Michigan dam failures, and makes reforms and improvements to dam and hydropower safety operations and oversight.
The lawmakers’ legislation, the National Dam and Hydropower Safety Improvements Act of 2020, would enhance dam and hydropower safety operation requirements nationwide, and aims to modernise existing infrastructure through the development of new best practices and improved communications between FERC and states.
“In the midst of a global health pandemic and economic devastation, Michigan experienced a catastrophic, avoidable infrastructure collapse. The breach of the Edenville and Sanford Dams caused extensive damage in Michigan and its downstream communities. It drowned homes, businesses, and whole cities,” said Dingell.
“It is clear there are serious gaps in existing laws that need to be addressed and this could have been prevented. We can never let this happen again in any city in America with a high-hazard dam. I look forward to continuing to advance this legislation next Congress and hope to enlist strong bipartisan support from my colleagues.”
Moolenaar added: “I’ve been working hard to help our community recover, including securing approval for more than $100m in federal assistance that has come to our community to rebuild homes, small businesses, and private wells, as well as roads and bridges.
“However, there’s no doubt that the federal and state regulators failed our community when they were working with an uncooperative private dam owner. Those failures compounded over more than a decade into a devastating event that affected the lives of thousands of residents.
“This bipartisan legislation will address gaps in existing law and do more to ensure compliance with the safety regulations that are paramount to protecting the people of Michigan.”
The National Dam and Hydropower Safety Improvements Act of 2020 would specifically:
- Require FERC to provide a briefing and a report to Congress on the findings of the independent forensic analysis of the Edenville Dam and Sanford Dam failures
- Add a new requirement to section 10 of the Federal Power Act to mandate dam and project works meet FERC’s dam safety requirements and to require the licensee to manage, operate, and maintain the dam and project works consistent with dam safety requirements
- Amend Section 15 of the Federal Power Act to require FERC to issue a new licence only if the Commission determines the dam and other project works meet the Commission’s dam safety requirements, and that the operating conditions of the licence are consistent with those requirements
- Require FERC to establish procedures for evaluating the financial health of prospective hydropower licensees
- Require FERC to convene a technical conference with state representatives to examine best practices for dam safety
Striving to help
EGLE director Clark said that since the moment the dams failed, EGLE has continued to work with local, state, and federal partners to help affected communities recover from their losses.
“We cannot overstate the extent to which the emergency preparedness planning and swift action from first responders helped prevent more disastrous outcomes,” she said, adding that public servants at all levels worked incredibly fast to fight back in every way possible and protect the community.
“I am very proud of our team’s work every day—our commitment to leadership, making decisions rooted in data, and partnering with the communities we serve. This tragedy reminds us that risk cannot be eliminated entirely. But at EGLE we are striving to move Michigan ever closer to that goal.”
This article originally appeared in International Water Power and Dam Construction magazine