Development of a Consistent Framework: Risk Prioritization for 36 Unsafe, High Hazard Dams in Massachusetts

Dam owners/regulators are responsible for addressing risks related to unsafe dams such as loss of life from predictable and unpredictable catastrophic events including dam failure. Aging infrastructure, limited resources, and increasing development along downstream reaches complicate this responsibility. Funding from the FEMA High Hazard Potential Dams (HHPD) Grant Program is helping owners/regulators address risks associated with dam safety issues.
The Massachusetts Department of Conservation & Recreation Office of Dam Safety (MA ODS) realized the importance of the FEMA HHPD program in addressing dam safety issues related to dams in Poor or Unsafe condition in Massachusetts. From a large portfolio of more than 300 high hazard dams, MA ODS identified 35 dams that would qualify for HHPD funding. With the FEMA funding award, MA ODS embarked on a portfolio screening level risk analysis for the 35 dams. The two objectives were to develop a risk prioritization matrix to allow for qualitative evaluation and comparison of the 35 dam and to rank the dams in order of priority for rehabilitation, partial breach, or removal (i.e., repair or removal). Consistency and efficiency were predominant goals in developing the risk screening program for the 35 high hazard dams. The approach was especially challenging given the inconsistencies in previous studies.
MA ODS will use the findings of risk informed dam prioritization to apply for future HHPD grant funding to repair/remove the dams, starting with those that pose the greatest risk to the public. This paper provides a summary of a combined quantitative and qualitative risk analysis framework developed to rank the 35 high hazard dams in the MA ODS portfolio based on likelihood of failure and consequences.