BOSTON — State Auditor Joe DeNucci’s Division of Local Mandates (DLM) reported that 100 Massachusetts dams owned by 62 localities are rated as unsafe or in poor condition and have the potential to cause loss of life or significant property damage in the event of dam failure.

The counties with the largest number of critical dams are: Worcester (32), Middlesex (14), Norfolk (13) , Bristol (11), and Essex (10). Municipalities with the highest concentrations of critical dams are: Fitchburg (6), Foxborough (5), Attleboro (4), Gloucester (4), Springfield (4), Worcester (4), Clinton (3), and North Adams (3). Only Suffolk, Dukes, and Nantucket counties do not have a municipally-owned critical dam.

Engineers’ inspections indicate that 94 of these 100 dams are in poor condition and six are rated as unsafe, posing a high risk of failure. The six unsafe dams are located in Foxborough (2), Athol, Bolton, Danvers, and Dudley.

DeNucci’s report found that 75 of the 100 dams reviewed do not have a formal, written emergency action plan to ensure a reasoned approach to evacuation and emergency management. Owners of only seven of the 63 dams rated as a significant hazard had a “well thought out” plan of emergency action; 22 had “some idea,” while 23 had “no idea of what to do in an emergency.” DeNucci estimated the collective cost of developing these emergency action plans at $800,000.

Of long-term significance, DeNucci recommended the legislature enact a previous proposal to institute a no-interest, revolving loan program to assist cities and towns in addressing the approximate $60 million in repairs needed to fix these 100 dams, or about $600,000 per dam.

The Office of Dam Safety (ODS) within the Department of Conservation and Recreation regulates 1,547 of the 2,892 dams in Massachusetts. Of the remaining dams, 1,264 don’t require regulation because of their small size, 77 fall under federal purview, and the status of four is listed as “unknown.”

Cities and towns own 647 of the dams regulated by ODS and 100 of these are in unsafe or poor condition and are classified as having high or significant hazard potential.

  • A high hazard dam is one “where failure will likely cause loss of life and serious damage to homes, industrial or commercial facilities, important utilities, main highways, or railroads.”
  • A significant hazard dam is one “where failure may cause loss of life or damage to homes, industrial or commercial facilities, secondary highways, or railroads, or cause interruption of use or service of relatively important facilities.”

DeNucci also reported that ODS does not have adequate staffing to provide the required oversight to ensure compliance with the dam safety law. Recent budget cuts have left ODS with 4.5 full-time equivalent positions resulting in a ratio of 640 regulated dams per employee, which is more than triple the case load recommended by the national Association of State Dam Safety Officials.

Data suggests that nearly 1,000 dams in Massachusetts were built between 50 and 100 years ago, hundreds are between 100 and 200 years old, and a small number exceed 200 years in age. Factors such as age, outmoded design standards, poor maintenance, earthquakes, and floods exacerbate the likelihood of dam failure. The vast majority of the critical 100 municipal dams are relatively large, at least 15 feet in height, or impounding at least 50 acre-feet of water.

“My report highlights a significant threat to public safety,” DeNucci said. “Local and state officials need to work together immediately to develop the mandated emergency action plans and devise a long-term financial solution to fix these dams. These are difficult times, but some prudent budgeting and financing now could avert a major crisis in the future.”