The Maine Section of the American Society of Civil Engineers gave the state’s infrastructure a C rating in its latest report card.

Over five evaluations, Maine has consistently gotten the mediocre ranking, according to the society’s latest report. The group releases a new report card every four years. In 2020, Maine secured a C-minus grade, meaning its score improved slightly this time around.

The society reviewed 16 categories, of which only three received B or B-minus grades signaling “good condition.” Nine categories were considered “mediocre” with C-level rankings, and four were given D-level grades indicating “poor condition,” according to the report.

“The maintenance and improvement of Maine’s infrastructure is vital to our economy, health, safety, security and environmental sustainability,” the society said in its report released Tuesday. The report card evaluates infrastructure based on its capacity compared to current and future demands, overall condition, funding and resilience to threats and incidents, among other factors.

Aviation was Maine’s strongest category, earning the state’s only B grade. Maine’s rail and port infrastructure each got B-minuses.

The state’s dams, bridges, levees and transit systems all got D-plus grades, Maine’s lowest scores. Only about half of tested dams are in satisfactory condition, while more than half the state’s bridges are over 50 years old – and nearly one in seven are in poor condition – according to the report.

The report also included a handful of recommendations for improvement, such as prioritizing public safety around dams and the prevalence of PFAS, or forever chemicals. Climate resilience and pursuing sustainable funding pools were also listed as key areas that need improvement.

The report suggests Maine set user fees that “accurately reflect the true costs of using, maintaining and improving our infrastructure,” arguing that the public must be willing to accept higher costs to fund necessary upgrades. Maine should also prioritize educating its next generation of workers, relying on the institutional knowledge carried by the state’s aging population, the report suggests.

The report notes that Maine is a national leader in renewable energy, but argues that new transmission lines and increased storage capacities are necessary to ensure a reliable supply of power without having to resort to non-renewables to fill short-term or emergency needs. The report estimates more than $2 billion annually would be required to fund these improvements.