While the Patriots didn’t rely on luck for another Superbowl victory on Sunday, when it comes to weather, Boston certainly has. Yes, you read that right. While it may not seem like it on days like today, Boston has hit the jackpot when it comes to avoiding major flooding.
According to the Boston Harbor Association, last week’s Blizzard Juno marks the fifth time Boston has nearly missed a 100-year flood since Superstorm Sandy. Had the blizzard’s storm surge hit during high-tide, we would have experienced a “100-year” flood event.
In addition to Juno, we have had four other near misses in the past 2 1/2 years:
- Superstorm Sandy
- Blizzard Nemo
- Nor’easter Saturn
- Nor’easter Hercules
So what does a 100 year storm look like? If any of these storms had hit during high tide all of the dark blue areas could have been underwater.
So what about the light blue? Well, if sea level rises 2.5 feet (which may be unavoidable at this point), than we’re dramatically raising the stakes. If any of these storms hit during high tide plus two 2.5 feet of sea level rise, the Charles River Dam could be over topped, flooding much of Cambridge, the Back Bay, South End and beyond.
Yeah, this weather is gross, but it could be a lot worse. These floods are called 100-year floods because they have a one percent chance of occurring in any given year, and therefore have an expected value of one over 100 years. However, researchers from MIT and Princeton have found that with climate change, this probability is increasing. The group looked at the impact of climate change on storm surges, using New York City as a case study. They found that a two-meter surge (New York’s current 100-year flood level) would occur once every 3-20 years; and a 3-meter surge (current 500-year flood) would occur every 25 to 240 years based on their models and assumptions.