By Emily Norton, Executive Director for the Charles River Watershed Association
Charles River Watershed Association held our annual “Three Rivers Report Card event” a couple weeks ago along with our friends at Mystic River Watershed Association and Neponset River Watershed Association. (MyRWA hosted at the beautiful River’s Edge in Medford)
We began grading the Charles in 1995, when it earned a D.
For this year, Charles River grades ranged from a B for Hopkinton to Medfield; A- from Medfield to Waltham; B- for Watertown to Boston; and a C in the Muddy River, which continues to be the most polluted tributary we sample.
(What does a B- mean? It means that in Cambridge and Boston, the Charles is safe to swim 50-75% of the time… which is better than it used to be, but not clean on a frequent enough basis to be re-opening beaches.)
The grades are based on water quality samples, collected by our dozens of dedicated volunteer monthly monitors, and the presence of cyanobacteria blooms and combined sewer overflow (CSO) discharges.
The story these grades tell is that areas with more impervious cover (pavement, buildings, development) are more polluted due especially to stormwater runoff while greener, more forested areas of the watershed are safe for swimming on most days, because those areas infiltrate more stormwater rather than sending it along paved surfaces into storm drains.
Climate change is making our job harder, by bringing more intense rainstorms that carry more polluted stormwater, and lead to more sewage discharges. However with the right investments we can absolutely achieve a swimmable Charles, and that is the work we do every day, getting us closer to that goal!
Thank you, Emily
Photo: CRWA
