Boathouses

Red flags are being flown at some boathouses due to a Combined Sewer Overflow (CSO). A discharge at CAM005 discharged on October 8, 2025 starting at 9:00AM, potentially affecting areas downstream of Eliot Bridge. Blue flags will be restored 48 hours from the end time. Public health officials recommend avoiding contact with the river during rainstorms and for 48 hours afterward, as there may be increased health risks due to bacteria or other pollutants discharged by CSOs. For more information see: https://www.cambridgema.gov/Departments/publicworks/combinedseweroverflowreporting

In accordance with the MA Dept. of Public Health (DPH), a cyanobacteria (blue-green algae) advisory has been posted in the Charles River downstream of the River Street Bridge (a.k.a. the Cambridge Street Bridge). Red flags are being flown at the Charles River Yacht Club, Union Boat Club, Paddle Boston at Kendall Square, the Charlesgate Yacht Club, and the Riverside Boat Club. Public health officials recommend that people and pets avoid contact in areas of algae concentration and rinse thoroughly in the event of contact.

For additional information on cyanobacteria blooms, we encourage you to visit the following websites:

https://www.mass.gov/lists/algae-information

https://www.mass.gov/guides/cyanobacterial-harmful-algal-blooms-cyanohabs-water

https://www.cdc.gov/habs/index.html

https://www.epa.gov/cyanohabs

Current Cyanobacteria Bloom Advisories - https://www.mass.gov/alerts/harmful-cyanobacterial-bloom-advisories-in-massachusetts

At this time, it is recommended that you avoid contact with the water. People should rinse off with fresh water immediately if they or their pet comes into contact with the water. If you believe you or your pet is experiencing adverse health effects, contact your doctor or veterinarian immediately. Blue-green algae is extremely toxic to pets.

CRWA’s water quality models are predicting blue flags at all boathouses, based only on E. coli bacteria predictions.