CRWA Daily Water Quality Flag Colors

Flag colors for Thursday, July 29, 2010

Flag colors are based on water quality forecasts from a statistical model. Flag colors are based on the probability of the water exceeding the state water quality standard for boating; please note swimming is prohibited in the Charles. CRWA takes a precautionary approach to be overly protective of human health, therefore, red flags are flown when the model forecasts a greater than 50% chance of water quality exceeding the state standard. Weekend flag colors are based on weather forecasts and are subject to change.

Click on boating center name for 2010 bacteria results:

1. Access Sport America at Spaulding Dock

6. Charles River Canoe & Kayak

2. Union Boat Club

7. Northeastern Boathouse

5. Harvard's Weld Boathouse

Yellow flags are being flown at the three downstream locations due to a cyanobacteria (a.k.a. blue-green algae) bloom in the Esplanade lagoon and the mainstem of the Charles near these three locations.  Cyanobacteria produce toxins that are potentially harmful to humans and pets.  The Massachusetts Department of Public Health has posted advisories along the Esplande.  For more information on cyanobacteria visit CRWA's website.

A blue flag indicates safe boating conditions.     

A yellow flag indicates inconclusive data to predict possible health risks.

A red flag indicates likely health risks.

Avoid areas where red flags are posted or make sure you wash after boating nearby.  Flag colors are based on bacteria levels and blue-green algae counts.  Today's flag colors are a conservative estimate of water quality conditions.  Actual water quality may vary from predictions.