CRWA is currently flying RED flags throughout the entire Lower Basin, indicating unsuitable boating conditions. The Cottage Farm Combined Sewage Overflow (CSO) Facility discharged yesterday, Monday, July 28th, beginning at 10:25 am and ending at approximately 12:50 pm. In addition to Cottage Farm, there are several other permitted combined sewer overflow outfalls which occasionally discharge untreated combined sewage to the lower Charles on both banks of the river. During large or intense storms, such as those that caused Cottage Farm's discharge, untreated CSOs can discharge to the Charles River. Pulbic health officials recommend avoiding contact with the river during rainstorms and for 48 hours afterwards, as there may be increased health risks due to bacteria or other pollutants. If you cannot avoid contact with the water, please make sure to avoid contact with mouth and eyes, and thoroughly wash after getting off the water.
CRWA's Water Quality Notification Program presents the daily flag colors of the river's health, which signify whether or not the river is safe for boating at ten boating locations from Watertown to Boston. Flag colors are based on bacteria levels and blue-green algae counts.
CRWA estimates bacteria levels using a model that takes into account a variety of environmental factors including antecedent rainfall and river flow. CRWA collects river samples for bacteria weekly to verify the model forecast. Blue-green algae monitoring is conducted at least every two weeks. Read more about the development of CRWA's bacteria prediction model.
Indicate suitable boating conditions
Indicate inconclusive data to preclude a possible health risks