Blog - Charles River Watershed Association

Record-breaking Season for CRWA’s Canoeing for Clean Water Program

Posted by Elisabeth Cianciola

12/2/16 1:51 PM


Volunteers pull invasive water chestnuts in the Charles River Lakes District.

Despite the emergence of water chestnut plants in the Lower Charles River Basin and on the Charles River in Cutler Park, the 2016 season of CRWA’s Canoeing for Clean Water program was a success.


CRWA’s Water Quality Notification Program Completes 15th Season

Posted by Elisabeth Cianciola

11/9/16 12:21 PM


CRWA volunteer Max Dulieu boats to the sampling site.

Since 2002, CRWA has partnered with boathouses in the Lower Charles River Basin to communicate potential public health risks to Charles River users during summer months. In the early years of the program, CRWA scientists would run recent rainfall data through simple models in Microsoft Excel first thing in the morning to estimate the concentrations of E. coli bacteria at four locations on the river: the North Beacon Street Bridge, the Larz Anderson Bridge, the BU Bridge, and the Longfellow Bridge. Our staff would then call boathouses to tell them which color flag they should fly: blue when there were no predicted public health risks and red when predicted E. coli bacteria levels exceeded the Massachusetts water quality standard for boating: 1,260 colony-forming units per 100 milliliters. CRWA also recorded predictions on a “hotline” that river users could call to find out the water quality predictions for the day.



Toward Clean Water in Rio and Boston

Posted by Jaya Rawla

8/19/16 3:42 PM

The 2016 Olympic Games have seen more than 10,000 athletes competing in dozens of sports in Rio de Janeiro. Water sports such as rowing and canoeing took place outdoors on some of Rio’s many waterways including the Marina da Glória. Amidst the sporting fervor, there has been a degree of concern about Rio’s water quality.



2015 Charles River Water Quality

Posted by Alexandra Ash

7/27/16 2:52 PM

Today, the U.S. EPA announced that the lower Charles River scored a B+ for its water quality in 2015. The annual Charles River Report Card focuses on the section of the Charles River downstream of the Watertown Dam and rates its cleanliness based on measured bacteria levels. EPA uses data collected year-round by Charles River Watershed Association's citizen scientist volunteers to assign the water quality grade each year.

CRWA's volunteer monthly monitoring program collects data at 37 sites up and down the river. In addition to bacteria, volunteers monitor water temperature, river depth and other indicators of water quality once a month during every month of the year. Our 2015 Year-End Report details our findings. Below, find some of the key takeaways. 


The Year in Review- Highlights from 2015

Posted by Alexandra Ash

12/17/15 12:44 PM

2015 was an exciting year for Charles River Watershed Association. In addition to celebrating our 50th Anniversary, in 2015 CRWA designed and implemented several projects that demonstrate our Blue Cities strategies, continued our field science program to better understand the Charles River, and advocated for policies to protect the Charles River. This was all made possible by support from friends just like you.

Below are just a few of the highlights from 2015. 



Fish Kill in Lower Charles River Basin

Posted by Elisabeth Cianciola

8/18/15 4:20 PM

While conducting routine water sampling on Wednesday, July 29th, Charles River Watershed Association (CRWA) spotted six dead fish between the North Beacon Street bridge in Watertown/Brighton and the Larz Anderson bridge in Cambridge. Since that initial observation, CRWA has received many reports of additional fish kill sightings via our website and social media. We estimate that between 61 and 103 dead fish, reported pimarily as carp and large-mouth bass, have been observed between the Galen Street bridge in Watertown and the Longfellow Bridge in Cambridge/Boston.


Fish Kill Map


Toxic Blue-Green Algae Outbreak Impacting Lower Charles River Basin

Posted by Margaret VanDeusen

8/13/15 11:09 AM

Algae at Weld Boathouse
  Algal bloom at Harvard's Weld Boathouse. Photo by CRWA
Alert issued by MA Department of Public Health
Yesterday, the MA Dept. of Public Health (DPH) received sampling results which confirmed that the Lower Charles River Basin is experiencing an extensive cyanobacteria, or toxic blue-green algae, bloom. Charles River Watershed Association (CRWA) scientists responded to reports of “gross, greenish” looking water at the Weld Boathouse, near the Larz Anderson Bridge in Cambridge on Friday, August 7th. Follow up water sampling by CRWA volunteers indicated that concentrations of cyanobacteria cells in the river exceed DPH guidelines for recreational waters. DPH sampling on Monday confirms that cyanobacteria concentrations in the Lower Basin are roughly double the guideline threshold. The bloom is believed to stretch from Weld Boathouse all the way downstream to the New Charles River Dam. Cyanobacteria, which are photosynthetic bacteria, can produce toxins during a bloom in high enough concentrations to harm people, pets and wildlife.



The malodorous toxins can contribute to minor health impacts such as eye, ear, and skin irritation, or have more severe consequences for humans or their pets ranging from liver and neurological damage to death. People and pets should avoid contact with or ingestion of water with high concentrations of cyanobacteria, and river bank areas where the bacteria have washed up. If contact occurs, individuals should rinse off as soon as possible following exposure. Dogs can become quite ill and even die from contact with cyanobacteria scum. They should be prevented from licking cyanobacteria out of their fur and rinsed off immediately. Inhaling water spray containing cyanobacteria can cause asthma-like symptoms. Because wind and flow patterns can affect the location of the bloom, all recreational users of the Charles River Lower Basin should take precautions. State and local officials will be posting signs along this stretch of the Charles advising river users of the bloom.     


Low river levels with elevated water temperatures, hot sunny weather, and high phosphorus concentrations from polluted stormwater runoff provide the ideal environment for rapid growth of cyanobacteria and harmful toxin levels. According to U.S. EPA, the relationship between high phosphorus levels from storm water discharges to the Charles and the proliferation of cyanobacteria is well-established. Studies show that phosphorus, a nutrient which cyanobacteria require to grow, is present in the Charles at more than twice the levels the river can safely handle. This phosphorus, carried into the river by stormwater runoff flowing over impervious surfaces, including roads, parking lots and roofs, and discharged via storm drains, causes cyanobacteria and invasive aquatic plants to grow explosively, smothering and shading other aquatic organisms.

“Until municipalities and owners of large paved surfaces dramatically reduce their phosphorus runoff, these outbreaks will continue to harm the Charles and people’s enjoyment of this tremendous resource,” said Bob Zimmerman, CRWA’s Executive Director. “It is far past time for EPA and MassDEP to issue new stormwater permits to reduce these polluted discharges.”

Cyanobacteria blooms are becoming increasingly common in the Charles River during the summer months. A bloom in early June caused the Charles River Swim Club’s 1-mile race in the Lower Basin near the Memorial Hatch Shell to be postponed until July. Last summer, a toxic cyanobacteria bloom in Lake Erie shut down the drinking water supply for more than 400,000 Toledo area residents.

For more information contact Julie Wood, Director of Projects or Logan Bailey, Rita Barron Fellow. 


Boating Safely in the Charles River

Posted by Elisabeth Cianciola

8/4/15 11:12 AM

Thanks to the historic cleanup of the Charles River, it is now safe to boat on the river most of the time. However, on some days the water quality in the Charles River does not meet public health standards for boating, especially after a heavy rain. On those days, although boating is still permissible, some people choose to stay off the water or take extra precautions.


New Buoy Able to Monitor Charles River Water Quality in Real Time

Posted by Alexandra Ash

6/29/15 12:51 PM

 Museum of Science

Location of the new water quality buoy

Water Quality Monitoring Buoy

EPA's new water quality monitoring buoy

Water quality in the Charles River requires constant monitoring by scientists and the public to ensure a healthy river. Earlier this year, the EPA launched a solar-powered and self-contained water quality monitoring buoy in the Charles River located outside the Museum of Science. This buoy takes water quality measurements every 15 minutes and is used to assess the water quality along with tracking cyanobacteria blooms (blue green algae). The measurements include temperature, dissolved oxygen, pH, specific conductance, turbidity, chlorophyll, and phycocyanin. The buoy transmits this data in real time using telemetry which is when measurements are taken at one location and transmitted to receiving equipment for monitoring. This means that real-time water quality data for the Charles River Lower Basin is now available to the public! You can access this data right from your own computer. The new Charles River Exhibit opening this winter at the Museum of Science will feature this data for the public to explore.

The buoy structure is fairly simple. The buoy collects these measurements by using sensors that are located one meter below the surface of the water. The sonde, a water quality measuring instrument that is used to measure things such as temperature, conductivity, salinity, dissolved oxygen, pH, turbidity, and depth, is mounted on the anchored floating buoy. The data collected by the sonde is then transmitted remotely to the EPA link above. At the surface, the buoy contains a solar panel to power the sensors and metal prongs to deter birds from landing to ensure more accurate readings.

Why does the buoy take the measurements that it does? Temperature is a controlling force in many biological and chemical processes. Increases in temperature can harm aquatic species as well as create a favorable environment for increased algal blooms. Massachusetts Surface Water Quality Standards set a maximum allowable water temperature of 28.3 degrees Celsius. Specific conductance is the measure of water’s ability to pass electrical current and can be an indicator of dissolved solids within the water, and in this location, the influx of daily tides from Boston Harbor. The measure of pH determines how acidic or basic the water is. For a Class B river, like the Charles River, the pH values must remain between 6.5 and 8.3. Dissolved oxygen measures the amount of oxygen dissolved within the water and is vital to the aquatic species that depend on this supply to survive, particularly native fish. Turbidity is a measure of the amount of suspended material in the water and is used as an indication of water clarity and light penetration.

The buoy only has the ability to collect data that can be measured using sensors, so it cannot measure cyanobacteria levels or bacteria levels within the water. The amount of cyanobacteria in the water is important because blooms increase the risk of toxic contamination of surface waters. Instead of measuring the cyanobacteria directly, the buoy measures chlorophyll and phycocyanin which are both pigments found within cyanobacteria and are used as indicators of the levels of cyanobacteria within the water. Chlorophyll a concentrations that exceed 0.00375 mg/L are considered to be high.

This real-time data will help scientists and river advocates craft effective policies for the Charles River and help boaters and residents make informed decisions about their use of the river.  

View Live Water Quality Data



Water Transformation Part 10: The Benefits

Posted by Robert Zimmerman

4/15/15 1:01 PM

PREVIOUS POST: Water Transformation Part 9 - Restored Streams and Green  Infrastructure


Subscribe to the CRWA Blog:

About Charles River Watershed Association:

One of the country's oldest watershed organizations, Charles River Watershed Association (CRWA) was formed in 1965 in response to public concern about the declining condition of the Charles. Since its earliest days of advocacy, CRWA has figured prominently in major clean-up and watershed protection efforts, working with government officials and citizen groups from 35 Massachusetts watershed towns from Hopkinton to Boston. Initiatives over the last fifty years have dramatically improved the quality of water in the watershed and fundamentally changed approaches to water resource management.