Charles River Swimming Initiative

The Charles River Swimming Initiative has been a key component of the Charles River Conservancy’s vision and work. Inspired by our founder’s memories of river swimming as a child, the CRC has advocated that swimming be an integral goal of restoring the health of the Charles. In the last 25 years, tremendous progress has been made, thanks to the EPA’s Charles River Initiative, significant clean up and advocacy by us and partners like the Charles River Watershed Association, and major infrastructure investments by the Commonwealth and cities. The EPA’s most recent grade for the Lower Basin of the Charles was a B- (for 2021), a significant improvement over the D it received in 1995. In order to balance safety considerations, swimming in the Charles is only allowed if a permit is obtained from the Massachusetts Department of Conservation and Recreation. The CRC is working to expand opportunities for swimming.

Our drive to return swimming rests on several goals:

  1. celebrate this incredible environmental comeback by giving people the opportunity to experience the river by swimming in it;
  2. inspire more stewards of the river and its parks; the more connected people feel to these spaces, the more they will support investments for these resources’ continued health;
  3. unlock new recreational opportunities and space in this urban environment by creating a designated place monitored for swimming.

Over the years, this initiative has evolved. Early work included advocacy for the creation and staffing of a governor-appointed Charles River Water Quality Commission, which has grown into an annual community swim event, plans for a seasonal facility, and greater investments and research in improving the health of the river.


City Splash 2017; photo by Aram Boghosian

City Splash, which first took place in 2013, has become an annual state-sanctioned community swim event that provides the public the rare opportunity to jump in the Charles River! The event is held in a demarcated deep-water area off the Fiedler Dock on the DCR Esplanade in Boston. The CRC works in partnership with the Massachusetts Department of Conservation and Recreation (DCR) to obtain a Special Use Permit in order to allow this unique opportunity. The success and positive responses from each City Splash show how much the community wants to see river swimming brought back to the Charles, which has inspired our work on a seasonal facility. Learn more about City Splash.


Rendering of Swim Park design concept by Stantec.

The Swim Park has grown out of the belief that one day of river swimming is not enough. As the CRC continues to engage the public and advocate for cleaner water, we are also designing a safe, fun, and accessible seasonal swimming facility to be enjoyed by all. This work kicked off with a feasibility study by Stantec and a crowd funding campaign. Subsequent work has included partnerships with local universities and MBAs to collect detailed water quality data, learn from similar projects, and develop a financial model. The CRC engaged an experienced marine engineer to bring the design to 30%. We are working with stakeholders to further develop programming and operations, which will in turn inform the final design. The CRC is excited for the day this park is open for all to enjoy. Learn more about the Swim Park.


Rendering of floating wetland design by Sasaki.

The Floating Wetland Project explores a complementary approach to infrastructure improvements, utilizing an ecological intervention to reduce harmful algal blooms, a remaining obstacle to swimming and the river’s health. Reducing nutrient pollution remains vital but depends on increasingly complex solutions. Ecological intervention offers another strategy. Experiments have shown that for bodies like the Charles, algal blooms can be understood as a symptom of a broken food chain. Strengthening zooplankton with additional habitat may help. Continuing a multi-year partnership with Northeastern PhD student Max Rome, and adding interpretative materials professional Penelope Taylor to our team, the CRC installed a floating wetland at North Point Park in Cambridge in June 2020 to test this hypothesis. The project goals include (1) design, permit, and install a floating wetland to demonstrate the importance (and absence) of shoreline vegetation; (2) research the impact on local zooplankton populations and quantify the scale at which water quality could be affected and improved, and (3) engage the public on the river’s health. Learn more about the Floating Wetlands.