A new proposal by the Massachusetts Water Resources Authority (MWRA) to change the Charles River's water-quality classification is sparking controversy, with advocates saying that sewage dumping could undo decades of cleanup. 

The plan announced at a meeting on Wednesday would declassify the Charles River as swimmable and allow sewage to flow into the water. 

Advocates were shocked to hear the news. 

"There could be more sewage, more trash, more debris, more odors," she said. "We could be going back to what we worked so hard to improve," said Laura Jasinski, executive director of the Charles River Conservancy.

The Charles River is now one of the cleanest urban rivers in the country, according to the MWRA. Jasinski says that the state of the river has come a long way.

"There was a time when people used to talk about the stench," she said. "We used to get a 'D' letter grade, like on a report card, from the EPA. Back up to we're getting a  'B', 'B+' these days." 

What would this mean for recreational activities?

Visitors like Rangan Gajural worry that the change could make it unsafe for recreational activities.

"I think it's kind of disgusting," he said. "I come over here to do paddleboating and canoeing. So this will definitely change my mind if it's going to stink." 

"It's a place where people come to make memories. It's a place where you can come and watch a sunset. People get engaged here," Jasinski said. 

The MWRA says the proposal would not make the river less safe. 

In a statement, the agency said, "The draft plan as presented reflects a responsible approach that balances potential environmental benefits with rate impacts to all MWRA customer communities." 

Officials said they are working with the cities of Cambridge and Somerville to reduce sewage overflows. The MWRA Board plans to discuss the proposal at its next meeting on Nov. 19.