If you were hoping to strip down to your swimsuit and jump from the dock along the Esplanade into the Charles River at the annual “City Splash’’ event, you’ll have to wait until next year.

For the first time in five years, the Charles River Conservancy said it won’t be hosting its annual swim for eager city dwellers trying to cool off. The nonprofit announced the cancellation in a newsletter sent out Thursday morning.

“We have decided to put City Splash on hiatus for 2018,’’ the organization said. “We recognize this will be disappointing news to many, and we appreciate your support over the years. We are looking for other engagement opportunities this year, and will be in touch as those develop.’’

Last year, around 300 people attended the event.

The conservancy says there’s a good reason it decided not to put on the annual event, however: Organizers are instead focusing their efforts on bringing a permanent, seasonal swimming location to the once-dirty water, because one day of Charles River swimming a year “is not enough.’’

In 2016, the conservancy announced its grand vision to develop a place along the Charles River where runners could stop mid-jog and plunge in, or people could swim laps. The proposed project calls for the construction of a floating dock near North Point Park, lined with plantings along the perimeter.

The news of the cancellation comes days after the Environmental Protection Agency gave the Charles River a winning grade for cleanliness. It’s only the second time the river has earned such a high grade in the past 23 years, the agency said.

Steve Annear can be reached at steve.annear@globe.com.