The National Capital Authority is letting us know ^[1] they’ve closed East Basin to primary water contact, on top of Weston Park East:

At present the water is closed to primary contact recreation due to microbiological contamination, as exposure to contaminated waters carries and increased risk of adverse health effects.

Primary contact recreation means recreation that involves whole-body water contact or submersion of the head. Examples include swimming, diving and windsurfing.

Secondary contact recreation (such as rowing, fishing, boating and canoeing) will still be permitted although persons engaged in secondary contact recreation should be careful to limit any water exposure