constantly updated, the red flags mean that swimming is not advisable, green flags mean waters are clean, and yellow flags suggest using own judgment. 

any of rio's beaches may have polluted waters within 24 to 48 hours following heavy rains.

on this link an early morning shot of the beach is posted daily, showing water conditions.

this link shows praia do leblon on a wikimapia - the link as we present it is best seen using google chrome, as it might not open correctly with other browsers, and the zoom setting could be off.