Bondi, Bronte and Tamarama beaches in Sydney are set to reopen for swimming and surfing a week after neighbouring Randwick council beaches were opened again.

Bondi is to reopen for swimming and surfing but the beach itself will remain closed given the local area has the highest number of COVID-19 cases in Australia.

Waverley Council mayor Paula Masselos says the waters at Bondi, Bronte and Tamarama beaches will reopen on Tuesday morning "for the sole purpose of exercising".

People will be able to swim or surf at Bondi and Bronte and surf only at Tamarama between 7am and 5pm on weekdays. Access to the water will be via designated entry and exit points.

"Our beaches remain closed to all land-based activities including social gatherings, sunbaking, walking and jogging," Ms Masselos said in a statement on Monday.

"There will be no relaxing or gathering around on the sand. The sand remains strictly off-limits other than for access to the water for exercising.

"Waverley is still a hot spot and presently has the highest number of COVID-19 cases in Australia."

The mayor said the "swim and go" and "surf and go" measures were strictly for Waverley residents exercising locally and people shouldn't drive to the beaches from further afield.

Neighbouring Randwick City Council reopened its beaches - including Clovelly, Coogee and Maroubra - a week ago but was forced to close them again on Friday when crowds descended on the sand and people couldn't follow safe social distancing practices.

The patrolled beaches were reopened on Saturday but only from 6am to 9am until Monday.

All of Randwick's beaches will again reopen from Tuesday without any time restrictions.

Residents are allowed on the sand so long as they are "jogging or doing some legitimate exercise".

"Lifeguards, rangers and other council staff will continue to monitor numbers on the sand and in the water and will restrict access or temporarily close beaches if crowd numbers exceed safe limits," Randwick council said in a statement on Monday.

Mayor Danny Said said: "Our message could not be simpler - Randwick City beaches are to be used for exercise only."

Manly and Dee Why are the only northern beaches that remain closed "due to COVID-19 community restrictions".