The first rescue happened on Saturday near the Broadway Bridge.
Fire officials said a call came in just before noon of a person in distress and being swept in the current toward the weir.
A person on a jet ski was reported to be attempting to keep the person from going further down the river, officials said.
The fire department said Water Rescue 1 was in the water within six minutes of the call coming in and was able to safely rescue the person.
The second rescue took place on Sunday near the Gordie Howe Bridge.
Multiple persons were reported in distress near the bridge and the Queen Elizabeth Power Station just after 6:30 p.m., the fire department said.
Four females on inflatable crafts were spotted trapped against a concrete structure by crews responding in two water rescue boats and on land.
One person was in the water and unable to support herself, officials said.
A firefighter trained in surface water rescues went into the river to rescue the woman, the fire department said.
The firefighter had to enter the water a second time to rescue a second person after a complication with one of the inflatable rafts.
The two remaining females were brought ashore in one of the water rescue boats.
Officials said the four were experiencing conditions consistent with fatigue and panic but were otherwise uninjured and medically cleared at the scene.
None of the four females were wearing personal flotation devices or lifejackets when they were rescued, they added.
The fire department said the second rescue happened due to a lack of preparation and experience by the river users, along with the high water levels and increased rate flow of the river.
The Saskatoon Fire Department says the river is not safe at this time for recreational use, with the river currently flowing at a rate that is four to six times its average speed.
Saskatchewan’s Water Security Agency (WSA) said it started a spillway release from the Gardiner Dam on July 2 due to high amounts of rainfall in southern Alberta last week.
Outflows from the dam, roughly 105 kilometres upstream of Saskatoon, were expected to peak at 900 cubic metres per second on Monday, which the WSA said will raise the river to near channel capacity.