The incident happened at 10 a.m. near where the channel funnels into Skaha Lake.
The woman, who is in her 50s, has mental health issues and had been issued a day pass from the hospital when she drove the vehicle into the water.
She managed to get out of the vehicle. Passerbys then helped her out of the water.
She was taken to Penticton Regional Hospital with unknown injuries.
The car has been removed from the water.
Read it on Global News: Global BC | Car plunges into Penticton River Channel