There is a specified 'swimming Beach' that has many basic regulations to keep it safe and clean for swimmers. fear not! This is only a very small section of the border of the reservoir. There are hiking trails that completely circle the reservoir and at any point except the designated area your pooch can enter.
I'm no expert, but there are areas that dont have a beach, but are still close to water that you can let your dog in the water.
We were on the east beach that is closest to the Wakara campground. Alot of people had dogs there and of course they were all on leashes. I think it is the north beach area that doesn't allow dogs.
Thanks! Your answer is awaiting moderation.