Country superstar Dolly Parton is set to expand her entertainment empire and open a water-snow theme park in Nashville, Tennessee.

The 9 To 5 hit-maker launched Dollywood in the Pigeon Forge area of Tennessee in 1986 and added a water park next door in 2001.

Now, Parton is working on a new addition to her popular attractions and she announced plans for the new $50 million venture on Thursday, her 66th birthday.

The project, located near the Smoky Mountains, will be a joint business deal with bosses at Gaylord Entertainment, who are in charge of the Grand Ole Opry country music mecca in Nashville.

However, don't expect the birthday girl to be among the first few to jump on the new rollercoasters - wig fan Parton confesses, "I will not ride rides - I got too much to lose, like my hair!"

The as-yet-unnamed theme park is expected to open in the summer of 2014.