2008 Toyota Prius steering problems

After having driven my prius nearly 15,000 miles in all types of weather (except snow) and on residential roads as well as interstate highways with no steering problems, on a single day on residential streets at 20 to 25 MPH and gentle rain, it hydroplaned twice with damages each time to the car and to a fire hydrant once. Each event was while going around a gentle left curve at reasonable speed.

I was traveling northbound on the saw mill river parkway. Exited on the northbound taconic state parkway ramp. After crossing the taconic state parkwat overpass. My 2008 toyota prius (without any input from my part) turned left and accelerated onto the grassy area. Even though made multiple attempts at correcting my direction by turning the car to the right and to stop the car, neither the steering inputs or engaging the brakes had any effect on the vehicle.