Evha Jannath sustained chest injuries and drowned after she fell from the Splash Canyon rapids ride at Drayton Manor Park in May 2017.
Staffordshire Police said Drayton Manor will not face corporate manslaughter or gross negligence charges. The investigation has been handed to the Health and Safety Executive (HSE), which could prosecute if the park is found to have breached safety and health regulations.
In a statement Staffordshire Police said its detectives had carried out a "thorough and lengthy investigation" into the circumstances surrounding Evha's death and handed a file of evidence to the Crown Prosecution Service (CPS) for review.
"A decision has been made that the circumstances surrounding Evha's death do not meet the threshold for gross negligence or corporate manslaughter. The file has now been passed to the HSE who will consider if any other offences are applicable," it said.
A file has been prepared for the Coroner and an inquest is expected to begin in November.
Detective inspector John Quilty said: "The investigation into the tragic death of Evha has been extremely complex and we have worked closely throughout with the park, HSE and CPS.
"Evha's family have been made aware of the findings and our thoughts remain with her family and friends."
A spokesperson for the HSE added: "This remains a criminal investigation and we will be considering whether there were any breaches of health and safety law relevant to the circumstances of this tragic event.
"HSE's thoughts remain with Evha's family, who we will keep updated as our investigation continues."
