An Ottawa-area water park is being accused of operating unsafe water slides and is facing 20 provincial safety act charges, each carrying a potential $1-million fine.

The Technical Standards and Safety Act charges were filed Tuesday against Calypso Theme Waterpark, following a year-long investigation.

Calypso, located in Limoges, Ont., east of Ottawa, bills itself as Canada's biggest theme water park.

The city of Ottawa announced Wednesday it would immediately cancel all of its summer programs' field trips to the water park until the charges are dealt with or more information is made available.

Park owner Guy Drouin said in a statement that the park is strongly committed to the safety of its visitors.

No outstanding concerns had been raised when he met with the agency last month, he said, and called the charges "very disappointing."

"Calypso is recognized as the award-winning world leader in water theme amusement parks and has an enviable record and reputation that it will defend if necessary," Drouin said.

The charges stem from incidents on three of the park's slides -- the Pirate's Aquaplay, the Steamer and the Bobsleigh -- during 2011 and 2012, some of which caused "serious injury", said Technical Standards and Safety Authority spokesman Wilson Lee.

Pictures of the "Pirate's Aquaplay" on the Calypso website show a jungle-gym style structure with multiple slides. The Steamer and the Bobsleigh slides are not listed under the website's list of current attractions.

The charges allege Calypso operated the slides in an unsafe manner, did not having enough attendants at the slides, and did not sufficiently train the attendants they do have.

Drouin's lawyer, Lawrence Greenspon, called the charges a "surprising abuse of power."

In response Lee said, "we obviously disagree", but said TSSA will leave the process to the courts.

The park is also accused of not reporting the incidents to the TSSA in a timely manner, after they discovered several of the incidents through other means, Lee said.

"In some instances we were first apprised of these incidents through media reports and some directly through public complaints that were made through us," he said.

Wilson would not go into detail about the nature of the incidents or the extent of the injuries, citing current civil suits against the park.

Investigations into water parks are "not a common occurrence", Lee said, and the large scope of the investigation is unusual.

Annual inspections of all rides and slides by the TSSA are mandatory, but these inspections ensure mechanics are properly licensed and slides are in good shape, he said, and don't examine day-to-day operation.

The park will remain open this summer. Calypso made several changes since the incidents occurred, Lee said, and the park has passed its most recent inspections.

Representatives of the park will appear in court on Aug. 22.