Although Teirney Park is listed on the City of Ottawa splash pad page at the time of writing, it seems like it’s no longer an actively maintained splash pad. (Teirney Park is currently not listed in the KML splash pad map data.)
The splash pad is pretty simple. There are two concrete walls with whales engraved on the side and a water spray nozzle.
You have to hold down the button to get the water to come out but it’s hard to tell because the park was broken. The one nozzle that had water leaking out only worked if you held the button in.