Hi Noah,
Thank you for your question. I understand the difficulty of finding data specifically for Port Stewart. I recommend checking the Bureau of Meteorology for river and rainfall data. Look into the peninsula river data if you cannot find data specific to Port Stewart.
Quantitative data is difficult track in Port Stewart. But when we were up there last, one of the rangers told us that the flood levels can get up to waist height at Lower Camp as it is at a lower elevation compared to Upper Camp. I hope this paints a picture of the rise of flood levels.
Kind regards,
Evelyn
Evelyn Todio