Harley, I see what you're saying, but you'll need that separate pool that zzptichka is showing. Maybe something more like the Iceberg's club in Bondi Beach? Their pool is absolutely fantistic, including Australia's awesome water cycling/wave/tide action traditional pools, coupled with a fitness club, cafe and restaurant. Maybe we can do something similar with a permanent anchored concrete structure with natural river flows through the pool. I once lived in a van down by the beach at Bondi for a few weeks, and used the Icebergs to take hot showers for a $5 daily access fee. Swimming in the tidal pool at high tide with large, fall season waves was absolutely terrifying and fantastic. I recommend watching a youtube.

The current in the Ottawa River in the area you're showing is actually very strong near the middle and north sides of the river. I don't know much about the south side. If you allow 'families' to paddleboard out there, you'll need like a full-time rescue crew to pull people off of your safety netting, not to mention the trees and debris that the netting would pick up and require constant attention and repair.
That said, plenty of people take canoes and kayaks out amongst the small islands west of Lemieux. Its a fascinating place, but again with strong currents not for the novice.
We can swim in the river, but we need direct safety controls. I like the floating pool idea.
How to protect from the massive ice shoves that come in spring?