I think drones could be appropriate downstream of the city, but within the city would not be worth the headache or liability.. way too many people, go through a provincial park, near highways, people... If there are a couple folks with drones out there that are willing to donate time, im sure BRC could line up something downstream of Police.
I'd question them being more accurate, but just a different way of doing them, and less people-intensive. Considering the number of redds that were associated with overhead cover, undercuts, and in varying water clarity.