I got a response from the Government about the FOI, and they directed me to some free resources on Geothermal Sites in Canada, which includes a map of all the Hot Springs and Boreholes in Canada</a>. A borehole is a geothermal well that is used to measure geothermal energy in exploration. The Hot Springs are diamond shaped and the wells are circular shaped on this Geothermal Map of BC. Now the Wikipedia Article mentions five hot springs around Mt. Cayley, but the map only shows two hot springs and three bore holes. Also, on further inspection, the Brandywine Borehole coordinates place it in the upper reaches of Mt. Fee. Now, I don’t know if there is a hotspring nearby the Borehole that wasn’t surveyed, but given the fact that August Jacob is on here, and that it’s one of the lesser known hot springs, I would say that the likelihood of there being a secret spring here is next to zero.
The other reason I suspect that the creek is at zero is because the borehole is 438 meters deep and only produces 98 mW per square meter. This seems somewhat low for an area with geothermal activity. Once again, I am fully aware that this is off-topic, but this was bothering me a bit, since it seems that if there were actual hot springs in the area, some property developer would have tried to put some resort there by now due to where it would be on Highway 99.