Humber River - Any time localized rain totals 30 mm or more this creeky run to the main flow is pretty cool, yet pretty much without problems after the narrow forest that may have branches blocking the way. This section was previously hindered by a small culvert that has recently been replaced by a massive one going under Scarlett road. This ensures that the fun is with less danger in flood conditions. Once on the Humber river, take either the river right or river left trail to walk up river to decide if you want to run the dam and the rapids below. They are pretty decent and have several surf spots in good levels. From here on it is pretty straight forward until nearing the weir dams. Start being alert for Dundas street after the railway and pedestrian bridge together. Get out with significant time to spare as these have very strong recirculation several metres beyond the drop. There are generally inescapable so keep clear.
Getting out at Dundas St is a good idea because of this. many of the drops beyond this are super dangerous. Beyond some of the drops have interesting rapids if at the right level. If you want to continue to Old Mill, some are worth it. Don't swim any of these.