Paul, I just revisited the thread and took a look at the link that you provided. The spot that you suggested is not a good place to park or access to the river.
The main access points to the lower section of the Chilliwack River are Keith Wilson Bridge, No. 3 Road bend parking lot, Bergman Road parking lot, Lickman Road parking lot, Peach Road parking lot, the Vedder River Campground, Vedder Crossing. These are access points, not necessarily good fishing spots. They can also be crowded at times due to the easy access. If you end up visiting the river alone, my advice would be to park your car at any of these spots, and walk up or downstream from the spots to explore and find more suitable, uncrowded spots, which are usually more productive. If you choose to speyfish/flyfish, the lower section of the river (downstream from the Vedder Crossing) is best.
Depending on weather and river conditions, spots for speyfishing maybe limited if the water is too coloured, or too high, or both.