I work for Metro Vancouver and if you live in one of the 22 municipalities surrounding vancouver, we provide your water. If you go to this website Turbidity
it will tell you the up to date turbidity reading of your areas water shed. if the reading is over 1.0 NTU's sometimes chlorine levels will be increased as a precaution. if your unsure which reservoir your municipalities water comes from check the attached image.
if anything you can check this site when its rainy to see if you should be worried about increased chlorine levels in the water, generally there is almost zero chlorine by the time it hits the tap but ofc it depends how far from the source you are, if your really close there might be some left.