After a quick search all I can find is this:

"7.2 (a) No person shall, in a park, engage in:
(i) Propelling a golf ball in any manner;
(ii) Archery;
(iii) The use of a sling-shot; or
(iv) The shooting of a projectile of any nature"

I can not find ay information that states you can't in your own yard, but I did not look overly hard.

Here is the link to cockrane's bylaws.

http://www.cochrane.ca/municipal/coc...7?OpenDocument